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1 | \input texinfo @c -*-texinfo-*- |
2 | @comment %**start of header | |
3 | @setfilename ../info/flymake | |
4 | @set VERSION 0.3 | |
5 | @set UPDATED April 2004 | |
6 | @settitle GNU Flymake @value{VERSION} | |
7 | @syncodeindex pg cp | |
8 | @comment %**end of header | |
9 | ||
10 | @copying | |
11 | This manual is for GNU Flymake (version @value{VERSION}, @value{UPDATED}), | |
12 | which is a universal on-the-fly syntax checker for GNU Emacs. | |
13 | ||
4e6835db | 14 | Copyright @copyright{} 2004, 2005, 2006, 2007 Free Software Foundation, Inc. |
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15 | |
16 | @quotation | |
17 | Permission is granted to copy, distribute and/or modify this document | |
678e7c71 | 18 | under the terms of the GNU Free Documentation License, Version 1.2 or |
4bcbcb9d | 19 | any later version published by the Free Software Foundation; with no |
5a7f4c1b | 20 | Invariant Sections, with the Front-Cover texts being ``A GNU Manual,'' |
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21 | and with the Back-Cover Texts as in (a) below. A copy of the license |
22 | is included in the section entitled ``GNU Free Documentation License'' | |
23 | in the Emacs manual. | |
24 | ||
25 | (a) The FSF's Back-Cover Text is: ``You have freedom to copy and modify | |
26 | this GNU Manual, like GNU software. Copies published by the Free | |
27 | Software Foundation raise funds for GNU development.'' | |
28 | ||
29 | This document is part of a collection distributed under the GNU Free | |
30 | Documentation License. If you want to distribute this document | |
31 | separately from the collection, you can do so by adding a copy of the | |
32 | license to the document, as described in section 6 of the license. | |
33 | @end quotation | |
34 | @end copying | |
35 | ||
36 | @dircategory Emacs | |
37 | @direntry | |
38 | * Flymake: (flymake). A universal on-the-fly syntax checker. | |
39 | @end direntry | |
40 | ||
41 | @titlepage | |
42 | @title GNU Flymake | |
43 | @subtitle for version @value{VERSION}, @value{UPDATED} | |
44 | @author Pavel Kobiakov(@email{pk_at_work@@yahoo.com}) | |
45 | @page | |
46 | @vskip 0pt plus 1filll | |
47 | @end titlepage | |
48 | ||
49 | @contents | |
50 | ||
51 | @ifnottex | |
52 | @node Top | |
53 | @top GNU Flymake | |
54 | @end ifnottex | |
55 | ||
56 | @menu | |
57 | * Overview of Flymake:: | |
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58 | * Installing Flymake:: |
59 | * Using Flymake:: | |
60 | * Configuring Flymake:: | |
61 | * Flymake Implementation:: | |
62 | * Index:: | |
63 | @end menu | |
64 | ||
65 | @node Overview of Flymake | |
66 | @chapter Overview | |
67 | @cindex Overview of Flymake | |
68 | ||
69 | Flymake is a universal on-the-fly syntax checker implemented as an | |
70 | Emacs minor mode. Flymake runs the pre-configured syntax check tool | |
71 | (compiler for C++ files, @code{perl} for perl files, etc.) in the | |
72 | background, passing it a temporary copy of the current buffer, and | |
73 | parses the output for known error/warning message patterns. Flymake | |
74 | then highlights erroneous lines (i.e. lines for which at least one | |
75 | error or warning has been reported by the syntax check tool), and | |
76 | displays an overall buffer status in the mode line. Status information | |
77 | displayed by Flymake contains total number of errors and warnings | |
78 | reported for the buffer during the last syntax check. | |
79 | ||
80 | @code{flymake-goto-next-error} and @code{flymake-goto-prev-error} | |
81 | functions allow for easy navigation to the next/previous erroneous | |
82 | line, respectively. | |
83 | ||
84 | Calling @code{flymake-display-err-menu-for-current-line} will popup a | |
85 | menu containing error messages reported by the syntax check tool for | |
86 | the current line. Errors/warnings belonging to another file, such as a | |
87 | @code{.h} header file included by a @code{.c} file, are shown in the | |
88 | current buffer as belonging to the first line. Menu items for such | |
89 | messages also contain a filename and a line number. Selecting such a | |
90 | menu item will automatically open the file and jump to the line with | |
91 | error. | |
92 | ||
93 | Syntax check is done 'on-the-fly'. It is started whenever | |
