diff options
| -rw-r--r-- | flymake-rust.el | 224 |
1 files changed, 147 insertions, 77 deletions
diff --git a/flymake-rust.el b/flymake-rust.el index f04051a..8092061 100644 --- a/flymake-rust.el +++ b/flymake-rust.el @@ -7,7 +7,7 @@ ;; Keywords: flymake, rust ;; Maintainer: Brian Cully <bjc@kublai.com> ;; Version: 0.1 -;; Package-Requires: ((emacs "26.1")) +;; Package-Requires: ((emacs "27.1")) ;;; License: @@ -50,15 +50,36 @@ :type 'string :group 'flymake-rust) +(defcustom flymake-rust-rustc-path "rustc" + "Path to rustc executable." + :type 'string + :group 'flymake-rust) + +(defcustom flymake-rust-checker 'cargo + "Which checker to use. + + * cargo (the default) can only check on save, but is suitable +for all projects. + + * rustc can check between saves, but isn’t project aware, and +will complain about things like missing main functions." + :type '(choice (const cargo) + (const rustc)) + :options '(cargo rustc) + :group 'flymake-rust) + (defvar-local flymake-rust--process nil "Flymake process associated with the current buffer.") -(defvar-local flymake-rust--parse-marker nil - "Last parse position in the current buffer.") +(defvar flymake-rust--cargo-flags '("check" "--quiet" "--message-format=json") + "Additional flags to pass to cargo.") + +(defvar flymake-rust--rustc-flags '("--error-format=json" "-") + "Additional flags to pass to rustc.") (defun flymake-rust--buffer-name (suffix) "What to name the flymake buffer for ‘SUFFIX’." - (format "*flymake-rust-cargo-check %s %s*" suffix buffer-file-name)) + (format "*flymake-rust[%s] %s*" suffix buffer-file-name)) (defmacro flymake-rust--with-proc-buf (&rest body) "Run ‘BODY’ in the buffer for the current buffer’s Flymake process." @@ -72,13 +93,15 @@ (defun flymake-rust--extract-error-location (hash) "Extract file location data from ‘HASH’. -Returns a sequence of data in the form of (BYTE-START . BYTE-END) -If any data are not available, nil will be used in its place." +Returns a sequence of data in the form of (FILE-NAME (BYTE-START +. BYTE-END)) If any data are not available, nil will be used in +its place." (let* ((spans (or (gethash "spans" hash) []))) (mapcar (lambda (span) - (let ((byte-start (or (1+ (gethash "byte_start" span)) nil)) + (let ((file-name (or (gethash "file_name" span) nil)) + (byte-start (or (1+ (gethash "byte_start" span)) nil)) (byte-end (or (1+ (gethash "byte_end" span)) nil))) - `(,byte-start . ,byte-end))) + `(,file-name (,byte-start . ,byte-end)))) spans))) (defun flymake-rust--level-to-action (level) @@ -87,64 +110,89 @@ If any data are not available, nil will be used in its place." ((string= level "warning") :warning) (t :note))) -(defun flymake-rust--report-errors (source-buffer report-fn hash) +(defun flymake-rust--extract-msghash (hash) + "Return the message hash from ‘HASH’. + +Cargo and rustc have slightly different formats for this." + (cond ((eq flymake-rust-checker 'cargo) + (when (string= (gethash "reason" hash) "compiler-message") + (gethash "message" hash))) + ((eq flymake-rust-checker 'rustc) hash))) + +(defun flymake-rust--normalize-path (hash file-name) + "Return full path to ‘FILE-NAME’. + +Cargo only puts the relative path in there, so we need to add the +path to the workspace from ‘HASH’ to get the full path." + (cond ((eq flymake-rust-checker 'cargo) + (gethash "src_path" (gethash "target" hash))) + ((eq flymake-rust-checker 'rustc) file-name))) + +;; See https://doc.rust-lang.org/rustc/json.html for a description of +;; the JSON format. +(defun flymake-rust--make-diagnostics (source-buffer hash) "Pull interesting things out of ‘HASH’ for ‘SOURCE-BUFFER ’and forward them to ‘REPORT-FN’." - (let ((reason (gethash "reason" hash)) - (msghash (gethash "message" hash))) - (when (and (string= reason "compiler-message") msghash) - (let ((message (gethash "message" msghash)) - (level (gethash "level" msghash)) - (errlocs (flymake-rust--extract-error-location msghash))) - (funcall report-fn - (mapcar (lambda (errloc) - (flymake-make-diagnostic source-buffer - (car errloc) (cdr errloc) - (flymake-rust--level-to-action level) - message)) - errlocs)))))) - -(defun flymake-rust--parse-json (source-buffer report-fn) - "Grab new JSON from ‘SOURCE-BUFFER’ and send it to ‘REPORT-FN’. - -This function attempts to parse JSON data beginning at - ‘flymake-rust--parse-marker’ and if successful, will update - the marker to the end of the parsed data." - (goto-char flymake-rust--parse-marker) - (while (condition-case err - (let ((parsed (json-parse-buffer))) - (set-marker flymake-rust--parse-marker (point)) - (flymake-rust--report-errors source-buffer report-fn parsed) - t) - (json-parse-error nil) - (json-end-of-file nil) - (t (error err))))) - -;; TODO: this blocks ‘C-g’, so it may be better to just do this in an -;; idle process. -(defun flymake-rust--filter (source-buffer report-fn proc string) - "Process ‘STRING’ as JSON from ‘PROC’ and send it to ‘REPORT-FN’ for ‘SOURCE-BUFFER’." + (when-let ((msghash (flymake-rust--extract-msghash hash))) + (let ((message (gethash "message" msghash)) + (level (gethash "level" msghash)) + (errlocs (flymake-rust--extract-error-location msghash))) + (mapcar (lambda (errloc) + (when-let ((start (caadr errloc)) + (end (cdadr errloc))) + ;; Filter out errors that don’t relate to + ;; ‘source-buffer’. + (when (or (string= (car errloc) "<anon>") + (string= (flymake-rust--normalize-path hash (car errloc)) + (file-local-name (buffer-file-name source-buffer)))) + (flymake-make-diagnostic source-buffer + start end + (flymake-rust--level-to-action level) + message)))) + errlocs)))) + +(defun flymake-rust--parse-buffer (source-buffer report-fn) + "Parse the diagnostics for ‘SOURCE-BUFFER’ and send to ‘REPORT-FN’." (flymake-rust--with-proc-buf - (let ((moving (= (point) (process-mark proc)))) + (let ((continue t) + (diags nil)) + (goto-char (point-min)) + (while continue + (if-let ((diag (condition-case err + (json-parse-buffer) + (json-end-of-file nil) + (t (error err))))) + (progn + (push (flymake-rust--make-diagnostics source-buffer diag) diags)) + (setq continue nil))) + (let ((diags (flatten-list diags))) + (if diags + (funcall report-fn (flatten-list diags)) + (funcall report-fn nil :explanation "no errors")))))) - (save-excursion - ;; Append the latest output to the end of the previous. - (setq buffer-read-only nil) - (goto-char (process-mark proc)) - (insert string) - (set-marker (process-mark proc) (point)) - (setq buffer-read-only t) - (flymake-rust--parse-json source-buffer report-fn)) +;; TODO: verify that idle timers don’t actually break anything, and +;; are, in fact, an improvement over just calling stuff in the +;; sentinel directly. +(defun flymake-rust--sentinel (source-buffer report-fn proc _event) + "Call ‘REPORT-FN’ for ‘SOURCE-BUFFER’ with diagnostics when ‘PROC’ finishes. - (when moving - (goto-char (process-mark proc)))))) +This function does not directly call ‘REPORT-FN’, but instead +sets up a short timer to do so. This is done because sentinel +processes inhibits Emacs handling of events like quit." + (when (eq 'exit (process-status proc)) + (process-put proc 'timer + (run-with-idle-timer 0.1 nil + 'flymake-rust--parse-buffer source-buffer