- Accumulation of half-understood design decisions eventually
- chokes a program as a water weed chokes a canal. By refactoring
- you can ensure that your full understanding of how the program
- should be designed is always reflected in the program. As a
- water weed quickly spreads its tendrils, partially understood
- design decisions quickly spread their effects throughout your
- program. No one or two or even ten individual actions will be
- enough to eradicate the problem.
- -- Martin Fowler, _Refactoring: Improving the Design
- of Existing Code_, p. 360
-===============================================================================
-some things that I'd like to do in 0.6.x, in no particular order:
--------------------------------------------------------------------------------
-PROBLEM:
- As long as I'm working on the batch-related command-line options,
- it would be reasonable to add one more option to "do what I'd want",
- testing standard input for non-TTY-ness and running in no-programmer
- mode if so.
-FIX:
- ?? Do it.
--------------------------------------------------------------------------------
-PROBLEM:
- I used CMU CL for years, and dozens of times I cursed the
- inadequate breakpoint-based TRACE facility which doesn't work on
- some functions, and I never realized that there's a wrapper-based
- facility too until I was wading through the source code for SBCL.
- Yes, I know I should have RTFM, but there is a lot of M..
- (By the way, it would also be nice to have tracing behave
- better with generic functions. TRACEing a generic function probably
- shouldn't prevent DEFMETHOD from being used to redefine its
- methods, and should perhaps trace each of its methods as well
- as the generic function itself.)
-FIX:
- ?? possibility 1: Add error-handling code in ntrace.lisp to
- catch failure to set breakpoints and retry using
- wrapper-based tracing.
- ?? possibility 2: Add error-handling code in ntrace.lisp to
- catch failure to catch failure to set breakpoints and output
- a message suggesting retrying with wrapper-based breakpoints
- ?? possibility 3: Fix the breakpoint-based TRACE facility so that
- it always works.
--------------------------------------------------------------------------------
-PROBLEM:
- My system of parallel build directories seems to add
- complexity without adding value.
-FIX:
- ?? Replace it with a system where fasl output files live in the
- same directories as the sources and have names a la
- "foo.fasl-from-host and "foo.fasl-from-xc".
- ?? (Perhaps something else will be required in order to port
- to Microsoft Windows, since its filesystem doesn't have
- symbolic links.)
--------------------------------------------------------------------------------
-PROBLEM:
- It might be good to use the syntax (DEBUGGER-SPECIAL *PRINT-LEVEL*)
- etc. to control the in-the-debug-context special variables. Then we
- wouldn't have to pick and choose which variables we shadow in the
- debugger.
- The shadowing values could also be made persistent between
- debugger invocations, so that entering the debugger, doing
- (SETF *PRINT-LEVEL* 2), and exiting the debugger would leave
- (DEBUGGER-SPECIAL *PRINT-LEVEL*) set to 2, and upon reentry to the
- debugger, *PRINT-LEVEL* would be set back to 2.
-FIX:
- ??
--------------------------------------------------------------------------------
-PROBLEM:
- I still haven't cleaned up the cut-and-paste programming in
- * DEF-BOOLEAN-ATTRIBUTE, DELETEF-IN, and PUSH-IN
- * SB!SYS:DEF!MACRO ASSEMBLE and SB!XC:DEFMACRO ASSEMBLE
-FIX:
- ??
--------------------------------------------------------------------------------
-PROBLEM:
- We be able to get rid of the IR1 interpreter, which would
- not only get rid of all the code in *eval*.lisp, but also allow us to
- reduce the number of special cases elsewhere in the system. (Try
- grepping for 'interpret' sometime.:-) Making this usable might
- require cleaning up %DEFSTRUCT, %DEFUN, etc. to use EVAL-WHEN
- instead of IR1 transform magic, which would be a good
- thing in itself, but might be a fair amount of work.)
-FIX:
- ?? Delete, delete, delete.
-===============================================================================
-other known issues with no particular target date:
+for 0.7.0:
-bugs listed on the man page
+* filed off the roughest edges (or, perhaps, at least hammered down the
+ protruding rusty nails and snipped off the trailing razor wire,
+ leaving some filing for later:-) from the monster
+ EVAL/EVAL-WHEN/%COMPILE/DEFUN/DEFSTRUCT cleanup:
+ ** substantially rewrote DEFSTRUCT implementation to work
+ cleanly with EVAL-WHEN, not sleazily use DEFUN for
+ structure functions, implement out-of-line structure
+ accessors as closures, reduce or eliminate non-ANSI
+ magicality of structure functions
+ *** made structure type tests work again
+ *** got rid of bogus warnings about "redefinition" of
+ structure accessors
+ ** made inlining DEFUN inside MACROLET work again
+ ** made %COMPILE set up debugging data more like the way the
+ debugger expects (and maybe even completely
+ correctly:-)
+* incompatible changes listed in NEWS:
+ ** changed debugger prompt to "5]", "5[2]", "5[3]", etc.
