;; original CMU CL code.)
; :sb-show-assem
+ ;; Compile the C runtime with support for low-level debugging output
+ ;; through FSHOW and FSHOW_SIGNAL. If enabled, this feature allows
+ ;; users to turn on such debugging output using environment variables at
+ ;; run-time.
+ ; :sb-qshow
+
;; Setting this makes SBCL more "fluid", i.e. more amenable to
;; modification at runtime, by suppressing various INLINE declarations,
;; compiler macro definitions, FREEZE-TYPE declarations; and by
;; thread local storage) is not reliably preserved in signal
;; handlers, so we need to restore its value from the pthread thread
;; local storage.
- ; :restore-tls-segment-register-from-tls
+ ; :restore-fs-segment-register-from-tls
;; On some x86oid operating systems (darwin) SIGTRAP is not reliably
;; delivered for the INT3 instruction, so we use the UD2 instruction
;; for the purpose of stopping and starting the world around GC can be
;; performed using safepoints instead of signals. Enable this feature
;; to compile with safepoints and to use them for GC.
+ ;; (Replaces use of SIG_STOP_FOR_GC.)
; :sb-safepoint
;; When compiling with safepoints, the INTERRUPT-THREAD mechanism can
;; can be interrupted safely, instead of using a signal for this
;; purpose. Enable this feature in addition to :SB-SAFEPOINT to enable
;; such behaviour.
+ ;; (Replaces use of SIGPIPE, except to wake up syscalls.)
; :sb-thruption
+ ;; When compiling with safepoints and thruptions, the TIMER facility
+ ;; can replace its use of setitimer with a background thread.
+ ;; (Replaces use of SIGALRM.)
+ ; :sb-wtimer
+
;;
;; miscellaneous notes on other things which could have special significance
;; in the *FEATURES* list