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1 | \input texinfo @c -*-texinfo-*- |
2 | @comment %**start of header | |
db78a8cb | 3 | @setfilename ../../info/flymake |
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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 | ||
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14 | Copyright @copyright{} 2004, 2005, 2006, 2007, 2008 Free Software |
15 | Foundation, Inc. | |
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16 | |
17 | @quotation | |
18 | Permission is granted to copy, distribute and/or modify this document | |
6a2c4aec | 19 | under the terms of the GNU Free Documentation License, Version 1.3 or |
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20 | any later version published by the Free Software Foundation; with no |
21 | Invariant Sections, with the Front-Cover texts being ``A GNU Manual,'' | |
22 | and with the Back-Cover Texts as in (a) below. A copy of the license | |
debf4439 | 23 | is included in the section entitled ``GNU Free Documentation License''. |
4009494e | 24 | |
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25 | (a) The FSF's Back-Cover Text is: ``You have the freedom to copy and |
26 | modify this GNU manual. Buying copies from the FSF supports it in | |
27 | developing GNU and promoting software freedom.'' | |
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28 | @end quotation |
29 | @end copying | |
30 | ||
31 | @dircategory Emacs | |
32 | @direntry | |
33 | * Flymake: (flymake). A universal on-the-fly syntax checker. | |
34 | @end direntry | |
35 | ||
36 | @titlepage | |
37 | @title GNU Flymake | |
38 | @subtitle for version @value{VERSION}, @value{UPDATED} | |
39 | @author Pavel Kobiakov(@email{pk_at_work@@yahoo.com}) | |
40 | @page | |
41 | @vskip 0pt plus 1filll | |
42 | @insertcopying | |
43 | @end titlepage | |
44 | ||
45 | @contents | |
46 | ||
47 | @ifnottex | |
48 | @node Top | |
49 | @top GNU Flymake | |
50 | @end ifnottex | |
51 | ||
52 | @menu | |
53 | * Overview of Flymake:: | |
54 | * Installing Flymake:: | |
55 | * Using Flymake:: | |
56 | * Configuring Flymake:: | |
57 | * Flymake Implementation:: | |
58 | * GNU Free Documentation License:: | |
59 | * Index:: | |
60 | @end menu | |
61 | ||
62 | @node Overview of Flymake | |
63 | @chapter Overview | |
64 | @cindex Overview of Flymake | |
65 | ||
66 | Flymake is a universal on-the-fly syntax checker implemented as an | |
67 | Emacs minor mode. Flymake runs the pre-configured syntax check tool | |
68 | (compiler for C++ files, @code{perl} for perl files, etc.) in the | |
69 | background, passing it a temporary copy of the current buffer, and | |
70 | parses the output for known error/warning message patterns. Flymake | |
71 | then highlights erroneous lines (i.e. lines for which at least one | |
72 | error or warning has been reported by the syntax check tool), and | |
73 | displays an overall buffer status in the mode line. Status information | |
74 | displayed by Flymake contains total number of errors and warnings | |
75 | reported for the buffer during the last syntax check. | |
76 | ||
77 | @code{flymake-goto-next-error} and @code{flymake-goto-prev-error} | |
78 | functions allow for easy navigation to the next/previous erroneous | |
79 | line, respectively. | |
80 | ||
81 | Calling @code{flymake-display-err-menu-for-current-line} will popup a | |
82 | menu containing error messages reported by the syntax check tool for | |
83 | the current line. Errors/warnings belonging to another file, such as a | |
84 | @code{.h} header file included by a @code{.c} file, are shown in the | |
85 | current buffer as belonging to the first line. Menu items for such | |
86 | messages also contain a filename and a line number. Selecting such a | |
87 | menu item will automatically open the file and jump to the line with | |
88 | error. | |
89 | ||
90 | Syntax check is done 'on-the-fly'. It is started whenever | |
91 | ||
92 | @itemize @bullet | |
93 | @item buffer is loaded | |
94 | @item a newline character is added to the buffer | |
95 | @item some changes were made to the buffer more than @code{0.5} seconds ago (the | |
96 | delay is configurable). | |
97 | @end itemize | |
98 | ||