94 | ||
95 | @itemize @bullet | |
96 | @item buffer is loaded | |
97 | @item a newline character is added to the buffer | |
98 | @item some changes were made to the buffer more than @code{0.5} seconds ago (the | |
99 | delay is configurable). | |
100 | @end itemize | |
101 | ||
102 | Flymake is a universal syntax checker in the sense that it's easily | |
103 | extended to support new syntax check tools and error message | |
104 | patterns. @xref{Configuring Flymake}. | |
105 | ||
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106 | @node Installing Flymake |
107 | @chapter Installing | |
108 | @cindex Installing Flymake | |
109 | ||
110 | ||
111 | Flymake is packaged in a single file, @code{flymake.el}. | |
112 | ||
113 | To install/update Flymake, place @code{flymake.el} to a directory | |
114 | somewhere on Emacs load path. You might also want to byte-compile | |
115 | @code{flymake.el} to improve performance. | |
116 | ||
117 | Also, place the following line in the @code{.emacs} file. | |
118 | ||
119 | @lisp | |
120 | (require 'flymake) | |
121 | @end lisp | |
122 | ||
123 | You might also map the most frequently used Flymake functions, such as | |
124 | @code{flymake-goto-next-error}, to some keyboard shortcuts: | |
125 | ||
126 | @lisp | |
127 | (global-set-key [f3] 'flymake-display-err-menu-for-current-line) | |
128 | (global-set-key [f4] 'flymake-goto-next-error) | |
129 | @end lisp | |
130 | ||
131 | @node Using Flymake | |
132 | @chapter Using Flymake | |
133 | @cindex Using Flymake | |
134 | ||
135 | @menu | |
136 | * Flymake mode:: | |
137 | * Running the syntax check:: | |
138 | * Navigating to error lines:: | |
139 | * Viewing error messages:: | |
140 | * Syntax check statuses:: | |
141 | * Troubleshooting:: | |
142 | @end menu | |
143 | ||
144 | @node Flymake mode | |
145 | @section Flymake mode | |
146 | @cindex flymake-mode | |
147 | ||
148 | Flymake is an Emacs minor mode. To use Flymake, you | |
149 | must first activate @code{flymake-mode} by using the | |
150 | @code{flymake-mode} function. | |
151 | ||
152 | Instead of manually activating @code{flymake-mode}, you can configure | |
153 | Flymake to automatically enable @code{flymake-mode} upon opening any | |
154 | file for which syntax check is possible. To do so, place the following | |
155 | line in @code{.emacs}: | |
156 | ||
157 | @lisp | |
fa6661a8 | 158 | (add-hook 'find-file-hook 'flymake-find-file-hook) |
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159 | @end lisp |
160 | ||
161 | @node Running the syntax check | |
162 | @section Running the syntax check | |
163 | @cindex Manually starting the syntax check | |
164 | ||
165 | When @code{flymake-mode} is active, syntax check is started | |
166 | automatically on any of the three conditions mentioned above. Syntax | |
167 | check can also be started manually by using the | |
168 | @code{flymake-start-syntax-check-for-current-buffer} function. This | |
169 | can be used, for example, when changes were made to some other buffer | |
170 | affecting the current buffer. | |
171 | ||
172 | @node Navigating to error lines | |
173 | @section Navigating to error lines | |
174 | @cindex Navigating to error lines | |
175 | ||
176 | After syntax check is completed, lines for which at least one error or | |
177 | warning has been reported are highlighted, and total number of errors | |
178 | and warning is shown in the mode line. Use the following functions to | |
179 | navigate the highlighted lines. | |
180 | ||
181 | @multitable @columnfractions 0.25 0.75 | |
182 | ||
183 | @item @code{flymake-goto-next-error} | |
184 | @tab Moves point to the next erroneous line, if any. | |
185 | ||
186 | @item @code{flymake-goto-prev-error} | |
187 | @tab Moves point to the previous erroneous line. | |
188 | ||
189 | @end multitable | |
190 | ||
191 | These functions treat erroneous lines as a linked list. Therefore, | |
192 | @code{flymake-goto-next-error} will go to the first erroneous line | |
193 | when invoked in the end of the buffer. | |
194 | ||
195 | @node Viewing error messages | |
196 | @section Viewing error messages | |
197 | @cindex Viewing error messages | |
198 | ||
199 | To view error messages belonging to the current line, use the | |
200 | @code{flymake-display-err-menu-for-current-line} function. If there's | |
