1 files changed, 79 insertions, 0 deletions
diff --git a/tools/clang-rename/clang-rename.el b/tools/clang-rename/clang-rename.el
new file mode 100644
index 0000000000000..b6c3ed4c686b7
--- /dev/null
+++ b/tools/clang-rename/clang-rename.el
@@ -0,0 +1,79 @@
+;;; clang-rename.el --- Renames every occurrence of a symbol found at <offset>.  -*- lexical-binding: t; -*-
+
+;; Keywords: tools, c
+
+;;; Commentary:
+
+;; To install clang-rename.el make sure the directory of this file is in your
+;; `load-path' and add
+;;
+;;   (require 'clang-rename)
+;;
+;; to your .emacs configuration.
+
+;;; Code:
+
+(defgroup clang-rename nil
+  "Integration with clang-rename"
+  :group 'c)
+
+(defcustom clang-rename-binary "clang-rename"
+  "Path to clang-rename executable."
+  :type '(file :must-match t)
+  :group 'clang-rename)
+
+;;;###autoload
+(defun clang-rename (new-name)
+  "Rename all instances of the symbol at point to NEW-NAME using clang-rename."
+  (interactive "sEnter a new name: ")
+  (save-some-buffers :all)
+  ;; clang-rename should not be combined with other operations when undoing.
+  (undo-boundary)
+  (let ((output-buffer (get-buffer-create "*clang-rename*")))
+    (with-current-buffer output-buffer (erase-buffer))
+    (let ((exit-code (call-process
+                      clang-rename-binary nil output-buffer nil
+                      (format "-offset=%d"
+                              ;; clang-rename wants file (byte) offsets, not
+                              ;; buffer (character) positions.
+                              (clang-rename--bufferpos-to-filepos
+                               ;; Emacs treats one character after a symbol as
+                               ;; part of the symbol, but clang-rename doesn’t.
+                               ;; Use the beginning of the current symbol, if
+                               ;; available, to resolve the inconsistency.
+                               (or (car (bounds-of-thing-at-point 'symbol))
+                                   (point))
+                               'exact))
+                      (format "-new-name=%s" new-name)
+                      "-i" (buffer-file-name))))
+      (if (and (integerp exit-code) (zerop exit-code))
+          ;; Success; revert current buffer so it gets the modifications.
+          (progn
+            (kill-buffer output-buffer)
+            (revert-buffer :ignore-auto :noconfirm :preserve-modes))
+        ;; Failure; append exit code to output buffer and display it.
+        (let ((message (clang-rename--format-message
+                        "clang-rename failed with %s %s"
+                        (if (integerp exit-code) "exit status" "signal")
+                        exit-code)))
+          (with-current-buffer output-buffer
+            (insert ?\n message ?\n))
+          (message "%s" message)
+          (display-buffer output-buffer))))))
+
+(defalias 'clang-rename--bufferpos-to-filepos
+  (if (fboundp 'bufferpos-to-filepos)
+      'bufferpos-to-filepos
+    ;; Emacs 24 doesn’t have ‘bufferpos-to-filepos’, simulate it using
+    ;; ‘position-bytes’.
+    (lambda (position &optional _quality _coding-system)
+      (1- (position-bytes position)))))
+
+;; ‘format-message’ is new in Emacs 25.1.  Provide a fallback for older
+;; versions.
+(defalias 'clang-rename--format-message
+  (if (fboundp 'format-message) 'format-message 'format))
+
+(provide 'clang-rename)
+
+;;; clang-rename.el ends here