Skip to content

HTTPS clone URL

Subversion checkout URL

You can clone with
or
.
Download ZIP
Fetching contributors…

Cannot retrieve contributors at this time

1008 lines (915 sloc) 43.359 kB
REPORTING BUGS
Bugs can be reported on the help mailing list
sbcl-help@lists.sourceforge.net
or on the development mailing list
sbcl-devel@lists.sourceforge.net
Please include enough information in a bug report that someone reading
it can reproduce the problem, i.e. don't write
Subject: apparent bug in PRINT-OBJECT (or *PRINT-LENGTH*?)
PRINT-OBJECT doesn't seem to work with *PRINT-LENGTH*. Is this a bug?
but instead
Subject: apparent bug in PRINT-OBJECT (or *PRINT-LENGTH*?)
In sbcl-1.2.3 running under OpenBSD 4.5 on my Alpha box, when
I compile and load the file
(DEFSTRUCT (FOO (:PRINT-OBJECT (LAMBDA (X Y)
(LET ((*PRINT-LENGTH* 4))
(PRINT X Y)))))
X Y)
then at the command line type
(MAKE-FOO)
the program loops endlessly instead of printing the object.
NOTES:
There is also some information on bugs in the manual page and
in the TODO file. Eventually more such information may move here.
The gaps in the number sequence belong to old bug descriptions which
have gone away (typically because they were fixed, but sometimes for
other reasons, e.g. because they were moved elsewhere).
KNOWN BUGS OF NO SPECIAL CLASS:
2:
DEFSTRUCT almost certainly should overwrite the old LAYOUT information
instead of just punting when a contradictory structure definition
is loaded. As it is, if you redefine DEFSTRUCTs in a way which
changes their layout, you probably have to rebuild your entire
program, even if you know or guess enough about the internals of
SBCL to wager that this (undefined in ANSI) operation would be safe.
3:
ANSI specifies that a type mismatch in a structure slot
initialization value should not cause a warning.
WORKAROUND:
This one might not be fixed for a while because while we're big
believers in ANSI compatibility and all, (1) there's no obvious
simple way to do it (short of disabling all warnings for type
mismatches everywhere), and (2) there's a good portable
workaround. ANSI justifies this specification by saying
The restriction against issuing a warning for type mismatches
between a slot-initform and the corresponding slot's :TYPE
option is necessary because a slot-initform must be specified
in order to specify slot options; in some cases, no suitable
default may exist.
In SBCL, as in CMU CL (or, for that matter, any compiler which
really understands Common Lisp types) a suitable default does
exist, in all cases, because the compiler understands the concept
of functions which never return (i.e. has return type NIL, e.g.
ERROR). Thus, as a portable workaround, you can use a call to
some known-never-to-return function as the default. E.g.
(DEFSTRUCT FOO
(BAR (ERROR "missing :BAR argument")
:TYPE SOME-TYPE-TOO-HAIRY-TO-CONSTRUCT-AN-INSTANCE-OF))
or
(DECLAIM (FTYPE () NIL) MISSING-ARG)
(DEFUN REQUIRED-ARG () ; workaround for SBCL non-ANSI slot init typing
(ERROR "missing required argument"))
(DEFSTRUCT FOO
(BAR (REQUIRED-ARG) :TYPE TRICKY-TYPE-OF-SOME-SORT)
(BLETCH (REQUIRED-ARG) :TYPE TRICKY-TYPE-OF-SOME-SORT)
(N-REFS-SO-FAR 0 :TYPE (INTEGER 0)))
Such code will compile without complaint and work correctly either
on SBCL or on a completely compliant Common Lisp system.
6:
bogus warnings about undefined functions for magic functions like
SB!C::%%DEFUN and SB!C::%DEFCONSTANT when cross-compiling files
like src/code/float.lisp. Fixing this will probably require
straightening out enough bootstrap consistency issues that
the cross-compiler can run with *TYPE-SYSTEM-INITIALIZED*.
Instead, the cross-compiler runs in a slightly flaky state
which is sane enough to compile SBCL itself, but which is
also unstable in several ways, including its inability
to really grok function declarations.
7:
The "byte compiling top-level form:" output ought to be condensed.
Perhaps any number of such consecutive lines ought to turn into a
single "byte compiling top-level forms:" line.
10:
The way that the compiler munges types with arguments together
with types with no arguments (in e.g. TYPE-EXPAND) leads to
weirdness visible to the user:
(DEFTYPE FOO () 'FIXNUM)
(TYPEP 11 'FOO) => T
(TYPEP 11 '(FOO)) => T, which seems weird
(TYPEP 11 'FIXNUM) => T
(TYPEP 11 '(FIXNUM)) signals an error, as it should
The situation is complicated by the presence of Common Lisp types
like UNSIGNED-BYTE (which can either be used in list form or alone)
so I'm not 100% sure that the behavior above is actually illegal.
But I'm 90+% sure, and the following related behavior,
(TYPEP 11 'AND) => T
treating the bare symbol AND as equivalent to '(AND), is specifically
forbidden (by the ANSI specification of the AND type).
11:
It would be nice if the
caught ERROR:
(during macroexpansion)
said what macroexpansion was at fault, e.g.
caught ERROR:
(during macroexpansion of IN-PACKAGE,
during macroexpansion of DEFFOO)
14:
The ANSI syntax for non-STANDARD method combination types in CLOS is
(DEFGENERIC FOO (X) (:METHOD-COMBINATION PROGN))
(DEFMETHOD FOO PROGN ((X BAR)) (PRINT 'NUMBER))
If you mess this up, omitting the PROGN qualifier in in DEFMETHOD,
(DEFGENERIC FOO (X) (:METHOD-COMBINATION PROGN))
(DEFMETHOD FOO ((X BAR)) (PRINT 'NUMBER))
the error mesage is not easy to understand:
INVALID-METHOD-ERROR was called outside the dynamic scope
of a method combination function (inside the body of
DEFINE-METHOD-COMBINATION or a method on the generic
function COMPUTE-EFFECTIVE-METHOD).
