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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 | ||
acaf905b | 14 | Copyright @copyright{} 2004-2012 |
9360256a | 15 | Free Software 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 | |
6f093307 GM |
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 | ||
0c973505 | 31 | @dircategory Emacs misc features |
4009494e | 32 | @direntry |
62e034c2 | 33 | * Flymake: (flymake). A universal on-the-fly syntax checker. |
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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 | |
5dc584b5 | 50 | @insertcopying |
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51 | @end ifnottex |
52 | ||
53 | @menu | |
54 | * Overview of Flymake:: | |
55 | * Installing Flymake:: | |
56 | * Using Flymake:: | |
57 | * Configuring Flymake:: | |
58 | * Flymake Implementation:: | |
59 | * GNU Free Documentation License:: | |
60 | * Index:: | |
61 | @end menu | |
62 | ||
63 | @node Overview of Flymake | |
64 | @chapter Overview | |
65 | @cindex Overview of Flymake | |
66 | ||
67 | Flymake is a universal on-the-fly syntax checker implemented as an | |
68 | Emacs minor mode. Flymake runs the pre-configured syntax check tool | |
69 | (compiler for C++ files, @code{perl} for perl files, etc.) in the | |
70 | background, passing it a temporary copy of the current buffer, and | |
71 | parses the output for known error/warning message patterns. Flymake | |
72 | then highlights erroneous lines (i.e. lines for which at least one | |
73 | error or warning has been reported by the syntax check tool), and | |
74 | displays an overall buffer status in the mode line. Status information | |
75 | displayed by Flymake contains total number of errors and warnings | |
76 | reported for the buffer during the last syntax check. | |
77 | ||
78 | @code{flymake-goto-next-error} and @code{flymake-goto-prev-error} | |
79 | functions allow for easy navigation to the next/previous erroneous | |
80 | line, respectively. | |
81 | ||
82 | Calling @code{flymake-display-err-menu-for-current-line} will popup a | |
83 | menu containing error messages reported by the syntax check tool for | |
84 | the current line. Errors/warnings belonging to another file, such as a | |
85 | @code{.h} header file included by a @code{.c} file, are shown in the | |
86 | current buffer as belonging to the first line. Menu items for such | |
87 | messages also contain a filename and a line number. Selecting such a | |
88 | menu item will automatically open the file and jump to the line with | |
89 | error. | |
90 | ||
91 | Syntax check is done 'on-the-fly'. It is started whenever | |
92 | ||
93 | @itemize @bullet | |
94 | @item buffer is loaded | |
95 | @item a newline character is added to the buffer | |
96 | @item some changes were made to the buffer more than @code{0.5} seconds ago (the | |
97 | delay is configurable). | |
98 | @end itemize | |
99 | ||
100 | Flymake is a universal syntax checker in the sense that it's easily | |
101 | extended to support new syntax check tools and error message | |
102 | patterns. @xref{Configuring Flymake}. | |
103 | ||
104 | @node Installing Flymake | |
105 | @chapter Installing | |
106 | @cindex Installing Flymake | |
107 | ||
108 | ||
109 | Flymake is packaged in a single file, @code{flymake.el}. | |
110 | ||
111 | To install/update Flymake, place @code{flymake.el} to a directory | |
112 | somewhere on Emacs load path. You might also want to byte-compile | |
113 | @code{flymake.el} to improve performance. | |
114 | ||
115 | Also, place the following line in the @code{.emacs} file. | |
116 | ||
117 | @lisp | |
118 | (require 'flymake) | |
119 | @end lisp | |
120 | ||
121 | You might also map the most frequently used Flymake functions, such as | |
122 | @code{flymake-goto-next-error}, to some keyboard shortcuts: | |
123 | ||
124 | @lisp | |
125 | (global-set-key [f3] 'flymake-display-err-menu-for-current-line) | |
126 | (global-set-key [f4] 'flymake-goto-next-error) | |
127 | @end lisp | |
128 | ||
129 | @node Using Flymake | |