99 | Flymake is a universal syntax checker in the sense that it's easily | |
100 | extended to support new syntax check tools and error message | |
101 | patterns. @xref{Configuring Flymake}. | |
102 | ||
103 | @node Installing Flymake | |
104 | @chapter Installing | |
105 | @cindex Installing Flymake | |
106 | ||
107 | ||
108 | Flymake is packaged in a single file, @code{flymake.el}. | |
109 | ||
110 | To install/update Flymake, place @code{flymake.el} to a directory | |
111 | somewhere on Emacs load path. You might also want to byte-compile | |
112 | @code{flymake.el} to improve performance. | |
113 | ||
114 | Also, place the following line in the @code{.emacs} file. | |
115 | ||
116 | @lisp | |
117 | (require 'flymake) | |
118 | @end lisp | |
119 | ||
120 | You might also map the most frequently used Flymake functions, such as | |
121 | @code{flymake-goto-next-error}, to some keyboard shortcuts: | |
122 | ||
123 | @lisp | |
124 | (global-set-key [f3] 'flymake-display-err-menu-for-current-line) | |
125 | (global-set-key [f4] 'flymake-goto-next-error) | |
126 | @end lisp | |
127 | ||
128 | @node Using Flymake | |
129 | @chapter Using Flymake | |
130 | @cindex Using Flymake | |
131 | ||
132 | @menu | |
133 | * Flymake mode:: | |
134 | * Running the syntax check:: | |
135 | * Navigating to error lines:: | |
136 | * Viewing error messages:: | |
137 | * Syntax check statuses:: | |
138 | * Troubleshooting:: | |
139 | @end menu | |
140 | ||
141 | @node Flymake mode | |
142 | @section Flymake mode | |
143 | @cindex flymake-mode | |
144 | ||
145 | Flymake is an Emacs minor mode. To use Flymake, you | |
146 | must first activate @code{flymake-mode} by using the | |
147 | @code{flymake-mode} function. | |
148 | ||
149 | Instead of manually activating @code{flymake-mode}, you can configure | |
150 | Flymake to automatically enable @code{flymake-mode} upon opening any | |
151 | file for which syntax check is possible. To do so, place the following | |
152 | line in @code{.emacs}: | |
153 | ||
154 | @lisp | |
155 | (add-hook 'find-file-hook 'flymake-find-file-hook) | |
156 | @end lisp | |
157 | ||
158 | @node Running the syntax check | |
159 | @section Running the syntax check | |
160 | @cindex Manually starting the syntax check | |
161 | ||
162 | When @code{flymake-mode} is active, syntax check is started | |
163 | automatically on any of the three conditions mentioned above. Syntax | |
164 | check can also be started manually by using the | |
165 | @code{flymake-start-syntax-check-for-current-buffer} function. This | |
166 | can be used, for example, when changes were made to some other buffer | |
167 | affecting the current buffer. | |
168 | ||
169 | @node Navigating to error lines | |
170 | @section Navigating to error lines | |
171 | @cindex Navigating to error lines | |
172 | ||
173 | After syntax check is completed, lines for which at least one error or | |
174 | warning has been reported are highlighted, and total number of errors | |
175 | and warning is shown in the mode line. Use the following functions to | |
176 | navigate the highlighted lines. | |
177 | ||
178 | @multitable @columnfractions 0.25 0.75 | |
179 | ||
180 | @item @code{flymake-goto-next-error} | |
181 | @tab Moves point to the next erroneous line, if any. | |
182 | ||
183 | @item @code{flymake-goto-prev-error} | |
184 | @tab Moves point to the previous erroneous line. | |
185 | ||
186 | @end multitable | |
187 | ||
188 | These functions treat erroneous lines as a linked list. Therefore, | |
189 | @code{flymake-goto-next-error} will go to the first erroneous line | |
190 | when invoked in the end of the buffer. | |
191 | ||
192 | @node Viewing error messages | |
193 | @section Viewing error messages | |
194 | @cindex Viewing error messages | |
195 | ||
196 | To view error messages belonging to the current line, use the | |
197 | @code{flymake-display-err-menu-for-current-line} function. If there's | |
198 | at least one error or warning reported for the current line, this | |
199 | function will display a popup menu with error/warning texts. | |
200 | Selecting the menu item whose error belongs to another file brings | |
201 | forward that file with the help of the | |
202 | @code{flymake-goto-file-and-line} function. | |