201 | at least one error or warning reported for the current line, this | |
202 | function will display a popup menu with error/warning texts. | |
203 | Selecting the menu item whose error belongs to another file brings | |
204 | forward that file with the help of the | |
205 | @code{flymake-goto-file-and-line} function. | |
206 | ||
207 | @node Syntax check statuses | |
208 | @section Syntax check statuses | |
209 | @cindex Syntax check statuses | |
210 | ||
211 | After syntax check is finished, its status is displayed in the mode line. | |
212 | The following statuses are defined. | |
213 | ||
214 | @multitable @columnfractions 0.25 0.75 | |
215 | @item Flymake* or Flymake:E/W* | |
216 | @tab Flymake is currently running. For the second case, E/W contains the | |
217 | error and warning count for the previous run. | |
218 | ||
219 | @item Flymake | |
220 | @tab Syntax check is not running. Usually this means syntax check was | |
221 | successfully passed (no errors, no warnings). Other possibilities are: | |
222 | syntax check was killed as a result of executing | |
223 | @code{flymake-compile}, or syntax check cannot start as compilation | |
224 | is currently in progress. | |
225 | ||
226 | @item Flymake:E/W | |
227 | @tab Number of errors/warnings found by the syntax check process. | |
228 | ||
229 | @item Flymake:! | |
230 | @tab Flymake was unable to find master file for the current buffer. | |
231 | @end multitable | |
232 | ||
233 | The following errors cause a warning message and switch flymake mode | |
234 | OFF for the buffer. | |
235 | ||
236 | @multitable @columnfractions 0.25 0.75 | |
237 | @item CFGERR | |
238 | @tab Syntax check process returned nonzero exit code, but no | |
239 | errors/warnings were reported. This indicates a possible configuration | |
240 | error (for example, no suitable error message patterns for the | |
241 | syntax check tool). | |
242 | ||
243 | @item NOMASTER | |
244 | @tab Flymake was unable to find master file for the current buffer. | |
245 | ||
246 | @item NOMK | |
247 | @tab Flymake was unable to find a suitable buildfile for the current buffer. | |
248 | ||
249 | @item PROCERR | |
250 | @tab Flymake was unable to launch a syntax check process. | |
251 | @end multitable | |
252 | ||
253 | ||
254 | @node Troubleshooting | |
255 | @section Troubleshooting | |
256 | @cindex Logging | |
257 | @cindex Troubleshooting | |
258 | ||
259 | Flymake uses a simple logging facility for indicating important points | |
260 | in the control flow. The logging facility sends logging messages to | |
261 | the @code{*Messages*} buffer. The information logged can be used for | |
262 | resolving various problems related to Flymake. | |
263 | ||
264 | Logging output is controlled by the @code{flymake-log-level} | |
265 | variable. @code{3} is the most verbose level, and @code{-1} switches | |
266 | logging off. | |
267 | ||
268 | @node Configuring Flymake | |
269 | @chapter Configuring and Extending Flymake | |
270 | @cindex Configuring and Extending Flymake | |
271 | ||
272 | @menu | |
273 | * Customizable variables:: | |
274 | * Adding support for a new syntax check tool:: | |
275 | @end menu | |
276 | ||
277 | Flymake was designed to be easily extended for supporting new syntax | |
278 | check tools and error message patterns. | |
279 | ||
280 | @node Customizable variables | |
281 | @section Customizable variables | |
282 | @cindex Customizable variables | |
283 | ||
3d80e1a2 | 284 | This section summarizes variables used for Flymake |
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285 | configuration. |
286 | ||
287 | @table @code | |
288 | @item flymake-log-level | |
289 | Controls logging output, see @ref{Troubleshooting}. | |
290 | ||
291 | @item flymake-allowed-file-name-masks | |
292 | A list of @code{(filename-regexp, init-function, cleanup-function | |
293 | getfname-function)} for configuring syntax check tools. @xref{Adding | |
294 | support for a new syntax check tool}. | |
295 | ||
296 | @item flymake-buildfile-dirs | |
297 | A list of directories (relative paths) for searching a | |
298 | buildfile. @xref{Locating the buildfile}. | |
299 | ||
300 | @item flymake-master-file-dirs | |
301 | A list of directories for searching a master file. @xref{Locating a | |
302 | master file}. | |
303 | ||
304 | @item flymake-get-project-include-dirs-function | |