130 | @chapter Using Flymake | |
131 | @cindex Using Flymake | |
132 | ||
133 | @menu | |
134 | * Flymake mode:: | |
135 | * Running the syntax check:: | |
136 | * Navigating to error lines:: | |
137 | * Viewing error messages:: | |
138 | * Syntax check statuses:: | |
139 | * Troubleshooting:: | |
140 | @end menu | |
141 | ||
142 | @node Flymake mode | |
143 | @section Flymake mode | |
144 | @cindex flymake-mode | |
145 | ||
146 | Flymake is an Emacs minor mode. To use Flymake, you | |
147 | must first activate @code{flymake-mode} by using the | |
148 | @code{flymake-mode} function. | |
149 | ||
150 | Instead of manually activating @code{flymake-mode}, you can configure | |
151 | Flymake to automatically enable @code{flymake-mode} upon opening any | |
152 | file for which syntax check is possible. To do so, place the following | |
153 | line in @code{.emacs}: | |
154 | ||
155 | @lisp | |
156 | (add-hook 'find-file-hook 'flymake-find-file-hook) | |
157 | @end lisp | |
158 | ||
159 | @node Running the syntax check | |
160 | @section Running the syntax check | |
161 | @cindex Manually starting the syntax check | |
162 | ||
163 | When @code{flymake-mode} is active, syntax check is started | |
164 | automatically on any of the three conditions mentioned above. Syntax | |
165 | check can also be started manually by using the | |
166 | @code{flymake-start-syntax-check-for-current-buffer} function. This | |
167 | can be used, for example, when changes were made to some other buffer | |
168 | affecting the current buffer. | |
169 | ||
170 | @node Navigating to error lines | |
171 | @section Navigating to error lines | |
172 | @cindex Navigating to error lines | |
173 | ||
174 | After syntax check is completed, lines for which at least one error or | |
175 | warning has been reported are highlighted, and total number of errors | |
176 | and warning is shown in the mode line. Use the following functions to | |
177 | navigate the highlighted lines. | |
178 | ||
179 | @multitable @columnfractions 0.25 0.75 | |
180 | ||
181 | @item @code{flymake-goto-next-error} | |
182 | @tab Moves point to the next erroneous line, if any. | |
183 | ||
184 | @item @code{flymake-goto-prev-error} | |
185 | @tab Moves point to the previous erroneous line. | |
186 | ||
187 | @end multitable | |
188 | ||
189 | These functions treat erroneous lines as a linked list. Therefore, | |
190 | @code{flymake-goto-next-error} will go to the first erroneous line | |
191 | when invoked in the end of the buffer. | |
192 | ||
193 | @node Viewing error messages | |
194 | @section Viewing error messages | |
195 | @cindex Viewing error messages | |
196 | ||
197 | To view error messages belonging to the current line, use the | |
198 | @code{flymake-display-err-menu-for-current-line} function. If there's | |
199 | at least one error or warning reported for the current line, this | |
200 | function will display a popup menu with error/warning texts. | |
201 | Selecting the menu item whose error belongs to another file brings | |
202 | forward that file with the help of the | |
203 | @code{flymake-goto-file-and-line} function. | |
204 | ||
205 | @node Syntax check statuses | |
206 | @section Syntax check statuses | |
207 | @cindex Syntax check statuses | |
208 | ||
209 | After syntax check is finished, its status is displayed in the mode line. | |
210 | The following statuses are defined. | |
211 | ||
212 | @multitable @columnfractions 0.25 0.75 | |
213 | @item Flymake* or Flymake:E/W* | |
214 | @tab Flymake is currently running. For the second case, E/W contains the | |
215 | error and warning count for the previous run. | |
216 | ||
217 | @item Flymake | |
218 | @tab Syntax check is not running. Usually this means syntax check was | |
219 | successfully passed (no errors, no warnings). Other possibilities are: | |
220 | syntax check was killed as a result of executing | |
221 | @code{flymake-compile}, or syntax check cannot start as compilation | |
222 | is currently in progress. | |
223 | ||
224 | @item Flymake:E/W | |
225 | @tab Number of errors/warnings found by the syntax check process. | |
