blob: c7e4171a9cb7cd2848c85bd64760b0b5e76695cd [file] [log] [blame]
Andreas Bollecd5c7c2012-06-12 09:05:03 +02001<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
2<html lang="en">
3<head>
4 <meta http-equiv="content-type" content="text/html; charset=utf-8">
5 <title>Development Notes</title>
6 <link rel="stylesheet" type="text/css" href="mesa.css">
7</head>
8<body>
Brian Paul0b27ace2003-03-08 17:38:57 +00009
Andreas Bollb5da52a2012-09-18 18:57:02 +020010<div class="header">
11 <h1>The Mesa 3D Graphics Library</h1>
12</div>
13
14<iframe src="contents.html"></iframe>
15<div class="content">
16
Andreas Bollecd5c7c2012-06-12 09:05:03 +020017<h1>Development Notes</h1>
Brian Paul0b27ace2003-03-08 17:38:57 +000018
19
Brian Paul51830612004-08-17 14:08:59 +000020<ul>
Brian Paul98f2f472015-05-25 09:13:09 -060021<li><a href="#style">Coding Style</a>
22<li><a href="#submitting">Submitting Patches</a>
23<li><a href="#release">Making a New Mesa Release</a>
24<li><a href="#extensions">Adding Extensions</a>
Brian Paul51830612004-08-17 14:08:59 +000025</ul>
Brian Paul0b27ace2003-03-08 17:38:57 +000026
27
Brian Paul98f2f472015-05-25 09:13:09 -060028<h2 id="style">Coding Style</h2>
Brian Paul0b27ace2003-03-08 17:38:57 +000029
30<p>
31Mesa's code style has changed over the years. Here's the latest.
32</p>
33
34<p>
35Comment your code! It's extremely important that open-source code be
36well documented. Also, strive to write clean, easily understandable code.
37</p>
38
39<p>
403-space indentation
41</p>
42
43<p>
44If you use tabs, set them to 8 columns
45</p>
46
47<p>
Paul Berry43968262011-08-16 14:09:32 -070048Line width: the preferred width to fill comments and code in Mesa is 78
49columns. Exceptions are sometimes made for clarity (e.g. tabular data is
50sometimes filled to a much larger width so that extraneous carriage returns
51don't obscure the table).
52</p>
53
54<p>
Brian Paul0b27ace2003-03-08 17:38:57 +000055Brace example:
56</p>
57<pre>
58 if (condition) {
59 foo;
60 }
61 else {
62 bar;
63 }
Paul Berry43968262011-08-16 14:09:32 -070064
65 switch (condition) {
66 case 0:
67 foo();
68 break;
69
70 case 1: {
71 ...
72 break;
73 }
74
75 default:
76 ...
77 break;
78 }
Brian Paul0b27ace2003-03-08 17:38:57 +000079</pre>
80
81<p>
82Here's the GNU indent command which will best approximate my preferred style:
Paul Berry43968262011-08-16 14:09:32 -070083(Note that it won't format switch statements in the preferred way)
Brian Paul0b27ace2003-03-08 17:38:57 +000084</p>
85<pre>
Brian Paule3f41ce2006-03-31 23:10:21 +000086 indent -br -i3 -npcs --no-tabs infile.c -o outfile.c
Brian Paul0b27ace2003-03-08 17:38:57 +000087</pre>
88
89
90<p>
91Local variable name example: localVarName (no underscores)
92</p>
93
94<p>
95Constants and macros are ALL_UPPERCASE, with _ between words
96</p>
97
98<p>
Brian Paul65b79052004-11-22 17:49:15 +000099Global variables are not allowed.
Brian Paul0b27ace2003-03-08 17:38:57 +0000100</p>
101
102<p>
103Function name examples:
104</p>
105<pre>
Chia-I Wu27d260b42010-02-24 11:20:14 +0800106 glFooBar() - a public GL entry point (in glapi_dispatch.c)
Brian Paul0b27ace2003-03-08 17:38:57 +0000107 _mesa_FooBar() - the internal immediate mode function
108 save_FooBar() - retained mode (display list) function in dlist.c
109 foo_bar() - a static (private) function
110 _mesa_foo_bar() - an internal non-static Mesa function
111</pre>
112
Kai Wasserbächdbec3a52011-08-23 10:48:58 +0200113<p>
114Places that are not directly visible to the GL API should prefer the use
115of <tt>bool</tt>, <tt>true</tt>, and
116<tt>false</tt> over <tt>GLboolean</tt>, <tt>GL_TRUE</tt>, and
117<tt>GL_FALSE</tt>. In C code, this may mean that
Kai Wasserbäche106d4c2011-08-27 17:51:47 +0200118<tt>#include &lt;stdbool.h&gt;</tt> needs to be added. The
Kai Wasserbächdbec3a52011-08-23 10:48:58 +0200119<tt>try_emit_</tt>* methods in src/mesa/program/ir_to_mesa.cpp and
Kai Wasserbäche106d4c2011-08-27 17:51:47 +0200120src/mesa/state_tracker/st_glsl_to_tgsi.cpp can serve as examples.