It would be better if it were more informative, a la
The method combination type for this method (STANDARD) does
not match the method combination type for the generic function
(PROGN).
Also, after you make the mistake of omitting the PROGN qualifier
on a DEFMETHOD, doing a new DEFMETHOD with the correct qualifier
no longer works:
(DEFMETHOD FOO PROGN ((X BAR)) (PRINT 'NUMBER))
gives
INVALID-METHOD-ERROR was called outside the dynamic scope
of a method combination function (inside the body of
DEFINE-METHOD-COMBINATION or a method on the generic
function COMPUTE-EFFECTIVE-METHOD).
This is not very helpful..
15:
(SUBTYPEP '(FUNCTION (T BOOLEAN) NIL)
'(FUNCTION (FIXNUM FIXNUM) NIL)) => T, T
(Also, when this is fixed, we can enable the code in PROCLAIM which
checks for incompatible FTYPE redeclarations.)
18:
from DTC on the CMU CL mailing list 25 Feb 2000:
;;; Compiler fails when this file is compiled.
;;;
;;; Problem shows up in delete-block within ir1util.lisp. The assertion
;;; (assert (member (functional-kind lambda) '(:let :mv-let :assignment)))
;;; fails within bind node branch.
;;;
;;; Note that if c::*check-consistency* is enabled then an un-reached
;;; entry is also reported.
;;;
(defun foo (val)
(declare (values nil))
nil)
(defun bug (val)
(multiple-value-call
#'(lambda (res)
(block nil
(tagbody
loop
(when res
(return nil))
(go loop))))
(foo val))
(catch 'ccc1
(throw 'ccc1
(block bbbb
(tagbody
(let ((ttt #'(lambda () (go cccc))))
(declare (special ttt))
(return-from bbbb nil))
cccc
(return-from bbbb nil))))))
19:
(I *think* this is a bug. It certainly seems like strange behavior. But
the ANSI spec is scary, dark, and deep..)
(FORMAT NIL "~,1G" 1.4) => "1. "
(FORMAT NIL "~3,1G" 1.4) => "1. "
20:
from Marco Antoniotti on cmucl-imp mailing list 1 Mar 2000:
(defclass ccc () ())
(setf (find-class 'ccc1) (find-class 'ccc))
(defmethod zut ((c ccc1)) 123)
DTC's recommended workaround from the mailing list 3 Mar 2000:
(setf (pcl::find-class 'ccc1) (pcl::find-class 'ccc))
22:
The ANSI spec, in section "22.3.5.2 Tilde Less-Than-Sign: Logical Block",
says that an error is signalled if ~W, ~_, ~<...~:>, ~I, or ~:T is used
inside "~<..~>" (without the colon modifier on the closing syntax).
However, SBCL doesn't do this:
* (FORMAT T "~<munge~wegnum~>" 12)
munge12egnum
NIL
23:
When too many files are opened, OPEN will fail with an
uninformative error message
error in function OPEN: error opening #P"/tmp/foo.lisp": NIL
instead of saying that too many files are open.
24:
Right now, when COMPILE-FILE has a read error, it actually pops
you into the debugger before giving up on the file. It should
instead handle the error, perhaps issuing (and handling)
a secondary error "caught ERROR: unrecoverable error during compilation"
and then return with FAILURE-P true,
26:
reported by Sam Steingold on the cmucl-imp mailing list 12 May 2000:
Also, there is another bug: `array-displacement' should return an
array or nil as first value (as per ANSI CL), while CMUCL declares
it as returning an array as first value always.
(Actually, I think the old CMU CL version in SBCL never returns NIL,
i.e. it's not just a declaration problem, but the definition doesn't
behave ANSIly.)
27:
Sometimes (SB-EXT:QUIT) fails with
Argh! maximum interrupt nesting depth (4096) exceeded, exiting
Process inferior-lisp exited abnormally with code 1
I haven't noticed a repeatable case of this yet.
29:
some sort of bug in inlining and RETURN-FROM in sbcl-0.6.5: Compiling
(DEFUN BAR? (X)
(OR (NAR? X)
(BLOCK USED-BY-SOME-Y?
(FLET ((FROB (STK)
(DOLIST (Y STK)
(UNLESS (REJECTED? Y)
(RETURN-FROM USED-BY-SOME-Y? T)))))
(DECLARE (INLINE FROB))
(FROB (RSTK X))
(FROB (MRSTK X)))
NIL)))
gives
error in function SB-KERNEL:ASSERT-ERROR:
The assertion (EQ (SB-C::CONTINUATION-KIND SB-C::CONT) :BLOCK-START) failed.
This is still present in sbcl-0.6.8.
31:
In some cases the compiler believes type declarations on array
elements without checking them, e.g.
(DECLAIM (OPTIMIZE (SAFETY 3) (SPEED 1) (SPACE 1)))
(DEFSTRUCT FOO A B)
(DEFUN BAR (X)
(DECLARE (TYPE (SIMPLE-ARRAY CONS 1) X))
(WHEN (CONSP (AREF X 0))
(PRINT (AREF X 0))))
(BAR (VECTOR (MAKE-FOO :A 11 :B 12)))
prints
#S(FOO :A 11 :B 12)
in SBCL 0.6.5 (and also in CMU CL 18b). This does not happen for
all cases, e.g. the type assumption *is* checked if the array
elements are declared to be of some structure type instead of CONS.