226 | ||
227 | @item Flymake:! | |
228 | @tab Flymake was unable to find master file for the current buffer. | |
229 | @end multitable | |
230 | ||
231 | The following errors cause a warning message and switch flymake mode | |
232 | OFF for the buffer. | |
233 | ||
234 | @multitable @columnfractions 0.25 0.75 | |
235 | @item CFGERR | |
236 | @tab Syntax check process returned nonzero exit code, but no | |
237 | errors/warnings were reported. This indicates a possible configuration | |
238 | error (for example, no suitable error message patterns for the | |
239 | syntax check tool). | |
240 | ||
241 | @item NOMASTER | |
242 | @tab Flymake was unable to find master file for the current buffer. | |
243 | ||
244 | @item NOMK | |
245 | @tab Flymake was unable to find a suitable buildfile for the current buffer. | |
246 | ||
247 | @item PROCERR | |
248 | @tab Flymake was unable to launch a syntax check process. | |
249 | @end multitable | |
250 | ||
251 | ||
252 | @node Troubleshooting | |
253 | @section Troubleshooting | |
254 | @cindex Logging | |
255 | @cindex Troubleshooting | |
256 | ||
257 | Flymake uses a simple logging facility for indicating important points | |
258 | in the control flow. The logging facility sends logging messages to | |
259 | the @code{*Messages*} buffer. The information logged can be used for | |
260 | resolving various problems related to Flymake. | |
261 | ||
262 | Logging output is controlled by the @code{flymake-log-level} | |
263 | variable. @code{3} is the most verbose level, and @code{-1} switches | |
264 | logging off. | |
265 | ||
266 | @node Configuring Flymake | |
267 | @chapter Configuring and Extending Flymake | |
268 | @cindex Configuring and Extending Flymake | |
269 | ||
270 | @menu | |
271 | * Customizable variables:: | |
272 | * Adding support for a new syntax check tool:: | |
273 | @end menu | |
274 | ||
275 | Flymake was designed to be easily extended for supporting new syntax | |
276 | check tools and error message patterns. | |
277 | ||
278 | @node Customizable variables | |
279 | @section Customizable variables | |
280 | @cindex Customizable variables | |
281 | ||
282 | This section summarizes variables used for Flymake | |
283 | configuration. | |
284 | ||
285 | @table @code | |
286 | @item flymake-log-level | |
287 | Controls logging output, see @ref{Troubleshooting}. | |
288 | ||
289 | @item flymake-allowed-file-name-masks | |
290 | A list of @code{(filename-regexp, init-function, cleanup-function | |
291 | getfname-function)} for configuring syntax check tools. @xref{Adding | |
292 | support for a new syntax check tool}. | |
293 | ||
294 | @item flymake-buildfile-dirs | |
295 | A list of directories (relative paths) for searching a | |
296 | buildfile. @xref{Locating the buildfile}. | |
297 | ||
298 | @item flymake-master-file-dirs | |
299 | A list of directories for searching a master file. @xref{Locating a | |
300 | master file}. | |
301 | ||
302 | @item flymake-get-project-include-dirs-function | |
303 | A function used for obtaining a list of project include dirs (C/C++ | |
304 | specific). @xref{Getting the include directories}. | |
305 | ||
306 | @item flymake-master-file-count-limit | |
307 | @itemx flymake-check-file-limit | |
308 | Used when looking for a master file. @xref{Locating a master file}. | |
309 | ||
310 | @item flymake-err-line-patterns | |
311 | Patterns for error/warning messages in the form @code{(regexp file-idx | |
176c6903 | 312 | line-idx col-idx err-text-idx)}. @xref{Parsing the output}. |
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313 | |
314 | @item flymake-compilation-prevents-syntax-check | |
315 | A flag indicating whether compilation and syntax check of the same | |
316 | file cannot be run simultaneously. | |
317 | ||
318 | @item flymake-no-changes-timeout | |
319 | If any changes are made to the buffer, syntax check is automatically | |
320 | started after @code{flymake-no-changes-timeout} seconds. | |
321 | ||
322 | @item flymake-gui-warnings-enabled | |
