sbcl.sbcl/NEWS

changes in sbcl-0.6.0 relative to sbcl-0.5.0:

* tidied up "make.sh" script
* tidied up system directory structure
* better "clean.sh" behavior
* added doc/FOR-CMUCL-DEVELOPERS
* many many small tweaks to output format, e.g. removing possibly-confusing
  trailing #\. character in DESCRIBE-INSTANCE
* (EQUALP #\A 'A) no longer signals an error.
* new hashing code, including EQUALP hashing
* tidied up Lisp initialization and toplevel
* initialization files (e.g. /etc/sbclrc and $HOME/.sbclrc)
* command line argument processing
* added POSIX-GETENV function to deal with Unix-ish environment variables
* more-Unixy handling of *STANDARD-INPUT* and other Lisp streams, e.g.
  terminating SBCL on EOF
* non-verbose GC by default
* There is no more "sbcl" shell script; the sbcl file is now the C
  runtime executable (just like CMU CL).
* removed some unused fops, e.g. FOP-UNIFORM-VECTOR, FOP-CHARACTER, and 
  FOP-POP-FOR-EFFECT
* tweaked debug-info.lisp and debug-int.lisp to make the debugger store
  symbol and package information as Lisp native symbol and package objects
  instead of strings naming symbols and strings naming packages. This way,
  whenever packages are renamed (as in warm init), debug information is
  transformed along with everything else.
* tweaked the optimization policy declarations which control the building
  of SBCL itself. Now, among other things, the system no longer saves
  source location debugging information. (This helps two problems at once
  by reducing SBCL size and by keeping SBCL from trying to look for its
  sources -- which may not exist -- when reporting errors.)
* added src/cold/chill.lisp, to let SBCL read its own cold sources for
  debugging and testing purposes
* cleaned up printing, making the printer call PRINT-OBJECT for
  instances, and using PRINT-UNREADABLE-OBJECT for most PRINT-OBJECT
  methods, giving nearly-ANSI behavior
* converted almost all special variables to use *FOO* naming convention
* deleted PARSE-TIME functionality, since it can be done portably
* moved some files out of cold init into warm init
* deleted DEFUN UNDEFINED-VALUE, replaced (UNDEFINED-VALUE) forms
  with (VALUES) forms
* regularized formatting of source files
* added an install.sh script
* fixed ridiculous memory usage of cross-compiler by making
  compiler/alloc.lisp not try to do pooling unless it can hook
  itself into the GC of the cross-compilation host. Now the system
  builds nicely on my old laptop.
* added :SB-ALLOC in target-features.lisp-expr
* deleted mention of :ANSI-DOC from target-features.lisp-expr (since it
  was not implemented)
* re-did condition handling and note reporting in the compiler. Notes
  are no longer handled by signalling conditions. Style warnings
  and warnings are handled more correctly and reported in such a way
  that it's easy to find one or the other in your output (so that you
  can e.g. figure out which of many problems caused COMPILE-FILE to 
  return FAILURE-P).
* changed the severity of several compiler warnings from full WARNING
  to STYLE-WARNING in order to conform with the ANSI spec; also changed
  compiler note reporting so that it doesn't use the condition system
  at all (and hence affects neither FAILURE-P nor WARNINGS-P in the 
  COMPILE-FILE command)
* made PROCLAIM and DECLAIM conform to ANSI. PROCLAIM is now an ordinary
  function. As a consequence, START-BLOCK and END-BLOCK declarations are
  no longer supported, since their implementation was deeply intertwingled
  with the magical, non-ANSI treatment that PROCLAIM received in CMU CL.
* removed bogus "support" for compiler macros named (SETF FOO), and
  removed the compiler macro for SETF INFO (but only after making a fool
  of myself on the cmucl-imp mailing list by posting a bogus patch for
  DEFINE-COMPILER-MACRO..)
* Compiled files containing forms which have side effects on the Lisp
  reader (such as DEFPACKAGE forms) are now handled more correctly.
  (Compiler queuing of top level lambdas has been suppressed by setting
  *TOP-LEVEL-LAMBDA-MAX* to 0. )
* deleted various currently-unused source files, e.g. gengc.lisp. They
  may be added back at some point e.g. when porting to other architectures,
  but until they are it's distracting to distribute them and to try to
  maintain them.
* deleted "UNCROSS couldn't recurse through.." style warnings, since 
  there were so many of them they're just distractions, and UNCROSS is
  known to be able to handle the current sources
* moved PROFILE functionality into TRACE, so that it will be clear
  how the wrapping and unwrapping of functions when you profile them
  interacts with the wrapping and unwrapping of functions when you
  trace them. (Actually, the functionality isn't there yet, but at least
  the interface specification is there. Hopefully, the functionality will
  arrive with some future maintenance release.)
* removed host-oops.lisp
* changed signature of QUIT function to allow UNIX-CODE argument
* fixed READ-SEQUENCE bug
* tweaked verbose GC output so that it looks more like the progress
  output that ANSI specifies for functions like LOAD
* set up the system on sourceforge.com, with home pages, mailing lists, etc.
* added <http://sbcl.sourceforge.com> to the banner information printed by
  the sbcl executable