32:
The printer doesn't report closures very well. This is true in
CMU CL 18b as well:
(PRINT #'CLASS-NAME)
gives
#<Closure Over Function "DEFUN STRUCTURE-SLOT-ACCESSOR" {134D1A1}>
It would be nice to make closures have a settable name slot,
and make things like DEFSTRUCT and FLET, which create closures,
set helpful values into this slot.
33:
And as long as we're wishing, it would be awfully nice if INSPECT could
also report on closures, telling about the values of the bound variables.
35:
The compiler assumes that any time a function of declared FTYPE
doesn't signal an error, its arguments were of the declared type.
E.g. compiling and loading
(DECLAIM (OPTIMIZE (SAFETY 3)))
(DEFUN FACTORIAL (X) (GAMMA (1+ X)))
(DECLAIM (FTYPE (FUNCTION (UNSIGNED-BYTE) FACTORIAL)))
(DEFUN FOO (X)
(COND ((> (FACTORIAL X) 1.0E6)
(FORMAT T "too big~%"))
((INTEGERP X)
(FORMAT T "exactly ~S~%" (FACTORIAL X)))
(T
(FORMAT T "approximately ~S~%" (FACTORIAL X)))))
then executing
(FOO 1.5)
will cause the INTEGERP case to be selected, giving bogus output a la
exactly 1.33..
This violates the "declarations are assertions" principle.
According to the ANSI spec, in the section "System Class FUNCTION",
this is a case of "lying to the compiler", but the lying is done
by the code which calls FACTORIAL with non-UNSIGNED-BYTE arguments,
not by the unexpectedly general definition of FACTORIAL. In any case,
"declarations are assertions" means that lying to the compiler should
cause an error to be signalled, and should not cause a bogus
result to be returned. Thus, the compiler should not assume
that arbitrary functions check their argument types. (It might
make sense to add another flag (CHECKED?) to DEFKNOWN to
identify functions which *do* check their argument types.)
38:
DEFMETHOD doesn't check the syntax of &REST argument lists properly,
accepting &REST even when it's not followed by an argument name:
(DEFMETHOD FOO ((X T) &REST) NIL)
41:
TYPEP of VALUES types is sometimes implemented very inefficiently, e.g. in
(DEFTYPE INDEXOID () '(INTEGER 0 1000))
(DEFUN FOO (X)
(DECLARE (TYPE INDEXOID X))
(THE (VALUES INDEXOID)
(VALUES X)))
where the implementation of the type check in function FOO
includes a full call to %TYPEP. There are also some fundamental problems
with the interpretation of VALUES types (inherited from CMU CL, and
from the ANSI CL standard) as discussed on the cmucl-imp@cons.org
mailing list, e.g. in Robert Maclachlan's post of 21 Jun 2000.
42:
The definitions of SIGCONTEXT-FLOAT-REGISTER and
%SET-SIGCONTEXT-FLOAT-REGISTER in x86-vm.lisp say they're not
supported on FreeBSD because the floating point state is not saved,
but at least as of FreeBSD 4.0, the floating point state *is* saved,
so they could be supported after all. Very likely
SIGCONTEXT-FLOATING-POINT-MODES could now be supported, too.
43:
(as discussed by Douglas Crosher on the cmucl-imp mailing list ca.
Aug. 10, 2000): CMUCL currently interprets 'member as '(member); same
issue with 'union, 'and, 'or etc. So even though according to the
ANSI spec, bare 'MEMBER, 'AND, and 'OR are not legal types, CMUCL
(and now SBCL) interpret them as legal types.
44:
ANSI specifies DEFINE-SYMBOL-MACRO, but it's not defined in SBCL.
CMU CL added it ca. Aug 13, 2000, after some discussion on the mailing
list, and it is probably possible to use substantially the same
patches to add it to SBCL.
45:
a slew of floating-point-related errors reported by Peter Van Eynde
on July 25, 2000:
a: (fixed in sbcl-0.6.11.25)
b: SBCL's value for LEAST-POSITIVE-SHORT-FLOAT is bogus, and
should probably be 1.4012985e-45. In SBCL,
(/ LEAST-POSITIVE-SHORT-FLOAT 2) returns a number smaller
than LEAST-POSITIVE-SHORT-FLOAT. Similar problems
exist for LEAST-NEGATIVE-SHORT-FLOAT, LEAST-POSITIVE-LONG-FLOAT,
and LEAST-NEGATIVE-LONG-FLOAT.
c: Many expressions generate floating infinity:
(/ 1 0.0)
(/ 1 0.0d0)
(EXPT 10.0 1000)
(EXPT 10.0d0 1000)
PVE's regression tests want them to raise errors. SBCL
generates the infinities instead, which may or may not be
conforming behavior.
d: (in section12.erg) various forms a la
(FLOAT 1 DOUBLE-FLOAT-EPSILON)
don't give the right behavior.
46:
type safety errors reported by Peter Van Eynde July 25, 2000:
a: (COERCE (QUOTE (A B C)) (QUOTE (VECTOR * 4)))
=> #(A B C)
In general lengths of array type specifications aren't
checked by COERCE, so it fails when the spec is
(VECTOR 4), (STRING 2), (SIMPLE-BIT-VECTOR 3), or whatever.
b: CONCATENATE has the same problem of not checking the length
of specified output array types. MAKE-SEQUENCE and MAP and
MERGE also have the same problem.
c: (COERCE 'AND 'FUNCTION) returns something related to
(MACRO-FUNCTION 'AND), but ANSI says it should raise an error.
d: ELT signals SIMPLE-ERROR if its index argument
isn't a valid index for its sequence argument, but should
signal TYPE-ERROR instead.
e: FILE-LENGTH is supposed to signal a type error when its
argument is not a stream associated with a file, but doesn't.
f: (FLOAT-RADIX 2/3) should signal an error instead of
returning 2.
g: (LOAD "*.lsp") should signal FILE-ERROR.
