Improves cmake-before-save-hook

Do not erase wrongly formatted buffer
Keeps the current region
Writes nice message to buffer

.emacs

@@ -447,25 +447,68 @@
 		                       )
 	:config
 	(setq cmake-tab-width 4)
+
+	(defun atu/create-or-erase-buffer (buffer-name)
+		""
+		(let ((existing-buffer (get-buffer buffer-name)))
+			(when existing-buffer
+				(with-current-buffer existing-buffer
+					(erase-buffer)))
+			(get-buffer-create buffer-name))
+		)
+
 	(defun atu/cmake-format-buffer ()
 		"Formats the current buffer using cmake-format"
 		(interactive)
-		(shell-command-on-region
+		(let ((error-buffer (atu/create-or-erase-buffer "*cmake-format:stderr*")))
-			;; region to execute on
+			(setq-local atu/after-save-message nil)
-			(point-min)
+			(if (eq 0 (call-process-region
-			(point-max)
+				          ;;region
-			;; command
+				          (point-min)
-			"cmake-format -"
+				          (point-max)
-			;; replace
+				          "cmake-format"
-			t
+				          nil ;do not delete buffer
-			;; name of the error bufer
+				          ;; discard stdout copy stderr to buffer
-			"* cmake-format Error Buffer *"
+				          error-buffer
-			;;
+				          nil ;dont-redisplay buffer
-			t))
+				          "-"
+				          ))
+				(let ((current-point (point)))
+					(call-process-region
+						(point-min) (point-max)
+						"cmake-format"
+						t t t; replace current buffer and redisplay it
+						"-"
+						)
+					(goto-char (+ (point-min) current-point))
+					nil
+					)
+				(message
+					"cmake-format: could not format %s see buffer %s for details"
+					(buffer-name) error-buffer)
+				(current-message)
+				)
+			)
+		)
+
+	(defun atu/cmake-before-save-hook ()
+		""
+		(setq-local atu/after-save-message (atu/cmake-format-buffer))
+		)
+
+	(defun atu/cmake-after-save-hook ()
+		""
+		(when atu/after-save-message
+			(message atu/after-save-message)
+			)
+		)
 
 	:hook
 	(cmake-mode . lsp-deferred)
-	(cmake-mode . (lambda () (add-hook 'before-save-hook 'atu/cmake-format-buffer nil 'local)))
+	(cmake-mode . (lambda ()
+		              (add-hook 'before-save-hook 'atu/cmake-before-save-hook nil 'local)
+		              (add-hook 'after-save-hook 'atu/cmake-after-save-hook nil 'local))
+		)
 	)
 
 (use-package cc-mode