203 | ||
204 | @node Syntax check statuses | |
205 | @section Syntax check statuses | |
206 | @cindex Syntax check statuses | |
207 | ||
208 | After syntax check is finished, its status is displayed in the mode line. | |
209 | The following statuses are defined. | |
210 | ||
211 | @multitable @columnfractions 0.25 0.75 | |
212 | @item Flymake* or Flymake:E/W* | |
213 | @tab Flymake is currently running. For the second case, E/W contains the | |
214 | error and warning count for the previous run. | |
215 | ||
216 | @item Flymake | |
217 | @tab Syntax check is not running. Usually this means syntax check was | |
218 | successfully passed (no errors, no warnings). Other possibilities are: | |
219 | syntax check was killed as a result of executing | |
220 | @code{flymake-compile}, or syntax check cannot start as compilation | |
221 | is currently in progress. | |
222 | ||
223 | @item Flymake:E/W | |
224 | @tab Number of errors/warnings found by the syntax check process. | |
225 | ||
226 | @item Flymake:! | |
227 | @tab Flymake was unable to find master file for the current buffer. | |
228 | @end multitable | |
229 | ||
230 | The following errors cause a warning message and switch flymake mode | |
231 | OFF for the buffer. | |
232 | ||
233 | @multitable @columnfractions 0.25 0.75 | |
234 | @item CFGERR | |
235 | @tab Syntax check process returned nonzero exit code, but no | |
236 | errors/warnings were reported. This indicates a possible configuration | |
237 | error (for example, no suitable error message patterns for the | |
238 | syntax check tool). | |
239 | ||
240 | @item NOMASTER | |
241 | @tab Flymake was unable to find master file for the current buffer. | |
242 | ||
243 | @item NOMK | |
244 | @tab Flymake was unable to find a suitable buildfile for the current buffer. | |
245 | ||
246 | @item PROCERR | |
247 | @tab Flymake was unable to launch a syntax check process. | |
248 | @end multitable | |
249 | ||
250 | ||
251 | @node Troubleshooting | |
252 | @section Troubleshooting | |
253 | @cindex Logging | |
254 | @cindex Troubleshooting | |
255 | ||
256 | Flymake uses a simple logging facility for indicating important points | |
257 | in the control flow. The logging facility sends logging messages to | |
258 | the @code{*Messages*} buffer. The information logged can be used for | |
259 | resolving various problems related to Flymake. | |
260 | ||
261 | Logging output is controlled by the @code{flymake-log-level} | |
262 | variable. @code{3} is the most verbose level, and @code{-1} switches | |
263 | logging off. | |
264 | ||
265 | @node Configuring Flymake | |
266 | @chapter Configuring and Extending Flymake | |
267 | @cindex Configuring and Extending Flymake | |
268 | ||
269 | @menu | |
270 | * Customizable variables:: | |
271 | * Adding support for a new syntax check tool:: | |
272 | @end menu | |
273 | ||
274 | Flymake was designed to be easily extended for supporting new syntax | |
275 | check tools and error message patterns. | |
276 | ||
277 | @node Customizable variables | |
278 | @section Customizable variables | |
279 | @cindex Customizable variables | |
280 | ||
281 | This section summarizes variables used for Flymake | |
282 | configuration. | |
283 | ||
284 | @table @code | |
285 | @item flymake-log-level | |
286 | Controls logging output, see @ref{Troubleshooting}. | |
287 | ||
288 | @item flymake-allowed-file-name-masks | |
289 | A list of @code{(filename-regexp, init-function, cleanup-function | |
290 | getfname-function)} for configuring syntax check tools. @xref{Adding | |
291 | support for a new syntax check tool}. | |
292 | ||
293 | @item flymake-buildfile-dirs | |
294 | A list of directories (relative paths) for searching a | |
295 | buildfile. @xref{Locating the buildfile}. | |
296 | ||
297 | @item flymake-master-file-dirs | |
298 | A list of directories for searching a master file. @xref{Locating a | |
299 | master file}. | |
300 | ||
301 | @item flymake-get-project-include-dirs-function | |
302 | A function used for obtaining a list of project include dirs (C/C++ | |
303 | specific). @xref{Getting the include directories}. | |
304 | ||
305 | @item flymake-master-file-count-limit | |
306 | @itemx flymake-check-file-limit | |
