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
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:
+3: "type checking of structure slots"
+ a:
ANSI specifies that a type mismatch in a structure slot
initialization value should not cause a warning.
WORKAROUND:
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
+ workaround, and (3) by their own reasoning, it looks as though
+ ANSI may have gotten it wrong. 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.
+ However, 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).
+ 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)
+ (DECLAIM (FTYPE (FUNCTION () 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.
+ Such code should compile without complaint and work correctly either
+ on SBCL or on any other completely compliant Common Lisp system.
+
+ b: &AUX argument in a boa-constructor without a default value means
+ "do not initilize this slot" and does not cause type error. But
+ an error may be signalled at read time and it would be good if
+ SBCL did it.
+
+ d: (fixed in 0.8.1.5)
7:
- The "byte compiling top-level form:" output ought to be condensed.
+ The "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).
+ single "compiling top-level forms:" line.
11:
It would be nice if the
(during macroexpansion of IN-PACKAGE,
during macroexpansion of DEFFOO)
-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..)
+ the ANSI spec is scary, dark, and deep.. -- WHN)
(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
-
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:
E.g. compiling and loading
(DECLAIM (OPTIMIZE (SAFETY 3)))
(DEFUN FACTORIAL (X) (GAMMA (1+ X)))
- (DECLAIM (FTYPE (FUNCTION (UNSIGNED-BYTE) FACTORIAL)))
+ (DEFUN GAMMA (X) X)
+ (DECLAIM (FTYPE (FUNCTION (UNSIGNED-BYTE)) FACTORIAL))
(DEFUN FOO (X)
(COND ((> (FACTORIAL X) 1.0E6)
(FORMAT T "too big~%"))
then executing
(FOO 1.5)
will cause the INTEGERP case to be selected, giving bogus output a la
- exactly 1.33..
+ exactly 2.5
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
(Also, verify that the compiler handles declared function
return types as assertions.)
-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
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:
+ c: Many expressions generate floating infinity on x86/Linux:
(/ 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.
+ PVE's regression tests want them to raise errors. sbcl-0.7.0.5
+ on x86/Linux generates the infinities instead. That might or
+ might not be conforming behavior, but it's also inconsistent,
+ which is almost certainly wrong. (Inconsistency: (/ 1 0.0)
+ should give the same result as (/ 1.0 0.0), but instead (/ 1 0.0)
+ generates SINGLE-FLOAT-POSITIVE-INFINITY and (/ 1.0 0.0)
+ signals an error.
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".
-
-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
-
60:
The debugger LIST-LOCATIONS command doesn't work properly.
+ (How should it work properly?)
61:
Compiling and loading
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
the new output block should start indented 2 or more characters
rightward of the correct location.
-65:
- (probably related to bug #70; maybe related to bug #109)
- 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; maybe related to bug #109)
- 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.
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.
+ (partially alleviated in sbcl-0.7.9.32 by a fix by Matthew Danish to
+ make the temporary filename less easily guessable)
83:
RANDOM-INTEGER-EXTRA-BITS=10 may not be large enough for the RANDOM
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))
(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.
+ probably wrong 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.)
+ In fact, the type system is likely to depend on this inequality not
+ holding... * is not equivalent to T in many cases, such as
+ (VECTOR *) /= (VECTOR T).
95:
The facility for dumping a running Lisp image to disk gets confused
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
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
+ To exercise the problem, compile and load
+ (cl:in-package :cl-user)
+ (defstruct foo
+ (bar (error "missing") :type bar))
+ (defvar *foo*)
+ (defun wastrel1 (x)
+ (loop (setf (foo-bar *foo*) x)))
+ (defstruct bar)
+ (defvar *bar* (make-bar))
+ (defvar *foo* (make-foo :bar *bar*))
+ (defvar *setf-foo-bar* #'(setf foo-bar))
+ (defun wastrel2 (x)
+ (loop (funcall *setf-foo-bar* x *foo*)))
+ then run (WASTREL1 *BAR*) or (WASTREL2 *BAR*), hit Ctrl-C, and
+ use BACKTRACE, to see it's spending all essentially all its time
+ in %TYPEP and VALUES-SPECIFIER-TYPE and so forth.
+ One possible solution would be simply to give up on
+ representing structure slot accessors as functions, and represent
+ them as macroexpansions instead. This can be inconvenient for users,
+ but it's not clear that it's worse than trying to help by expanding
+ into a horribly inefficient implementation.
+ 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)
+ (or #+sbcl (and (sb-int: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
;; 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,
- #<HASH-TABLE :TEST EQL :COUNT 0 {90BBFC5}> is an . (EQL)
- Its SIZE is 16.
- Its REHASH-SIZE is 1.5. Its REHASH-THRESHOLD is . (1.0)
- It holds 0 key/value pairs.
- where the ". (EQL)" and ". (1.0)" substrings are screwups.
- (This is likely a pretty-printer problem which happens to
- be exercised by DESCRIBE, not actually a DESCRIBE problem.)
-
100:
There's apparently a bug in CEILING optimization which caused
Douglas Crosher to patch the CMU CL version. Martin Atzmueller
the first time around, until regression tests are written I'm not
comfortable merging the patches in the CVS version of SBCL.
-101:
- The error message for calls to structure accessors with the
- wrong number of arguments is confusing and of the wrong
- condition class (TYPE-ERROR instead of PROGRAM-ERROR):
- * (defstruct foo x y)
- * (foo-x)
- debugger invoked on condition of type SIMPLE-TYPE-ERROR:
- Structure for accessor FOO-X is not a FOO:
- 301988783
-
-102:
- As reported by Arthur Lemmens sbcl-devel 2001-05-05, ANSI
- requires that SYMBOL-MACROLET refuse to rebind special variables,
- but SBCL doesn't do this. (Also as reported by AL in the same
- message, SBCL depended on this nonconforming behavior to build
- itself, because of the way that **CURRENT-SEGMENT** was implemented.
- As of sbcl-0.6.12.x, this dependence on the nonconforming behavior
- has been fixed, but the nonconforming behavior remains.)
-
-103:
- As reported by Arthur Lemmens sbcl-devel 2001-05-05, ANSI's
- definition of (LOOP .. DO ..) requires that the terms following
- DO all be compound forms. SBCL's implementation of LOOP allows
- non-compound forms (like the bare symbol COUNT, in his example)
- here.
