clang-include-fixer.el: support remote files

[phst]

Summary

Support remote files (e.g., Tramp) in the Emacs integration for clang-include-fixer

[klimek]

LG

include-fixer/tool/clang-include-fixer.el

 (defun clang-include-fixer--start (callback &rest args)
   "Asynchronously start clang-include-fixer with parameters ARGS.
 The current file name is passed after ARGS as last argument.  If
 the call was successful the returned result is stored in a
 temporary buffer, and CALLBACK is called with the temporary
 buffer as only argument."
   (unless buffer-file-name
     (user-error "clang-include-fixer works only in buffers that visit a file"))
-  (let ((process (if (fboundp 'make-process)
-                     ;; Prefer using ‘make-process’ if available, because
+  (let ((process (if (and (fboundp 'make-process)
+                          ;; ‘make-process’ doesn’t support remote files
+                          ;; (https://debbugs.gnu.org/cgi/bugreport.cgi?bug=28691).
+                          (not (find-file-name-handler default-directory
+                                                       'start-file-process)))
+                     ;; Prefer using ‘make-process’ if possible, because
                      ;; ‘start-process’ doesn’t allow us to separate the
                      ;; standard error from the output.
                      (clang-include-fixer--make-process callback args)
                    (clang-include-fixer--start-process callback args))))
     (save-restriction
       (widen)
       (process-send-region process (point-min) (point-max)))
     (process-send-eof process))
(make-process :name "clang-include-fixer"
                   :coding 'utf-8-unix
                   :noquery t
                   :connection-type 'pipe
                   :sentinel (clang-include-fixer--sentinel stdin stdout stderr
                                                            callback)
                   :stderr stderr)))
 
 (defun clang-include-fixer--start-process (callback args)
-  "Start a new clang-incude-fixer process using `start-process'.
+  "Start a new clang-incude-fixer process using `start-file-process'.
 CALLBACK is called after the process finishes successfully; it is
 called with a single argument, the buffer where standard output
 has been inserted.  ARGS is a list of additional command line
 arguments.  Return the new process object."
   (let* ((stdin (current-buffer))
          (stdout (generate-new-buffer "*clang-include-fixer output*"))
          (process-connection-type nil)
-         (process (apply #'start-process "clang-include-fixer" stdout
+         (process (apply #'start-file-process "clang-include-fixer" stdout
                          (clang-include-fixer--command args))))
     (set-process-coding-system process 'utf-8-unix 'utf-8-unix)
     (set-process-query-on-exit-flag process nil)
     (set-process-sentinel process
                           (clang-include-fixer--sentinel stdin stdout nil
                                                          callback))
     process))
 
 (defun clang-include-fixer--command (args)
   "Return the clang-include-fixer command line.
 Returns a list; the first element is the binary to
 execute (`clang-include-fixer-executable'), and the remaining
 elements are the command line arguments.  Adds proper arguments
 for `clang-include-fixer-input-format' and
 `clang-include-fixer-init-string'.  Appends the current buffer's
 file name; prepends ARGS directly in front of it."
   (cl-check-type args list)
   `(,clang-include-fixer-executable
     ,(format "-db=%s" clang-include-fixer-input-format)
     ,(format "-input=%s" clang-include-fixer-init-string)
     "-stdin"
     ,@args
-    ,(buffer-file-name)))
+    ,(clang-include-fixer--file-local-name buffer-file-name)))
 
 (defun clang-include-fixer--sentinel (stdin stdout stderr callback)
   "Return a process sentinel for clang-include-fixer processes.
 STDIN, STDOUT, and STDERR are buffers for the standard streams;
 only STDERR may be nil.  CALLBACK is called in the case of
 success; it is called with a single argument, STDOUT.  On
 failure, a buffer containing the error output is displayed."
   (cl-check-type stdin buffer-live)
(if (fboundp 'filepos-to-bufferpos)
     (lambda (byte &optional _quality _coding-system)
       (byte-to-position (1+ byte)))))
 
 ;; ‘format-message’ is new in Emacs 25.1.  Provide a fallback for older
 ;; versions.
 (defalias 'clang-include-fixer--format-message
   (if (fboundp 'format-message) 'format-message 'format))
 
+;; ‘file-local-name’ is new in Emacs 26.1.  Provide a fallback for older
+;; versions.
+(defalias 'clang-include-fixer--file-local-name
+  (if (fboundp 'file-local-name) #'file-local-name
+    (lambda (file) (or (file-remote-p file 'localname) file))))
+
 (provide 'clang-include-fixer)
 ;;; clang-include-fixer.el ends here