307 | Used when looking for a master file. @xref{Locating a master file}. | |
308 | ||
309 | @item flymake-err-line-patterns | |
310 | Patterns for error/warning messages in the form @code{(regexp file-idx | |
176c6903 | 311 | line-idx col-idx err-text-idx)}. @xref{Parsing the output}. |
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312 | |
313 | @item flymake-compilation-prevents-syntax-check | |
314 | A flag indicating whether compilation and syntax check of the same | |
315 | file cannot be run simultaneously. | |
316 | ||
317 | @item flymake-no-changes-timeout | |
318 | If any changes are made to the buffer, syntax check is automatically | |
319 | started after @code{flymake-no-changes-timeout} seconds. | |
320 | ||
321 | @item flymake-gui-warnings-enabled | |
322 | A boolean flag indicating whether Flymake will show message boxes for | |
323 | non-recoverable errors. If @code{flymake-gui-warnings-enabled} is | |
324 | @code{nil}, these errors will only be logged to the @code{*Messages*} | |
325 | buffer. | |
326 | ||
327 | @item flymake-start-syntax-check-on-newline | |
328 | A boolean flag indicating whether to start syntax check after a | |
329 | newline character is added to the buffer. | |
330 | ||
176c6903 | 331 | @item flymake-errline |
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332 | A custom face for highlighting lines for which at least one error has |
333 | been reported. | |
334 | ||
176c6903 | 335 | @item flymake-warnline |
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336 | A custom face for highlighting lines for which at least one warning |
337 | and no errors have been reported. | |
338 | ||
339 | @end table | |
340 | ||
341 | @node Adding support for a new syntax check tool | |
342 | @section Adding support for a new syntax check tool | |
343 | @cindex Adding support for a new syntax check tool | |
344 | ||
345 | @menu | |
346 | * Example -- Configuring a tool called directly:: | |
347 | * Example -- Configuring a tool called via make:: | |
348 | @end menu | |
349 | ||
350 | Syntax check tools are configured using the | |
351 | @code{flymake-allowed-file-name-masks} list. Each item of this list | |
352 | has the following format: | |
353 | ||
354 | @lisp | |
355 | (filename-regexp, init-function, cleanup-function, getfname-function) | |
356 | @end lisp | |
357 | ||
358 | @table @code | |
359 | @item filename-regexp | |
360 | This field is used as a key for locating init/cleanup/getfname | |
361 | functions for the buffer. Items in | |
362 | @code{flymake-allowed-file-name-masks} are searched sequentially. The | |
363 | first item with @code{filename-regexp} matching buffer filename is | |
364 | selected. If no match is found, @code{flymake-mode} is switched off. | |
365 | ||
366 | @item init-function | |
367 | @code{init-function} is required to initialize the syntax check, | |
368 | usually by creating a temporary copy of the buffer contents. The | |
369 | function must return @code{(list cmd-name arg-list)}. If | |
370 | @code{init-function} returns null, syntax check is aborted, by | |
371 | @code{flymake-mode} is not switched off. | |
372 | ||
373 | @item cleanup-function | |
374 | @code{cleanup-function} is called after the syntax check process is | |
375 | complete and should take care of proper deinitialization, which is | |
376 | usually deleting a temporary copy created by the @code{init-function}. | |
377 | ||
378 | @item getfname-function | |
379 | This function is used for translating filenames reported by the syntax | |
380 | check tool into ``real'' filenames. Filenames reported by the tool | |
381 | will be different from the real ones, as actually the tool works with | |
382 | the temporary copy. In most cases, the default implementation | |
383 | provided by Flymake, @code{flymake-get-real-file-name}, can be used as | |
384 | @code{getfname-function}. | |
385 | ||
386 | @end table | |
387 | ||
388 | To add support for a new syntax check tool, write corresponding | |
389 | @code{init-function}, and, optionally @code{cleanup-function} and | |
390 | @code{getfname-function}. If the format of error messages reported by | |
391 | the new tool is not yet supported by Flymake, add a new entry to | |
392 | the @code{flymake-err-line-patterns} list. | |