305 | A function used for obtaining a list of project include dirs (C/C++ | |
306 | specific). @xref{Getting the include directories}. | |
307 | ||
308 | @item flymake-master-file-count-limit | |
309 | @itemx flymake-check-file-limit | |
310 | Used when looking for a master file. @xref{Locating a master file}. | |
311 | ||
312 | @item flymake-err-line-patterns | |
313 | Patterns for error/warning messages in the form @code{(regexp file-idx | |
314 | line-idx err-text-idx)}. @xref{Parsing the output}. | |
315 | ||
316 | @item flymake-compilation-prevents-syntax-check | |
317 | A flag indicating whether compilation and syntax check of the same | |
318 | file cannot be run simultaneously. | |
319 | ||
320 | @item flymake-no-changes-timeout | |
321 | If any changes are made to the buffer, syntax check is automatically | |
322 | started after @code{flymake-no-changes-timeout} seconds. | |
323 | ||
324 | @item flymake-gui-warnings-enabled | |
325 | A boolean flag indicating whether Flymake will show message boxes for | |
326 | non-recoverable errors. If @code{flymake-gui-warnings-enabled} is | |
327 | @code{nil}, these errors will only be logged to the @code{*Messages*} | |
328 | buffer. | |
329 | ||
330 | @item flymake-start-syntax-check-on-newline | |
331 | A boolean flag indicating whether to start syntax check after a | |
332 | newline character is added to the buffer. | |
333 | ||
334 | @item flymake-errline-face | |
335 | A custom face for highlighting lines for which at least one error has | |
336 | been reported. | |
337 | ||
338 | @item flymake-warnline-face | |
339 | A custom face for highlighting lines for which at least one warning | |
340 | and no errors have been reported. | |
341 | ||
342 | @end table | |
343 | ||
344 | @node Adding support for a new syntax check tool | |
345 | @section Adding support for a new syntax check tool | |
346 | @cindex Adding support for a new syntax check tool | |
347 | ||
348 | @menu | |
349 | * Example -- Configuring a tool called directly:: | |
350 | * Example -- Configuring a tool called via make:: | |
351 | @end menu | |
352 | ||
353 | Syntax check tools are configured using the | |
354 | @code{flymake-allowed-file-name-masks} list. Each item of this list | |
355 | has the following format: | |
356 | ||
357 | @lisp | |
358 | (filename-regexp, init-function, cleanup-function, getfname-function) | |
359 | @end lisp | |
360 | ||
361 | @table @code | |
362 | @item filename-regexp | |
363 | This field is used as a key for locating init/cleanup/getfname | |
364 | functions for the buffer. Items in | |
365 | @code{flymake-allowed-file-name-masks} are searched sequentially. The | |
366 | first item with @code{filename-regexp} matching buffer filename is | |
367 | selected. If no match is found, @code{flymake-mode} is switched off. | |
368 | ||
369 | @item init-function | |
3d80e1a2 | 370 | @code{init-function} is required to initialize the syntax check, |
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371 | usually by creating a temporary copy of the buffer contents. The |
372 | function must return @code{(list cmd-name arg-list)}. If | |
373 | @code{init-function} returns null, syntax check is aborted, by | |
374 | @code{flymake-mode} is not switched off. | |
375 | ||
376 | @item cleanup-function | |
377 | @code{cleanup-function} is called after the syntax check process is | |
378 | complete and should take care of proper deinitialization, which is | |
379 | usually deleting a temporary copy created by the @code{init-function}. | |
380 | ||
381 | @item getfname-function | |
382 | This function is used for translating filenames reported by the syntax | |
383 | check tool into ``real'' filenames. Filenames reported by the tool | |
384 | will be different from the real ones, as actually the tool works with | |
385 | the temporary copy. In most cases, the default implementation | |
386 | provided by Flymake, @code{flymake-get-real-file-name}, can be used as | |
387 | @code{getfname-function}. | |
388 | ||
389 | @end table | |
390 | ||
391 | To add support for a new syntax check tool, write corresponding | |
392 | @code{init-function}, and, optionally @code{cleanup-function} and | |
393 | @code{getfname-function}. If the format of error messages reported by | |
394 | the new tool is not yet supported by Flymake, add a new entry to | |