-
-104:
- (DESCRIBE 'SB-ALIEN:DEF-ALIEN-TYPE) reports the macro argument list
- incorrectly:
- DEF-ALIEN-TYPE is
- an external symbol
- in #<PACKAGE "SB-ALIEN">.
- Macro-function: #<FUNCTION "DEF!MACRO DEF-ALIEN-TYPE" {19F4A39}>
- Macro arguments: (#:whole-470 #:environment-471)
- On Sat, May 26, 2001 09:45:57 AM CDT it was compiled from:
- /usr/stuff/sbcl/src/code/host-alieneval.lisp
- Created: Monday, March 12, 2001 07:47:43 AM CST
-
-105:
- (DESCRIBE 'STREAM-READ-BYTE)
-
-106:
- (reported by Eric Marsden on cmucl-imp 2001-06-15)
- Executing
- (TYPEP 0 '(COMPLEX (EQL 0)))
- signals an error in sbcl-0.6.12.34,
- The component type for COMPLEX is not numeric: (EQL 0)
- This is funny since sbcl-0.6.12.34 knows
- (SUBTYPEP '(EQL 0) 'NUMBER) => T
-
108:
(TIME (ROOM T)) reports more than 200 Mbytes consed even for
a clean, just-started SBCL system. And it seems to be right:
time trying to GC afterwards. Surely there's some more economical
way to implement (ROOM T).
-109:
- reported by Martin Atzmueller 2001-06-25; originally from CMU CL bugs
- collection:
- ;;; This file fails to compile.
- ;;; Maybe this bug is related to bugs #65, #70 in the BUGS file.
- (in-package :cl-user)
- (defun tst2 ()
- (labels
- ((eff (&key trouble)
- (eff)
- ;; nil
- ;; Uncomment and it works
- ))
- (eff)))
- In SBCL 0.6.12.42, the problem is
- internal error, failed AVER:
- "(COMMON-LISP:EQ (SB!C::LAMBDA-TAIL-SET SB!C::CALLER)
- (SB!C::LAMBDA-TAIL-SET (SB!C::LAMBDA-HOME SB!C::CALLEE)))"
-
-110:
- reported by Martin Atzmueller 2001-06-25; originally from CMU CL bugs
- collection:
- ;;; The compiler is flushing the argument type test, and the default
- ;;; case in the cond, so that calling with say a fixnum 0 causes a
- ;;; SIGBUS.
- (declaim (optimize (safety 2) (speed 3)))
- (defun tst (x)
- (declare (type (or string stream) x))
- (cond ((typep x 'string) 'string)
- ((typep x 'stream) 'stream)
- (t
- 'none)))
- The symptom in sbcl-0.6.12.42 on OpenBSD is actually (TST 0)=>STREAM
- (not the SIGBUS reported in the comment) but that's broken too;
- type declarations are supposed to be treated as assertions unless
- SAFETY 0, so we should be getting a TYPE-ERROR.
-
-111:
- reported by Martin Atzmueller 2001-06-25; originally from CMU CL bugs
- collection:
- (in-package :cl-user)
- ;;; Produces an assertion failures when compiled.
- (defun foo (z)
- (declare (type (or (function (t) t) null) z))
- (let ((z (or z #'identity)))
- (declare (type (function (t) t) z))
- (funcall z 1)))
- The error in sbcl-0.6.12.42 is
- internal error, failed AVER:
- "(COMMON-LISP:NOT (COMMON-LISP:EQ SB!C::CHECK COMMON-LISP:T))"
-
-112:
- reported by Martin Atzmueller 2001-06-25; taken from CMU CL bugs
- collection; apparently originally reported by Bruno Haible
- (in-package :cl-user)
- ;;; From: Bruno Haible
- ;;; Subject: scope of SPECIAL declarations
- ;;; It seems CMUCL has a bug relating to the scope of SPECIAL
- ;;; declarations. I observe this with "CMU Common Lisp 18a x86-linux
- ;;; 1.4.0 cvs".
- (let ((x 0))
- (declare (special x))
- (let ((x 1))
- (let ((y x))
- (declare (special x)) y)))
- ;;; Gives: 0 (this should return 1 according to CLHS)
- (let ((x 0))
- (declare (special x))
- (let ((x 1))
- (let ((y x) (x 5))
- (declare (special x)) y)))
- ;;; Gives: 1 (correct).
- The reported results match what we get from the interpreter
- in sbcl-0.6.12.42.
-
-113:
- reported by Martin Atzmueller 2001-06-25; originally from CMU CL bugs
- collection:
- (in-package :cl-user)
- ;;; From: David Gadbois <gadbois@cyc.com>
- ;;;
- ;;; Logical pathnames aren't externalizable.
- ;;; Test case:
- (let ((tempfile "/tmp/test.lisp"))
- (setf (logical-pathname-translations "XXX")
- '(("XXX:**;*.*" "/tmp/**/*.*")))
- (with-open-file (out tempfile :direction :output)
- (write-string "(defvar *path* #P\"XXX:XXX;FOO.LISP\")" out))
- (compile-file tempfile))
- The error message in sbcl-0.6.12.42 is
- ; caught ERROR:
- ; (while making load form for #<SB-IMPL::LOGICAL-HOST "XXX">)
- ; A logical host can't be dumped as a constant: #<SB-IMPL::LOGICAL-HOST "XXX">
-
-114:
- reported by Martin Atzmueller 2001-06-25; originally from CMU CL bugs
- collection:
- (in-package :cl-user)
- ;;; This file causes the byte compiler to fail.
- (declaim (optimize (speed 0) (safety 1)))
- (defun tst1 ()
- (values
- (multiple-value-list
- (catch 'a
- (return-from tst1)))))
- The error message in sbcl-0.6.12.42 is
- internal error, failed AVER:
- "(COMMON-LISP:EQUAL (SB!C::BYTE-BLOCK-INFO-START-STACK SB!INT:INFO) SB!C::STACK)"
-
-115:
- reported by Martin Atzmueller 2001-06-25; originally from CMU CL bugs
- collection:
- (in-package :cl-user)
- ;;; The following invokes a compiler error.
