News
New SBCL versions are usually released at the end of each
month: check the Sourceforge File List to see the current version. The new features of the two most recent SBCL releases are listed below.
Please see the complete news page for details on all historical SBCL releases.
New in version 2.5.3, 2025-03-30
Back to top- enhancement: breakpoint debugger commands have been added. Included is a
stepper based on breakpoints requiring no extra instrumentation. However,
it still has less functionality than the existing single stepper. See the
new debugger manual section titled "Breakpoint Commands" for more
information on the new commands.
- minor incompatible change: the behaviour of :save-runtime-options has been
restored to match the documentation. (#2096995, reported by Zach Beane)
- minor incompatible change: invoking CHANGE-CLASS from user code no longer
grabs the CLOS world lock. Callers must take responsibility for ordering
execution of CHANGE-CLASS and any changes to the class hierarchy.
- platform support:
- (CAS SAP) is implemented on ARM v8.1 directly with CAS instructions.
- on x86-64, list constructors emit more compact code sequences,
particularly in the presence of multiple references to the same object.
- on x86 and x86-64, fix the stack overflow check to use signed
comparisons.
- on Darwin/arm64 and Linux/x86-64, provide a restart to disable
floating-point exceptions of the type signalled, and another to disable
all floating-point exceptions.
- bug fix: cycle detection in class precedence lists happens before adding
classes to the direct subclasses of the parent.
- bug fix: stack-allocated unaligned cons cells no longer cause errors in
the debugger.
- bug fix: local function type declarations no longer inhibit tail calls in
(SAFETY 0) code. (#2039301)
- bug fix: bad or unknown type specifiers in CHECK-TYPE do not crash or slow
down the compiler. (#2102644, #2102653, #2102714, #2104048)
- bug fix: numerous bug fixes relating to the type system's handling of
arrays make SUBTYPEP more reliable and less likely to express a
contradiction. (#1996980, #2100563, #2100728, #2100779,
#2100784, #2100812, #2100825, #2101192, #2101215, #2101803,
#2102684)
- bug fix: improve other aspects of the type system's self-consistency.
(#2101073, #2101170, #2101183, #2101189, #2101399, #2101589)
- bug fix: fix compiler type error when deriving the type of FTRUNCATE.
(#2101073)
- bug fix: fix compiler error when deriving constraints for single-floats.
(#2102759)
- bug fix: startup tuning for particular microarchitectures no longer
accidentally disables one of the optimizations.
- optimization: ROW-MAJOR-AREF is transformed to use the same array
machinery as one-dimensional array references. (Thanks to Scott Burson
for the suggestion)
- optimization: list constructors emit shorter code sequences on x86-64,
particularly in the presence of multiple references to the same object.
- optimization: FLOOR and CEILING on ratios do not unnecessarily cons.
- optimization: provide specialized CALL-NEXT-METHOD functions for the
no-argument and full-argument cases.
New in version 2.5.2, 2025-02-28
Back to top- minor incompatible change: in some instances when the compiler cannot
prove that a NIL-valued branch is unreachable, where NIL is not compatible
with the expected type, a type warning will no longer be issued.
- minor incompatible change: the compiler will more strictly treat type
declarations for &OPTIONAL and &KEY arguments in FTYPE declarations, no
longer effectively adding an implicit (OR ... <default>) type when the
function itself has a default value not matching the declared type for
that argument.
- enhancement: type errors in structure constructors are now restartable,
with a USE-VALUE restart provided.
- enhancement: CHECK-TYPE warns about type conflicts at compile-time.
- enhancement: FTYPE declarations for functions which set their parameters
are checked.
- enhancement: new print control variable SB-EXT:*PRINT-CIRCLE-NOT-SHARED*,
when used in conjunction with *PRINT-CIRCLE*, prints #1# only for
circularities and not simple sharing.
- platform support
- on Windows, make sure to commit memory after zeroing during
save-lisp-and-die. (#2097197, reported by _3b)
- on Linux, add the TCP_USER_TIMEOUT constant to SB-BSD-SOCKETS. (thanks
to Mihai Bazon)
- on *BSD, make TCP_KEEPCNT, TCP_KEEPIDLE and TCP_KEEPINTVL available
where the OS supports it.
- on x86-64, optimize BOUNDP for known-global symbols.
- on x86-64, optimize KEYWORDP for some arguments.
- on arm64, don't trigger an assertion when using FMOV on complex
single-float registers.
- on arm64, improve type checking for (AND SYMBOL (NOT NULL)).
- bug fix: using structure read macros with shared structure markers no
longer signals type errors when the shared structure is in a slot with a
type. (#308936)
- bug fix: non-conforming user macros which modify their source no longer
trigger internal errors. (#1371719, reported by _3b)
- bug fix: the combination of CONSTANTLY and DYNAMIC-EXTENT declarations no
longer causes an internal compiler error. (#2059950, reported by
bohonghuang)
- bug fix: treat inlined functions analogously to constants in the compiler.
(#2095560, reported by Vasiliy Postnicov)
- bug fix: FTYPE declarations for &optional and &key arguments do not
include default values when checking types.
- bug fix: Storing coverage data no longer leads to miscompilations allowing
reachability of unreachable code. (#2092451, reported by mrkissinger)
- optimization: elide bounds-checking for multidimensional arrays with known
dimensions. (reported by aeth)
- optimization: alien callbacks are generally less heavyweight.
- optimization: REMOVE shares the tail of the input list when there's
nothing to remove.