393 | ||
394 | The following sections contain some examples of configuring Flymake | |
395 | support for various syntax check tools. | |
396 | ||
397 | @node Example -- Configuring a tool called directly | |
398 | @subsection Example -- Configuring a tool called directly | |
399 | @cindex Adding support for perl | |
400 | ||
401 | In this example, we will add support for @code{perl} as a syntax check | |
402 | tool. @code{perl} supports the @code{-c} option which does syntax | |
403 | checking. | |
404 | ||
405 | First, we write the @code{init-function}: | |
406 | ||
407 | @lisp | |
176c6903 | 408 | (defun flymake-perl-init () |
4009494e | 409 | (let* ((temp-file (flymake-init-create-temp-buffer-copy |
176c6903 | 410 | 'flymake-create-temp-inplace)) |
5ef5ef3f RS |
411 | (local-file (file-relative-name |
412 | temp-file | |
413 | (file-name-directory buffer-file-name)))) | |
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414 | (list "perl" (list "-wc " local-file)))) |
415 | @end lisp | |
416 | ||
417 | @code{flymake-perl-init} creates a temporary copy of the buffer | |
418 | contents with the help of | |
419 | @code{flymake-init-create-temp-buffer-copy}, and builds an appropriate | |
420 | command line. | |
421 | ||
422 | Next, we add a new entry to the | |
423 | @code{flymake-allowed-file-name-masks}: | |
424 | ||
425 | @lisp | |
426 | (setq flymake-allowed-file-name-masks | |
427 | (cons '(".+\\.pl$" | |
428 | flymake-perl-init | |
429 | flymake-simple-cleanup | |
430 | flymake-get-real-file-name) | |
431 | flymake-allowed-file-name-masks)) | |
432 | @end lisp | |
433 | ||
434 | Note that we use standard @code{cleanup-function} and | |
435 | @code{getfname-function}. | |
436 | ||
437 | Finally, we add an entry to @code{flymake-err-line-patterns}: | |
438 | ||
439 | @lisp | |
440 | (setq flymake-err-line-patterns | |
441 | (cons '("\\(.*\\) at \\([^ \n]+\\) line \\([0-9]+\\)[,.\n]" | |
442 | 2 3 nil 1) | |
443 | flymake-err-line-patterns)) | |
444 | @end lisp | |
445 | ||
446 | @node Example -- Configuring a tool called via make | |
447 | @subsection Example -- Configuring a tool called via make | |
448 | @cindex Adding support for C (gcc+make) | |
449 | ||
450 | In this example we will add support for C files syntax checked by | |
451 | @code{gcc} called via @code{make}. | |
452 | ||
453 | We're not required to write any new functions, as Flymake already has | |
454 | functions for @code{make}. We just add a new entry to the | |
455 | @code{flymake-allowed-file-name-masks}: | |
456 | ||
457 | @lisp | |
458 | (setq flymake-allowed-file-name-masks | |
459 | (cons '(".+\\.c$" | |
460 | flymake-simple-make-init | |
461 | flymake-simple-cleanup | |
462 | flymake-get-real-file-name) | |
463 | flymake-allowed-file-name-masks)) | |
464 | @end lisp | |
465 | ||
466 | @code{flymake-simple-make-init} builds the following @code{make} | |
467 | command line: | |
468 | ||
469 | @lisp | |
470 | (list "make" | |
471 | (list "-s" "-C" | |
472 | base-dir | |
473 | (concat "CHK_SOURCES=" source) | |
474 | "SYNTAX_CHECK_MODE=1" | |
475 | "check-syntax")) | |
476 | @end lisp | |
477 | ||
478 | @code{base-dir} is a directory containing @code{Makefile}, see @ref{Locating the buildfile}. | |
479 | ||
480 | Thus, @code{Makefile} must contain the @code{check-syntax} target. In | |
481 | our case this target might look like this: | |
482 | ||
483 | @verbatim | |
484 | check-syntax: | |
485 | gcc -o nul -S ${CHK_SOURCES} | |
486 | @end verbatim | |
487 | ||
488 | The format of error messages reported by @code{gcc} is already | |
489 | supported by Flymake, so we don't have to add a new entry to | |
490 | @code{flymake-err-line-patterns}. | |
491 | ||
492 | @node Flymake Implementation | |
493 | @chapter Flymake Implementation | |
494 | @cindex Implementation details | |
495 | ||
496 | @menu | |
497 | * Determining whether syntax check is possible:: | |
498 | * Making a temporary copy:: | |
499 | * Locating a master file:: | |
500 | * Getting the include directories:: | |
501 | * Locating the buildfile:: | |
502 | * Starting the syntax check process:: | |
503 | * Parsing the output:: | |
504 | * Highlighting erroneous lines:: | |
505 | * Interaction with other modes:: | |