h: (MAKE-CONCATENATED-STREAM (MAKE-STRING-OUTPUT-STREAM))
should signal TYPE-ERROR.
i: MAKE-TWO-WAY-STREAM doesn't check that its arguments can
be used for input and output as needed. It should fail with
TYPE-ERROR when handed e.g. the results of
MAKE-STRING-INPUT-STREAM or MAKE-STRING-OUTPUT-STREAM in
the inappropriate positions, but doesn't.
j: (PARSE-NAMESTRING (COERCE (LIST #\f #\o #\o (CODE-CHAR 0) #\4 #\8)
(QUOTE STRING)))
should probably signal an error instead of making a pathname with
a null byte in it.
k: READ-BYTE is supposed to signal TYPE-ERROR when its argument is
not a binary input stream, but instead cheerfully reads from
character streams, e.g. (MAKE-STRING-INPUT-STREAM "abc").
47:
DEFCLASS bugs reported by Peter Van Eynde July 25, 2000:
a: (DEFCLASS FOO () (A B A)) should signal a PROGRAM-ERROR, and
doesn't.
b: (DEFCLASS FOO () (A B A) (:DEFAULT-INITARGS X A X B)) should
signal a PROGRAM-ERROR, and doesn't.
c: (DEFCLASS FOO07 NIL ((A :ALLOCATION :CLASS :ALLOCATION :CLASS))),
and other DEFCLASS forms with duplicate specifications in their
slots, should signal a PROGRAM-ERROR, and doesn't.
d: (DEFGENERIC IF (X)) should signal a PROGRAM-ERROR, but instead
causes a COMPILER-ERROR.
48:
SYMBOL-MACROLET bugs reported by Peter Van Eynde July 25, 2000:
a: (SYMBOL-MACROLET ((T TRUE)) ..) should probably signal
PROGRAM-ERROR, but SBCL accepts it instead.
b: SYMBOL-MACROLET should refuse to bind something which is
declared as a global variable, signalling PROGRAM-ERROR.
c: SYMBOL-MACROLET should signal PROGRAM-ERROR if something
it binds is declared SPECIAL inside.
49:
LOOP bugs reported by Peter Van Eynde July 25, 2000:
a: (LOOP WITH (A B) DO (PRINT 1)) is a syntax error according to
the definition of WITH clauses given in the ANSI spec, but
compiles and runs happily in SBCL.
b: a messy one involving package iteration:
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<))))
Should be: (("blah" "blah2") ("blah2"))
SBCL: (("blah") ("blah2"))
* (LET ((X 1)) (LOOP FOR I BY (INCF X) FROM X TO 10 COLLECT I))
doesn't work -- SBCL's LOOP says BY isn't allowed in a FOR clause.
50:
type system errors reported by Peter Van Eynde July 25, 2000:
a: (SUBTYPEP 'BIGNUM 'INTEGER) => NIL, NIL
but should be (VALUES T T) instead.
b: (SUBTYPEP 'EXTENDED-CHAR 'CHARACTER) => NIL, NIL
but should be (VALUES T T) instead.
c: (SUBTYPEP '(INTEGER (0) (0)) 'NIL) dies with nested errors.
d: In general, the system doesn't like '(INTEGER (0) (0)) -- it
blows up at the level of SPECIFIER-TYPE with
"Lower bound (0) is greater than upper bound (0)." Probably
SPECIFIER-TYPE should return NIL instead.
e: (TYPEP 0 '(COMPLEX (EQL 0)) fails with
"Component type for Complex is not numeric: (EQL 0)."
This might be easy to fix; the type system already knows
that (SUBTYPEP '(EQL 0) 'NUMBER) is true.
f: The type system doesn't know about the condition system,
so that e.g. (TYPEP 'SIMPLE-ERROR 'ERROR)=>NIL.
g: The type system isn't all that smart about relationships
between hairy types, as shown in the type.erg test results,
e.g. (SUBTYPEP 'CONS '(NOT ATOM)) => NIL, NIL.
51:
miscellaneous errors reported by Peter Van Eynde July 25, 2000:
a: (PROGN
(DEFGENERIC FOO02 (X))
(DEFMETHOD FOO02 ((X NUMBER)) T)
(LET ((M (FIND-METHOD (FUNCTION FOO02)
NIL
(LIST (FIND-CLASS (QUOTE NUMBER))))))
(REMOVE-METHOD (FUNCTION FOO02) M)
(DEFGENERIC FOO03 (X))
(ADD-METHOD (FUNCTION FOO03) M)))
should give an error, but SBCL allows it.
b: READ should probably return READER-ERROR, not the bare
arithmetic error, when input a la "1/0" or "1e1000" causes
an arithmetic error.
52:
It has been reported (e.g. by Peter Van Eynde) that there are
several metaobject protocol "errors". (In order to fix them, we might
need to document exactly what metaobject protocol specification
we're following -- the current code is just inherited from PCL.)
53:
another error from Peter Van Eynde 5 September 2000:
(FORMAT NIL "~F" "FOO") should work, but instead reports an error.
PVE submitted a patch to deal with this bug, but it exposes other
comparably serious bugs, so I didn't apply it. It looks as though
the FORMAT code needs a fair amount of rewriting in order to comply
with the various details of the ANSI spec.
54:
The implementation of #'+ returns its single argument without
type checking, e.g. (+ "illegal") => "illegal".
55:
In sbcl-0.6.7, there is no doc string for CL:PUSH, probably
because it's defined with the DEFMACRO-MUNDANELY macro and something
is wrong with doc string setting in that macro.
56:
Attempting to use COMPILE on something defined by DEFMACRO fails:
(DEFMACRO FOO (X) (CONS X X))
(COMPILE 'FOO)
Error in function C::GET-LAMBDA-TO-COMPILE:
#<Closure Over Function "DEFUN (SETF MACRO-FUNCTION)" {480E21B1}> was defined in a non-null environment.