- (declaim (optimize (speed 2) (debug 3)))
- (defun tst ()
- (flet ((m1 ()
- (unwind-protect nil)))
- (if (catch nil)
- (m1)
- (m1))))
- The error message in sbcl-0.6.12.42 is
- internal error, failed AVER:
- "(COMMON-LISP:EQ (SB!C::TN-ENVIRONMENT SB!C:TN) SB!C::TN-ENV)"
-
117:
When the compiler inline expands functions, it may be that different
kinds of return values are generated from different code branches.
your pre-0.7.0 state of grace with
#+sbcl (declaim (notinline find position find-if position-if)) ; bug 117..
+ (see also bug 279)
+
118:
as reported by Eric Marsden on cmucl-imp@cons.org 2001-08-14:
(= (FLOAT 1 DOUBLE-FLOAT-EPSILON)
Raymond Toy comments that this is tricky on the X86 since its FPU
uses 80-bit precision internally.
-119:
- a bug in the byte compiler and/or interpreter: Compile
- (IN-PACKAGE :CL-USER)
- (DECLAIM (OPTIMIZE (SPEED 0) (SAFETY 1) (DEBUG 1)))
- (DEFUN BAR (&REST DIMS)
- (IF (EVERY #'INTEGERP DIMS)
- 1
- 2))
- then execute (BAR '(1 2 3 4)). In sbcl-0.pre7.14.flaky4.8
- this gives a TYPE-ERROR,
- The value #:UNINITIALIZED-EVAL-STACK-ELEMENT is not
- of type (MOD 536870911).
- The same error will probably occur in earlier versions as well,
- although the name of the uninitialized-element placeholder will
- be shorter.
-
- The same thing happens if the compiler macro expansion of
- EVERY into MAP is hand-expanded:
- (defun bar2 (dims)
- (if (block blockname
- (map nil
- (lambda (dim)
- (let ((pred-value (funcall #'integerp dim)))
- (unless pred-value
- (return-from blockname
- nil))))
- dims)
- t)
- 1
- 2))
- CMU CL doesn't have this compiler macro expansion, so it was
- immune to the original bug in BAR, but once we hand-expand it
- into BAR2, CMU CL 18c has the same bug. (Run (BAR '(NIL NIL)).)
-
- The native compiler handles it fine, both in SBCL and in CMU CL.
-
-120a:
- The compiler incorrectly figures the return type of
- (DEFUN FOO (FRAME UP-FRAME)
- (IF (OR (NOT FRAME)
- T)
- FRAME
- "BAR"))
- as NIL.
-
- This problem exists in CMU CL 18c too. When I reported it on
- cmucl-imp@cons.org, Raymond Toy replied 23 Aug 2001 with
- a partial explanation, but no fix has been found yet.
-
-120b:
- Even in sbcl-0.pre7.x, which is supposed to be free of the old
- non-ANSI behavior of treating the function return type inferred
- from the current function definition as a declaration of the
- return type from any function of that name, the return type of NIL
- is attached to FOO in 120a above, and used to optimize code which
- calls FOO.
-
-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.]
-
-IR1-6:
- (another wishlist thing..) Reimplement DEFMACRO to be basically
- like DEFMACRO-MUNDANELY, just using EVAL-WHEN.
+124:
+ As of version 0.pre7.14, SBCL's implementation of MACROLET makes
+ the entire lexical environment at the point of MACROLET available
+ in the bodies of the macroexpander functions. In particular, it
+ allows the function bodies (which run at compile time) to try to
+ access lexical variables (which are only defined at runtime).
+ It doesn't even issue a warning, which is bad.
+
+ The SBCL behavior arguably conforms to the ANSI spec (since the
+ spec says that the behavior is undefined, ergo anything conforms).
+ However, it would be better to issue a compile-time error.
+ Unfortunately I (WHN) don't see any simple way to detect this
+ condition in order to issue such an error, so for the meantime
+ SBCL just does this weird broken "conforming" thing.
+
+ The ANSI standard says, in the definition of the special operator
+ MACROLET,
+ The macro-expansion functions defined by MACROLET are defined
+ in the lexical environment in which the MACROLET form appears.
+ Declarations and MACROLET and SYMBOL-MACROLET definitions affect
+ the local macro definitions in a MACROLET, but the consequences
+ are undefined if the local macro definitions reference any
+ local variable or function bindings that are visible in that
+ lexical environment.
+ Then it seems to contradict itself by giving the example
+ (defun foo (x flag)
+ (macrolet ((fudge (z)
+ ;The parameters x and flag are not accessible
+ ; at this point; a reference to flag would be to
+ ; the global variable of that name.
+ ` (if flag (* ,z ,z) ,z)))
+ ;The parameters x and flag are accessible here.
+ (+ x
+ (fudge x)
+ (fudge (+ x 1)))))
+ The comment "a reference to flag would be to the global variable
+ of the same name" sounds like good behavior for the system to have.
+ but actual specification quoted above says that the actual behavior
+ is undefined.
+
+ (Since 0.7.8.23 macroexpanders are defined in a restricted version
+ of the lexical environment, containing no lexical variables and
+ functions, which seems to conform to ANSI and CLtL2, but signalling
+ a STYLE-WARNING for references to variables similar to locals might
+ be a good thing.)
+
+125:
+ (as reported by Gabe Garza on cmucl-help 2001-09-21)
+ (defvar *tmp* 3)
+ (defun test-pred (x y)
+ (eq x y))
+ (defun test-case ()
+ (let* ((x *tmp*)
+ (func (lambda () x)))
+ (print (eq func func))
+ (print (test-pred func func))
+ (delete func (list func))))
+ Now calling (TEST-CASE) gives output
+ NIL
+ NIL
+ (#<FUNCTION {500A9EF9}>)
+ Evidently Python thinks of the lambda as a code transformation so
+ much that it forgets that it's also an object.
+
+135:
+ Ideally, uninterning a symbol would allow it, and its associated
+ FDEFINITION and PROCLAIM data, to be reclaimed by the GC. However,
+ at least as of sbcl-0.7.0, this isn't the case. Information about
+ FDEFINITIONs and PROCLAIMed properties is stored in globaldb.lisp
+ essentially in ordinary (non-weak) hash tables keyed by symbols.
+ Thus, once a system has an entry in this system, it tends to live
+ forever, even when it is uninterned and all other references to it
+ are lost.
+
+141: "pretty printing and backquote"
+ a.