506 | @end menu | |
507 | ||
508 | Syntax check is started by calling @code{flymake-start-syntax-check-for-current-buffer}. | |
509 | Flymake first determines whether it is able to do syntax | |
510 | check. It then saves a copy of the buffer in a temporary file in the | |
511 | buffer's directory (or in the system temp directory -- for java | |
512 | files), creates a syntax check command and launches a process with | |
513 | this command. The output is parsed using a list of error message patterns, | |
514 | and error information (file name, line number, type and text) is | |
515 | saved. After the process has finished, Flymake highlights erroneous | |
516 | lines in the buffer using the accumulated error information. | |
517 | ||
518 | @node Determining whether syntax check is possible | |
519 | @section Determining whether syntax check is possible | |
520 | @cindex Syntax check models | |
521 | @cindex Master file | |
522 | ||
523 | Syntax check is considered possible if there's an entry in | |
524 | @code{flymake-allowed-file-name-masks} matching buffer's filename and | |
525 | its @code{init-function} returns non-@code{nil} value. | |
526 | ||
527 | Two syntax check modes are distinguished: | |
528 | ||
529 | @enumerate | |
530 | ||
531 | @item | |
532 | Buffer can be syntax checked in a standalone fashion, that is, the | |
533 | file (its temporary copy, in fact) can be passed over to the compiler to | |
534 | do the syntax check. Examples are C/C++ (.c, .cpp) and Java (.java) | |
535 | sources. | |
536 | ||
537 | @item | |
538 | Buffer can be syntax checked, but additional file, called master file, | |
539 | is required to perform this operation. A master file is a file that | |
540 | includes the current file, so that running a syntax check tool on it | |
541 | will also check syntax in the current file. Examples are C/C++ (.h, | |
542 | .hpp) headers. | |
543 | ||
544 | @end enumerate | |
545 | ||
546 | These modes are handled inside init/cleanup/getfname functions, see | |
547 | @ref{Adding support for a new syntax check tool}. | |
548 | ||
549 | Flymake contains implementations of all functionality required to | |
550 | support different syntax check modes described above (making | |
551 | temporary copies, finding master files, etc.), as well as some | |
552 | tool-specific (routines for @code{make}, @code{Ant}, etc.) code. | |
553 | ||
554 | ||
555 | @node Making a temporary copy | |
556 | @section Making a temporary copy | |
557 | @cindex Temporary copy of the buffer | |
558 | @cindex Master file | |
559 | ||
560 | After the possibility of the syntax check has been determined, a | |
561 | temporary copy of the current buffer is made so that the most recent | |
562 | unsaved changes could be seen by the syntax check tool. Making a copy | |
563 | is quite straightforward in a standalone case (mode @code{1}), as it's | |
564 | just saving buffer contents to a temporary file. | |
565 | ||
566 | Things get trickier, however, when master file is involved, as it | |
567 | requires to | |
568 | ||
569 | @itemize @bullet | |
570 | @item locate a master file | |
571 | @item patch it to include the current file using its new (temporary) | |
572 | name. | |
573 | @end itemize | |
574 | ||
575 | Locating a master file is discussed in the following section. | |
576 | ||
577 | Patching just changes all appropriate lines of the master file so that they | |
578 | use the new (temporary) name of the current file. For example, suppose current | |
579 | file name is @code{file.h}, the master file is @code{file.cpp}, and | |
580 | it includes current file via @code{#include "file.h"}. Current file's copy | |
581 | is saved to file @code{file_flymake.h}, so the include line must be | |
582 | changed to @code{#include "file_flymake.h"}. Finally, patched master file | |
583 | is saved to @code{file_flymake_master.cpp}, and the last one is passed to | |
584 | the syntax check tool. | |
585 | ||
586 | @node Locating a master file | |
587 | @section Locating a master file | |
588 | @cindex Master file | |
589 | ||
590 | Master file is located in two steps. | |
591 | ||
592 | First, a list of possible master files is built. A simple name | |
593 | matching is used to find the files. For a C++ header @code{file.h}, | |
