[sbcl.git] / BUGS

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 bugs which have been
fixed.


KNOWN BUGS OF NO SPECIAL CLASS:

2:
  DEFSTRUCT should almost certainly overwrite the old LAYOUT information
  instead of just punting when a contradictory structure definition
  is loaded.

3:
  It should cause a STYLE-WARNING, not a full WARNING, when a structure
  slot default value does not match the declared structure slot type.
  (The current behavior is consistent with SBCL's behavior elsewhere,
  and would not be a problem, except that the other behavior is 
  specifically required by the ANSI spec.)

4:
  It should cause a note, not a WARNING, when the system ignores
  an FTYPE proclamation for a slot accessor.

5:
  Error reporting on various stream-requiring operations is not 
  very good when the stream argument has the wrong type, because
  the operation tries to fall through to Gray stream code, and then
  dies because it's undefined. E.g. 
    (PRINT-UNREADABLE-OBJECT (*STANDARD-OUTPUT* 1))
  gives the error message
    error in SB-KERNEL::UNDEFINED-SYMBOL-ERROR-HANDLER:
      The function SB-IMPL::STREAM-WRITE-STRING is undefined.
  It would be more useful and correct to signal a TYPE-ERROR:
    not a STREAM: 1
  (It wouldn't be terribly difficult to write stubs for all the 
  Gray stream functions that the old CMU CL code expects, with
  each stub just raising the appropriate TYPE-ERROR.)

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

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.

8:
  Compiling a file containing the erroneous program
        (DEFSTRUCT FOO
          A
          B)
        (DEFSTRUCT (BAR (:INCLUDE FOO))
          A
          B)
  gives only the not-very-useful message
        caught ERROR:
          (during macroexpansion)
        Condition PROGRAM-ERROR was signalled.
  (The specific message which says that the problem was duplicate
  slot names gets lost.)

9:
  The handling of IGNORE declarations on lambda list arguments of
  DEFMETHOD is at least weird, and in fact seems broken and useless.
  I should fix up another layer of binding, declared IGNORABLE, for
  typed lambda list arguments.

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 someday perhaps I'll be motivated to look it up..

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)

12:
  The type system doesn't understand the KEYWORD type very well:
        (SUBTYPEP 'KEYWORD 'SYMBOL) => NIL, NIL
  It might be possible to fix this by changing the definition of
  KEYWORD to (AND SYMBOL (SATISFIES KEYWORDP)), but the type system
  would need to be a bit smarter about AND types, too:
        (SUBTYPEP '(AND SYMBOL KEYWORD) 'SYMBOL) => NIL, NIL
  (The type system does know something about AND types already,
        (SUBTYPEP '(AND INTEGER FLOAT) 'NUMBER) => T, T
        (SUBTYPEP '(AND INTEGER FIXNUM) 'NUMBER) =>T, T
  so likely this is a small patch.)

13:
  Floating point infinities are screwed up. [When I was converting CMU CL
  to SBCL, I was looking for complexity to delete, and I thought it was safe
  to just delete support for floating point infinities. It wasn't: they're
  generated by the floating point hardware even when we remove support
  for them in software. -- WHN] Support for them should be restored.

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.)

16:
  The ANSI spec says that CONS can be a compound type spec, e.g.
  (CONS FIXNUM REAL). SBCL doesn't support this.