+ * '``(FOO ,@',@S)
+ ``(FOO SB-IMPL::BACKQ-COMMA-AT S)
+
+ b. (fixed in 0.8.4.7)
+
+143:
+ (reported by Jesse Bouwman 2001-10-24 through the unfortunately
+ prominent SourceForge web/db bug tracking system, which is
+ unfortunately not a reliable way to get a timely response from
+ the SBCL maintainers)
+ In the course of trying to build a test case for an
+ application error, I encountered this behavior:
+ If you start up sbcl, and then lay on CTRL-C for a
+ minute or two, the lisp process will eventually say:
+ %PRIMITIVE HALT called; the party is over.
+ and throw you into the monitor. If I start up lisp,
+ attach to the process with strace, and then do the same
+ (abusive) thing, I get instead:
+ access failure in heap page not marked as write-protected
+ and the monitor again. I don't know enough to have the
+ faintest idea of what is going on here.
+ This is with sbcl 6.12, uname -a reports:
+ Linux prep 2.2.19 #4 SMP Tue Apr 24 13:59:52 CDT 2001 i686 unknown
+ I (WHN) have verified that the same thing occurs on sbcl-0.pre7.141
+ under OpenBSD 2.9 on my X86 laptop. Do be patient when you try it:
+ it took more than two minutes (but less than five) for me.
+
+145:
+ a.
+ ANSI allows types `(COMPLEX ,FOO) to use very hairy values for
+ FOO, e.g. (COMPLEX (AND REAL (SATISFIES ODDP))). The old CMU CL
+ COMPLEX implementation didn't deal with this, and hasn't been
+ upgraded to do so. (This doesn't seem to be a high priority
+ conformance problem, since seems hard to construct useful code
+ where it matters.)
+
+ b. (fixed in 0.8.3.43)
+
+146:
+ Floating point errors are reported poorly. E.g. on x86 OpenBSD
+ with sbcl-0.7.1,
+ * (expt 2.0 12777)
+ debugger invoked on condition of type SB-KERNEL:FLOATING-POINT-EXCEPTION:
+ An arithmetic error SB-KERNEL:FLOATING-POINT-EXCEPTION was signalled.
+ No traps are enabled? How can this be?
+ It should be possible to be much more specific (overflow, division
+ by zero, etc.) and of course the "How can this be?" should be fixable.
+
+ See also bugs #45.c and #183
+
+162:
+ (reported by Robert E. Brown 2002-04-16)
+ When a function is called with too few arguments, causing the
+ debugger to be entered, the uninitialized slots in the bad call frame
+ seem to cause GCish problems, being interpreted as tagged data even
+ though they're not. In particular, executing ROOM in the
+ debugger at that point causes AVER failures:
+ * (machine-type)
+ "X86"
+ * (lisp-implementation-version)
+ "0.7.2.12"
+ * (typep 10)
+ ...
+ 0] (room)
+ ...
+ failed AVER: "(SAP= CURRENT END)"
+ (Christophe Rhodes reports that this doesn't occur on the SPARC, which
+ isn't too surprising since there are many differences in stack
+ implementation and GC conservatism between the X86 and other ports.)
+
+ This is probably the same bug as 216
+
+167:
+ In sbcl-0.7.3.11, compiling the (illegal) code
+ (in-package :cl-user)
+ (defmethod prove ((uustk uustk))
+ (zap ((frob () nil))
+ (frob)))
+ gives the (not terribly clear) error message
+ ; caught ERROR:
+ ; (during macroexpansion of (DEFMETHOD PROVE ...))
+ ; can't get template for (FROB NIL NIL)
+ The problem seems to be that the code walker used by the DEFMETHOD
+ macro is unhappy with the illegal syntax in the method body, and
+ is giving an unclear error message.
+
+173:
+ The compiler sometimes tries to constant-fold expressions before
+ it checks to see whether they can be reached. This can lead to
+ bogus warnings about errors in the constant folding, e.g. in code
+ like
+ (WHEN X
+ (WRITE-STRING (> X 0) "+" "0"))
+ compiled in a context where the compiler can prove that X is NIL,
+ and the compiler complains that (> X 0) causes a type error because
+ NIL isn't a valid argument to #'>. Until sbcl-0.7.4.10 or so this
+ caused a full WARNING, which made the bug really annoying because then
+ COMPILE and COMPILE-FILE returned FAILURE-P=T for perfectly legal
+ code. Since then the warning has been downgraded to STYLE-WARNING,
+ so it's still a bug but at least it's a little less annoying.
+
+183: "IEEE floating point issues"
+ Even where floating point handling is being dealt with relatively
+ well (as of sbcl-0.7.5, on sparc/sunos and alpha; see bug #146), the
+ accrued-exceptions and current-exceptions part of the fp control
+ word don't seem to bear much relation to reality. E.g. on
+ SPARC/SunOS:
+ * (/ 1.0 0.0)
+
+ debugger invoked on condition of type DIVISION-BY-ZERO:
+ arithmetic error DIVISION-BY-ZERO signalled
+ 0] (sb-vm::get-floating-point-modes)
+
+ (:TRAPS (:OVERFLOW :INVALID :DIVIDE-BY-ZERO)
+ :ROUNDING-MODE :NEAREST
+ :CURRENT-EXCEPTIONS NIL
+ :ACCRUED-EXCEPTIONS (:INEXACT)
+ :FAST-MODE NIL)
+ 0] abort
+ * (sb-vm::get-floating-point-modes)
+ (:TRAPS (:OVERFLOW :INVALID :DIVIDE-BY-ZERO)
+ :ROUNDING-MODE :NEAREST
+ :CURRENT-EXCEPTIONS (:INEXACT)
+ :ACCRUED-EXCEPTIONS (:INEXACT)
+ :FAST-MODE NIL)
+
+188: "compiler performance fiasco involving type inference and UNION-TYPE"
+ (time (compile
+ nil
+ '(lambda ()
+ (declare (optimize (safety 3)))
+ (declare (optimize (compilation-speed 2)))
+ (declare (optimize (speed 1) (debug 1) (space 1)))
+ (let ((start 4))
+ (declare (type (integer 0) start))
+ (print (incf start 22))
+ (print (incf start 26))
+ (print (incf start 28)))
+ (let ((start 6))
+ (declare (type (integer 0) start))
+ (print (incf start 22))
+ (print (incf start 26)))
+ (let ((start 10))
+ (declare (type (integer 0) start))
+ (print (incf start 22))
+ (print (incf start 26))))))
+
+ This example could be solved with clever enough constraint
+ propagation or with SSA, but consider
+
+ (let ((x 0))
+ (loop (incf x 2)))
+
+ The careful type of X is {2k} :-(. Is it really important to be
+ able to work with unions of many intervals?
