From: Lele Gaifax Date: Fri, 3 Nov 2017 12:20:36 +0000 (+0000) Subject: Add a Flymake backend for Python (bug#28808) X-Git-Tag: emacs-26.0.91~377 X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=3ad712ebc91438838df29b0e12b3103d409ee3a4;p=emacs.git Add a Flymake backend for Python (bug#28808) Implement new Flymake backend with related customizable settings. * lisp/progmodes/python.el (python-flymake-command) (python-flymake-command-output-pattern) (python-flymake-msg-alist): New defcustom. (python--flymake-parse-output): New function, able to parse python-flymake-command output accordingly to python-flymake-command-output-pattern. (python-flymake): New function implementing the backend interface using python--flymake-parse-output for the real work. (python-mode): Add python-flymake to flymake-diagnostic-functions. --- diff --git a/lisp/progmodes/python.el b/lisp/progmodes/python.el index 895117b9ee3..b7902fb9786 100644 --- a/lisp/progmodes/python.el +++ b/lisp/progmodes/python.el @@ -5141,6 +5141,138 @@ returned as is." "Return non-nil if REGEXP is valid." (ignore-errors (string-match regexp "") t)) + +;;; Flymake integration + +(defgroup python-flymake nil + "Integration between Python and Flymake." + :group 'python + :link '(custom-group-link :tag "Flymake" flymake) + :version "26.1") + +(defcustom python-flymake-command '("pyflakes") + "The external tool that will be used to perform the syntax check. +This is a non empty list of strings, the checker tool possibly followed by +required arguments. Once launched it will receive the Python source to be +checked as its standard input. +To use `flake8' you would set this to (\"flake8\" \"-\")." + :group 'python-flymake + :type '(repeat string)) + +;; The default regexp accomodates for older pyflakes, which did not +;; report the column number, and at the same time it's compatible with +;; flake8 output, although it may be redefined to explicitly match the +;; TYPE +(defcustom python-flymake-command-output-pattern + (list + "^\\(?:?\\):\\(?1:[0-9]+\\):\\(?:\\(?2:[0-9]+\\):\\)? \\(?3:.*\\)$" + 1 2 nil 3) + "Specify how to parse the output of `python-flymake-command'. +The value has the form (REGEXP LINE COLUMN TYPE MESSAGE): if +REGEXP matches, the LINE'th subexpression gives the line number, +the COLUMN'th subexpression gives the column number on that line, +the TYPE'th subexpression gives the type of the message and the +MESSAGE'th gives the message text itself. + +If COLUMN or TYPE are nil or that index didn't match, that +information is not present on the matched line and a default will +be used." + :group 'python-flymake + :type '(list regexp + (integer :tag "Line's index") + (choice + (const :tag "No column" nil) + (integer :tag "Column's index")) + (choice + (const :tag "No type" nil) + (integer :tag "Type's index")) + (integer :tag "Message's index"))) + +(defcustom python-flymake-msg-alist + '(("\\(^redefinition\\|.*unused.*\\|used$\\)" . :warning)) + "Alist used to associate messages to their types. +Each element should be a cons-cell (REGEXP . TYPE), where TYPE must be +one defined in the variable `flymake-diagnostic-types-alist'. +For example, when using `flake8' a possible configuration could be: + + ((\"\\(^redefinition\\|.*unused.*\\|used$\\)\" . :warning) + (\"^E999\" . :error) + (\"^[EW][0-9]+\" . :note)) + +By default messages are considered errors." + :group 'python-flymake + :type `(alist :key-type (regexp) + :value-type (symbol))) + +(defvar-local python--flymake-proc nil) + +(defun python--flymake-parse-output (source proc report-fn) + "Collect diagnostics parsing checker tool's output line by line." + (let ((rx (nth 0 python-flymake-command-output-pattern)) + (lineidx (nth 1 python-flymake-command-output-pattern)) + (colidx (nth 2 python-flymake-command-output-pattern)) + (typeidx (nth 3 python-flymake-command-output-pattern)) + (msgidx (nth 4 python-flymake-command-output-pattern))) + (with-current-buffer (process-buffer proc) + (goto-char (point-min)) + (cl-loop + while (search-forward-regexp rx nil t) + for msg = (match-string msgidx) + for (beg . end) = (flymake-diag-region + source + (string-to-number + (match-string lineidx)) + (and colidx + (match-string colidx) + (string-to-number + (match-string colidx)))) + for type = (or (and typeidx + (match-string typeidx) + (assoc-default + (match-string typeidx) + python-flymake-msg-alist + #'string-match)) + (assoc-default msg + python-flymake-msg-alist + #'string-match) + :error) + collect (flymake-make-diagnostic + source beg end type msg) + into diags + finally (funcall report-fn diags))))) + +(defun python-flymake (report-fn &rest _args) + "Flymake backend for Python. +This backend uses `python-flymake-command' (which see) to launch a process +that is passed the current buffer's content via stdin. +REPORT-FN is Flymake's callback function." + (unless (executable-find (car python-flymake-command)) + (error "Cannot find a suitable checker")) + + (when (process-live-p python--flymake-proc) + (kill-process python--flymake-proc)) + + (let ((source (current-buffer))) + (save-restriction + (widen) + (setq python--flymake-proc + (make-process + :name "python-flymake" + :noquery t + :connection-type 'pipe + :buffer (generate-new-buffer " *python-flymake*") + :command python-flymake-command + :sentinel + (lambda (proc _event) + (when (eq 'exit (process-status proc)) + (unwind-protect + (when (with-current-buffer source + (eq proc python--flymake-proc)) + (python--flymake-parse-output source proc report-fn)) + (kill-buffer (process-buffer proc))))))) + (process-send-region python--flymake-proc (point-min) (point-max)) + (process-send-eof python--flymake-proc)))) + (defun python-electric-pair-string-delimiter () (when (and electric-pair-mode @@ -5255,7 +5387,9 @@ returned as is." (make-local-variable 'python-shell-internal-buffer) (when python-indent-guess-indent-offset - (python-indent-guess-indent-offset))) + (python-indent-guess-indent-offset)) + + (add-hook 'flymake-diagnostic-functions #'python-flymake nil t)) (provide 'python)