report-fn)))) -(defun flymake-rust--make-filter (source-buffer report-fn) - "Create a process filter for ‘SOURCE-BUFFER’ reporting to ‘REPORT-FN’." - (lambda (proc string) - (flymake-rust--filter source-buffer report-fn proc string))) +(defun flymake-rust--make-sentinel (source-buffer report-fn) + "Create a sentinel for ‘SOURCE-BUFFER’ reporting to ‘REPORT-FN’." + (lambda (proc event) + (flymake-rust--sentinel source-buffer report-fn proc event))) (defun flymake-rust--cleanup () "Clean up and leftover processes and buffers for the current buffer." + (when-let ((timer (and flymake-rust--process + (process-get flymake-rust--process 'timer)))) + (cancel-timer timer)) (when (process-live-p flymake-rust--process) (flymake-log :warning "Killing out-of-date checker process.") (delete-process flymake-rust--process)) @@ -153,29 +201,51 @@ This function attempts to parse JSON data beginning at (kill-buffer buf))) '("stdout" "stderr"))) -(defun flymake-rust--setup-proc-buf () - "Set up stdout process buffer for scanning." - ;; Save the position where output will begin so we can know where to - ;; start scanning from when output is done. - (flymake-rust--with-proc-buf - (setq buffer-read-only t) - (setq flymake-rust--parse-marker (make-marker)) - (set-marker flymake-rust--parse-marker (point)))) +(defun flymake-rust--cargo-command () + "Return an appropriate cargo check command line." + (cons (executable-find flymake-rust-cargo-path t) + flymake-rust--cargo-flags)) + +(defun flymake-rust--rustc-command () + "Return a command line for rustc reading from standard input." + (cons (executable-find flymake-rust-rustc-path t) flymake-rust--rustc-flags)) + +(defun flymake-rust--ignore-stderr-p () + "Return t if the stderr output of ‘flymake-rust-checker’ should be ignored. + +Cargo puts non-JSON data on stderr as it runs, so it has to be +shunted elsewhere or it breaks parsing." + (eq flymake-rust-checker 'cargo)) + +(defun flymake-rust--checker-command () + "Return a command line to check ‘PATH’. + +This will use the value configured in ‘flymake-rust-checker’ to what to run." + (cond ((eq flymake-rust-checker 'cargo) (flymake-rust--cargo-command)) + ((eq flymake-rust-checker 'rustc) (flymake-rust--rustc-command)))) (defun flymake-rust--call (source-buffer report-fn) - "Call out to the syntax checker for ‘SOURCE-BUFFER’ and report to ‘REPORT-FN’." + "Begin checking ‘SOURCE-BUFFER’ and report to ‘REPORT-FN’." (with-current-buffer source-buffer (flymake-rust--cleanup) - (setq flymake-rust--process - (make-process :name "flymake-rust-cargo-check" - :buffer (flymake-rust--buffer-name "stdout") - :command `(,flymake-rust-cargo-path "check" "--quiet" "--message-format" "json") - :noquery nil - :filter (flymake-rust--make-filter source-buffer report-fn) - :stderr (flymake-rust--buffer-name "stderr") - :stderr nil - :file-handler t)) - (flymake-rust--setup-proc-buf))) + (let ((buf (get-buffer-create (flymake-rust--buffer-name "stdout")))) + (with-current-buffer buf + (js-mode)) + (setq flymake-rust--process + (make-process :name "flymake-rust" + :buffer buf + :command (flymake-rust--checker-command) + :connection-type 'pipe + :noquery nil + :sentinel (flymake-rust--make-sentinel source-buffer report-fn) + :stderr (and (flymake-rust--ignore-stderr-p) + (flymake-rust--buffer-name "stderr")) + :file-handler t))) + + (when (eq flymake-rust-checker 'rustc) + (process-send-region flymake-rust--process + (point-min) (point-max)) + (process-send-eof flymake-rust--process)))) (defun flymake-rust--backend (report-fn &rest args) "Send Flymake diagnostics to ‘REPORT-FN’. |