+
+190: "PPC/Linux pipe? buffer? bug"
+ In sbcl-0.7.6, the run-program.test.sh test script sometimes hangs
+ on the PPC/Linux platform, waiting for a zombie env process. This
+ is a classic symptom of buffer filling and deadlock, but it seems
+ only sporadically reproducible.
+
+191: "Miscellaneous PCL deficiencies"
+ (reported by Alexey Dejneka sbcl-devel 2002-08-04)
+ a. DEFCLASS does not inform the compiler about generated
+ functions. Compiling a file with
+ (DEFCLASS A-CLASS ()
+ ((A-CLASS-X)))
+ (DEFUN A-CLASS-X (A)
+ (WITH-SLOTS (A-CLASS-X) A
+ A-CLASS-X))
+ results in a STYLE-WARNING:
+ undefined-function
+ SB-SLOT-ACCESSOR-NAME::|COMMON-LISP-USER A-CLASS-X slot READER|
+
+ APD's fix for this was checked in to sbcl-0.7.6.20, but Pierre
+ Mai points out that the declamation of functions is in fact
+ incorrect in some cases (most notably for structure
+ classes). This means that at present erroneous attempts to use
+ WITH-SLOTS and the like on classes with metaclass STRUCTURE-CLASS
+ won't get the corresponding STYLE-WARNING.
+ c. (fixed in 0.8.4.23)
+
+201: "Incautious type inference from compound types"
+ a. (reported by APD sbcl-devel 2002-09-17)
+ (DEFUN FOO (X)
+ (LET ((Y (CAR (THE (CONS INTEGER *) X))))
+ (SETF (CAR X) NIL)
+ (FORMAT NIL "~S IS ~S, Y = ~S"
+ (CAR X)
+ (TYPECASE (CAR X)
+ (INTEGER 'INTEGER)
+ (T '(NOT INTEGER)))
+ Y)))
+
+ (FOO ' (1 . 2)) => "NIL IS INTEGER, Y = 1"
+
+ b.
+ * (defun foo (x)
+ (declare (type (array * (4 4)) x))
+ (let ((y x))
+ (setq x (make-array '(4 4)))
+ (adjust-array y '(3 5))
+ (= (array-dimension y 0) (eval `(array-dimension ,y 0)))))
+ FOO
+ * (foo (make-array '(4 4) :adjustable t))
+ NIL
+
+205: "environment issues in cross compiler"
+ (These bugs have no impact on user code, but should be fixed or
+ documented.)
+ a. Macroexpanders introduced with MACROLET are defined in the null
+ lexical environment.
+ b. The body of (EVAL-WHEN (:COMPILE-TOPLEVEL) ...) is evaluated in
+ the null lexical environment.
+ c. The cross-compiler cannot inline functions defined in a non-null
+ lexical environment.
+
+206: ":SB-FLUID feature broken"
+ (reported by Antonio Martinez-Shotton sbcl-devel 2002-10-07)
+ Enabling :SB-FLUID in the target-features list in sbcl-0.7.8 breaks
+ the build.
+
+207: "poorly distributed SXHASH results for compound data"
+ SBCL's SXHASH could probably try a little harder. ANSI: "the
+ intent is that an implementation should make a good-faith
+ effort to produce hash-codes that are well distributed
+ within the range of non-negative fixnums". But
+ (let ((hits (make-hash-table)))
+ (dotimes (i 16)
+ (dotimes (j 16)
+ (let* ((ij (cons i j))
+ (newlist (push ij (gethash (sxhash ij) hits))))
+ (when (cdr newlist)
+ (format t "~&collision: ~S~%" newlist))))))
+ reports lots of collisions in sbcl-0.7.8. A stronger MIX function
+ would be an obvious way of fix. Maybe it would be acceptably efficient
+ to redo MIX using a lookup into a 256-entry s-box containing
+ 29-bit pseudorandom numbers?
+
+211: "keywords processing"
+ a. :ALLOW-OTHER-KEYS T should allow a function to receive an odd
+ number of keyword arguments.
+ e. Compiling
+
+ (flet ((foo (&key y) (list y)))
+ (list (foo :y 1 :y 2)))
+
+ issues confusing message
+
+ ; in: LAMBDA NIL
+ ; (FOO :Y 1 :Y 2)
+ ;
+ ; caught STYLE-WARNING:
+ ; The variable #:G15 is defined but never used.
+
+212: "Sequence functions and circular arguments"
+ COERCE, MERGE and CONCATENATE go into an infinite loop when given
+ circular arguments; it would be good for the user if they could be
+ given an error instead (ANSI 17.1.1 allows this behaviour on the part
+ of the implementation, as conforming code cannot give non-proper
+ sequences to these functions. MAP also has this problem (and
+ solution), though arguably the convenience of being able to do
+ (MAP 'LIST '+ FOO '#1=(1 . #1#))
+ might be classed as more important (though signalling an error when
+ all of the arguments are circular is probably desireable).
+
+213: "Sequence functions and type checking"
+ a. (fixed in 0.8.4.36)
+ b. MAP, when given a type argument that is SUBTYPEP LIST, does not
+ check that it will return a sequence of the given type. Fixing
+ it along the same lines as the others (cf. work done around
+ sbcl-0.7.8.45) is possible, but doing so efficiently didn't look
+ entirely straightforward.
+ c. All of these functions will silently accept a type of the form
+ (CONS INTEGER *)
+ whether or not the return value is of this type. This is
+ probably permitted by ANSI (see "Exceptional Situations" under
+ ANSI MAKE-SEQUENCE), but the DERIVE-TYPE mechanism does not
+ know about this escape clause, so code of the form
+ (INTEGERP (CAR (MAKE-SEQUENCE '(CONS INTEGER *) 2)))
+ can erroneously return T.
+
+215: ":TEST-NOT handling by functions"
+ a. FIND and POSITION currently signal errors when given non-NIL for
+ both their :TEST and (deprecated) :TEST-NOT arguments, but by
+ ANSI 17.2 "the consequences are unspecified", which by ANSI 1.4.2
+ means that the effect is "unpredictable but harmless". It's not
+ clear what that actually means; it may preclude conforming
+ implementations from signalling errors.
