address@hidden (João Távora) writes:
No, I was aiming for something more generic that includes at least Emacs
and perhaps other GNU projects.
FWIW, here's what I hacked up so far. Seems to work OK in two GNU
projects: Emacs and Hello (after ./configure, of course).
Probably flawed, but it's a start. Feedback welcome. To test, just load
this file and M-x flymake-mode in a C file.
Another option, as suggested previously, is to have a special Makefile
target (that'll need reconfiguring for each project, though).
João
;;; flymake-gcc.el --- naive gcc Flymake backend -*- lexical-binding: t; -*-
(defvar flymake-gcc-program "gcc"
"GCC program")
(defun flymake--gcc-heroic-unescape (string)
(with-temp-buffer
(let ((error-buffer (current-buffer)))
(with-temp-buffer
(cond
((zerop
;; I suspect "shell-command" makes windows even when called
;; from lisp.
(save-window-excursion
(shell-command
(format
"%s -Q --batch --eval \"%s\" -- %s"
(expand-file-name invocation-name
invocation-directory)
"(mapc 'print (nthcdr 4 command-line-args))"
string)
(current-buffer)
error-buffer)))
(goto-char (point-min))
(cl-loop with eof = (make-symbol "eof")
for form =
(condition-case _err
(read (current-buffer))
(error eof))
while (not (eq form eof))
collect form))
(t
(with-current-buffer error-buffer
(error (buffer-string)))))))))
(defvar flymake-gcc-flags 'flymake-gcc-guess-flags
"A list of flags passed to GCC.
Alternatively, a symbol naming a function called with no
arguments that should produce this list of flags, or error if it
cannot do so.")
(defvar flymake-gcc-extra-flags '("-Wextra" "-Wall")
"A list of extra flags passed to GCC.")
(defvar-local flymake--gcc-cached-flags nil
"Internal variable for `flymake-gcc-guess-flags'")
(defun flymake-gcc-guess-flags (&optional trash-cache)
"Guess GCC flags for compiling current buffer "
(interactive "P")
(unless (executable-find "make") (error "Cannot find a suitable make"))
(when trash-cache (setq flymake--gcc-cached-flags nil))
(catch 'retval
(unless (buffer-file-name)
;; don't error and don't cache, so that when the buffer is saved
;; we get another chance.
(throw 'retval nil))
(when-let* ((makefile-dir
(locate-dominating-file default-directory "Makefile"))
(makefile (expand-file-name "Makefile" makefile-dir))
(mtime (file-attribute-modification-time
(file-attributes makefile))))
(cond
((equal (list makefile mtime)
(cdr flymake--gcc-cached-flags))
(when (called-interactively-p 'interactive)
(message "cached hit for flags for this buffer: %s"
(car flymake--gcc-cached-flags)))
(throw 'retval (car flymake--gcc-cached-flags)))
(t
(let*
((sans-nothing
(file-name-nondirectory
(file-name-sans-extension
(buffer-file-name))))
(blob (shell-command-to-string
(format "make -C %s -f %s --just-print %s.o"
makefile-dir
makefile
sans-nothing)))
(match (string-match
(format "gcc[[:space:]]+\\(\\(?:-.*\\)*\\)%s"
sans-nothing)
blob))
(flag-string (and match
(match-string 1 blob)))
(flags (and flag-string
(flymake--gcc-heroic-unescape flag-string))))
(when (or flags (string= "" flag-string))
(setq flymake--gcc-cached-flags (list flags makefile mtime))
(when (called-interactively-p 'interactive)
(message "cached miss for flags for this buffer: %s" flags))
(throw 'retval flags))))))
(error "Could not guess gcc flags")))
(defvar-local flymake--gcc-proc nil
"Internal variable for `flymake-gcc'")
(defun flymake-gcc (report-fn &rest _args)
"Flymake backend for GCC"
(unless (executable-find flymake-gcc-program)
(error "Cannot find a suitable gcc"))
(when (process-live-p flymake--gcc-proc)
(kill-process flymake--gcc-proc))
(let ((source (current-buffer)))
(save-restriction
(widen)
(setq flymake--gcc-proc
(make-process
:name "gcc-flymake"
:buffer (generate-new-buffer "*gcc-flymake*")
:command `(,flymake-gcc-program
"-fsyntax-only"
,@flymake-gcc-extra-flags
,@(if (symbolp flymake-gcc-flags)
(funcall flymake-gcc-flags)
flymake-gcc-flags)
"-x" "c" "-")
:noquery t :connection-type 'pipe
:sentinel
(lambda (p _ev)
(when (eq 'exit (process-status p))
(unwind-protect
(when (eq p flymake--gcc-proc)
(with-current-buffer (process-buffer p)
(goto-char (point-min))
(cl-loop
while (search-forward-regexp
"^<stdin>:\\([0-9]+\\):\\([0-9]+\\): \\(.*\\):
\\(.*\\)$"
nil t)
for msg = (match-string 4)
for (beg . end) =
(flymake-diag-region
source
(string-to-number (match-string 1))
(string-to-number (match-string 2)))
for type = (assoc-default
(match-string 3)
'(("error" . :error)
("note" . :note)
("warning" . :warning))
#'string-match)
collect (flymake-make-diagnostic source beg end type
msg)
into diags
finally (funcall report-fn diags))))
;; (display-buffer (process-buffer p)) ; use this instead
of the next one for debug
(kill-buffer (process-buffer p))
))
)))
(process-send-region flymake--gcc-proc (point-min) (point-max))
(process-send-eof flymake--gcc-proc))))
(defun flymake--setup-gcc-flymake ()
(add-hook 'flymake-diagnostic-functions 'flymake-gcc nil t))
(add-hook 'c-mode-hook 'flymake--setup-gcc-flymake)
;;; flymake-gcc.el ends here