594 | Flymake searches for all @code{.cpp} files in the directories whose relative paths are | |
595 | stored in a customizable variable @code{flymake-master-file-dirs}, which | |
596 | usually contains something like @code{("." "./src")}. No more than | |
597 | @code{flymake-master-file-count-limit} entries is added to the master file | |
598 | list. The list is then sorted to move files with names @code{file.cpp} to | |
599 | the top. | |
600 | ||
601 | Next, each master file in a list is checked to contain the appropriate | |
602 | include directives. No more than @code{flymake-check-file-limit} of each | |
603 | file are parsed. | |
604 | ||
605 | For @code{file.h}, the include directives to look for are | |
606 | @code{#include "file.h"}, @code{#include "../file.h"}, etc. Each | |
607 | include is checked against a list of include directories | |
608 | (see @ref{Getting the include directories}) to be sure it points to the | |
609 | correct @code{file.h}. | |
610 | ||
611 | First matching master file found stops the search. The master file is then | |
612 | patched and saved to disk. In case no master file is found, syntax check is | |
613 | aborted, and corresponding status (!) is reported in the mode line. | |
614 | ||
615 | @node Getting the include directories | |
616 | @section Getting the include directories | |
617 | @cindex Include directories (C/C++ specific) | |
618 | ||
619 | Two sets of include directories are distinguished: system include directories | |
620 | and project include directories. The former is just the contents of the | |
621 | @code{INCLUDE} environment variable. The latter is not so easy to obtain, | |
622 | and the way it can be obtained can vary greatly for different projects. | |
623 | Therefore, a customizable variable | |
624 | @code{flymake-get-project-include-dirs-function} is used to provide the | |
625 | way to implement the desired behavior. | |
626 | ||
627 | The default implementation, @code{flymake-get-project-include-dirs-imp}, | |
628 | uses a @code{make} call. This requires a correct base directory, that is, a | |
629 | directory containing a correct @code{Makefile}, to be determined. | |
630 | ||
631 | As obtaining the project include directories might be a costly operation, its | |
632 | return value is cached in the hash table. The cache is cleared in the beginning | |
633 | of every syntax check attempt. | |
634 | ||
635 | @node Locating the buildfile | |
636 | @section Locating the buildfile | |
637 | @cindex Locating the buildfile | |
638 | @cindex buildfile, locating | |
639 | @cindex Makefile, locating | |
640 | ||
641 | Flymake can be configured to use different tools for performing syntax | |
642 | checks. For example, it can use direct compiler call to syntax check a perl | |
643 | script or a call to @code{make} for a more complicated case of a | |
644 | @code{C/C++} source. The general idea is that simple files, like perl | |
645 | scripts and html pages, can be checked by directly invoking a | |
646 | corresponding tool. Files that are usually more complex and generally | |
647 | used as part of larger projects, might require non-trivial options to | |
648 | be passed to the syntax check tool, like include directories for | |
649 | C++. The latter files are syntax checked using some build tool, like | |
650 | @code{make} or @code{Ant}. | |
651 | ||
652 | All @code{make} configuration data is usually stored in a file called | |
653 | @code{Makefile}. To allow for future extensions, flymake uses a notion of | |
654 | buildfile to reference the 'project configuration' file. | |
655 | ||
656 | Special function, @code{flymake-find-buildfile} is provided for locating buildfiles. | |
657 | Searching for a buildfile is done in a manner similar to that of searching | |
658 | for possible master files. A customizable variable | |
659 | @code{flymake-buildfile-dirs} holds a list of relative paths to the | |
660 | buildfile. They are checked sequentially until a buildfile is found. In case | |
661 | there's no build file, syntax check is aborted. | |
662 | ||
663 | Buildfile values are also cached. | |
664 | ||
665 | @node Starting the syntax check process | |
666 | @section Starting the syntax check process | |