+ b. COUNT, REMOVE and the like give priority to a :TEST-NOT argument
+ when conflict occurs. As a quality of implementation issue, it
+ might be preferable to treat :TEST and :TEST-NOT as being in some
+ sense the same &KEY, and effectively take the first test function in
+ the argument list.
+ c. Again, a quality of implementation issue: it would be good to issue a
+ STYLE-WARNING at compile-time for calls with :TEST-NOT, and a
+ WARNING for calls with both :TEST and :TEST-NOT; possibly this
+ latter should be WARNed about at execute-time too.
+
+216: "debugger confused by frames with invalid number of arguments"
+ In sbcl-0.7.8.51, executing e.g. (VECTOR-PUSH-EXTEND T), BACKTRACE, Q
+ leaves the system confused, enough so that (QUIT) no longer works.
+ It's as though the process of working with the uninitialized slot in
+ the bad VECTOR-PUSH-EXTEND frame causes GC problems, though that may
+ not be the actual problem. (CMU CL 18c doesn't have problems with this.)
+
+ This is probably the same bug as 162
+
+217: "Bad type operations with FUNCTION types"
+ In sbcl.0.7.7:
+
+ * (values-type-union (specifier-type '(function (base-char)))
+ (specifier-type '(function (integer))))
+
+ #<FUN-TYPE (FUNCTION (BASE-CHAR) *)>
+
+ It causes insertion of wrong type assertions into generated
+ code. E.g.
+
+ (defun foo (x s)
+ (let ((f (etypecase x
+ (character #'write-char)
+ (integer #'write-byte))))
+ (funcall f x s)
+ (etypecase x
+ (character (write-char x s))
+ (integer (write-byte x s)))))
+
+ Then (FOO #\1 *STANDARD-OUTPUT*) signals type error.
+
+ (In 0.7.9.1 the result type is (FUNCTION * *), so Python does not
+ produce invalid code, but type checking is not accurate.)
+
+233: bugs in constraint propagation
+ b.
+ (declaim (optimize (speed 2) (safety 3)))
+ (defun foo (x y)
+ (if (typep (prog1 x (setq x y)) 'double-float)
+ (+ x 1d0)
+ (+ x 2)))
+ (foo 1d0 5) => segmentation violation
+
+235: "type system and inline expansion"
+ a.
+ (declaim (ftype (function (cons) number) acc))
+ (declaim (inline acc))
+ (defun acc (c)
+ (the number (car c)))
+
+ (defun foo (x y)
+ (values (locally (declare (optimize (safety 0)))
+ (acc x))
+ (locally (declare (optimize (safety 3)))
+ (acc y))))
+
+ (foo '(nil) '(t)) => NIL, T.
+
+237: "Environment arguments to type functions"
+ a. Functions SUBTYPEP, TYPEP, UPGRADED-ARRAY-ELEMENT-TYPE, and
+ UPGRADED-COMPLEX-PART-TYPE now have an optional environment
+ argument, but they ignore it completely. This is almost
+ certainly not correct.
+ b. Also, the compiler's optimizers for TYPEP have not been informed
+ about the new argument; consequently, they will not transform
+ calls of the form (TYPEP 1 'INTEGER NIL), even though this is
+ just as optimizeable as (TYPEP 1 'INTEGER).
+
+238: "REPL compiler overenthusiasm for CLOS code"
+ From the REPL,
+ * (defclass foo () ())
+ * (defmethod bar ((x foo) (foo foo)) (call-next-method))
+ causes approximately 100 lines of code deletion notes. Some
+ discussion on this issue happened under the title 'Three "interesting"
+ bugs in PCL', resulting in a fix for this oververbosity from the
+ compiler proper; however, the problem persists in the interactor
+ because the notion of original source is not preserved: for the
+ compiler, the original source of the above expression is (DEFMETHOD
+ BAR ((X FOO) (FOO FOO)) (CALL-NEXT-METHOD)), while by the time the
+ compiler gets its hands on the code needing compilation from the REPL,
+ it has been macroexpanded several times.
+
+ A symptom of the same underlying problem, reported by Tony Martinez:
+ * (handler-case
+ (with-input-from-string (*query-io* " no")
+ (yes-or-no-p))
+ (simple-type-error () 'error))
+ ; in: LAMBDA NIL
+ ; (SB-KERNEL:FLOAT-WAIT)
+ ;
+ ; note: deleting unreachable code
+ ; compilation unit finished
+ ; printed 1 note
+
+241: "DEFCLASS mysteriously remembers uninterned accessor names."
+ (from tonyms on #lisp IRC 2003-02-25)
+ In sbcl-0.7.12.55, typing
+ (defclass foo () ((bar :accessor foo-bar)))
+ (profile foo-bar)
+ (unintern 'foo-bar)
+ (defclass foo () ((bar :accessor foo-bar)))
+ gives the error message
+ "#:FOO-BAR already names an ordinary function or a macro."
+ So it's somehow checking the uninterned old accessor name instead
+ of the new requested accessor name, which seems broken to me (WHN).
+
+242: "WRITE-SEQUENCE suboptimality"
+ (observed from clx performance)
+ In sbcl-0.7.13, WRITE-SEQUENCE of a sequence of type
+ (SIMPLE-ARRAY (UNSIGNED-BYTE 8) (*)) on a stream with element-type
+ (UNSIGNED-BYTE 8) will write to the stream one byte at a time,
+ rather than writing the sequence in one go, leading to severe
+ performance degradation.
+
+243: "STYLE-WARNING overenthusiasm for unused variables"
+ (observed from clx compilation)
+ In sbcl-0.7.14, in the presence of the macros
+ (DEFMACRO FOO (X) `(BAR ,X))
+ (DEFMACRO BAR (X) (DECLARE (IGNORABLE X)) 'NIL)
+ somewhat surprising style warnings are emitted for
+ (COMPILE NIL '(LAMBDA (Y) (FOO Y))):
+ ; in: LAMBDA (Y)
+ ; (LAMBDA (Y) (FOO Y))
+ ;
+ ; caught STYLE-WARNING:
+ ; The variable Y is defined but never used.
+
+245: bugs in disassembler
+ a. On X86 an immediate operand for IMUL is printed incorrectly.
+ b. On X86 operand size prefix is not recognized.