changes in sbcl-0.6.1 relative to sbcl-0.6.0:

* changed build optimization from (SAFETY 1) to (SAFETY 3) as a short-term
  fix for various type-unsafety bugs, e.g. failures with (LENGTH 123) and
  (MAKE-LIST -1). In the longer term, it ought to become true
  that declarations are assertions even at SAFETY 1. For now, it's not
  quite true even at SAFETY 3, but it's at least more nearly true..
  (Note that this change seems to increases the size of the system by
  O(5%) and to decrease the speed of the compiler by 20% or more.)
* changed ALIEN printing to be much more abbreviated, as a short-term fix
  for the problem of printing dozens of lines of distracting information
  about low-level system machinery as part of the top stack frame
  on entry to the debugger when an undefined function was called.
* tweaked the debugger's use of WITH-STANDARD-IO-SYNTAX so that *PACKAGE*
  is not reset to COMMON-LISP-USER. 
* Compilation of stuff related to dyncount.lisp has been made conditional
  on the :SB-DYNCOUNT target feature, so that the ordinary core system is
  smaller. The various dyncount-related symbols have been moved into
  a new "SB-DYNCOUNT" package.
* tty-inspect.lisp has been renamed to inspect.lisp.
* unix-glibc2.lisp has been renamed to unix.lisp, and the :GLIBC2
  feature has gone away. (When we eventually port to other flavors of 
  libc and/or Unix, we'll try to make the differences between flavors
  invisible at the user level.)
* Various other *FEATURES* tags, and/or their associated conditionals,
  have been removed if obsolescent, or given better documentation, or
  sometimes given more-mnemonic names.

changes in sbcl-0.6.2 relative to sbcl-0.6.1:

* (Note that the way that the PCL macroexpansions were rewritten
  to accommodate the change in DEFGENERIC below breaks binary
  compatibility. That is, fasl files compiled under sbcl-0.6.1 may
  not run under sbcl-0.6.2. Once we get out of alpha releases,
  i.e. hit release 1.0.0, we'll probably try to maintain binary
  compatibility between maintenance releases, e.g. between sbcl-1.4.3
  and sbcl-1.4.4. Until then, however, it might be fairly common
  for maintenance releases to break binary compatibility.)
* A bug in the calculation of WARNINGS-P and FAILURE-P in COMPILE-FILE
  has been fixed.
* The reporting of unhandled signals has been changed to print some
  explanatory text as well as the report form. (Previously only
  the report form was printed.)
* The macroexpansion for DEFGENERIC now DECLAIMs the function that
  it defines, so that the compiler no longer issues undefined function
  warnings for compiled-but-not-yet-loaded generic functions. 
* The CLTL-style "LISP" and "USER" nicknames for the "COMMON-LISP"
  and "COMMON-LISP-USER" packages have been removed. Now only the "CL"
  and "CL-USER" standard nicknames from the "11.1.2 Standardized Packages"
  section of the ANSI spec are supported.
* The "" nickname for the "KEYWORD" package has been removed. 
  The reader still handles symbol tokens which begin with a package marker
  as keywords, but it doesn't expose its mechanism for doing so in the
  (PACKAGE-NICKNAMES (FIND-PACKAGE "KEYWORD")) list.
* The system now issues STYLE-WARNINGs for contradictory TYPE 
  proclamations. (Warnings for contradictory FTYPE proclamations would
  be nice too, but those can't be done usefully unless the type system
  is made smarter about FUNCTION types.)
* The names of source files "*host-*.lisp" and "*target-*.lisp" have been 
  systematized, so that "*target-*.lisp is supposed to exist only on the
  target and imply that there's a related file which exists on the
  host, and *host-*.lisp is supposed to exist only on the host and imply
  that there's a related file which exists on the target. This involves a
  lot of renaming. Hopefully the acute confusion caused by the renaming
  will be justified by the reduction in chronic confusion..
  ** runtime-type.lisp    -> early-target-type.lisp
  ** target-type.lisp     -> late-target-type.lisp
  ** early-host-format.lisp -> early-format.lisp
  ** late-host-format.lisp -> late-format.lisp
  ** host-error.lisp      -> misc-error.lisp
  ** early-error.lisp     -> early-target-error.lisp
  ** late-error.lisp      -> late-target-error.lisp
  ** host-defboot.lisp    -> early-defboot.lisp
  ** code/misc.lisp       -> code/target-misc.lisp
  ** code/host-misc.lisp  -> code/misc.lisp
  ** code/numbers.lisp    -> code/target-numbers.lisp
  ** code/early-numbers.lisp -> numbers.lisp
  ** early-host-type.lisp -> early-type.lisp
  ** late-host-type.lisp  -> late-type.lisp
  ** host-typep.lisp      -> typep.lisp
  ** load.lisp            -> target-load.lisp
  ** host-load.lisp       -> load.lisp
  ** host-disassem.lisp   -> disassem.lisp
  ** host-insts.lisp      -> insts.lisp
  ** byte-comp.lisp       -> target-byte-comp.lisp
  ** host-byte-comp.lisp  -> byte-comp.lisp
  ** host-signal.lisp     -> signal.lisp
  ** host-defstruct.lisp  -> defstruct.lisp
  ** late-target-type.lisp -> deftypes-for-target.lisp
  Furthermore, several other previously target-only files foo.lisp (e.g.
  hash-table.lisp and random.lisp) have been split into a target-and-host
  foo.lisp file and a target-only target-foo.lisp file, with their key type
  definitions in the target-and-host part, so that the cross-compiler will
  know more about target types.
* DEFSTRUCT BACKEND, and the BACKEND-valued *BACKEND* variable, have 
  gone away. In their place are various *BACKEND-FOO* variables
  corresponding to the slots of the old structure.
* A bug which caused the SB-COLD bootstrap-time package to be propagated
  into the target SBCL has been fixed.
* The chill.lisp system for loading cold code into a running SBCL
  now works better.
* Support for the CMU CL "scavenger hook" extension has been removed.
  (It was undocumented and unused in the CMU CL sources that SBCL was
  derived from, and stale in sbcl-0.6.1.)
* Various errors in the cross-compiler type system were detected
  by running the cross-compiler with *TYPE-SYSTEM-INITIALIZED*
  (enabling various consistency checks). Many of them were fixed,
  but some hard problems remain, so the compiler is back to 
  running without *TYPE-SYSTEM-INITIALIZED* for now.
* As part of the cross-compiler type system cleanup, I implemented
  DEF!TYPE and got rid of early-ugly-duplicates.lisp.
* I have started adding UNCROSS calls throughout the type system
  and the INFO database. (Thus perhaps eventually the blanket UNCROSS
  on cross-compiler input files will be able to go away, and various
  kludges with it).
* CONSTANTP now returns true for quoted forms (as explicitly required
  by the ANSI spec).

changes in sbcl-0.6.3 relative to sbcl-0.6.2:

* The system still can't cross-compile itself with
  *TYPE-SYSTEM-INITIALIZED* (and all the consistency checks that
  entails), but at least it can compile more of itself that way
  than it used to be able to, and various buglets which were uncovered
  by trying to cross-compile itself that way have now been fixed.
* This release breaks binary compatibility again. This time 
  at least I've incremented the FASL file format version to 2, so that the
  problem can be detected reliably instead of just causing weird errors.
* various new style warnings:
  ** using DEFUN, DEFMETHOD, or DEFGENERIC to overwrite an old definition
  ** using the deprecated EVAL/LOAD/COMPILE situation names in EVAL-WHEN
  ** using the lexical binding of a variable named in the *FOO* style
* DESCRIBE has been substantially rewritten. It now calls DESCRIBE-OBJECT
  as specified by ANSI.
* *RANDOM-STATE* is no longer automatically initialized from 
  (GET-UNIVERSAL-TIME), but instead from a constant seed. Thus, the
  default behavior of the system is to repeat its behavior every time
  it's run. If you'd like to change this behavior, you can always
  explicitly set the seed from (GET-UNIVERSAL-TIME); whereas under the 
  old convention there was no comparably easy way to get the system to 
  repeat its behavior every time it was run.
* Support for the pre-CLTL2 interpretation of FUNCTION declarations as
  FTYPE declarations has been removed, in favor of their ANSI
  interpretation as TYPE FUNCTION declarations. (See p. 228 of CLTL2.)
* The quantifiers SOME, EVERY, NOTANY, and NOTEVERY no longer cons when
  the types of their sequence arguments can be determined at compile time.
  This is done through a new open code expansion for MAP which eliminates
  consing for (MAP NIL ..), and reduces consing otherwise, when sequence
  argument types can be determined at compile time.
* The optimizer now transforms COERCE into an identity operation when it 
  can prove that the coerced object is already of the correct type. (This 
  can be a win for machine generated code, including the output of other
  optimization transforms, such as the MAP transform above.)
* Credit information has been moved from source file headers into CREDITS.
* Source file headers have been made more standard.
* The CASE macro now compiles without complaining even when it has
  no clauses.

changes in sbcl-0.6.4 relative to sbcl-0.6.3:

* There is now a partial SBCL user manual (with some new text and some
  text cribbed from the CMU CL manual). 
* The beginnings of a profiler have been added (starting with the
  CMU CL profiler and simplifying and cleaning up). Eventually the
  main interface should be through the TRACE macro, but for now, 
  it's still accessed through vaguely CMU-CL-style functions and macros
  exported from the package SB-PROFILE.
* Some problems left over from porting CMU CL to the new
  cross-compilation bootstrap process have been cleaned up:
  ** DISASSEMBLE now works. (There was a problem in using DEFMACRO
     instead of SB!XC:DEFMACRO, compounded by an oversight on my 
     part when getting rid of the compiler *BACKEND* stuff.)
  ** The value of *NULL-TYPE* was screwed up, because it was
     being initialized before the type system knew the final
     definition of the 'NULL type. This screwed up several key
     optimizations in the compiler, causing inefficiency in all sorts
     of places. (I found it because I wanted to understand why
     GET-INTERNAL-RUN-TIME was consing.) 
* fixed a bug in DEFGENERIC which was causing it to overwrite preexisting
  PROCLAIM FTYPE information. Unfortunately this broke binary 
  compatibility again, since now the forms output by DEFGENERIC
  to refer to functions which didn't exist in 0.6.3.
* added declarations so that SB-PCL::USE-CACHING-DFUN-P 
  can use the new (as of 0.6.3) transform for SOME into MAP into 
  inline code
* changed (MOD 1000000) type declarations for Linux timeval.tv_usec slot
  values to (INTEGER 0 1000000), so that the time code will no longer
  occasionally get blown up by Linux returning 1000000 microseconds
* PRINT-UNREADABLE-OBJECT has been tweaked to make the spacing of
  its output conform to the ANSI spec. (Alas, this makes its output
  uglier in the :TYPE T :IDENTITY NIL case, but them's the breaks.)
* A full call to MAP NIL with a single sequence argument no longer conses.
* fixes to problems pointed out by Martin Atzmueller:
  * The manual page no longer talks about multiprocessing as though
    it were currently supported.
  * The ILISP support patches have been removed from the distribution,
    because as of version 5.10.1, ILISP now supports SBCL without us
    having to maintain patches.
* added a modified version of Raymond Toy's recent CMU CL patch for
  EQUALP comparison of HASH-TABLE

changes in sbcl-0.6.5 relative to sbcl-0.6.4:

* Raymond Wiker's patches to port the system to FreeBSD have been merged.
* The build process now looks for GNU make under the default name "gmake",
  instead of "make" as it used to. If GNU make is not available as "gmake"
  on your system, you can change this default behavior by setting the 
  GNUMAKE environment variable.
* Replace #+SB-DOC with #!+SB-DOC in seq.lisp so that the system 
  can build without error under CMU CL.

changes in sbcl-0.6.6 relative to sbcl-0.6.5:

* DESCRIBE no longer tries to call itself recursively to describe
  bound/fbound values, so that it no longer fails on symbols which are
  bound to themselves (like keywords, T, and NIL).
* DESCRIBE now works on generic functions.
* The printer now prints less-screwed-up representations of closures
  (not naively trying to bogusly use the %FUNCTION-NAME accessor on them).
* A private symbol is used instead of the :EMPTY keyword previously 
  used to mark empty slots in hash tables. Thus 
	(DEFVAR *HT* (MAKE-HASH-TABLE))
	(SETF (GETHASH :EMPTY *HT*) :EMPTY)
	(MAPHASH (LAMBDA (K V) (FORMAT T "~&~S ~S~%" K V)))
  now does what ANSI says that it should. (You can still get 
  similar noncompliant behavior if bang on the hash table
  implementation with all the symbols you get back from 
  DO-ALL-SYMBOLS, but at least that's a little harder to do.)
  This breaks binary compatibility, since tests for equality to 
  :EMPTY are wired into things like the macroexpansion of 
  WITH-HASH-TABLE-ITERATOR in FASL files produced by earlier
  implementations.
* There's now a minimal placeholder implementation for CL:STEP,
  as required by ANSI.
* An obscure bug in the interaction of the normal compiler, the byte
  compiler, inlining, and structure predicates has been patched
  by setting the flags for the DEFTRANSFORM of %INSTANCE-TYPEP as
  :WHEN :BOTH (as per Raymond Toy's suggestion on the cmucl-imp@cons.org
  mailing list).
* Missing ordinary arguments in a macro call are now detected even
  when the macro lambda list contains &KEY or &REST.
* The debugger no longer complains about encountering the top of the
  stack when you type "FRAME 0" to explicitly instruct it to go to
  the top of the stack. And it now prints the frame you request even
  if it's the current frame (instead of saying "You are here.").
* As specified by ANSI, the system now always prints keywords
  as #\: followed by SYMBOL-NAME, even when *PACKAGE* is the
  KEYWORD package.
* The default initial SIZE of HASH-TABLEs is now smaller.
* Type information from CLOS class dispatch is now propagated
  into DEFMETHOD bodies, so that e.g.
	(DEFMETHOD FOO ((X SINGLE-FLOAT))
	  (+ X 123.0))
  is now basically equivalent to 
	(DEFMETHOD FOO ((X SINGLE-FLOAT))
	  (DECLARE (TYPE SINGLE-FLOAT X))
	  (+ X 123.0))
  and the compiler can compile (+ X 123.0) as a SINGLE-FLOAT-only
  operation, without having to do run-time type dispatch.
* The macroexpansion of DEFMETHOD has been tweaked so that it has
  reasonable behavior when arguments are declared IGNORE or IGNORABLE.
* Since I don't seem to be making big file reorganizations very often
  any more (and since my archive of sbcl-x.y.zv.tar.bz2 snapshots
  is overflowing my ability to conveniently back them up), I've finally
  checked the system into CVS. (The CVS repository is on my home system,
  not at SourceForge -- putting it on SourceForge might come later.)
* SB-EXT:*GC-NOTIFY-STREAM* has been added, to control where the 
  high-level GC-NOTIFY-FOO functions send their output. (There's
  still very little control of where low-level verbose GC functions
  send their output.) The SB-EXT:*GC-VERBOSE* variable now controls
  less than it used to -- the GC-NOTIFY-FOO functions are now under
  the control of *GC-NOTIFY-STREAM*, not *GC-VERBOSE*.
* The system now stores the version string (LISP-IMPLEMENTATION-VERSION)
  in only one place in the source code, and propagates it automatically
  everywhere that it's needed. Thus e.g. when I bump the version from
  0.6.6 to 0.6.7, I'll only need to modify the sources in one place.
* The C source files now include boilerplate legalese and documentation
  at the head of each file (just as the Lisp source files already did).
* At Dan Barlow's suggestion, the hyperlink from the SBCL website
  to his page will be replaced with a link to his new CLiki service.