395 | the @code{flymake-err-line-patterns} list. | |
396 | ||
397 | The following sections contain some examples of configuring Flymake | |
398 | support for various syntax check tools. | |
399 | ||
400 | @node Example -- Configuring a tool called directly | |
401 | @subsection Example -- Configuring a tool called directly | |
402 | @cindex Adding support for perl | |
403 | ||
404 | In this example, we will add support for @code{perl} as a syntax check | |
405 | tool. @code{perl} supports the @code{-c} option which does syntax | |
406 | checking. | |
407 | ||
408 | First, we write the @code{init-function}: | |
409 | ||
410 | @lisp | |
93261462 TTN |
411 | (defun flymake-perl-init (buffer) |
412 | (let* ((temp-file (flymake-init-create-temp-buffer-copy | |
413 | buffer 'flymake-create-temp-inplace)) | |
99f71598 | 414 | (local-file (concat (flymake-build-relative-filename |
93261462 TTN |
415 | (file-name-directory |
416 | (buffer-file-name | |
417 | (current-buffer))) | |
418 | (file-name-directory temp-file)) | |
419 | (file-name-nondirectory temp-file)))) | |
420 | (list "perl" (list "-wc " local-file)))) | |
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421 | @end lisp |
422 | ||
423 | @code{flymake-perl-init} creates a temporary copy of the buffer | |
424 | contents with the help of | |
425 | @code{flymake-init-create-temp-buffer-copy}, and builds an appropriate | |
426 | command line. | |
427 | ||
428 | Next, we add a new entry to the | |
429 | @code{flymake-allowed-file-name-masks}: | |
430 | ||
431 | @lisp | |
432 | (setq flymake-allowed-file-name-masks | |
93261462 TTN |
433 | (cons '(".+\\.pl$" |
434 | flymake-perl-init | |
435 | flymake-simple-cleanup | |
436 | flymake-get-real-file-name) | |
437 | flymake-allowed-file-name-masks)) | |
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438 | @end lisp |
439 | ||
440 | Note that we use standard @code{cleanup-function} and | |
441 | @code{getfname-function}. | |
442 | ||
443 | Finally, we add an entry to @code{flymake-err-line-patterns}: | |
444 | ||
445 | @lisp | |
446 | (setq flymake-err-line-patterns | |
93261462 TTN |
447 | (cons '("\\(.*\\) at \\([^ \n]+\\) line \\([0-9]+\\)[,.\n]" |
448 | 2 3 nil 1) | |
449 | flymake-err-line-patterns)) | |
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450 | @end lisp |
451 | ||
452 | @node Example -- Configuring a tool called via make | |
453 | @subsection Example -- Configuring a tool called via make | |
454 | @cindex Adding support for C (gcc+make) | |
455 | ||
456 | In this example we will add support for C files syntax checked by | |
457 | @code{gcc} called via @code{make}. | |
458 | ||
459 | We're not required to write any new functions, as Flymake already has | |
460 | functions for @code{make}. We just add a new entry to the | |
461 | @code{flymake-allowed-file-name-masks}: | |
462 | ||
463 | @lisp | |
464 | (setq flymake-allowed-file-name-masks | |
93261462 TTN |
465 | (cons '(".+\\.c$" |
466 | flymake-simple-make-init | |
467 | flymake-simple-cleanup | |
468 | flymake-get-real-file-name) | |
469 | flymake-allowed-file-name-masks)) | |
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470 | @end lisp |
471 | ||
472 | @code{flymake-simple-make-init} builds the following @code{make} | |
473 | command line: | |
474 | ||
475 | @lisp | |
476 | (list "make" | |
93261462 TTN |
477 | (list "-s" "-C" |
478 | base-dir | |
479 | (concat "CHK_SOURCES=" source) | |
480 | "SYNTAX_CHECK_MODE=1" | |
481 | "check-syntax")) | |
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482 | @end lisp |
483 | ||
484 | @code{base-dir} is a directory containing @code{Makefile}, see @ref{Locating the buildfile}. | |
485 | ||
486 | Thus, @code{Makefile} must contain the @code{check-syntax} target. In | |
487 | our case this target might look like this: | |
488 | ||
489 | @verbatim | |
490 | check-syntax: | |
491 | gcc -o nul -S ${CHK_SOURCES} | |
492 | @end verbatim | |
493 | ||
494 | The format of error messages reported by @code{gcc} is already | |
495 | supported by Flymake, so we don't have to add a new entry to | |
496 | @code{flymake-err-line-patterns}. | |
497 | ||
498 | @node Flymake Implementation | |
499 | @chapter Flymake Implementation | |
500 | @cindex Implementation details | |
501 | ||
502 | @menu | |
503 | * Determining whether syntax check is possible:: | |