+
+251:
+ (defun foo (&key (a :x))
+ (declare (fixnum a))
+ a)
+
+ does not cause a warning. (BTW: old SBCL issued a warning, but for a
+ function, which was never called!)
+
+256:
+ Compiler does not emit warnings for
+
+ a. (lambda () (svref (make-array 8 :adjustable t) 1))
+
+ b. (lambda (x)
+ (list (let ((y (the real x)))
+ (unless (floatp y) (error ""))
+ y)
+ (integer-length x)))
+
+ c. (lambda (x)
+ (declare (optimize (debug 0)))
+ (declare (type vector x))
+ (list (fill-pointer x)
+ (svref x 1)))
+
+257:
+ Complex array type does not have corresponding type specifier.
+
+ This is a problem because the compiler emits optimization notes when
+ you use a non-simple array, and without a type specifier for hairy
+ array types, there's no good way to tell it you're doing it
+ intentionally so that it should shut up and just compile the code.
+
+ Another problem is confusing error message "asserted type ARRAY
+ conflicts with derived type (VALUES SIMPLE-VECTOR &OPTIONAL)" during
+ compiling (LAMBDA (V) (VALUES (SVREF V 0) (VECTOR-POP V))).
+
+ The last problem is that when type assertions are converted to type
+ checks, types are represented with type specifiers, so we could lose
+ complex attribute. (Now this is probably not important, because
+ currently checks for complex arrays seem to be performed by
+ callees.)
+
+259:
+ (compile nil '(lambda () (aref (make-array 0) 0))) compiles without
+ warning. Analogous cases with the index and length being equal and
+ greater than 0 are warned for; the problem here seems to be that the
+ type required for an array reference of this type is (INTEGER 0 (0))
+ which is canonicalized to NIL.
+
+260:
+ a.
+ (let* ((s (gensym))
+ (t1 (specifier-type s)))
+ (eval `(defstruct ,s))
+ (type= t1 (specifier-type s)))
+ => NIL, NIL
+
+ (fixed in 0.8.1.24)
+
+ b. The same for CSUBTYPEP.
+
+262: "yet another bug in inline expansion of local functions"
+ Compiler fails on
+
+ (defun foo (x y)
+ (declare (integer x y))
+ (+ (block nil
+ (flet ((xyz (u)
+ (declare (integer u))
+ (if (> (1+ (the unsigned-byte u)) 0)
+ (+ 1 u)
+ (return (+ 38 (cos (/ u 78)))))))
+ (declare (inline xyz))
+ (return-from foo
+ (* (funcall (eval #'xyz) x)
+ (if (> x 30)
+ (funcall (if (> x 5) #'xyz #'identity)
+ (+ x 13))
+ 38)))))
+ (sin (* x y))))
+
+ Urgh... It's time to write IR1-copier.
+
+266:
+ David Lichteblau provided (sbcl-devel 2003-06-01) a patch to fix
+ behaviour of streams with element-type (SIGNED-BYTE 8). The patch
+ looks reasonable, if not obviously correct; however, it caused the
+ PPC/Linux port to segfault during warm-init while loading
+ src/pcl/std-class.fasl. A workaround patch was made, but it would
+ be nice to understand why the first patch caused problems, and to
+ fix the cause if possible.
+
+268: "wrong free declaration scope"
+ The following code must signal type error:
+
+ (locally (declare (optimize (safety 3)))
+ (flet ((foo (x &optional (y (car x)))
+ (declare (optimize (safety 0)))
+ (list x y)))
+ (funcall (eval #'foo) 1)))
+
+269:
+ SCALE-FLOAT should accept any integer for its second argument.
+
+270:
+ In the following function constraint propagator optimizes nothing:
+
+ (defun foo (x)
+ (declare (integer x))
+ (declare (optimize speed))
+ (typecase x
+ (fixnum "hala")
+ (fixnum "buba")
+ (bignum "hip")
+ (t "zuz")))
+
+273:
+ Compilation of the following two forms causes "X is unbound" error:
+
+ (symbol-macrolet ((x pi))
+ (macrolet ((foo (y) (+ x y)))
+ (declaim (inline bar))
+ (defun bar (z)
+ (* z (foo 4)))))
+ (defun quux (z)
+ (bar z))
+
+ (See (COERCE (CDR X) 'FUNCTION) in IR1-CONVERT-INLINE-LAMBDA.)
+
+274:
+ CLHS says that type declaration of a symbol macro should not affect
+ its expansion, but in SBCL it does. (If you like magic and want to
+ fix it, don't forget to change all uses of MACROEXPAND to
+ MACROEXPAND*.)
+
+275:
+ The following code (taken from CLOCC) takes a lot of time to compile:
+
+ (defun foo (n)
+ (declare (type (integer 0 #.large-constant) n))
+ (expt 1/10 n))
+
+ (fixed in 0.8.2.51, but a test case would be good)
+
+276:
+ (defmethod fee ((x fixnum))
+ (setq x (/ x 2))
+ x)
+ (fee 1) => type error
+
+ (taken from CLOCC)
+
+278:
+ a.
+ (defun foo ()
+ (declare (optimize speed))
+ (loop for i of-type (integer 0) from 0 by 2 below 10
+ collect i))
+
+ uses generic arithmetic.
+
+ b. (fixed in 0.8.3.6)
+
+279: type propagation error -- correctly inferred type goes astray?
+ In sbcl-0.8.3 and sbcl-0.8.1.47, the warning
+ The binding of ABS-FOO is a (VALUES (INTEGER 0 0)
+ &OPTIONAL), not a (INTEGER 1 536870911)
+ is emitted when compiling this file:
+ (declaim (ftype (function ((integer 0 #.most-positive-fixnum))
+ (integer #.most-negative-fixnum 0))
+ foo))
+ (defun foo (x)
+ (- x))
+ (defun bar (x)
+ (let* (;; Uncomment this for a type mismatch warning indicating
+ ;; that the type of (FOO X) is correctly understood.
+ #+nil (fs-foo (float-sign (foo x)))
+ ;; Uncomment this for a type mismatch warning
+ ;; indicating that the type of (ABS (FOO X)) is
+ ;; correctly understood.