17:
  from Paolo Amoroso on the CMU CL mailing list 27 Feb 2000:
I use CMU CL 18b under Linux. When COMPILE-FILE is supplied a physical
pathname, the type of the corresponding compiled file is X86F:
        * (compile-file "/home/paolo/lisp/tools/foo")
        Python version 1.0, VM version Intel x86 on 27 FEB 0 06:00:46 pm.
        Compiling: /home/paolo/lisp/tools/foo.lisp 27 FEB 0 05:57:42 pm
        Converted SQUARE.
        Compiling DEFUN SQUARE:
        Byte Compiling Top-Level Form:
        /home/paolo/lisp/tools/foo.x86f written.
        Compilation finished in 0:00:00.
        #p"/home/paolo/lisp/tools/foo.x86f"
        NIL
        NIL
But when the function is called with a logical pathname, the file type
becomes FASL:
        * (compile-file "tools:foo")
        Python version 1.0, VM version Intel x86 on 27 FEB 0 06:01:04 pm.
        Compiling: /home/paolo/lisp/tools/foo.lisp 27 FEB 0 05:57:42 pm
        Converted SQUARE.
        Compiling DEFUN SQUARE:
        Byte Compiling Top-Level Form:
        TOOLS:FOO.FASL written.
        Compilation finished in 0:00:00.
        #p"/home/paolo/lisp/tools/foo.fasl"
        NIL
        NIL

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,

25:
  from CMU CL mailing list 01 May 2000 

I realize I can take care of this by doing (proclaim (ignore pcl::.slots1.))
but seeing as .slots0. is not-exported, shouldn't it be ignored within the
+expansion
when not used?
 
In: DEFMETHOD FOO-BAR-BAZ (RESOURCE-TYPE)
  (DEFMETHOD FOO-BAR-BAZ
             ((SELF RESOURCE-TYPE))
             (SETF (SLOT-VALUE SELF 'NAME) 3))
--> BLOCK MACROLET PCL::FAST-LEXICAL-METHOD-FUNCTIONS
--> PCL::BIND-FAST-LEXICAL-METHOD-MACROS MACROLET
--> PCL::BIND-LEXICAL-METHOD-FUNCTIONS LET PCL::BIND-ARGS LET* PCL::PV-BINDING
--> PCL::PV-BINDING1 PCL::PV-ENV LET
==>
  (LET ((PCL::.SLOTS0. #))
    (PROGN SELF)
    (BLOCK FOO-BAR-BAZ
      (LET #
        #)))
Warning: Variable PCL::.SLOTS0. defined but never used.
 
Compilation unit finished.
  1 warning

#<Standard-Method FOO-BAR-BAZ (RESOURCE-TYPE) {480918FD}>

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.

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.

28:
  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.

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.

30:
  The CMU CL reader code takes liberties in binding the standard read table
  when reading the names of characters. Tim Moore posted a patch to the 
  CMU CL mailing list Mon, 22 May 2000 21:30:41 -0700.

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.

34:
  as reported by Robert Strandh on the CMU CL mailing list 12 Jun 2000:
    $ cat xx.lisp
    (defconstant +a-constant+ (make-instance 'a-class))
    (defconstant +another-constant+ (vector +a-constant+))
    $ lisp
    CMU Common Lisp release x86-linux 2.4.19  8 February 2000 build 456,
    running on
    bobby
    Send bug reports and questions to your local CMU CL maintainer,
    or to pvaneynd@debian.org
    or to cmucl-help@cons.org. (prefered)
    type (help) for help, (quit) to exit, and (demo) to see the demos
    Loaded subsystems:
      Python 1.0, target Intel x86
      CLOS based on PCL version:  September 16 92 PCL (f)
    * (defclass a-class () ())
    #<STANDARD-CLASS A-CLASS {48027BD5}>
    * (compile-file "xx.lisp")
    Python version 1.0, VM version Intel x86 on 12 JUN 00 08:12:55 am.
    Compiling:
    /home/strandh/Research/Functional/Common-Lisp/CLIM/Development/McCLIM
    /xx.lisp 12 JUN 00 07:47:14 am
    Compiling Load Time Value of (PCL::GET-MAKE-INSTANCE-FUNCTION-SYMBOL
    '(A-CLASS NIL NIL)):
    Byte Compiling Top-Level Form:
    Error in function C::DUMP-STRUCTURE:  Attempt to dump invalid
    structure:
      #<A-CLASS {4803A5B5}>
    How did this happen?

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.)