504 | * Making a temporary copy:: | |
505 | * Locating a master file:: | |
506 | * Getting the include directories:: | |
507 | * Locating the buildfile:: | |
508 | * Starting the syntax check process:: | |
509 | * Parsing the output:: | |
510 | * Highlighting erroneous lines:: | |
511 | * Interaction with other modes:: | |
512 | @end menu | |
513 | ||
514 | Syntax check is started by calling @code{flymake-start-syntax-check-for-current-buffer}. | |
515 | Flymake first determines whether it is able to do syntax | |
516 | check. It then saves a copy of the buffer in a temporary file in the | |
517 | buffer's directory (or in the system temp directory -- for java | |
518 | files), creates a syntax check command and launches a process with | |
519 | this command. The output is parsed using a list of error message patterns, | |
520 | and error information (file name, line number, type and text) is | |
521 | saved. After the process has finished, Flymake highlights erroneous | |
522 | lines in the buffer using the accumulated error information. | |
523 | ||
524 | @node Determining whether syntax check is possible | |
525 | @section Determining whether syntax check is possible | |
526 | @cindex Syntax check models | |
527 | @cindex Master file | |
528 | ||
529 | Syntax check is considered possible if there's an entry in | |
530 | @code{flymake-allowed-file-name-masks} matching buffer's filename and | |
bf301e70 | 531 | its @code{init-function} returns non-@code{nil} value. |
4bcbcb9d EZ |
532 | |
533 | Two syntax check modes are distinguished: | |
534 | ||
535 | @enumerate | |
536 | ||
537 | @item | |
538 | Buffer can be syntax checked in a standalone fashion, that is, the | |
539 | file (its temporary copy, in fact) can be passed over to the compiler to | |
540 | do the syntax check. Examples are C/C++ (.c, .cpp) and Java (.java) | |
541 | sources. | |
542 | ||
543 | @item | |
544 | Buffer can be syntax checked, but additional file, called master file, | |
545 | is required to perform this operation. A master file is a file that | |
546 | includes the current file, so that running a syntax check tool on it | |
547 | will also check syntax in the current file. Examples are C/C++ (.h, | |
548 | .hpp) headers. | |
549 | ||
550 | @end enumerate | |
551 | ||
552 | These modes are handled inside init/cleanup/getfname functions, see | |
553 | @ref{Adding support for a new syntax check tool}. | |
554 | ||
555 | Flymake contains implementations of all functionality required to | |
556 | support different syntax check modes described above (making | |
557 | temporary copies, finding master files, etc.), as well as some | |
558 | tool-specific (routines for @code{make}, @code{Ant}, etc.) code. | |
559 | ||
560 | ||
561 | @node Making a temporary copy | |
562 | @section Making a temporary copy | |
563 | @cindex Temporary copy of the buffer | |
564 | @cindex Master file | |
565 | ||
566 | After the possibility of the syntax check has been determined, a | |
567 | temporary copy of the current buffer is made so that the most recent | |
568 | unsaved changes could be seen by the syntax check tool. Making a copy | |
569 | is quite straightforward in a standalone case (mode @code{1}), as it's | |
570 | just saving buffer contents to a temporary file. | |
571 | ||
572 | Things get trickier, however, when master file is involved, as it | |
573 | requires to | |
574 | ||
575 | @itemize @bullet | |
576 | @item locate a master file | |
577 | @item patch it to include the current file using its new (temporary) | |
578 | name. | |
579 | @end itemize | |
580 | ||
581 | Locating a master file is discussed in the following section. | |
582 | ||
583 | Patching just changes all appropriate lines of the master file so that they | |
584 | use the new (temporary) name of the current file. For example, suppose current | |
585 | file name is @code{file.h}, the master file is @code{file.cpp}, and | |
586 | it includes current file via @code{#include "file.h"}. Current file's copy | |
587 | is saved to file @code{file_flymake.h}, so the include line must be | |
588 | changed to @code{#include "file_flymake.h"}. Finally, patched master file | |
589 | is saved to @code{file_flymake_master.cpp}, and the last one is passed to | |
590 | the syntax check tool. | |
591 | ||
592 | @node Locating a master file | |