323 | A boolean flag indicating whether Flymake will show message boxes for | |
324 | non-recoverable errors. If @code{flymake-gui-warnings-enabled} is | |
325 | @code{nil}, these errors will only be logged to the @code{*Messages*} | |
326 | buffer. | |
327 | ||
328 | @item flymake-start-syntax-check-on-newline | |
329 | A boolean flag indicating whether to start syntax check after a | |
330 | newline character is added to the buffer. | |
331 | ||
176c6903 | 332 | @item flymake-errline |
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333 | A custom face for highlighting lines for which at least one error has |
334 | been reported. | |
335 | ||
176c6903 | 336 | @item flymake-warnline |
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337 | A custom face for highlighting lines for which at least one warning |
338 | and no errors have been reported. | |
339 | ||
340 | @end table | |
341 | ||
342 | @node Adding support for a new syntax check tool | |
343 | @section Adding support for a new syntax check tool | |
344 | @cindex Adding support for a new syntax check tool | |
345 | ||
346 | @menu | |
347 | * Example -- Configuring a tool called directly:: | |
348 | * Example -- Configuring a tool called via make:: | |
349 | @end menu | |
350 | ||
351 | Syntax check tools are configured using the | |
352 | @code{flymake-allowed-file-name-masks} list. Each item of this list | |
353 | has the following format: | |
354 | ||
355 | @lisp | |
356 | (filename-regexp, init-function, cleanup-function, getfname-function) | |
357 | @end lisp | |
358 | ||
359 | @table @code | |
360 | @item filename-regexp | |
361 | This field is used as a key for locating init/cleanup/getfname | |
362 | functions for the buffer. Items in | |
363 | @code{flymake-allowed-file-name-masks} are searched sequentially. The | |
364 | first item with @code{filename-regexp} matching buffer filename is | |
365 | selected. If no match is found, @code{flymake-mode} is switched off. | |
366 | ||
367 | @item init-function | |
368 | @code{init-function} is required to initialize the syntax check, | |
369 | usually by creating a temporary copy of the buffer contents. The | |
370 | function must return @code{(list cmd-name arg-list)}. If | |
371 | @code{init-function} returns null, syntax check is aborted, by | |
372 | @code{flymake-mode} is not switched off. | |
373 | ||
374 | @item cleanup-function | |
375 | @code{cleanup-function} is called after the syntax check process is | |
376 | complete and should take care of proper deinitialization, which is | |
377 | usually deleting a temporary copy created by the @code{init-function}. | |
378 | ||
379 | @item getfname-function | |
380 | This function is used for translating filenames reported by the syntax | |
381 | check tool into ``real'' filenames. Filenames reported by the tool | |
382 | will be different from the real ones, as actually the tool works with | |
383 | the temporary copy. In most cases, the default implementation | |
384 | provided by Flymake, @code{flymake-get-real-file-name}, can be used as | |
385 | @code{getfname-function}. | |
386 | ||
387 | @end table | |
388 | ||
389 | To add support for a new syntax check tool, write corresponding | |
390 | @code{init-function}, and, optionally @code{cleanup-function} and | |
391 | @code{getfname-function}. If the format of error messages reported by | |
392 | the new tool is not yet supported by Flymake, add a new entry to | |
393 | the @code{flymake-err-line-patterns} list. | |
394 | ||
395 | The following sections contain some examples of configuring Flymake | |
396 | support for various syntax check tools. | |
397 | ||
398 | @node Example -- Configuring a tool called directly | |
399 | @subsection Example -- Configuring a tool called directly | |
400 | @cindex Adding support for perl | |
401 | ||
402 | In this example, we will add support for @code{perl} as a syntax check | |
403 | tool. @code{perl} supports the @code{-c} option which does syntax | |
404 | checking. | |
405 | ||
406 | First, we write the @code{init-function}: | |
407 | ||
408 | @lisp | |
176c6903 | 409 | (defun flymake-perl-init () |
