(help-xref-on-pp): New function.

(describe-variable): Use it to display xrefs in a symbol's value.

1 files changed, 38 insertions, 8 deletions

diff --git a/lisp/help.el b/lisp/help.el
index 12ef3ab81e2..fed3dd7f691 100644
--- a/lisp/help.el
+++ b/lisp/help.el
@@ -751,6 +751,29 @@ Return 0 if there is no such symbol."
           (set-syntax-table stab)))
     (error 0)))
 
+(defun help-xref-on-pp (from to)
+  "Add xrefs for symbols in `pp's output between FROM and TO."
+  (let ((ost (syntax-table)))
+    (unwind-protect
+        (save-excursion
+          (save-restriction
+            (set-syntax-table emacs-lisp-mode-syntax-table)
+            (narrow-to-region from to)
+            (goto-char (point-min))
+            (while (not (eobp))
+              (cond
+               ((looking-at "\"") (forward-sexp 1))
+               ((looking-at "#<") (search-forward ">" nil 'move))
+               ((looking-at "\\(\\(\\sw\\|\\s_\\)+\\)")
+                (let* ((sym (intern-soft
+                             (buffer-substring (match-beginning 1) (match-end 1))))
+                       (fn (cond ((fboundp sym) #'describe-function)
+                                 ((and sym (boundp sym)) #'describe-variable))))
+                  (when fn (help-xref-button 1 fn sym)))
+                (goto-char (match-end 1)))
+               (t (forward-char 1))))))
+      (set-syntax-table ost))))
+
 (defun describe-variable (variable)
   "Display the full documentation of VARIABLE (a symbol).
 Returns the documentation as a string, also."
@@ -772,20 +795,27 @@ Returns the documentation as a string, also."
           (if (not (boundp variable))
               (progn
                 (princ " is void")
-                (terpri)
                 (setq valvoid t))
-            (princ "'s value is ")
-            (terpri)
-            (pp (symbol-value variable))
-            (terpri))
+            (let ((val (symbol-value variable)))
+              (with-current-buffer standard-output
+                (princ "'s value is ")
+                (terpri)
+                (let ((from (point)))
+                  (pp val)
+                  (help-xref-on-pp from (point))))))
+          (terpri)
           (if (local-variable-p variable)
               (progn
                 (princ (format "Local in buffer %s; " (buffer-name)))
                 (if (not (default-boundp variable))
                     (princ "globally void")
-                  (princ "global value is ")
-                  (terpri)
-                  (pp (default-value variable)))
+                  (let ((val (default-value variable)))
+                    (with-current-buffer standard-output
+                      (princ "global value is ")
+                      (terpri)
+                      (let ((from (point)))
+                        (pp val)
+                        (help-xref-on-pp from (point))))))
                 (terpri)))
           (terpri)
           (save-current-buffer