changes in sbcl-0.6.7 relative to sbcl-0.6.6:

* The system has been ported to OpenBSD.
* The system now compiles with a simple "sh make.sh" on the systems
  that it's supported on. I.e., now you no longer need to tweak 
  text in the target-features.lisp-expr and symlinks in src/runtime/
  by hand, the make.sh takes care of it for you.
* The system is no longer so grossly inefficient when compiling code
  involving vectors implemented as general (not simple) vectors (VECTOR T),
  so code which dares to use VECTOR-PUSH-EXTEND and FILL-POINTER, or
  which dares to use the various sequence functions on non-simple 
  vectors, takes less of a performance hit.
  * There is now a primitive type predicate VECTOR-T-P
    to test for the (VECTOR T) type, so that e.g.
	(DEFUN FOO (V) (DECLARE (TYPE (VECTOR T) V)) (AREF V 3))
    can now be compiled with some semblance of efficiency. (The old code
    turned the type declaration into a full call to %TYPEP at runtime!)
  * AREF on (VECTOR T) is still not fast, since it's still compiled
    as a full call to SB-KERNEL:DATA-VECTOR-REF, but at least the
    ETYPECASE used in DATA-VECTOR-REF is now compiled reasonably
    efficiently. (The old version made full calls to SUBTYPEP at runtime!)
  * (MAKE-ARRAY 12 :FILL-POINTER T) is now executed less inefficiently,
    without making full calls to SUBTYPEP at runtime.
  (Some analogous efficiency issues for non-simple vectors specialized to
  element types other than T, or for non-simple multidimensional arrays,
  have not been addressed. They could almost certainly be handled the
  same way if anyone is motivated to do so.)
* The changes in array handling break binary compatibility, so
  *BACKEND-FASL-FILE-VERSION* has been bumped to 4.
* (TYPEP (MAKE-ARRAY 12 :FILL-POINTER 4) 'VECTOR) now returns (VALUES T)
  instead of (VALUES T T).
* By following the instructions that Dan Barlow posted to sbcl-devel
  on 2 July 2000, I was able to enable primitive dynamic object
  file loading code for Linux. The full-blown CMU CL LOAD-FOREIGN
  functionality is not implemented (since it calls ld to resolve
  library references automatically, requiring RUN-PROGRAM for its
  implementation), but a simpler SB-EXT:LOAD-1-FOREIGN (which doesn't
  try to resolve library references) is now supported.
* The system now flushes the standard output streams when it terminates,
  unless QUIT is used with the RECKLESSLY-P option set. It also flushes
  them at several other probably-convenient times, e.g. in each pass of
  the toplevel read-eval-print loop, and after evaluating a form given
  as an "--eval" command-line option. (These changes were motivated by a
  discussion of stream flushing issues on cmucl-imp in August 2000.) 
* The source transform for TYPEP of array types no longer assumes
  that an array whose element type is a not-yet-defined type 
  is implemented as an array of T, but instead punts, so that the 
  type will be interpreted at runtime.
* There is now some support for cross-compiling in make.sh: each of
  the phases of make.sh has its own script. (This should be transparent
  to people doing ordinary, non-cross-compile builds.)
* Since my laptop doesn't have hundreds of megabytes of memory like
  my desktop machine, I became more motivated to do some items on
  my to-do list in order to reduce the size of the system a little:
  ** Arrange for various needed-only-at-cold-init things to be
     uninterned after cold init. To support this, those things have
     been renamed from FOO and *FOO* to !FOO and *!FOO* (i.e., all
     symbols with such names are now uninterned after cold init).
  ** Bind SB!C::*TOP-LEVEL-LAMBDA-MAX* to a nonzero value when building
     fasl files for cold load.
  ** Remove the old compiler structure pooling code (which used to 
     be conditional on the target feature :SB-ALLOC) completely.
  ** Redo the representation of some data in cold init to be more compact.
  (I also looked into supporting byte compiled code at bootstrap time,
  which would probably reduce the size of the system a lot, but that
  looked too complicated, so I punted for now.)
* The maximum signal nesting depth in the src/runtime/ support code has
  been reduced from 4096 to 256. (I don't know any reason for the very
  large old value. If the new smaller value turns out to break something,
  I'll probably just bump it back up.)
* PPRINT-LOGICAL-BLOCK is now pickier about the types of its arguments,
  as per ANSI.
* Many, many bugs reported by Peter Van Eynde have been added to
  the BUGS list; some have even been fixed.
* While enabling dynamic object file loading, I tried to make the 
  code easier to understand, renaming various functions and variables
  with less ambiguous names, and changing some function calling
  conventions to be Lispier (e.g. returning NIL instead of 0 for failure).
* While trying to figure out how to do the OpenBSD port, I tried to 
  clean up some of the code in src/runtime/. In particular, I dropped
  support for non-POSIX signal handling, added various comments, 
  tweaked the code to reduce the number of compilation warnings, and
  renamed some files to increase consistency.
* To support the new automatic configuration functionality in make.sh,
  the source file target-features.lisp-expr has been replaced with the
  source file base-target-features.lisp-expr and the machine-generated
  file local-target-features.lisp-expr.
* fixed a stupid quoting error in make.sh so that using CMU CL
  "lisp -batch" as cross-compilation host works again