Kai Wasserbächdbec3a52011-08-23 10:48:58 +0200121</p>
122
Brian Paul98f2f472015-05-25 09:13:09 -0600123
124<h2 id="submitting">Submitting patches</h2>
Timothy Arceri23820112013-09-05 02:54:00 -0600125
126<p>
127You should always run the Mesa Testsuite before submitting patches.
128The Testsuite can be run using the 'make check' command. All tests
129must pass before patches will be accepted, this may mean you have
130to update the tests themselves.
131</p>
132
133<p>
134Patches should be sent to the Mesa mailing list for review.
135When submitting a patch make sure to use git send-email rather than attaching
136patches to emails. Sending patches as attachments prevents people from being
137able to provide in-line review comments.
138</p>
139
140<p>
141When submitting follow-up patches you can use --in-reply-to to make v2, v3,
142etc patches show up as replies to the originals. This usually works well
143when you're sending out updates to individual patches (as opposed to
144re-sending the whole series). Using --in-reply-to makes
145it harder for reviewers to accidentally review old patches.
146</p>
Brian Paul0b27ace2003-03-08 17:38:57 +0000147
Brian Paul98f2f472015-05-25 09:13:09 -0600148<h3>Marking a commit as a candidate for a stable branch</h3>
Andreas Bollf07784d2012-10-02 13:37:34 +0200149
150<p>
151If you want a commit to be applied to a stable branch,
152you should add an appropriate note to the commit message.
153</p>
154
155<p>
156Here are some examples of such a note:
157</p>
158<ul>
Carl Worthd6c83652013-12-12 23:07:26 -0800159 <li>CC: &lt;mesa-stable@lists.freedesktop.org&gt;</li>
160 <li>CC: "9.2 10.0" &lt;mesa-stable@lists.freedesktop.org&gt;</li>
161 <li>CC: "10.0" &lt;mesa-stable@lists.freedesktop.org&gt;</li>
Andreas Bollf07784d2012-10-02 13:37:34 +0200162</ul>
163
Carl Worthd6c83652013-12-12 23:07:26 -0800164Simply adding the CC to the mesa-stable list address is adequate to nominate
165the commit for the most-recently-created stable branch. It is only necessary
166to specify a specific branch name, (such as "9.2 10.0" or "10.0" in the
167examples above), if you want to nominate the commit for an older stable
168branch. And, as in these examples, you can nominate the commit for the older
169branch in addition to the more recent branch, or nominate the commit
170exclusively for the older branch.
171
172This "CC" syntax for patch nomination will cause patches to automatically be
173copied to the mesa-stable@ mailing list when you use "git send-email" to send
174patches to the mesa-dev@ mailing list. Also, if you realize that a commit
Nathan Kidd0691b372014-01-03 16:44:00 -0700175should be nominated for the stable branch after it has already been committed,
Carl Worthd6c83652013-12-12 23:07:26 -0800176you can send a note directly to the mesa-stable@lists.freedesktop.org where
177the Mesa stable-branch maintainers will receive it. Be sure to mention the
178commit ID of the commit of interest (as it appears in the mesa master branch).
Andreas Boll1f38fb22012-10-02 13:55:53 +0200179
Carl Worth4546b702014-04-30 16:27:03 -0700180The latest set of patches that have been nominated, accepted, or rejected for
181the upcoming stable release can always be seen on the
Carl Worth399b4e22014-08-21 09:46:57 -0700182<a href="http://cworth.org/~cworth/mesa-stable-queue/">Mesa Stable Queue</a>
Carl Worth4546b702014-04-30 16:27:03 -0700183page.