4009494e | 410 | (let* ((temp-file (flymake-init-create-temp-buffer-copy |
176c6903 | 411 | 'flymake-create-temp-inplace)) |
9360256a | 412 | (local-file (file-relative-name |
5ef5ef3f RS |
413 | temp-file |
414 | (file-name-directory buffer-file-name)))) | |
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415 | (list "perl" (list "-wc " local-file)))) |
416 | @end lisp | |
417 | ||
418 | @code{flymake-perl-init} creates a temporary copy of the buffer | |
419 | contents with the help of | |
420 | @code{flymake-init-create-temp-buffer-copy}, and builds an appropriate | |
421 | command line. | |
422 | ||
423 | Next, we add a new entry to the | |
424 | @code{flymake-allowed-file-name-masks}: | |
425 | ||
426 | @lisp | |
427 | (setq flymake-allowed-file-name-masks | |
428 | (cons '(".+\\.pl$" | |
429 | flymake-perl-init | |
430 | flymake-simple-cleanup | |
431 | flymake-get-real-file-name) | |
432 | flymake-allowed-file-name-masks)) | |
433 | @end lisp | |
434 | ||
435 | Note that we use standard @code{cleanup-function} and | |
436 | @code{getfname-function}. | |
437 | ||
438 | Finally, we add an entry to @code{flymake-err-line-patterns}: | |
439 | ||
440 | @lisp | |
441 | (setq flymake-err-line-patterns | |
442 | (cons '("\\(.*\\) at \\([^ \n]+\\) line \\([0-9]+\\)[,.\n]" | |
443 | 2 3 nil 1) | |
444 | flymake-err-line-patterns)) | |
445 | @end lisp | |
446 | ||
447 | @node Example -- Configuring a tool called via make | |
448 | @subsection Example -- Configuring a tool called via make | |
449 | @cindex Adding support for C (gcc+make) | |
450 | ||
451 | In this example we will add support for C files syntax checked by | |
452 | @code{gcc} called via @code{make}. | |
453 | ||
454 | We're not required to write any new functions, as Flymake already has | |
455 | functions for @code{make}. We just add a new entry to the | |
456 | @code{flymake-allowed-file-name-masks}: | |
457 | ||
458 | @lisp | |
459 | (setq flymake-allowed-file-name-masks | |
460 | (cons '(".+\\.c$" | |
461 | flymake-simple-make-init | |
462 | flymake-simple-cleanup | |
463 | flymake-get-real-file-name) | |
464 | flymake-allowed-file-name-masks)) | |
465 | @end lisp | |
466 | ||
467 | @code{flymake-simple-make-init} builds the following @code{make} | |
468 | command line: | |
469 | ||
470 | @lisp | |
471 | (list "make" | |
472 | (list "-s" "-C" | |
473 | base-dir | |
474 | (concat "CHK_SOURCES=" source) | |
475 | "SYNTAX_CHECK_MODE=1" | |
476 | "check-syntax")) | |
477 | @end lisp | |
478 | ||
479 | @code{base-dir} is a directory containing @code{Makefile}, see @ref{Locating the buildfile}. | |
480 | ||
481 | Thus, @code{Makefile} must contain the @code{check-syntax} target. In | |
482 | our case this target might look like this: | |
483 | ||
484 | @verbatim | |
485 | check-syntax: | |
064e2d08 | 486 | gcc -o /dev/null -S ${CHK_SOURCES} |
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487 | @end verbatim |
488 | ||
489 | The format of error messages reported by @code{gcc} is already | |
490 | supported by Flymake, so we don't have to add a new entry to | |
491 | @code{flymake-err-line-patterns}. | |
492 | ||
493 | @node Flymake Implementation | |
494 | @chapter Flymake Implementation | |
495 | @cindex Implementation details | |
496 | ||
497 | @menu | |
498 | * Determining whether syntax check is possible:: | |
499 | * Making a temporary copy:: | |
500 | * Locating a master file:: | |
501 | * Getting the include directories:: | |
502 | * Locating the buildfile:: | |
503 | * Starting the syntax check process:: | |
504 | * Parsing the output:: | |
505 | * Highlighting erroneous lines:: | |
506 | * Interaction with other modes:: | |
507 | @end menu | |
508 | ||
509 | Syntax check is started by calling @code{flymake-start-syntax-check-for-current-buffer}. | |
510 | Flymake first determines whether it is able to do syntax | |
511 | check. It then saves a copy of the buffer in a temporary file in the | |
512 | buffer's directory (or in the system temp directory -- for java | |
513 | files), creates a syntax check command and launches a process with | |