593 | @section Locating a master file | |
594 | @cindex Master file | |
595 | ||
596 | Master file is located in two steps. | |
597 | ||
598 | First, a list of possible master files is built. A simple name | |
599 | matching is used to find the files. For a C++ header @code{file.h}, | |
600 | Flymake searches for all @code{.cpp} files in the directories whose relative paths are | |
601 | stored in a customizable variable @code{flymake-master-file-dirs}, which | |
602 | usually contains something like @code{("." "./src")}. No more than | |
603 | @code{flymake-master-file-count-limit} entries is added to the master file | |
604 | list. The list is then sorted to move files with names @code{file.cpp} to | |
605 | the top. | |
606 | ||
607 | Next, each master file in a list is checked to contain the appropriate | |
608 | include directives. No more than @code{flymake-check-file-limit} of each | |
609 | file are parsed. | |
610 | ||
611 | For @code{file.h}, the include directives to look for are | |
612 | @code{#include "file.h"}, @code{#include "../file.h"}, etc. Each | |
613 | include is checked against a list of include directories | |
614 | (see @ref{Getting the include directories}) to be sure it points to the | |
615 | correct @code{file.h}. | |
616 | ||
617 | First matching master file found stops the search. The master file is then | |
618 | patched and saved to disk. In case no master file is found, syntax check is | |
619 | aborted, and corresponding status (!) is reported in the mode line. | |
620 | ||
621 | @node Getting the include directories | |
622 | @section Getting the include directories | |
623 | @cindex Include directories (C/C++ specific) | |
624 | ||
625 | Two sets of include directories are distinguished: system include directories | |
626 | and project include directories. The former is just the contents of the | |
627 | @code{INCLUDE} environment variable. The latter is not so easy to obtain, | |
628 | and the way it can be obtained can vary greatly for different projects. | |
629 | Therefore, a customizable variable | |
630 | @code{flymake-get-project-include-dirs-function} is used to provide the | |
3d80e1a2 | 631 | way to implement the desired behavior. |
4bcbcb9d EZ |
632 | |
633 | The default implementation, @code{flymake-get-project-include-dirs-imp}, | |
634 | uses a @code{make} call. This requires a correct base directory, that is, a | |
635 | directory containing a correct @code{Makefile}, to be determined. | |
636 | ||
637 | As obtaining the project include directories might be a costly operation, its | |
638 | return value is cached in the hash table. The cache is cleared in the beginning | |
639 | of every syntax check attempt. | |
640 | ||
641 | @node Locating the buildfile | |
642 | @section Locating the buildfile | |
643 | @cindex Locating the buildfile | |
644 | @cindex buildfile, locating | |
645 | @cindex Makefile, locating | |
646 | ||
647 | Flymake can be configured to use different tools for performing syntax | |
648 | checks. For example, it can use direct compiler call to syntax check a perl | |
649 | script or a call to @code{make} for a more complicated case of a | |
3d80e1a2 | 650 | @code{C/C++} source. The general idea is that simple files, like perl |
4bcbcb9d EZ |
651 | scripts and html pages, can be checked by directly invoking a |
652 | corresponding tool. Files that are usually more complex and generally | |
653 | used as part of larger projects, might require non-trivial options to | |
654 | be passed to the syntax check tool, like include directories for | |
655 | C++. The latter files are syntax checked using some build tool, like | |
656 | @code{make} or @code{Ant}. | |
657 | ||
658 | All @code{make} configuration data is usually stored in a file called | |
659 | @code{Makefile}. To allow for future extensions, flymake uses a notion of | |
660 | buildfile to reference the 'project configuration' file. | |
661 | ||
662 | Special function, @code{flymake-find-buildfile} is provided for locating buildfiles. | |
663 | Searching for a buildfile is done in a manner similar to that of searching | |
664 | for possible master files. A customizable variable | |
665 | @code{flymake-buildfile-dirs} holds a list of relative paths to the | |
666 | buildfile. They are checked sequentially until a buildfile is found. In case | |