+ #+nil (fs-abs-foo (float-sign (abs (foo x))))
+ ;; something wrong with this one though
+ (abs-foo (abs (foo x))))
+ (declare (type (integer 1 100) abs-foo))
+ (print abs-foo)))
+
+ (see also bug 117)
+
+280: bogus WARNING about duplicate function definition
+ In sbcl-0.8.3 and sbcl-0.8.1.47, if BS.MIN is defined inline,
+ e.g. by
+ (declaim (inline bs.min))
+ (defun bs.min (bases) nil)
+ before compiling the file below, the compiler warns
+ Duplicate definition for BS.MIN found in one static
+ unit (usually a file).
+ when compiling
+ (declaim (special *minus* *plus* *stagnant*))
+ (defun b.*.min (&optional (x () xp) (y () yp) &rest rest)
+ (bs.min avec))
+ (define-compiler-macro b.*.min (&rest rest)
+ `(bs.min ,@rest))
+ (defun afish-d-rbd (pd)
+ (if *stagnant*
+ (b.*.min (foo-d-rbd *stagnant*))
+ (multiple-value-bind (reduce-fn initial-value)
+ (etypecase pd
+ (list (values #'bs.min 0))
+ (vector (values #'bs.min *plus*)))
+ (let ((cv-ks (cv (kpd.ks pd))))
+ (funcall reduce-fn d-rbds)))))
+ (defun bfish-d-rbd (pd)
+ (if *stagnant*
+ (b.*.min (foo-d-rbd *stagnant*))
+ (multiple-value-bind (reduce-fn initial-value)
+ (etypecase pd
+ (list (values #'bs.min *minus*))
+ (vector (values #'bs.min 0)))
+ (let ((cv-ks (cv (kpd.ks pd))))
+ (funcall reduce-fn d-rbds)))))
+
+281: COMPUTE-EFFECTIVE-METHOD error signalling.
+ (slightly obscured by a non-0 default value for
+ SB-PCL::*MAX-EMF-PRECOMPUTE-METHODS*)
+ It would be natural for COMPUTE-EFFECTIVE-METHOD to signal errors
+ when it finds a method with invalid qualifiers. However, it
+ shouldn't signal errors when any such methods are not applicable to
+ the particular call being evaluated, and certainly it shouldn't when
+ simply precomputing effective methods that may never be called.
+ (setf sb-pcl::*max-emf-precompute-methods* 0)
+ (defgeneric foo (x)
+ (:method-combination +)
+ (:method ((x symbol)) 1)
+ (:method + ((x number)) x))
+ (foo 1) -> ERROR, but should simply return 1
+
+ The issue seems to be that construction of a discriminating function
+ calls COMPUTE-EFFECTIVE-METHOD with methods that are not all applicable.
+
+283: Thread safety: libc functions
+ There are places that we call unsafe-for-threading libc functions
+ that we should find alternatives for, or put locks around. Known or
+ strongly suspected problems, as of 0.8.3.10: please update this
+ bug instead of creating new ones
+
+ localtime() - called for timezone calculations in code/time.lisp
+
+284: Thread safety: special variables
+ There are lots of special variables in SBCL, and I feel sure that at
+ least some of them are indicative of potentially thread-unsafe
+ parts of the system. See doc/internals/notes/threading-specials
+
+286: "recursive known functions"
+ Self-call recognition conflicts with known function
+ recognition. Currently cross compiler and target COMPILE do not
+ recognize recursion, and in target compiler it can be disabled. We
+ can always disable it for known functions with RECURSIVE attribute,
+ but there remains a possibility of a function with a
+ (tail)-recursive simplification pass and transforms/VOPs for base
+ cases.
+
+287: PPC/Linux miscompilation or corruption in first GC
+ When the runtime is compiled with -O3 on certain PPC/Linux machines, a
+ segmentation fault is reported at the point of first triggered GC,
+ during the compilation of DEFSTRUCT WRAPPER. As a temporary workaround,
+ the runtime is no longer compiled with -O3 on PPC/Linux, but it is likely
+ that this merely obscures, not solves, the underlying problem; as and when
+ underlying problems are fixed, it would be worth trying again to provoke
+ this problem.
+
+288: fundamental cross-compilation issues (from old UGLINESS file)
+ Using host floating point numbers to represent target floating point
+ numbers, or host characters to represent target characters, is
+ theoretically shaky. (The characters are OK as long as the characters
+ are in the ANSI-guaranteed character set, though, so they aren't a
+ real problem as long as the sources don't need anything but that;
+ the floats are a real problem.)
+
+289: "type checking and source-transforms"
+ a.
+ (block nil (let () (funcall #'+ (eval 'nil) (eval '1) (return :good))))
+ signals type error.
+
+ Our policy is to check argument types at the moment of a call. It
+ disagrees with ANSI, which says that type assertions are put
+ immediately onto argument expressions, but is easier to implement in
+ IR1 and is more compatible to type inference, inline expansion,
+ etc. IR1-transforms automatically keep this policy, but source
+ transforms for associative functions (such as +), being applied
+ during IR1-convertion, do not. It may be tolerable for direct calls
+ (+ x y z), but for (FUNCALL #'+ x y z) it is non-conformant.
+
+ b. Another aspect of this problem is efficiency. [x y + z +]
+ requires less registers than [x y z + +]. This transformation is
+ currently performed with source transforms, but it would be good to
+ also perform it in IR1 optimization phase.
+
+290: Alpha floating point and denormalized traps
+ In SBCL 0.8.3.6x on the alpha, we work around what appears to be a
+ hardware or kernel deficiency: the status of the enable/disable
+ denormalized-float traps bit seems to be ambiguous; by the time we
+ get to os_restore_fp_control after a trap, denormalized traps seem
+ to be enabled. Since we don't want a trap every time someone uses a
+ denormalized float, in general, we mask out that bit when we restore
+ the control word; however, this clobbers any change the user might
+ have made.
+
+296:
+ (reported by Adam Warner, sbcl-devel 2003-09-23)
+
+ The --load toplevel argument does not perform any sanitization of its
+ argument. As a result, files with Lisp pathname pattern characters
+ (#\* or #\?, for instance) or quotation marks can cause the system
+ to perform arbitrary behaviour.
+
+297:
+ LOOP with non-constant arithmetic step clauses suffers from overzealous
+ type constraint: code of the form
+ (loop for d of-type double-float from 0d0 to 10d0 by x collect d)
+ compiles to a type restriction on X of (AND DOUBLE-FLOAT (REAL
+ (0))). However, an integral value of X should be legal, because
+ successive adds of integers to double-floats produces double-floats,
+ so none of the type restrictions in the code is violated.
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