+ ** changed default output representation of *PRINT-ESCAPE*-ed
+ unprintable ASCII characters to #\Nul, #\Soh, etc.
+* some easy FIXMEs with high disruptive potential:
+ ** Search lists go away.
+ ** Grep for ~D and and change most of them to ~S.
+* more renaming in global external names:
+ ** used DEFINE-THE-FOO-THING and DEFFOO style consistently (and
+ deprecated supported extensions named in the DEF-FOO
+ style, e.g. SB-ALIEN:DEF-ALIEN-ROUTINE)
+ ** reserved DO-FOO-style names for iteration macros
+ ** finished s/FUNCTION/FUN/
+ ** s/VARIABLE/VAR/
+ ** s/TOPLEVEL/TOP-LEVEL/
+* global style systematization:
+ ** s/#'(lambda/(lambda/
+ ** four-space indentation in C
+=======================================================================
+for early 0.7.x:
-more regression tests
+* building with CLISP (or explaining why not)
+* faster bootstrapping (both make.sh and slam.sh)
+ ** added mechanisms for automatically finding dead code, and
+ used them to remove dead code
+ ** moved stuff from warm init into cold init where possible
+ (so that slam.sh will run faster and also just because
+ ideally everything would be in cold init)
+ ** profiled and tweaked
+* more EVAL/EVAL-WHEN/%COMPILE/DEFUN/DEFSTRUCT cleanup:
+ ** made %COMPILE understand magicality of DEFUN FOO
+ w.r.t. e.g. preexisting inlineness of FOO
+ ** used %COMPILE where COMPILE-TOP-LEVEL used to be used
+ ** removed now-redundant COMPILE-TOP-LEVEL and
+ FUNCTIONAL-KIND=:TOP-LEVEL stuff from the compiler
+ ** made FUNCTION-NAME logic work on closures, so that
+ various public functions like CL:PACKAGEP which
+ are now implemented as closures (because
+ they're structure slot accessors) won't be so
+ nasty in the debugger
+* rewrote long-standing confusing error restarts for redefining
+ DEFSTRUCTs
+* outstanding embarrassments
+ ** cut-and-pasted DEF-BOOLEAN-ATTRIBUTE (maybe easier to fix
+ now that EVAL-WHEN does what it should..)
+ ** incomplete manual
+ ** :IGNORE-ERRORS-P cruft in stems-and-flags.lisp-expr
+ ** weird double-loading (first in GENESIS, then in warm init)
+ of src/assembly/target/*.lisp stuff, and the associated
+ weirdness of the half-baked state (compiler almost but
+ not quite ready for prime time..) of the system after
+ cold init
+* fixups now feasible because of pre7 changes
+ ** ANSIfied DECLAIM INLINE stuff (deprecating MAYBE-INLINE)
+* miscellaneous simple refactoring
+ * belated renaming:
+ ** renamed %PRIMITIVE to %VOP
+ * These days ANSI C has inline functions, so..
+ ** redid many cpp macros as inline functions:
+ HeaderValue, Pointerp, CEILING, ALIGNED_SIZE,
+ GET_FREE_POINTER, SET_FREE_POINTER,
+ GET_GC_TRIGGER, SET_GC_TRIGGER, GetBSP, SetBSP,
+ os_trunc_foo(), os_round_up_foo()
+ ** removed various avoid-evaluating-C-macro-arg-twice
+ cruft
+* added mechanisms for automatically finding dead symbols is
+ package-data.lisp-expr (i.e. those symbols not bound,
+ fbound, defined as types, or whatever), and used them
+ to remove dead symbols
+* made system handle stack overflow safely unless SAFETY is dominated
+ by SPEED or SPACE
+=======================================================================
+for 1.0:
-byte compilation of appropriate parts of the system, so that the
-system core isn't so big
+* refactored in preparation for moving CLOS into cold init and merging
+ SB-PCL:FOO with CL:FOO (for FOO=CLASS, FOO=CLASS-OF, etc.)
+ ** systematized support for MOP (new regression tests, maybe
+ new SB-MOP package..) to try to make sure things don't
+ get mislaid in the upcoming CLOS restructuring
+ ** extracted type system from SB-KERNEL into new SB-TYPE
+ package
+ ** reimplemented GENERIC-FUNCTION as a primitive object (or
+ maybe made SB-MOP:FUNCALLABLE-STANDARD-OBJECT the
+ primitive object, and then let GENERIC-FUNCTIONs
+ inherit from that) instead of structures with
+ :ALTERNATE-METACLASS and funcallableness. Now
+ FUNCALLABLE-INSTANCE can go away. (And now the new
+ funcallable primitive objects need to go into
+ collections like *FUN-HEADER-WIDETAGS* where
+ FUNCALLABLE-INSTANCE objects used to be.)