58:
(SUBTYPEP '(AND ZILCH INTEGER) 'ZILCH) => NIL, NIL
Note: I looked into fixing this in 0.6.11.15, but gave up. The
problem seems to be that there are two relevant type methods for
the subtypep operation, HAIRY :COMPLEX-SUBTYPEP-ARG2 and
INTERSECTION :COMPLEX-SUBTYPEP-ARG1, and only the first is
called. This could be fixed, but type dispatch is messy and
confusing enough already, I don't want to complicate it further.
Perhaps someday we can make CLOS cross-compiled (instead of compiled
after bootstrapping) so that we don't need to have the type system
available before CLOS, and then we can rewrite the type methods to
CLOS methods, and then expressing the solutions to stuff like this
should become much more straightforward. -- WHN 2001-03-14
59:
CL:*DEFAULT-PATHNAME-DEFAULTS* doesn't behave as ANSI suggests (reflecting
current working directory). And there's no supported way to update
or query the current working directory (a la Unix "chdir" and "pwd"),
which is functionality that ILISP needs (and currently gets with low-level
hacks).
60:
The debugger LIST-LOCATIONS command doesn't work properly.
61:
Compiling and loading
(DEFUN FAIL (X) (THROW 'FAIL-TAG X))
(FAIL 12)
then requesting a BACKTRACE at the debugger prompt gives no information
about where in the user program the problem occurred.
62:
The compiler is supposed to do type inference well enough that
the declaration in
(TYPECASE X
((SIMPLE-ARRAY SINGLE-FLOAT)
(LOCALLY
(DECLARE (TYPE (SIMPLE-ARRAY SINGLE-FLOAT) X))
..))
..)
is redundant. However, as reported by Juan Jose Garcia Ripoll for
CMU CL, it sometimes doesn't. Adding declarations is a pretty good
workaround for the problem for now, but can't be done by the TYPECASE
macros themselves, since it's too hard for the macro to detect
assignments to the variable within the clause.
Note: The compiler *is* smart enough to do the type inference in
many cases. This case, derived from a couple of MACROEXPAND-1
calls on Ripoll's original test case,
(DEFUN NEGMAT (A)
(DECLARE (OPTIMIZE SPEED (SAFETY 0)))
(COND ((TYPEP A '(SIMPLE-ARRAY SINGLE-FLOAT)) NIL
(LET ((LENGTH (ARRAY-TOTAL-SIZE A)))
(LET ((I 0) (G2554 LENGTH))
(DECLARE (TYPE REAL G2554) (TYPE REAL I))
(TAGBODY
SB-LOOP::NEXT-LOOP
(WHEN (>= I G2554) (GO SB-LOOP::END-LOOP))
(SETF (ROW-MAJOR-AREF A I) (- (ROW-MAJOR-AREF A I)))
(GO SB-LOOP::NEXT-LOOP)
SB-LOOP::END-LOOP))))))
demonstrates the problem; but the problem goes away if the TAGBODY
and GO forms are removed (leaving the SETF in ordinary, non-looping
code), or if the TAGBODY and GO forms are retained, but the
assigned value becomes 0.0 instead of (- (ROW-MAJOR-AREF A I)).
63:
Paul Werkowski wrote on cmucl-imp@cons.org 2000-11-15
I am looking into this problem that showed up on the cmucl-help
list. It seems to me that the "implementation specific environment
hacking functions" found in pcl/walker.lisp are completely messed
up. The good thing is that they appear to be barely used within
PCL and the munged environment object is passed to cmucl only
in calls to macroexpand-1, which is probably why this case fails.
SBCL uses essentially the same code, so if the environment hacking
is screwed up, it affects us too.
64:
Using the pretty-printer from the command prompt gives funny
results, apparently because the pretty-printer doesn't know
about user's command input, including the user's carriage return
that the user, and therefore the pretty-printer thinks that
the new output block should start indented 2 or more characters
rightward of the correct location.
65:
(probably related to bug #70)
As reported by Carl Witty on submit@bugs.debian.org 1999-05-08,
compiling this file
(in-package "CL-USER")
(defun equal-terms (termx termy)
(labels
((alpha-equal-bound-term-lists (listx listy)
(or (and (null listx) (null listy))
(and listx listy
(let ((bindings-x (bindings-of-bound-term (car listx)))
(bindings-y (bindings-of-bound-term (car listy))))
(if (and (null bindings-x) (null bindings-y))
(alpha-equal-terms (term-of-bound-term (car listx))
(term-of-bound-term (car listy)))
(and (= (length bindings-x) (length bindings-y))
(prog2
(enter-binding-pairs (bindings-of-bound-term (car listx))
(bindings-of-bound-term (car listy)))
(alpha-equal-terms (term-of-bound-term (car listx))
(term-of-bound-term (car listy)))
(exit-binding-pairs (bindings-of-bound-term (car listx))
(bindings-of-bound-term (car listy)))))))
(alpha-equal-bound-term-lists (cdr listx) (cdr listy)))))
(alpha-equal-terms (termx termy)
(if (and (variable-p termx)
(variable-p termy))
(equal-bindings (id-of-variable-term termx)
(id-of-variable-term termy))
(and (equal-operators-p (operator-of-term termx) (operator-of-term termy))
(alpha-equal-bound-term-lists (bound-terms-of-term termx)
(bound-terms-of-term termy))))))
(or (eq termx termy)
(and termx termy
(with-variable-invocation (alpha-equal-terms termx termy))))))
causes an assertion failure
The assertion (EQ (C::LAMBDA-TAIL-SET C::CALLER)
(C::LAMBDA-TAIL-SET (C::LAMBDA-HOME C::CALLEE))) failed.
