summaryrefslogtreecommitdiff
path: root/lisp/progmodes/flymake-cc.el
blob: bddd1a39fc27fe8d9a86ad1aa7951adb37f38527 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
;;; flymake-cc.el --- Flymake support for GNU tools for C/C++     -*- lexical-binding: t; -*-

;; Copyright (C) 2018-2020 Free Software Foundation, Inc.

;; Author: João Távora <joaotavora@gmail.com>
;; Keywords: languages, c

;; This program is free software; you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation, either version 3 of the License, or
;; (at your option) any later version.

;; This program is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;; GNU General Public License for more details.

;; You should have received a copy of the GNU General Public License
;; along with this program.  If not, see <https://www.gnu.org/licenses/>.

;;; Commentary:

;; Flymake support for C/C++.

;;; Code:

(require 'cl-lib)

(defcustom flymake-cc-command 'flymake-cc-use-special-make-target
  "Command used by the `flymake-cc' backend.
A list of strings, or a symbol naming a function that produces one
such list when called with no arguments in the buffer where the
variable `flymake-mode' is active.

The command should invoke a GNU-style compiler that checks the
syntax of a (Obj)C(++) program passed to it via its standard
input and prints the result on its standard output."
  :type '(choice
          (symbol :tag "Function")
          (repeat :tag "Command(s)" string))
  :version "27.1"
  :group 'flymake-cc)

(defun flymake-cc--make-diagnostics (source)
  "Parse GNU-compatible compilation messages in current buffer.
Return a list of Flymake diagnostic objects for the source buffer
SOURCE."
  ;; TODO: if you can understand it, use `compilation-mode's regexps
  ;; or even some of its machinery here.
  ;;
  ;;    (set (make-local-variable 'compilation-locs)
  ;;         (make-hash-table :test 'equal :weakness 'value))
  ;;    (compilation-parse-errors (point-min) (point-max)
  ;;                              'gnu 'gcc-include)
  ;;    (while (next-single-property-change 'compilation-message)
  ;;       ...)
  ;;
  ;; For now, this works minimally well.
  (cl-loop
   while
   (search-forward-regexp
    "^\\(In file included from \\)?<stdin>:\\([0-9]+\\)\\(?::\\([0-9]+\\)\\)?:\n?\\(.*\\): \\(.*\\)$"
    nil t)
   for msg = (match-string 5)
   for (beg . end) = (flymake-diag-region
                      source
                      (string-to-number (match-string 2))
                      (and (match-string 3) (string-to-number (match-string 3))))
   for type = (if (match-string 1)
                  :error
                (assoc-default
                 (match-string 4)
                 '(("error" . :error)
                   ("note" . :note)
                   ("warning" . :warning))
                 #'string-match
                 :error))
   collect (flymake-make-diagnostic source beg end type msg)))

(defun flymake-cc-use-special-make-target ()
  "Command for checking a file via a CHK_SOURCES Make target."
  (unless (executable-find "make") (error "Make not found"))
  `("make"
    "check-syntax"
    ,(format "CHK_SOURCES=-x %s -c -"
             (cond ((derived-mode-p 'c++-mode) "c++")
                   (t "c")))))

(defvar-local flymake-cc--proc nil "Internal variable for `flymake-gcc'")

;; forward declare this to shoosh compiler (instead of requiring
;; flymake-proc)
;;
(defvar flymake-proc-allowed-file-name-masks)

;;;###autoload
(defun flymake-cc (report-fn &rest _args)
  "Flymake backend for GNU-style C compilers.
This backend uses `flymake-cc-command' (which see) to launch a
process that is passed the current buffer's contents via stdin.
REPORT-FN is Flymake's callback."
  ;; HACK: XXX: Assuming this backend function is run before it in
  ;; `flymake-diagnostic-functions', very hackingly convince the other
  ;; backend `flymake-proc-legacy-backend', which is on by default, to
  ;; disable itself.
  ;;
  (setq-local flymake-proc-allowed-file-name-masks nil)
  (when (process-live-p flymake-cc--proc)
    (kill-process flymake-cc--proc))
  (let ((source (current-buffer)))
    (save-restriction
      (widen)
      (setq
       flymake-cc--proc
       (make-process
        :name "gcc-flymake"
        :buffer (generate-new-buffer "*gcc-flymake*")
        :command (if (symbolp flymake-cc-command)
                     (funcall flymake-cc-command)
                   flymake-cc-command)
        :noquery t :connection-type 'pipe
        :sentinel
        (lambda (p _ev)
          (unwind-protect
              (when (eq 'exit (process-status p))
                (when (with-current-buffer source (eq p flymake-cc--proc))
                  (with-current-buffer (process-buffer p)
                    (goto-char (point-min))
                    (let ((diags
                           (flymake-cc--make-diagnostics source)))
                      (if (or diags (zerop (process-exit-status p)))
                          (funcall report-fn diags)
                        ;; non-zero exit with no diags is cause
                        ;; for alarm
                        (funcall report-fn
                                 :panic :explanation
                                 (buffer-substring
                                  (point-min) (progn (goto-char (point-min))
                                                     (line-end-position)))))))))
            (unless (process-live-p p)
              ;; (display-buffer (process-buffer p)) ; uncomment to debug
              (kill-buffer (process-buffer p)))))))
      (process-send-region flymake-cc--proc (point-min) (point-max))
      (process-send-eof flymake-cc--proc))))

(provide 'flymake-cc)
;;; flymake-cc.el ends here