184
Brian Paul98f2f472015-05-25 09:13:09 -0600185<h3>Criteria for accepting patches to the stable branch</h3>
Andreas Boll1f38fb22012-10-02 13:55:53 +0200186
Carl Worth399b4e22014-08-21 09:46:57 -0700187Mesa has a designated release manager for each stable branch, and the release
188manager is the only developer that should be pushing changes to these
189branches. Everyone else should simply nominate patches using the mechanism
190described above.
191
192The stable-release manager will work with the list of nominated patches, and
193for each patch that meets the crtieria below will cherry-pick the patch with:
194<code>git cherry-pick -x &lt;commit&gt;</code>. The <code>-x</code> option is
195important so that the picked patch references the comit ID of the original
196patch.
197
198The stable-release manager may at times need to force-push changes to the
199stable branches, for example, to drop a previously-picked patch that was later
200identified as causing a regression). These force-pushes may cause changes to
201be lost from the stable branch if developers push things directly. Consider
202yourself warned.
203
204The stable-release manager is also given broad discretion in rejecting patches
205that have been nominated for the stable branch. The most basic rule is that
206the stable branch is for bug fixes only, (no new features, no
207regressions). Here is a non-exhaustive list of some reasons that a patch may
208be rejected:
209
210<ul>
211 <li>Patch introduces a regression. Any reported build breakage or other
212 regression caused by a particular patch, (game no longer work, piglit test
213 changes from PASS to FAIL), is justification for rejecting a patch.</li>
214
215 <li>Patch is too large, (say, larger than 100 lines)</li>
216
217 <li>Patch is not a fix. For example, a commit that moves code around with no
218 functional change should be rejected.</li>
219
220 <li>Patch fix is not clearly described. For example, a commit message
221 of only a single line, no description of the bug, no mention of bugzilla,
222 etc.</li>
223
224 <li>Patch has not obviously been reviewed, For example, the commit message
225 has no Reviewed-by, Signed-off-by, nor Tested-by tags from anyone but the
226 author.</li>
227
228 <li>Patch has not already been merged to the master branch. As a rule, bug
229 fixes should never be applied first to a stable branch. Patches should land
230 first on the master branch and then be cherry-picked to a stable
231 branch. (This is to avoid future releases causing regressions if the patch
232 is not also applied to master.) The only things that might look like
233 exceptions would be backports of patches from master that happen to look
234 significantly different.</li>
235
236 <li>Patch depends on too many other patches. Ideally, all stable-branch
237 patches should be self-contained. It sometimes occurs that a single, logical
238 bug-fix occurs as two separate patches on master, (such as an original
239 patch, then a subsequent fix-up to that patch). In such a case, these two
240 patches should be squashed into a single, self-contained patch for the
241 stable branch. (Of course, if the squashing makes the patch too large, then
242 that could be a reason to reject the patch.)</li>
243
244 <li>Patch includes new feature development, not bug fixes. New OpenGL
245 features, extensions, etc. should be applied to Mesa master and included in
246 the next major release. Stable releases are intended only for bug fixes.
247
248 Note: As an exception to this rule, the stable-release manager may accept
249 hardware-enabling "features". For example, backports of new code to support
250 a newly-developed hardware product can be accepted if they can be reasonably
251 determined to not have effects on other hardware.</li>
252
253 <li>Patch is a performance optimization. As a rule, performance patches are
254 not candidates for the stable branch. The only exception might be a case
255 where an application's performance was recently severely impacted so as to
256 become unusable. The fix for this performance regression could then be
257 considered for a stable branch. The optimization must also be
258 non-controversial and the patches still need to meet the other criteria of
259 being simple and self-contained</li>
260
261 <li>Patch introduces a new failure mode (such as an assert). While the new
262 assert might technically be correct, for example to make Mesa more
263 conformant, this is not the kind of "bug fix" we want in a stable
264 release. The potential problem here is that an OpenGL program that was
265 previously working, (even if technically non-compliant with the
266 specification), could stop working after this patch. So that would be a
267 regression that is unaacceptable for the stable branch.</li>
268</ul>
Andreas Boll1f38fb22012-10-02 13:55:53 +0200269
Brian Paul98f2f472015-05-25 09:13:09 -0600270
271<h2 id="release">Making a New Mesa Release</h2>
Brian Paul0b27ace2003-03-08 17:38:57 +0000272
273<p>
274These are the instructions for making a new Mesa release.