changes in sbcl-0.6.8 relative to sbcl-0.6.7:

?? The system is now under CVS at SourceForge (instead of the
  CVS repository on my home machine).
?? The INSTALL file has been updated with some information 
  about using anonymous CVS to download the most recent version
  from SourceForge.
?? There's now code in the tests/ subdirectory to run the system
  through the clocc/ansi-tests/ suite, and to run additional
  SBCL-specific regression tests as well. (It's not particularly
  mature right now, but it's a start.)
?? The system now uses code based on Colin Walters' O(N)
  implementation of MAP (from the cmucl-imp@cons.org mailing
  list, 2 September 2000) when it can't use a DEFTRANSFORM to
  inline the MAP operation, and there is more than one
  sequence argument to the MAP call (so that it can't just
  do ETYPECASE once and for all based on the type of the
  single sequence argument). (The old non-inline implementation
  of the general M-argument sequence-of-length-N case required
  O(M*N*N) time when any of the sequence arguments were LISTs.)
?? Raymond Wiker's port of CMU CL's RUN-PROGRAM has been added.
(?? Don't forget to mention Colin Walters and Raymond Wiker in the
  CREDITS file.)
?? The debugger now flushes standard output streams before it begins
  its output ("debugger invoked" and so forth).
?? The two problem cases reported by Peter Van Eynde on 8 Sep 2000, 
  (BUTLAST '(1 2 3) -1) and (MAKE-LIST -1), now work, and test cases
  have now been added to the regression test suite to keep them
  from appearing again. (This was a repeat appearance, alas!)
  As the regression test system gets more mature, I intend to add
  most future fixed bugs to it, but at this point I'm still playing
  with it.
?? The patch for the SUBSEQ bug reported on the cmucl-imp mailing
  list 12 September 2000 has been applied to SBCL.
?? Martin Atzmueller's versions of two CMU CL patches, as posted on 
  sbcl-devel 13 September 2000, have been installed. (The patches fix
  a bug in SUBSEQ and <a bug in ??>.)
?? A bug in signal handling which kept TRACE from working on OpenBSD
  has been fixed.
?? The signal handling bug reported by Martin Atzmueller on 
  sbcl-devel 13 September 2000, which caused the debugger to 
  get confused after a Ctrl-C interrupt under ILISP, has been fixed.