514 | this command. The output is parsed using a list of error message patterns, | |
515 | and error information (file name, line number, type and text) is | |
516 | saved. After the process has finished, Flymake highlights erroneous | |
517 | lines in the buffer using the accumulated error information. | |
518 | ||
519 | @node Determining whether syntax check is possible | |
520 | @section Determining whether syntax check is possible | |
521 | @cindex Syntax check models | |
522 | @cindex Master file | |
523 | ||
524 | Syntax check is considered possible if there's an entry in | |
525 | @code{flymake-allowed-file-name-masks} matching buffer's filename and | |
526 | its @code{init-function} returns non-@code{nil} value. | |
527 | ||
528 | Two syntax check modes are distinguished: | |
529 | ||
530 | @enumerate | |
531 | ||
532 | @item | |
533 | Buffer can be syntax checked in a standalone fashion, that is, the | |
534 | file (its temporary copy, in fact) can be passed over to the compiler to | |
535 | do the syntax check. Examples are C/C++ (.c, .cpp) and Java (.java) | |
536 | sources. | |
537 | ||
538 | @item | |
539 | Buffer can be syntax checked, but additional file, called master file, | |
540 | is required to perform this operation. A master file is a file that | |
541 | includes the current file, so that running a syntax check tool on it | |
542 | will also check syntax in the current file. Examples are C/C++ (.h, | |
543 | .hpp) headers. | |
544 | ||
545 | @end enumerate | |
546 | ||
547 | These modes are handled inside init/cleanup/getfname functions, see | |
548 | @ref{Adding support for a new syntax check tool}. | |
549 | ||
550 | Flymake contains implementations of all functionality required to | |
551 | support different syntax check modes described above (making | |
552 | temporary copies, finding master files, etc.), as well as some | |
553 | tool-specific (routines for @code{make}, @code{Ant}, etc.) code. | |
554 | ||
555 | ||
556 | @node Making a temporary copy | |
557 | @section Making a temporary copy | |
558 | @cindex Temporary copy of the buffer | |
559 | @cindex Master file | |
560 | ||
561 | After the possibility of the syntax check has been determined, a | |
562 | temporary copy of the current buffer is made so that the most recent | |
563 | unsaved changes could be seen by the syntax check tool. Making a copy | |
564 | is quite straightforward in a standalone case (mode @code{1}), as it's | |
565 | just saving buffer contents to a temporary file. | |
566 | ||
567 | Things get trickier, however, when master file is involved, as it | |
568 | requires to | |
569 | ||
570 | @itemize @bullet | |
571 | @item locate a master file | |
572 | @item patch it to include the current file using its new (temporary) | |
573 | name. | |
574 | @end itemize | |
575 | ||
576 | Locating a master file is discussed in the following section. | |
577 | ||
578 | Patching just changes all appropriate lines of the master file so that they | |
579 | use the new (temporary) name of the current file. For example, suppose current | |
580 | file name is @code{file.h}, the master file is @code{file.cpp}, and | |
581 | it includes current file via @code{#include "file.h"}. Current file's copy | |
582 | is saved to file @code{file_flymake.h}, so the include line must be | |
583 | changed to @code{#include "file_flymake.h"}. Finally, patched master file | |
584 | is saved to @code{file_flymake_master.cpp}, and the last one is passed to | |
585 | the syntax check tool. | |
586 | ||
587 | @node Locating a master file | |
588 | @section Locating a master file | |
589 | @cindex Master file | |
590 | ||
591 | Master file is located in two steps. | |
592 | ||
593 | First, a list of possible master files is built. A simple name | |
594 | matching is used to find the files. For a C++ header @code{file.h}, | |
595 | Flymake searches for all @code{.cpp} files in the directories whose relative paths are | |
596 | stored in a customizable variable @code{flymake-master-file-dirs}, which | |
