+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,
+ #<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
+ applied the patches to SBCL and they didn't seem to cause problems
+ (as reported sbcl-devel 2001-05-04). However, since the patches
+ modify nontrivial code which was apparently written incorrectly
+ the first time around, until regression tests are written I'm not
+ comfortable merging the patches in the CVS version of SBCL.
projects / sbcl.git / blobdiff