Bob Rogers reports (1999-07-28 on cmucl-imp@cons.org) a smaller test
case with the same problem:
(defun parse-fssp-alignment ()
;; Given an FSSP alignment file named by the argument . . .
(labels ((get-fssp-char ()
(get-fssp-char))
(read-fssp-char ()
(get-fssp-char)))
;; Stub body, enough to tickle the bug.
(list (read-fssp-char)
(read-fssp-char))))
66:
ANSI specifies that the RESULT-TYPE argument of CONCATENATE must be
a subtype of SEQUENCE, but CONCATENATE doesn't check this properly:
(CONCATENATE 'SIMPLE-ARRAY #(1 2) '(3)) => #(1 2 3)
This also leads to funny behavior when derived type specifiers
are used, as originally reported by Milan Zamazal for CMU CL (on the
Debian bugs mailing list (?) 2000-02-27), then reported by Martin
Atzmueller for SBCL (2000-10-01 on sbcl-devel@lists.sourceforge.net):
(DEFTYPE FOO () 'SIMPLE-ARRAY)
(CONCATENATE 'FOO #(1 2) '(3))
=> #<ARRAY-TYPE SIMPLE-ARRAY> is a bad type specifier for
sequence functions.
The derived type specifier FOO should act the same way as the
built-in type SIMPLE-ARRAY here, but it doesn't. That problem
doesn't seem to exist for sequence types:
(DEFTYPE BAR () 'SIMPLE-VECTOR)
(CONCATENATE 'BAR #(1 2) '(3)) => #(1 2 3)
67:
As reported by Winton Davies on a CMU CL mailing list 2000-01-10,
and reported for SBCL by Martin Atzmueller 2000-10-20: (TRACE GETHASH)
crashes SBCL. In general tracing anything which is used in the
implementation of TRACE is likely to have the same problem.
68:
As reported by Daniel Solaz on cmucl-help@cons.org 2000-11-23,
SXHASH returns the same value for all non-STRUCTURE-OBJECT instances,
notably including all PCL instances. There's a limit to how much
SXHASH can do to return unique values for instances, but at least
it should probably look at the class name, the way that it does
for STRUCTURE-OBJECTs.
69:
As reported by Martin Atzmueller on the sbcl-devel list 2000-11-22,
> There remains one issue, that is a bug in SBCL:
> According to my interpretation of the spec, the ":" and "@" modifiers
> should appear _after_ the comma-seperated arguments.
> Well, SBCL (and CMUCL for that matter) accept
> (ASSERT (STRING= (FORMAT NIL "~:8D" 1) " 1"))
> where the correct way (IMHO) should be
> (ASSERT (STRING= (FORMAT NIL "~8:D" 1) " 1"))
Probably SBCL should stop accepting the "~:8D"-style format arguments,
or at least issue a warning.
70:
(probably related to bug #65)
The compiler doesn't like &OPTIONAL arguments in LABELS and FLET
forms. E.g.
(DEFUN FIND-BEFORE (ITEM SEQUENCE &KEY (TEST #'EQL))
(LABELS ((FIND-ITEM (OBJ SEQ TEST &OPTIONAL (VAL NIL))
(LET ((ITEM (FIRST SEQ)))
(COND ((NULL SEQ)
(VALUES NIL NIL))
((FUNCALL TEST OBJ ITEM)
(VALUES VAL SEQ))
(T
(FIND-ITEM OBJ (REST SEQ) TEST (NCONC VAL `(,ITEM))))))))
(FIND-ITEM ITEM SEQUENCE TEST)))
from David Young's bug report on cmucl-help@cons.org 30 Nov 2000
causes sbcl-0.6.9 to fail with
error in function SB-KERNEL:ASSERT-ERROR:
The assertion (EQ (SB-C::LAMBDA-TAIL-SET SB-C::CALLER)
(SB-C::LAMBDA-TAIL-SET
(SB-C::LAMBDA-HOME SB-C::CALLEE))) failed.
71:
(DECLAIM (OPTIMIZE ..)) doesn't work. E.g. even after
(DECLAIM (OPTIMIZE (SPEED 3))), things are still optimized with
the previous SPEED policy. This bug will probably get fixed in
0.6.9.x in a general cleanup of optimization policy.
72:
(DECLAIM (OPTIMIZE ..)) doesn't work properly inside LOCALLY forms.
74:
As noted in the ANSI specification for COERCE, (COERCE 3 'COMPLEX)
gives a result which isn't COMPLEX. The result type optimizer
for COERCE doesn't know this, perhaps because it was written before
ANSI threw this curveball: the optimizer thinks that COERCE always
returns a result of the specified type. Thus while the interpreted
function
(DEFUN TRICKY (X) (TYPEP (COERCE X 'COMPLEX) 'COMPLEX))
returns the correct result,
(TRICKY 3) => NIL
the compiled function
(COMPILE 'TRICKY)
does not:
(TRICKY 3) => T
75:
As reported by Martin Atzmueller on sbcl-devel 26 Dec 2000,
ANSI says that WITH-OUTPUT-TO-STRING should have a keyword
:ELEMENT-TYPE, but in sbcl-0.6.9 this is not defined for
WITH-OUTPUT-TO-STRING.
78:
ANSI says in one place that type declarations can be abbreviated even
when the type name is not a symbol, e.g.
(DECLAIM ((VECTOR T) *FOOVECTOR*))
SBCL doesn't support this. But ANSI says in another place that this
isn't allowed. So it's not clear this is a bug after all. (See the
e-mail on cmucl-help@cons.org on 2001-01-16 and 2001-01-17 from WHN
and Pierre Mai.)