597 | usually contains something like @code{("." "./src")}. No more than | |
598 | @code{flymake-master-file-count-limit} entries is added to the master file | |
599 | list. The list is then sorted to move files with names @code{file.cpp} to | |
600 | the top. | |
601 | ||
602 | Next, each master file in a list is checked to contain the appropriate | |
603 | include directives. No more than @code{flymake-check-file-limit} of each | |
604 | file are parsed. | |
605 | ||
606 | For @code{file.h}, the include directives to look for are | |
607 | @code{#include "file.h"}, @code{#include "../file.h"}, etc. Each | |
608 | include is checked against a list of include directories | |
609 | (see @ref{Getting the include directories}) to be sure it points to the | |
610 | correct @code{file.h}. | |
611 | ||
612 | First matching master file found stops the search. The master file is then | |
613 | patched and saved to disk. In case no master file is found, syntax check is | |
614 | aborted, and corresponding status (!) is reported in the mode line. | |
615 | ||
616 | @node Getting the include directories | |
617 | @section Getting the include directories | |
618 | @cindex Include directories (C/C++ specific) | |
619 | ||
620 | Two sets of include directories are distinguished: system include directories | |
621 | and project include directories. The former is just the contents of the | |
622 | @code{INCLUDE} environment variable. The latter is not so easy to obtain, | |
623 | and the way it can be obtained can vary greatly for different projects. | |
624 | Therefore, a customizable variable | |
625 | @code{flymake-get-project-include-dirs-function} is used to provide the | |
626 | way to implement the desired behavior. | |
627 | ||
628 | The default implementation, @code{flymake-get-project-include-dirs-imp}, | |
629 | uses a @code{make} call. This requires a correct base directory, that is, a | |
630 | directory containing a correct @code{Makefile}, to be determined. | |
631 | ||
632 | As obtaining the project include directories might be a costly operation, its | |
633 | return value is cached in the hash table. The cache is cleared in the beginning | |
634 | of every syntax check attempt. | |
635 | ||
636 | @node Locating the buildfile | |
637 | @section Locating the buildfile | |
638 | @cindex Locating the buildfile | |
639 | @cindex buildfile, locating | |
640 | @cindex Makefile, locating | |
641 | ||
642 | Flymake can be configured to use different tools for performing syntax | |
643 | checks. For example, it can use direct compiler call to syntax check a perl | |
644 | script or a call to @code{make} for a more complicated case of a | |
645 | @code{C/C++} source. The general idea is that simple files, like perl | |
646 | scripts and html pages, can be checked by directly invoking a | |
647 | corresponding tool. Files that are usually more complex and generally | |
648 | used as part of larger projects, might require non-trivial options to | |
649 | be passed to the syntax check tool, like include directories for | |
650 | C++. The latter files are syntax checked using some build tool, like | |
651 | @code{make} or @code{Ant}. | |
652 | ||
653 | All @code{make} configuration data is usually stored in a file called | |
654 | @code{Makefile}. To allow for future extensions, flymake uses a notion of | |
655 | buildfile to reference the 'project configuration' file. | |
656 | ||
657 | Special function, @code{flymake-find-buildfile} is provided for locating buildfiles. | |
658 | Searching for a buildfile is done in a manner similar to that of searching | |
659 | for possible master files. A customizable variable | |
660 | @code{flymake-buildfile-dirs} holds a list of relative paths to the | |
661 | buildfile. They are checked sequentially until a buildfile is found. In case | |
662 | there's no build file, syntax check is aborted. | |
663 | ||
664 | Buildfile values are also cached. | |
665 | ||
666 | @node Starting the syntax check process | |
667 | @section Starting the syntax check process | |
668 | @cindex Syntax check process | |