667 | @cindex Syntax check process | |
668 | ||
669 | The command line (command name and the list of arguments) for launching a process is returned by the | |
670 | initialization function. Flymake then just calls @code{start-process} | |
671 | to start an asynchronous process and configures process filter and | |
672 | sentinel which is used for processing the output of the syntax check | |
673 | tool. | |
674 | ||
675 | @node Parsing the output | |
676 | @section Parsing the output | |
677 | @cindex Parsing the output | |
678 | ||
679 | The output generated by the syntax check tool is parsed in the process | |
680 | filter/sentinel using the error message patterns stored in the | |
681 | @code{flymake-err-line-patterns} variable. This variable contains a | |
682 | list of items of the form @code{(regexp file-idx line-idx | |
683 | err-text-idx)}, used to determine whether a particular line is an | |
684 | error message and extract file name, line number and error text, | |
685 | respectively. Error type (error/warning) is also guessed by matching | |
686 | error text with the '@code{^[wW]arning}' pattern. Anything that was not | |
687 | classified as a warning is considered an error. Type is then used to | |
688 | sort error menu items, which shows error messages first. | |
689 | ||
690 | Flymake is also able to interpret error message patterns missing err-text-idx | |
691 | information. This is done by merely taking the rest of the matched line | |
692 | (@code{(substring line (match-end 0))}) as error text. This trick allows | |
693 | to make use of a huge collection of error message line patterns from | |
694 | @code{compile.el}. All these error patterns are appended to | |
695 | the end of @code{flymake-err-line-patterns}. | |
696 | ||
697 | The error information obtained is saved in a buffer local | |
698 | variable. The buffer for which the process output belongs is | |
699 | determined from the process-id@w{}->@w{}buffer mapping updated | |
700 | after every process launch/exit. | |
701 | ||
702 | @node Highlighting erroneous lines | |
703 | @section Highlighting erroneous lines | |
704 | @cindex Erroneous lines, faces | |
705 | ||
706 | Highlighting is implemented with overlays and happens in the process | |
707 | sentinel, after calling the cleanup function. Two customizable faces | |
176c6903 RS |
708 | are used: @code{flymake-errline} and |
709 | @code{flymake-warnline}. Errors belonging outside the current | |
4009494e GM |
710 | buffer are considered to belong to line 1 of the current buffer. |
711 | ||
712 | @node Interaction with other modes | |
713 | @section Interaction with other modes | |
714 | @cindex Interaction with other modes | |
715 | @cindex Interaction with compile mode | |
716 | ||
717 | The only mode flymake currently knows about is @code{compile}. | |
718 | ||
719 | Flymake can be configured to not start syntax check if it thinks the | |
720 | compilation is in progress. The check is made by the | |
721 | @code{flymake-compilation-is-running}, which tests the | |
722 | @code{compilation-in-progress} variable. The reason why this might be | |
723 | useful is saving CPU time in case both syntax check and compilation | |
724 | are very CPU intensive. The original reason for adding this feature, | |
725 | though, was working around a locking problem with MS Visual C++ compiler. | |
726 | ||
727 | Flymake also provides an alternative command for starting compilation, | |
728 | @code{flymake-compile}: | |
729 | ||
730 | @lisp | |
731 | (defun flymake-compile () | |
732 | "Kill all flymake syntax checks then start compilation." | |
733 | (interactive) | |
734 | (flymake-stop-all-syntax-checks) | |
735 | (call-interactively 'compile)) | |
736 | @end lisp | |
737 | ||
738 | It just kills all the active syntax check processes before calling | |
739 | @code{compile}. | |
740 | ||
741 | @node GNU Free Documentation License | |
742 | @appendix GNU Free Documentation License | |
743 | @include doclicense.texi | |
744 | ||
745 | @node Index | |
746 | @unnumbered Index | |
747 | ||
748 | @printindex cp | |
749 | ||
750 | @bye | |
751 | ||
752 | @ignore | |
753 | arch-tag: 9f0db077-5598-49ab-90b9-8df9248a63ec | |
754 | @end ignore |