79:
as pointed out by Dan Barlow on sbcl-devel 2000-07-02:
The PICK-TEMPORARY-FILE-NAME utility used by LOAD-FOREIGN uses
an easily guessable temporary filename in a way which might open
applications using LOAD-FOREIGN to hijacking by malicious users
on the same machine. Incantations for doing this safely are
floating around the net in various "how to write secure programs
despite Unix" documents, and it would be good to (1) fix this in
LOAD-FOREIGN, and (2) hunt for any other code which uses temporary
files and make it share the same new safe logic.
80:
(fixed early Feb 2001 by MNA)
81:
As reported by wbuss@TELDA.NET (Wolfhard Buss) on cmucl-help
2001-02-14,
According to CLHS
(loop with (a . b) of-type float = '(0.0 . 1.0)
and (c . d) of-type float = '(2.0 . 3.0)
return (list a b c d))
should evaluate to (0.0 1.0 2.0 3.0). cmucl-18c disagrees and
invokes the debugger: "B is not of type list".
SBCL does the same thing.
82:
Functions are assigned names based on the context in which they're
defined. This is less than ideal for the functions which are
used to implement CLOS methods. E.g. the output of
(DESCRIBE 'PRINT-OBJECT) lists functions like
#<FUNCTION "DEF!STRUCT (TRACE-INFO (:MAKE-LOAD-FORM-FUN SB-KERNEL:JUST-DUMP-IT-NORMALLY) (:PRINT-OBJECT #))" {1020E49}>
and
#<FUNCTION "MACROLET ((FORCE-DELAYED-DEF!METHODS NIL #))" {1242871}>
It would be better if these functions' names always identified
them as methods, and identified their generic functions and
specializers.
83:
RANDOM-INTEGER-EXTRA-BITS=10 may not be large enough for the RANDOM
RNG to be high quality near RANDOM-FIXNUM-MAX; it looks as though
the mean of the distribution can be systematically O(0.1%) wrong.
Just increasing R-I-E-B is probably not a good solution, since
it would decrease efficiency more than is probably necessary. Perhaps
using some sort of accept/reject method would be better.
84:
(SUBTYPEP '(SATISFIES SOME-UNDEFINED-FUN) NIL)=>NIL,T (should be NIL,NIL)
85:
Internally the compiler sometimes evaluates
(sb-kernel:type/= (specifier-type '*) (specifier-type t))
(I stumbled across this when I added an
(assert (not (eq type1 *wild-type*)))
in the NAMED :SIMPLE-= type method.) '* isn't really a type, and
in a type context should probably be translated to T, and so it's
probably to ask whether it's equal to the T type and then (using the
EQ type comparison in the NAMED :SIMPLE-= type method) return NIL.
(I haven't tried to investigate this bug enough to guess whether
there might be any user-level symptoms.)
90:
a latent cross-compilation/bootstrapping bug: The cross-compilation
host's CL:CHAR-CODE-LIMIT is used in target code in readtable.lisp
and possibly elsewhere. Instead, we should use the target system's
CHAR-CODE-LIMIT. This will probably cause problems if we try to
bootstrap on a system which uses a different value of CHAR-CODE-LIMIT
than SBCL does.
91:
(subtypep '(or (integer -1 1)
unsigned-byte)
'(or (rational -1 7)
unsigned-byte
(integer -1 1))) => NIL,T
An analogous problem with SINGLE-FLOAT and REAL types was fixed in
sbcl-0.6.11.22, but some peculiarites of the RATIO type make it
awkward to generalize the fix to INTEGER and RATIONAL. It's not
clear what's the best fix. (See the "bug in type handling" discussion
on cmucl-imp ca. 2001-03-22 and ca. 2001-02-12.)
93:
In sbcl-0.6.11.26, (COMPILE 'IN-HOST-COMPILATION-MODE) in
src/cold/shared.lisp doesn't correctly translate the
interpreted function
(defun in-host-compilation-mode (fn)
(let ((*features* (cons :sb-xc-host *features*))
;; the CROSS-FLOAT-INFINITY-KLUDGE, as documented in
;; base-target-features.lisp-expr:
(*shebang-features* (set-difference *shebang-features*
'(:sb-propagate-float-type
:sb-propagate-fun-type))))
(with-additional-nickname ("SB-XC" "SB!XC")
(funcall fn))))
No error is reported by the compiler, but when the function is executed,
it causes an error
TYPE-ERROR in SB-KERNEL::OBJECT-NOT-TYPE-ERROR-HANDLER:
(:LINUX :X86 :IEEE-FLOATING-POINT :SB-CONSTRAIN-FLOAT-TYPE :SB-TEST
:SB-INTERPRETER :SB-DOC :UNIX ...) is not of type SYMBOL.
94a:
Inconsistencies between derived and declared VALUES return types for
DEFUN aren't checked very well. E.g. the logic which successfully
catches problems like
(declaim (ftype (function (fixnum) float) foo))
(defun foo (x)
(declare (type integer x))
(values x)) ; wrong return type, detected, gives warning, good!
fails to catch
(declaim (ftype (function (t) (values t t)) bar))
(defun bar (x)
(values x)) ; wrong number of return values, no warning, bad!
The cause of this is seems to be that (1) the internal function
VALUES-TYPES-EQUAL-OR-INTERSECT used to make the check handles its
arguments symmetrically, and (2) when the type checking code was
written back when when SBCL's code was still CMU CL, the intent
was that this case
(declaim (ftype (function (t) t) bar))
(defun bar (x)
(values x x)) ; wrong number of return values; should give warning?
not be warned for, because a two-valued return value is considered
to be compatible with callers who expects a single value to be
returned. That intent is probably not appropriate for modern ANSI
Common Lisp, but fixing this might be complicated because of other
divergences between auld-style and new-style handling of
multiple-VALUES types. (Some issues related to this were discussed
on cmucl-imp at some length sometime in 2000.)
