1.0.45.13: physenvanal: Treat all functions without XEPs as being D-X.

  * In order for a function to be returned or passed as a parameter,
it must have an XEP.

  * Functions without XEPs, therefore, can only be called directly
from within their lexical scope.  They are, therefore,
dynamic-extent.

  * But wait, you say, they could be called from a closure that is
not dynamic-extent, which clearly shows such an analysis to be false.

  * It turns out that this doesn't matter, because the non-dynamic-
extent closure also has to close over the variables passed to the
supposedly-dynamic-extent closure, and that will cause explicit
value-cells to be allocated anyway.

  * So, it's a bit of an abuse to say that the functions have dynamic
extent, but it does no harm (and quite a bit of good) to treat them
as if they do.

diff --git a/src/compiler/physenvanal.lisp b/src/compiler/physenvanal.lisp
index d067c27..6148f67 100644 (file)
--- a/src/compiler/physenvanal.lisp
+++ b/src/compiler/physenvanal.lisp
@@ -230,8 +230,16 @@
       ;; functions), or a pointer from an underlying function to its
       ;; XEP (for non-:TOPLEVEL functions with XEPs).
       (unless (or (leaf-dynamic-extent fun)
-                  (and entry-fun
-                       (leaf-dynamic-extent entry-fun)))
+                  ;; Functions without XEPs can be treated as if they
+                  ;; are DYNAMIC-EXTENT, even without being so
+                  ;; declared, as any escaping closure which /isn't/
+                  ;; DYNAMIC-EXTENT but calls one of these functions
+                  ;; will also close over the required variables, thus
+                  ;; forcing the allocation of value cells.  Since the
+                  ;; XEP is stored in the ENTRY-FUN slot, we can pick
+                  ;; off the non-XEP case here.
+                  (not entry-fun)
+                  (leaf-dynamic-extent entry-fun))
         (let ((closure (physenv-closure (lambda-physenv fun))))
           (dolist (var closure)
             (when (and (lambda-var-p var)

diff --git a/version.lisp-expr b/version.lisp-expr
index 2a3ca87..f3c41e2 100644 (file)
--- a/version.lisp-expr
+++ b/version.lisp-expr
@@ -20,4 +20,4 @@
 ;;; checkins which aren't released. (And occasionally for internal
 ;;; versions, especially for internal versions off the main CVS
 ;;; branch, it gets hairier, e.g. "0.pre7.14.flaky4.13".)
-"1.0.45.12"
+"1.0.45.13"