(sh-shell-variables-initialized): New variable.

(sh-mode): Make sh-shell-variables and
sh-shell-variables-initialized local.
(sh-set-shell): Don't scan the buffer for variable assignments.
Set sh-shell-variables-initialized to nil.
(sh-shell-initialize-variables): New function.
(sh-add-completer): New function.  Initialize sh-shell-variables
here if not yet done.
(sh-add): Use sh-add-completer for completion.

diff --git a/lisp/progmodes/sh-script.el b/lisp/progmodes/sh-script.el
index 99f0121284ea00990ccfc4d3cc564889b8fb3c1c..039dc470a16bb784dbe42f0b05b002ded9ff7c01 100644 (file)
--- a/lisp/progmodes/sh-script.el
+++ b/lisp/progmodes/sh-script.el
@@ -121,6 +121,9 @@ These are used for completion in addition to all the variables named
 in `process-environment'.  Each element looks like (VAR . VAR), where
 the car and cdr are the same symbol.")
 
+(defvar sh-shell-variables-initialized nil
+  "Non-nil if `sh-shell-variables' is initialized.")
+
 (defun sh-canonicalize-shell (shell)
   "Convert a shell name SHELL to the one we should handle it as."
   (or (symbolp shell)
@@ -614,6 +617,8 @@ with your script for an edit-interpret-debug cycle."
   (make-local-variable 'font-lock-defaults)
   (make-local-variable 'skeleton-filter)
   (make-local-variable 'skeleton-newline-indent-rigidly)
+  (make-local-variable 'sh-shell-variables)
+  (make-local-variable 'sh-shell-variables-initialized)
   (setq major-mode 'sh-mode
        mode-name "Shell-script"
        indent-line-function 'sh-indent-line
@@ -721,11 +726,9 @@ Calls the value of `sh-set-shell-hook' if set."
        comment-start-skip (concat (sh-feature sh-comment-prefix) "#+[\t ]*")
        mode-line-process (format "[%s]" sh-shell)
        sh-shell-variables nil
+       sh-shell-variables-initialized nil
        shell (sh-feature sh-variables))
   (set-syntax-table (sh-feature sh-mode-syntax-table))
-  (save-excursion
-    (while (search-forward "=" nil t)
-      (sh-assignment 0)))
   (while shell
     (sh-remember-variable (car shell))
     (setq shell (cdr shell)))
@@ -1024,17 +1027,55 @@ region, clear header."
       < "done"))
 
 
+(defun sh-shell-initialize-variables ()
+  "Scan the buffer for variable assignments.
+Add these variables to `sh-shell-variables'."
+  (message "Scanning buffer `%s' for variable assignments..." (buffer-name))
+  (save-excursion
+    (goto-char (point-min))
+    (setq sh-shell-variables-initialized t)
+    (while (search-forward "=" nil t)
+      (sh-assignment 0)))
+  (message "Scanning buffer `%s' for variable assignments...done"
+          (buffer-name)))
+
+(defvar sh-add-buffer)
+
+(defun sh-add-completer (string predicate code)
+  "Do completion using `sh-shell-variables', but initialize it first.
+This function is designed for use as the \"completion table\",
+so it takes three arguments:
+  STRING, the current buffer contents;
+  PREDICATE, the predicate for filtering possible matches;
+  CODE, which says what kind of things to do.
+CODE can be nil, t or `lambda'.
+nil means to return the best completion of STRING, or nil if there is none.
+t means to return a list of all possible completions of STRING.
+`lambda' means to return t if STRING is a valid completion as it stands."
+  (let ((sh-shell-variables
+        (save-excursion
+          (set-buffer sh-add-buffer)
+          (or sh-shell-variables-initialized
+              (sh-shell-initialize-variables))
+          (nconc (mapcar (lambda (var)
+                           (let ((name
+                                  (substring var 0 (string-match "=" var))))
+                             (cons name name)))
+                         process-environment)
+                 sh-shell-variables))))
+    (cond ((null code)
+          (try-completion string sh-shell-variables predicate))
+         ((eq code t)
+          (all-completions string sh-shell-variables predicate))
+         ((eq code 'lambda)
+          (assoc string sh-shell-variables)))))
+
 (defun sh-add (var delta)
   "Insert an addition of VAR and prefix DELTA for Bourne (type) shell."
   (interactive
-   (list (completing-read "Variable: "
-                         (nconc (mapcar (lambda (var)
-                                          (let ((name
-                                                 (substring var 0 (string-match "=" var))))
-                                            (cons name name)))
-                                        process-environment)
-                                sh-shell-variables))
-        (prefix-numeric-value current-prefix-arg)))
+   (let ((sh-add-buffer (current-buffer)))
+     (list (completing-read "Variable: " 'sh-add-completer)
+          (prefix-numeric-value current-prefix-arg))))
   (insert (sh-feature '((bash . "$[ ")
                        (ksh88 . "$(( ")
                        (posix . "$(( ")