667 | there's no build file, syntax check is aborted. | |
668 | ||
669 | Buildfile values are also cached. | |
670 | ||
671 | @node Starting the syntax check process | |
672 | @section Starting the syntax check process | |
673 | @cindex Syntax check process | |
674 | ||
675 | The command line (command name and the list of arguments) for launching a process is returned by the | |
676 | initialization function. Flymake then just calls @code{start-process} | |
677 | to start an asynchronous process and configures process filter and | |
678 | sentinel which is used for processing the output of the syntax check | |
679 | tool. | |
680 | ||
681 | @node Parsing the output | |
682 | @section Parsing the output | |
683 | @cindex Parsing the output | |
684 | ||
685 | The output generated by the syntax check tool is parsed in the process | |
686 | filter/sentinel using the error message patterns stored in the | |
687 | @code{flymake-err-line-patterns} variable. This variable contains a | |
688 | list of items of the form @code{(regexp file-idx line-idx | |
689 | err-text-idx)}, used to determine whether a particular line is an | |
690 | error message and extract file name, line number and error text, | |
691 | respectively. Error type (error/warning) is also guessed by matching | |
692 | error text with the '@code{^[wW]arning}' pattern. Anything that was not | |
693 | classified as a warning is considered an error. Type is then used to | |
694 | sort error menu items, which shows error messages first. | |
695 | ||
696 | Flymake is also able to interpret error message patterns missing err-text-idx | |
697 | information. This is done by merely taking the rest of the matched line | |
698 | (@code{(substring line (match-end 0))}) as error text. This trick allows | |
699 | to make use of a huge collection of error message line patterns from | |
700 | @code{compile.el}. All these error patterns are appended to | |
701 | the end of @code{flymake-err-line-patterns}. | |
702 | ||
703 | The error information obtained is saved in a buffer local | |
704 | variable. The buffer for which the process output belongs is | |
705 | determined from the process-id@w{}->@w{}buffer mapping updated | |
706 | after every process launch/exit. | |
707 | ||
708 | @node Highlighting erroneous lines | |
709 | @section Highlighting erroneous lines | |
710 | @cindex Erroneous lines, faces | |
711 | ||
712 | Highlighting is implemented with overlays and happens in the process | |
713 | sentinel, after calling the cleanup function. Two customizable faces | |
714 | are used: @code{flymake-errline-face} and | |
715 | @code{flymake-warnline-face}. Errors belonging outside the current | |
716 | buffer are considered to belong to line 1 of the current buffer. | |
717 | ||
718 | @node Interaction with other modes | |
719 | @section Interaction with other modes | |
720 | @cindex Interaction with other modes | |
721 | @cindex Interaction with compile mode | |
722 | ||
723 | The only mode flymake currently knows about is @code{compile}. | |
724 | ||
725 | Flymake can be configured to not start syntax check if it thinks the | |
726 | compilation is in progress. The check is made by the | |
727 | @code{flymake-compilation-is-running}, which tests the | |
728 | @code{compilation-in-progress} variable. The reason why this might be | |
729 | useful is saving CPU time in case both syntax check and compilation | |
730 | are very CPU intensive. The original reason for adding this feature, | |
731 | though, was working around a locking problem with MS Visual C++ compiler. | |
732 | ||
733 | Flymake also provides an alternative command for starting compilation, | |
734 | @code{flymake-compile}: | |
735 | ||
736 | @lisp | |
93261462 TTN |
737 | (defun flymake-compile () |
738 | "Kill all flymake syntax checks then start compilation." | |
739 | (interactive) | |
740 | (flymake-stop-all-syntax-checks) | |
741 | (call-interactively 'compile)) | |
4bcbcb9d EZ |
742 | @end lisp |
743 | ||
744 | It just kills all the active syntax check processes before calling | |
745 | @code{compile}. | |
746 | ||
747 | @node Index | |
748 | @unnumbered Index | |
749 | ||
750 | @printindex cp | |
751 | ||
752 | @bye | |
8ad27ccc MB |
753 | |
754 | @ignore | |
755 | arch-tag: 9f0db077-5598-49ab-90b9-8df9248a63ec | |
756 | @end ignore |