36:
  As pointed out by Martin Cracauer on the CMU CL mailing list
  13 Jun 2000, the :FILE-LENGTH operation for 
  FD-STREAM-MISC-ROUTINE is broken for large files: it says
  (THE INDEX SIZE) even though SIZE can be larger than INDEX.

37:
  In SBCL 0.6.5 (and CMU CL 18b) compiling and loading
        (in-package :cl-user)
        (declaim (optimize (safety 3)
                           (debug 3)
                           (compilation-speed 2)
                           (space 1)
                           (speed 2)
                           #+nil (sb-ext:inhibit-warnings 2)))
        (declaim (ftype (function * (values)) emptyvalues))
        (defun emptyvalues (&rest rest) (declare (ignore rest)) (values))
        (defstruct foo x y)
        (defgeneric assertoid ((x t)))
        (defmethod assertoid ((x t)) "just a placeholder")
        (defun bar (ht)
          (declare (type hash-table ht))
          (let ((res
                 (block blockname
                   (progn
                    (prog1
                        (emptyvalues)
                      (assertoid (hash-table-count ht)))))))
            (unless (typep res 'foo)
              (locally
               (common-lisp-user::bad-result-from-assertive-typed-fun
                'bar
                res)))))
  then executing
        (bar (make-hash-table))
  causes the failure
        Error in KERNEL::UNDEFINED-SYMBOL-ERROR-HANDLER:
          the function C::%INSTANCE-TYPEP is undefined.
  %INSTANCE-TYPEP is always supposed to be IR1-transformed away, but for
  some reason -- the (VALUES) return value declaration? -- the optimizer is
  confused and compiles a full call to %INSTANCE-TYPEP (which doesn't exist
  as a function) instead.

37a:
  The %INSTANCE-TYPEP problem in bug 37 comes up also when compiling
  and loading
        (IN-PACKAGE :CL-USER)
        (LOCALLY
          (DECLARE (OPTIMIZE (SAFETY 3) (SPEED 2) (SPACE 2)))
          (DECLAIM (FTYPE (FUNCTION (&REST T) (VALUES)) EMPTYVALUES))
          (DEFUN EMPTYVALUES (&REST REST)
            (DECLARE (IGNORE REST))
            (VALUES))
          (DEFSTRUCT DUMMYSTRUCT X Y)
          (DEFUN FROB-EMPTYVALUES (X)
            (LET ((RES (EMPTYVALUES X X X)))
              (UNLESS (TYPEP RES 'DUMMYSTRUCT)
                'EXPECTED-RETURN-VALUE))))
        (ASSERT (EQ (FROB-EMPTYVALUES 11) 'EXPECTED-RETURN-VALUE))


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)

39:
  On the CMU CL mailing list 26 June 2000, Douglas Crosher wrote

  Hannu Rummukainen wrote:
  ...
  > There's something weird going on with the compilation of the attached
  > code.  Compiling and loading the file in a fresh lisp, then invoking
  > (test-it) gives
  Thanks for the bug report, nice to have this one fixed. It was a bug
  in the x86 backend, the < VOP. A fix has been committed to the main
  source, see the file compiler/x86/float.lisp.

  Probably the same bug exists in SBCL.

40:
  TYPEP treats the result of UPGRADED-ARRAY-ELEMENT-TYPE as gospel,
  so that (TYPEP (MAKE-ARRAY 3) '(VECTOR SOMETHING-NOT-DEFINED-YET))
  returns (VALUES T T). Probably it should be an error instead,
  complaining that the type SOMETHING-NOT-DEFINED-YET is not defined.

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: (SQRT -9.0) fails, because SB-KERNEL::COMPLEX-SQRT is undefined.
           Similarly, COMPLEX-ASIN, COMPLEX-ACOS, COMPLEX-ACOSH, and others
           aren't found.
        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, but then blow it by being unable to
           output the infinities, since support for infinities is generally
           broken, and in particular SB-IMPL::OUTPUT-FLOAT-INFINITY is
           undefined.
        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

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)).
  

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.