X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~mdw/git/sod/blobdiff_plain/f960a07b6cdf61ef8173dbb3e504f880cfdc17f6..d1c01c331ae3f2994d65b9d41655b0d4f2fcbf3d:/src/class-make-impl.lisp

diff --git a/src/class-make-impl.lisp b/src/class-make-impl.lisp
index d719cc6..5a897d4 100644
--- a/src/class-make-impl.lisp
+++ b/src/class-make-impl.lisp
@@ -28,6 +28,16 @@ (cl:in-package #:sod)
 ;;;--------------------------------------------------------------------------
 ;;; Classes.
 
+(defmethod guess-metaclass ((class sod-class))
+  "Default metaclass-guessing function for classes.
+
+   Return the most specific metaclass of any of the CLASS's direct
+   superclasses."
+
+  (select-minimal-class-property (sod-class-direct-superclasses class)
+				 #'sod-class-metaclass
+				 #'sod-subclass-p class "metaclass"))
+
 (defmethod shared-initialize :after ((class sod-class) slot-names &key pset)
   "Specific behaviour for SOD class initialization.
 
@@ -42,18 +52,28 @@ (defmethod shared-initialize :after ((class sod-class) slot-names &key pset)
        `finalize-sod-class'.
 
      * `:link' names the chained superclass.  If unspecified, this class will
-       be left at the head of its chain."
+       be left at the head of its chain.
+
+   Usually, the class's metaclass is determined here, either direcly from the
+   `:metaclass' property or by calling `guess-metaclass'.  Guessing is
+   inhibited if the `:%bootstrapping' property is non-nil."
 
   ;; If no nickname, copy the class name.  It won't be pretty, though.
   (default-slot-from-property (class 'nickname slot-names)
       (pset :nick :id)
     (string-downcase (slot-value class 'name)))
 
-  ;; Set the metaclass if the appropriate property has been provided;
-  ;; otherwise leave it unbound for now, and we'll sort out the mess during
-  ;; finalization.
-  (default-slot-from-property (class 'metaclass slot-names)
-      (pset :metaclass :id meta (find-sod-class meta)))
+  ;; Set the metaclass if the appropriate property has been provided or we're
+  ;; not bootstreapping; otherwise leave it unbound for now, and trust the
+  ;; caller to sort out the mess.
+  (multiple-value-bind (meta floc) (get-property pset :metaclass :id)
+    (cond (floc
+	   (setf (slot-value class 'metaclass)
+		 (with-default-error-location (floc)
+		   (find-sod-class meta))))
+	  ((not (get-property pset :%bootstrapping :boolean))
+	   (default-slot (class 'metaclass slot-names)
+	     (guess-metaclass class)))))
 
   ;; If no chain-link, then start a new chain here.
   (default-slot-from-property (class 'chain-link slot-names)