X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;f=src%2Fcode%2Fprimordial-extensions.lisp;h=9e7eb4782842c52375457f38df67e7fb773b8c92;hb=334af30b26555f0bf706f7157b399bdbd4fad548;hp=cb45dc3ac169da18a59425a1ae52b733f64b9919;hpb=993d5b779638756473181dda8d928d33038d4cc3;p=sbcl.git

diff --git a/src/code/primordial-extensions.lisp b/src/code/primordial-extensions.lisp
index cb45dc3..9e7eb47 100644
--- a/src/code/primordial-extensions.lisp
+++ b/src/code/primordial-extensions.lisp
@@ -12,6 +12,46 @@
 
 (in-package "SB!INT")
 
+;;;; target constants which need to appear as early as possible
+
+;;; an internal tag for marking empty slots, which needs to be defined
+;;; as early as possible because it appears in macroexpansions for
+;;; iteration over hash tables
+;;;
+;;; CMU CL 18b used :EMPTY for this purpose, which was somewhat nasty
+;;; since it's easily accessible to the user, so that e.g.
+;;;	(DEFVAR *HT* (MAKE-HASH-TABLE))
+;;;	(SETF (GETHASH :EMPTY *HT*) :EMPTY)
+;;;	(MAPHASH (LAMBDA (K V) (FORMAT T "~&~S ~S~%" K V)))
+;;; gives no output -- oops!
+;;;
+;;; FIXME: It'd probably be good to use the unbound marker for this.
+;;; However, there might be some gotchas involving assumptions by
+;;; e.g. AREF that they're not going to return the unbound marker,
+;;; and there's also the noted-below problem that the C-level code
+;;; contains implicit assumptions about this marker.
+;;;
+;;; KLUDGE: Note that as of version 0.6.6 there's a dependence in the
+;;; gencgc.c code on this value being a symbol. (This is only one of
+;;; many nasty dependencies between that code and this, alas.)
+;;; -- WHN 2001-02-28
+(defconstant +empty-ht-slot+ '%empty-ht-slot%)
+;;; KLUDGE: Using a private symbol still leaves us vulnerable to users
+;;; getting nonconforming behavior by messing around with
+;;; DO-ALL-SYMBOLS. That seems like a fairly obscure problem, so for
+;;; now we just don't worry about it. If for some reason it becomes
+;;; worrisome and the magic value needs replacement:
+;;;   * The replacement value needs to be LOADable with EQL preserved,
+;;;     so that macroexpansion for WITH-HASH-TABLE-ITERATOR will work
+;;;     when compiled into a file and loaded back into SBCL.
+;;;     (Thus, just uninterning %EMPTY-HT-SLOT% doesn't work.)
+;;;   * The replacement value needs to be acceptable to the
+;;;     low-level gencgc.lisp hash table scavenging code. 
+;;;   * The change will break binary compatibility, since comparisons
+;;;     against the value used at the time of compilation are wired
+;;;     into FASL files.
+;;; -- WHN 20000622
+
 ;;;; DO-related stuff which needs to be visible on the cross-compilation host
 
 (eval-when (:compile-toplevel :load-toplevel :execute)
@@ -68,8 +108,6 @@
 		   (unless ,(first endlist) (go ,label-1))
 		   (return-from ,block (progn ,@(rest endlist))))))))))
 
-;;; DO-ANONYMOUS ({(Var [Init] [Step])}*) (Test Exit-Form*) Declaration* Form*
-;;;
 ;;; This is like DO, except it has no implicit NIL block. Each VAR is
 ;;; initialized in parallel to the value of the specified INIT form.
 ;;; On subsequent iterations, the VARS are assigned the value of the
@@ -120,10 +158,13 @@
 	     ;; Then complain.
 	     (error 'simple-type-error
 		    :datum maybe-package
-		    :expected-type 'package
+		    :expected-type '(and package (satisfies package-name))
 		    :format-control
-		    "~@<~S can't be a ~S: ~2I~_~S has been reset to ~S.~:>"
-		    :format-arguments (list '*package* (type-of maybe-package)
+		    "~@<~S can't be a ~A: ~2I~_~S has been reset to ~S.~:>"
+		    :format-arguments (list '*package*
+					    (if (packagep maybe-package)
+						"deleted package"
+						(type-of maybe-package))
 					    '*package* really-package)))))))
 
 ;;; Give names to elements of a numeric sequence.
@@ -182,7 +223,14 @@
 					,expr-tmp))
 		    (error "already bound differently: ~S")))
 		 (t
-		  (defconstant ,symbol ,expr-tmp ,@(when doc `(,doc)))))))
+		  (defconstant ,symbol
+                    ;; KLUDGE: This is a very ugly hack, to be able to
+                    ;; build SBCL with CMU CL (2.4.19), because there
+                    ;; seems to be some confusion in CMU CL about
+                    ;; ,EXPR-TEMP at EVAL-WHEN time ... -- MNA 2000-02-23
+                    #-cmu ,expr-tmp
+                    #+cmu ,expr
+                    ,@(when doc `(,doc)))))))
        ;; The #+SB-XC :COMPILE-TOPLEVEL situation is special, since we
        ;; want to define the symbol not just in the cross-compilation
        ;; host Lisp (which was handled above) but also in the