669 | ||
670 | The command line (command name and the list of arguments) for launching a process is returned by the | |
671 | initialization function. Flymake then just calls @code{start-process} | |
672 | to start an asynchronous process and configures process filter and | |
673 | sentinel which is used for processing the output of the syntax check | |
674 | tool. | |
675 | ||
676 | @node Parsing the output | |
677 | @section Parsing the output | |
678 | @cindex Parsing the output | |
679 | ||
680 | The output generated by the syntax check tool is parsed in the process | |
681 | filter/sentinel using the error message patterns stored in the | |
682 | @code{flymake-err-line-patterns} variable. This variable contains a | |
683 | list of items of the form @code{(regexp file-idx line-idx | |
684 | err-text-idx)}, used to determine whether a particular line is an | |
685 | error message and extract file name, line number and error text, | |
686 | respectively. Error type (error/warning) is also guessed by matching | |
687 | error text with the '@code{^[wW]arning}' pattern. Anything that was not | |
688 | classified as a warning is considered an error. Type is then used to | |
689 | sort error menu items, which shows error messages first. | |
690 | ||
691 | Flymake is also able to interpret error message patterns missing err-text-idx | |
692 | information. This is done by merely taking the rest of the matched line | |
693 | (@code{(substring line (match-end 0))}) as error text. This trick allows | |
694 | to make use of a huge collection of error message line patterns from | |
695 | @code{compile.el}. All these error patterns are appended to | |
696 | the end of @code{flymake-err-line-patterns}. | |
697 | ||
698 | The error information obtained is saved in a buffer local | |
699 | variable. The buffer for which the process output belongs is | |
700 | determined from the process-id@w{}->@w{}buffer mapping updated | |
701 | after every process launch/exit. | |
702 | ||
703 | @node Highlighting erroneous lines | |
704 | @section Highlighting erroneous lines | |
705 | @cindex Erroneous lines, faces | |
706 | ||
707 | Highlighting is implemented with overlays and happens in the process | |
708 | sentinel, after calling the cleanup function. Two customizable faces | |
176c6903 RS |
709 | are used: @code{flymake-errline} and |
710 | @code{flymake-warnline}. Errors belonging outside the current | |
4009494e GM |
711 | buffer are considered to belong to line 1 of the current buffer. |
712 | ||
713 | @node Interaction with other modes | |
714 | @section Interaction with other modes | |
715 | @cindex Interaction with other modes | |
716 | @cindex Interaction with compile mode | |
717 | ||
718 | The only mode flymake currently knows about is @code{compile}. | |
719 | ||
720 | Flymake can be configured to not start syntax check if it thinks the | |
721 | compilation is in progress. The check is made by the | |
722 | @code{flymake-compilation-is-running}, which tests the | |
723 | @code{compilation-in-progress} variable. The reason why this might be | |
724 | useful is saving CPU time in case both syntax check and compilation | |
725 | are very CPU intensive. The original reason for adding this feature, | |
726 | though, was working around a locking problem with MS Visual C++ compiler. | |
727 | ||
728 | Flymake also provides an alternative command for starting compilation, | |
729 | @code{flymake-compile}: | |
730 | ||
731 | @lisp | |
732 | (defun flymake-compile () | |
733 | "Kill all flymake syntax checks then start compilation." | |
734 | (interactive) | |
735 | (flymake-stop-all-syntax-checks) | |
736 | (call-interactively 'compile)) | |
737 | @end lisp | |
738 | ||
739 | It just kills all the active syntax check processes before calling | |
740 | @code{compile}. | |
741 | ||
742 | @node GNU Free Documentation License | |
743 | @appendix GNU Free Documentation License | |
744 | @include doclicense.texi | |
745 | ||
746 | @node Index | |
747 | @unnumbered Index | |
748 | ||
749 | @printindex cp | |
750 | ||
751 | @bye |