0.8.13.41: Require robustness

[sbcl.git] / base-target-features.lisp-expr

diff --git a/base-target-features.lisp-expr b/base-target-features.lisp-expr
index c6e3c90..0dad915 100644 (file)
--- a/base-target-features.lisp-expr
+++ b/base-target-features.lisp-expr
@@ -157,18 +157,29 @@
  ;; As of SBCL 0.8,  this is only supposed to work in x86 Linux, on which
  ;; system it's implemented using clone(2) and the %fs segment register.
  ;; Note that no consistent effort to audit the SBCL library code for
- ;; thread safety has been performed, so caveat executor
+ ;; thread safety has been performed, so caveat executor.
  ; :sb-thread
+
+ ;; Kernel support for futexes (so-called "fast userspace mutexes") is
+ ;; available in Linux 2.6 and some versions of 2.4 (Red Hat vendor
+ ;; kernels, possibly other vendors too).  We can take advantage of
+ ;; these to do faster and probably more reliable mutex and condition
+ ;; variable support.  An SBCL built with this feature will fall back
+ ;; to the old system if the futex() syscall is not available at
+ ;; runtime
+ ; :sb-futex
+
+ ;; Support for detection of unportable code (when applied to the
+ ;; COMMON-LISP package, or SBCL-internal pacakges) or bad-neighbourly
+ ;; code (when applied to user-level packages), relating to material
+ ;; alteration to packages or to bindings in symbols in packages.
+ :sb-package-locks
  
  ;; This affects the definition of a lot of things in bignum.lisp. It
  ;; doesn't seem to be documented anywhere what systems it might apply
  ;; to. It doesn't seem to be needed for X86 systems anyway.
  ; :32x16-divide
 
- ;; This is probably true for some processor types, but not X86. It
- ;; affects a lot of floating point code.
- ; :negative-zero-is-not-zero
-
  ;; This is set in classic CMU CL, and presumably there it means
  ;; that the floating point arithmetic implementation
  ;; conforms to IEEE's standard. Here it definitely means that the
@@ -199,6 +210,10 @@
  ;; in the *FEATURES* list
  ;;
 
+ ;; Any target feature which affects binary compatibility of fasl files
+ ;; needs to be recorded in *FEATURES-POTENTIALLY-AFFECTING-FASL-FORMAT*
+ ;; (elsewhere).
+
  ;; notes on the :NIL and :IGNORE features:
  ;;
  ;; #+NIL is used to comment out forms. Occasionally #+IGNORE is used
@@ -268,6 +283,7 @@
  ;;              particular version of BSD we're intended to run under.)
  ;;   :freebsd = We're intended to run under FreeBSD.
  ;;   :openbsd = We're intended to run under OpenBSD.
+ ;;   :netbsd  = We're intended to run under NetBSD.
  ;;   :sunos   = We're intended to run under Solaris user environment
  ;;              with the SunOS kernel.
  ;;   :osf1    = We're intended to run under Tru64 (aka Digital Unix