misc/emacs: various cleanups

- Use #' for function symbols
- Remove unused variables
- Use declare-function to shut up byte compiler

This is identical to CL 19010044 with one exception: Making sure
it doesn't break on Emacs 22.1

R=adonovan, bradfitz, shendaras
CC=golang-dev
https://golang.org/cl/20100043

misc/emacs/go-mode.el

@@ -41,8 +41,8 @@
 
 (defalias 'go--kill-whole-line
   (if (fboundp 'kill-whole-line)
-      'kill-whole-line
-    'kill-entire-line))
+      #'kill-whole-line
+    #'kill-entire-line))
 
 ;; Delete the current line without putting it in the kill-ring.
 (defun go--delete-whole-line (&optional arg)
@@ -56,12 +56,16 @@
          (kill-new (s) ()))
     (go--kill-whole-line arg)))
 
-
+;; declare-function is an empty macro that only byte-compile cares
+;; about. Wrap in always false if to satisfy Emacsen without that
+;; macro.
+(if nil
+    (declare-function go--position-bytes "go-mode" (point)))
 ;; XEmacs unfortunately does not offer position-bytes. We can fall
 ;; back to just using (point), but it will be incorrect as soon as
 ;; multibyte characters are being used.
 (if (fboundp 'position-bytes)
-    (defalias 'go--position-bytes 'position-bytes)
+    (defalias 'go--position-bytes #'position-bytes)
   (defun go--position-bytes (point) point))
 
 (defun go--old-completion-list-style (list)
@@ -279,15 +283,15 @@ For mode=set, all covered lines will have this weight."
 
 (defvar go-mode-map
   (let ((m (make-sparse-keymap)))
-    (define-key m "}" 'go-mode-insert-and-indent)
-    (define-key m ")" 'go-mode-insert-and-indent)
-    (define-key m "," 'go-mode-insert-and-indent)
-    (define-key m ":" 'go-mode-insert-and-indent)
-    (define-key m "=" 'go-mode-insert-and-indent)
-    (define-key m (kbd "C-c C-a") 'go-import-add)
-    (define-key m (kbd "C-c C-j") 'godef-jump)
-    (define-key m (kbd "C-x 4 C-c C-j") 'godef-jump-other-window)
-    (define-key m (kbd "C-c C-d") 'godef-describe)
+    (define-key m "}" #'go-mode-insert-and-indent)
+    (define-key m ")" #'go-mode-insert-and-indent)
+    (define-key m "," #'go-mode-insert-and-indent)
+    (define-key m ":" #'go-mode-insert-and-indent)
+    (define-key m "=" #'go-mode-insert-and-indent)
+    (define-key m (kbd "C-c C-a") #'go-import-add)
+    (define-key m (kbd "C-c C-j") #'godef-jump)
+    (define-key m (kbd "C-x 4 C-c C-j") #'godef-jump-other-window)
+    (define-key m (kbd "C-c C-d") #'godef-describe)
     m)
   "Keymap used by Go mode to implement electric keys.")
 
@@ -396,7 +400,7 @@ current line will be returned."
 
 (defun go-indentation-at-point ()
   (save-excursion
-    (let (start-nesting (outindent 0))
+    (let (start-nesting)
       (back-to-indentation)
       (setq start-nesting (go-paren-level))
 
@@ -426,7 +430,6 @@ current line will be returned."
   (interactive)
   (let (indent
         shift-amt
-        end
         (pos (- (point-max) (point)))
         (point (point))
         (beg (line-beginning-position)))
@@ -517,7 +520,7 @@ consider binding godef-jump to `M-.', which is the default key
 for `find-tag':
 
 \(add-hook 'go-mode-hook (lambda ()
-                          (local-set-key (kbd \"M-.\") 'godef-jump)))
+                          (local-set-key (kbd \"M-.\") #'godef-jump)))
 
 Please note that godef is an external dependency. You can install
 it with
@@ -537,7 +540,7 @@ recommended that you look at goflymake
        '(go--build-font-lock-keywords))
 
   ;; Indentation
-  (set (make-local-variable 'indent-line-function) 'go-mode-indent-line)
+  (set (make-local-variable 'indent-line-function) #'go-mode-indent-line)
 
   ;; Comments
   (set (make-local-variable 'comment-start) "// ")
@@ -545,12 +548,12 @@ recommended that you look at goflymake
   (set (make-local-variable 'comment-use-syntax) t)
   (set (make-local-variable 'comment-start-skip) "\\(//+\\|/\\*+\\)\\s *")
 
-  (set (make-local-variable 'beginning-of-defun-function) 'go-beginning-of-defun)
-  (set (make-local-variable 'end-of-defun-function) 'go-end-of-defun)
+  (set (make-local-variable 'beginning-of-defun-function) #'go-beginning-of-defun)
+  (set (make-local-variable 'end-of-defun-function) #'go-end-of-defun)
 
   (set (make-local-variable 'parse-sexp-lookup-properties) t)
   (if (boundp 'syntax-propertize-function)
-      (set (make-local-variable 'syntax-propertize-function) 'go-propertize-syntax))
+      (set (make-local-variable 'syntax-propertize-function) #'go-propertize-syntax))
 
   (set (make-local-variable 'go-dangling-cache) (make-hash-table :test 'eql))
   (add-hook 'before-change-functions (lambda (x y) (setq go-dangling-cache (make-hash-table :test 'eql))) t t)
@@ -904,13 +907,13 @@ If IGNORE-CASE is non-nil, the comparison is case-insensitive."
                    (mapcar (lambda (file)
                              (let ((sub (substring file (length pkgdir) -2)))
                                (unless (or (go--string-prefix-p "obj/" sub) (go--string-prefix-p "tool/" sub))
-                                 (mapconcat 'identity (cdr (split-string sub "/")) "/"))))
+                                 (mapconcat #'identity (cdr (split-string sub "/")) "/"))))
                            (if (file-directory-p dir)
                                (directory-files dir t "\\.a$"))))
                  (if (file-directory-p pkgdir)
                      (go--directory-dirs pkgdir)))))
      (go-root-and-paths)))
-   'string<))
+   #'string<))
 
 (defun go-unused-imports-lines ()
   ;; FIXME Technically, -o /dev/null fails in quite some cases (on
@@ -1000,7 +1003,7 @@ description at POINT."
       (let ((description (cdr (butlast (godef--call point) 1))))
         (if (not description)
             (message "No description found for expression at point")
-          (message "%s" (mapconcat 'identity description "\n"))))
+          (message "%s" (mapconcat #'identity description "\n"))))
     (file-error (message "Could not run godef binary"))))
 
 (defun godef-jump (point &optional other-window)
@@ -1151,6 +1154,6 @@ for."
           (go--coverage-make-overlay range (cadr ranges-and-divisor))))
 
       (if (not (eq cur-buffer (current-buffer)))
-          (display-buffer (current-buffer) 'display-buffer-reuse-window)))))
+          (display-buffer (current-buffer) #'display-buffer-reuse-window)))))
 
 (provide 'go-mode)