95:
The facility for dumping a running Lisp image to disk gets confused
when run without the PURIFY option, and creates an unnecessarily large
core file (apparently representing memory usage up to the previous
high-water mark). Moreover, when the file is loaded, it confuses the
GC, so that thereafter memory usage can never be reduced below that
level.
96:
The TRACE facility can't be used on some kinds of functions.
(Basically, the breakpoint facility was incompletely implemented
in the X86 port of CMU CL, and hasn't been fixed in SBCL.)
98:
In sbcl-0.6.11.41 (and in all earlier SBCL, and in CMU
CL), out-of-line structure slot setters are horribly inefficient
whenever the type of the slot is declared, because out-of-line
structure slot setters are implemented as closures to save space,
so the compiler doesn't compile the type test into code, but
instead just saves the type in a lexical closure and interprets it
at runtime.
A proper solution involves deciding whether it's really worth
saving space by implementing structure slot accessors as closures.
(If it's not worth it, the problem vanishes automatically. If it
is worth it, there are hacks we could use to force type tests to
be compiled anyway, and even shared. E.g. we could implement
an EQUAL hash table mapping from types to compiled type tests,
and save the appropriate compiled type test as part of each lexical
closure; or we could make the lexical closures be placeholders
which overwrite their old definition as a lexical closure with
a new compiled definition the first time that they're called.)
As a workaround for the problem, #'(SETF FOO) expressions can
be replaced with (EFFICIENT-SETF-FUNCTION FOO), where
(defmacro efficient-setf-function (place-function-name)
(or #+sbcl (and (sb-impl::info :function :accessor-for place-function-name)
;; a workaround for the problem, encouraging the
;; inline expansion of the structure accessor, so
;; that the compiler can optimize its type test
(let ((new-value (gensym "NEW-VALUE-"))
(structure-value (gensym "STRUCTURE-VALUE-")))
`(lambda (,new-value ,structure-value)
(setf (,place-function-name ,structure-value)
,new-value))))
;; no problem, can just use the ordinary expansion
`(function (setf ,place-function-name))))
99:
DESCRIBE interacts poorly with *PRINT-CIRCLE*, e.g. the output from
(let ((*print-circle* t)) (describe (make-hash-table)))
is weird. (This is likely a pretty-printer problem which happens to
be exercised by DESCRIBE, not actually a DESCRIBE problem.)
KNOWN BUGS RELATED TO THE IR1 INTERPRETER
(Note: At some point, the pure interpreter (actually a semi-pure
interpreter aka "the IR1 interpreter") will probably go away, replaced
by constructs like
(DEFUN EVAL (X) (FUNCALL (COMPILE NIL (LAMBDA ..)))))
and at that time these bugs should either go away automatically or
become more tractable to fix. Until then, they'll probably remain,
since some of them aren't considered urgent, and the rest are too hard
to fix as long as so many special cases remain. After the IR1
interpreter goes away is also the preferred time to start
systematically exterminating cases where debugging functionality
(backtrace, breakpoint, etc.) breaks down, since getting rid of the
IR1 interpreter will reduce the number of special cases we need to
support.)
IR1-1:
The FUNCTION special operator doesn't check properly whether its
argument is a function name. E.g. (FUNCTION (X Y)) returns a value
instead of failing with an error. (Later attempting to funcall the
value does cause an error.)
IR1-2:
COMPILED-FUNCTION-P bogusly reports T for interpreted functions:
* (DEFUN FOO (X) (- 12 X))
FOO
* (COMPILED-FUNCTION-P #'FOO)
T
IR1-3:
Executing
(DEFVAR *SUPPRESS-P* T)
(EVAL '(UNLESS *SUPPRESS-P*
(EVAL-WHEN (:COMPILE-TOPLEVEL :LOAD-TOPLEVEL :EXECUTE)
(FORMAT T "surprise!"))))
prints "surprise!". Probably the entire EVAL-WHEN mechanism ought to be
rewritten from scratch to conform to the ANSI definition, abandoning
the *ALREADY-EVALED-THIS* hack which is used in sbcl-0.6.8.9 (and
in the original CMU CL source, too). This should be easier to do --
though still nontrivial -- once the various IR1 interpreter special
cases are gone.
IR1-3a:
EVAL-WHEN's idea of what's a toplevel form is even more screwed up
than the example in IR1-3 would suggest, since COMPILE-FILE and
COMPILE both print both "right now!" messages when compiling the
following code,
(LAMBDA (X)
(COND (X
(EVAL-WHEN (:COMPILE-TOPLEVEL :LOAD-TOPLEVEL :EXECUTE)
(PRINT "yes! right now!"))
"yes!")
(T
(EVAL-WHEN (:COMPILE-TOPLEVEL :LOAD-TOPLEVEL :EXECUTE)
(PRINT "no! right now!"))
"no!")))
and while EVAL doesn't print the "right now!" messages, the first
FUNCALL on the value returned by EVAL causes both of them to be printed.
IR1-4:
The system accepts DECLAIM in most places where DECLARE would be
accepted, without even issuing a warning. ANSI allows this, but since
it's fairly easy to mistype DECLAIM instead of DECLARE, and the
meaning is rather different, and it's unlikely that the user
has a good reason for doing DECLAIM not at top level, it would be
good to issue a STYLE-WARNING when this happens. A possible
fix would be to issue STYLE-WARNINGs for DECLAIMs not at top level,
or perhaps to issue STYLE-WARNINGs for any EVAL-WHEN not at top level.
[This is considered an IR1-interpreter-related bug because until
EVAL-WHEN is rewritten, which won't happen until after the IR1
interpreter is gone, the system's notion of what's a top-level form
and what's not will remain too confused to fix this problem.]
Jump to Line
Something went wrong with that request. Please try again.