+ ** reimplemented CONDITIONs as primitive objects instead of
+ structures with :ALTERNATE-METACLASS. Now (between
+ this and the change to GENERIC-FUNCTIONs)
+ DEFSTRUCT :ALTERNATE-METACLASS can go away.
+ ** (maybe) Now INSTANCE_POINTER_LOWTAG can become just
+ STRUCTURE_POINTER_LOWTAG, and the concept of
+ SB-KERNEL:INSTANCE (including INSTANCEP,
+ (SPECIFIER-TYPE 'INSTANCE), etc.) can go away.
+* moved CLOS into cold init, in order to allow CLOS to be used in the
+ implementation of the core system (e.g. the type system and the
+ compiler) and in order to support merger of CL:CLASS with
+ SB-PCL:CLASS
+* (maybe) eliminated warm init altogether in favor of cold init
+* (maybe, especially if warm init can be eliminated) rationalized
+ the build process, fixing miscellaneous pre-0.5.0 stuff that's
+ transparently not the right thing
+ ** removed separate build directories, now just building in
+ place with .sbclcoldfasl extensions
+* (maybe) more refactoring in preparation for merging SB-PCL:FOO
+ into CL:FOO: reimplemented type system OO dispatch
+ (!DEFINE-TYPE-METHOD, etc.) in terms of CLOS OO dispatch
+* merged SB-PCL:FOO into CL:FOO (and similarly CLASS-OF, etc.)
+* added some automatic tests for basic binary compatibility, in hopes
+ that it might be practical to maintain binary compatibility
+ between minor maintenance releases on the stable branch (but no
+ promises, sorry, since I've never tried to do this before, and
+ have no idea how much of a pain this'll be)
+=======================================================================
+other priorities, no particular time:
-Search for unused external symbols (ones which are not bound, fbound,
-types, or whatever, and also have no other uses as e.g. flags) and
-delete them. This should make the system core a little smaller, but
-is mostly useful just to make the source code smaller and simpler.
+* bug fixes, especially really annoying bugs (ANSI or not) and any
+ ANSI bugs (i.e. not just bugs in extras like the debugger or
+ "declarations are assertions", but violations of the standard)
+* better communication with the outside world (scratching WHN's
+ personal itch): I don't want socket-level stuff so much as I
+ want RPC-level or higher (CORBA?) interfaces and (possibly
+ through RPC or CORBA) GUI support
+=======================================================================
+important but out of scope (for WHN, anyway: Patches from other people
+are still welcome!) until after 1.0:
+ * DYNAMIC-EXTENT
+ * sadly deteriorated support for ANSI-style block compilation
+ (static linking of DEFUNs within a single file or
+ WITH-COMPILATION-UNIT)
+ * various GC issues (exuberant cut-and-paste coding,
+ possibly dangerously over-conservative handling
+ of neighbors of function objects, general GC efficiency)
+ * package issues other than SB!TYPE, SB!MOP, and dead exported
+ symbols
+ * Any systematic effort to fix compiler consistency checks is
+ out of scope. (However, it still might be possible to
+ determine that some or all of them are hopelessly stale
+ and delete them.)
+===============================================================================
+other known issues with no particular target date:
-adding new FOPs to provide something like CMU CL's FOP-SYMBOL-SAVE and
-FOP-SMALL-SYMBOL-SAVE functionality, so that fasl files will be more
-compact. (FOP-SYMBOL-SAVE used *PACKAGE*, which was concise but allowed
-obscure bugs. Something like FOP-LAST-PACKAGE-SYMBOL-SAVE could have
-much of the same conciseness advantage without the bugs.)
+bugs listed on the man page
hundreds of FIXME notes in the sources from WHN
(Things marked as KLUDGE are in general things which are ugly or
confusing, but that, for whatever reason, may stay that way
indefinitely.)
+=======================================================================
+"There's nothing an agnostic can't do as long as he doesn't know
+whether he believes in anything or not."
+ -- Monty Python.
+
+"God grant me serenity to accept the code I cannot change, courage to
+change the code I can, and wisdom to know the difference."
+ -- Erik Naggum
+
+"Accumulation of half-understood design decisions eventually chokes a
+program as a water weed chokes a canal. By refactoring you can ensure
+that your full understanding of how the program should be designed is
+always reflected in the program. As a water weed quickly spreads its
+tendrils, partially understood design decisions quickly spread their
+effects throughout your program. No one or two or even ten individual
+actions will be enough to eradicate the problem."
+ -- Martin Fowler, in _Refactoring: Improving the Design of Existing
+ Code_, p. 360
+
+"I wish I didn't know now what I didn't know then."
+ -- Bob Seger
projects / sbcl.git / blobdiff