Guarantee that source binding of an import is defined. Source binding

of an export is always defined by the package description.

diff --git a/v7/src/runtime/packag.scm b/v7/src/runtime/packag.scm
index d6bb9f716a5bdc4191bc1130737808f01cb4359f..3a3fa5e81781259e08c58678c0c2d2841ac54598 100644 (file)
--- a/v7/src/runtime/packag.scm
+++ b/v7/src/runtime/packag.scm
@@ -1,6 +1,6 @@
 #| -*-Scheme-*-
 
-$Id: packag.scm,v 14.36 2001/12/17 17:40:59 cph Exp $
+$Id: packag.scm,v 14.37 2001/12/18 19:35:50 cph Exp $
 
 Copyright (c) 1988-1999, 2001 Massachusetts Institute of Technology
 
@@ -379,12 +379,15 @@ USA.
        (do ((i 0 (fix:+ i 1)))
            ((fix:= i n))
          (let ((binding (vector-ref bindings i)))
-           (link-variables environment
-                           (vector-ref binding 0)
-                           (find-package-environment (vector-ref binding 1))
-                           (if (fix:= (vector-length binding) 3)
-                               (vector-ref binding 2)
-                               (vector-ref binding 0)))))))))
+           (let ((source-environment
+                  (find-package-environment (vector-ref binding 1)))
+                 (source-name
+                  (if (fix:= (vector-length binding) 3)
+                      (vector-ref binding 2)
+                      (vector-ref binding 0))))
+             (guarantee-binding source-environment source-name)
+             (link-variables environment (vector-ref binding 0)
+                             source-environment source-name))))))))
 \f
 (define (extend-package-environment environment . name-sources)
   (let ((n
@@ -427,8 +430,18 @@ USA.
 (define (find-package-environment name)
   (package/environment (find-package name)))
 
+(define (guarantee-binding environment name)
+  (if (lexical-unbound? environment name)
+      (local-assignment environment
+                       name
+                       (primitive-object-set-type (ucode-type reference-trap)
+                                                  0))))
+
 (define-primitives
-  link-variables)
+  lexical-unbound?
+  link-variables
+  local-assignment
+  primitive-object-set-type)
 \f
 ;; LOAD-PACKAGES-FROM-FILE is called from the cold load and must only
 ;; use procedures that are inline-coded by the compiler.