275</p>
276
Andreas Boll210a27d2012-06-12 09:05:36 +0200277<h3>Get latest source files</h3>
Brian Paul0b27ace2003-03-08 17:38:57 +0000278<p>
Brian Paul84c5e482009-06-23 19:21:04 -0600279Use git to get the latest Mesa files from the git repository, from whatever
Carl Worth619505a2014-08-21 10:44:35 -0700280branch is relevant. This document uses the convention X.Y.Z for the release
281being created, which should be created from a branch named X.Y.
Brian Paul0b27ace2003-03-08 17:38:57 +0000282</p>
283
Carl Worth619505a2014-08-21 10:44:35 -0700284<h3>Perform basic testing</h3>
Brian Paul65b79052004-11-22 17:49:15 +0000285<p>
Carl Worth619505a2014-08-21 10:44:35 -0700286The release manager should, at the very least, test the code by compiling it,
287installing it, and running the latest piglit to ensure that no piglit tests
288have regressed since the previous release.
Brian Paul65b79052004-11-22 17:49:15 +0000289</p>
290
291<p>
Carl Worth619505a2014-08-21 10:44:35 -0700292The release manager should do this testing with at least one hardware driver,
293(say, whatever is contained in the local development machine), as well as on
294both Gallium and non-Gallium software drivers. The software testing can be
295performed by running piglit with the following environment-variable set:
Andreas Bollb347bb52012-06-25 21:53:06 +0200296</p>
297
Brian Paul0b27ace2003-03-08 17:38:57 +0000298<pre>
Carl Worth619505a2014-08-21 10:44:35 -0700299LIBGL_ALWAYS_SOFTWARE=1
300</pre>
301
302And Gallium vs. non-Gallium software drivers can be obtained by using the
303following configure flags on separate builds:
304
305<pre>
306--with-dri-drivers=swrast
307--with-gallium-drivers=swrast
Brian Paul0b27ace2003-03-08 17:38:57 +0000308</pre>
309
310<p>
Carl Worth619505a2014-08-21 10:44:35 -0700311Note: If both options are given in one build, both swrast_dri.so drivers will
312be compiled, but only one will be installed. The following command can be used
313to ensure the correct driver is being tested:
314</p>
315
316<pre>
317LIBGL_ALWAYS_SOFTWARE=1 glxinfo | grep "renderer string"
318</pre>
319
320If any regressions are found in this testing with piglit, stop here, and do
321not perform a release until regressions are fixed.
322
323<h3>Update version in file VERSION</h3>
324
325<p>
326Increment the version contained in the file VERSION at Mesa's top-level, then
327commit this change.
328</p>
329
330<h3>Create release notes for the new release</h3>
331
332<p>
333Create a new file docs/relnotes/X.Y.Z.html, (follow the style of the previous
334release notes). Note that the sha256sums section of the release notes should
335be empty at this point.
Brian Paul65b79052004-11-22 17:49:15 +0000336</p>
337
338<p>
Carl Worth619505a2014-08-21 10:44:35 -0700339Two scripts are available to help generate portions of the release notes:
Brian Paul0b27ace2003-03-08 17:38:57 +0000340
Carl Worth619505a2014-08-21 10:44:35 -0700341<pre>
342 ./bin/bugzilla_mesa.sh
343 ./bin/shortlog_mesa.sh
344</pre>
345
Brian Paul0b27ace2003-03-08 17:38:57 +0000346<p>
Carl Worth619505a2014-08-21 10:44:35 -0700347The first script identifies commits that reference bugzilla bugs and obtains
348the descriptions of those bugs from bugzilla. The second script generates a
349log of all commits. In both cases, HTML-formatted lists are printed to stdout
350to be included in the release notes.
Brian Paul0b27ace2003-03-08 17:38:57 +0000351</p>
352
353<p>
Carl Worth619505a2014-08-21 10:44:35 -0700354Commit these changes
355</p>
356
357<h3>Make the release archives, signatures, and the release tag</h3>
358<p>
359From inside the Mesa directory:
360<pre>
361 ./autogen.sh
362 make -j1 tarballs
363</pre>
364
365<p>
366After the tarballs are created, the sha256 checksums for the files will
367be computed and printed. These will be used in a step below.
368</p>
369
370<p>
371It's important at this point to also verify that the constructed tar file
372actually builds:
373</p>
374
375<pre>
376 tar xjf MesaLib-X.Y.Z.tar.bz2
377 cd Mesa-X.Y.Z
378 ./configure --enable-gallium-llvm
379 make -j6
380 make install
381</pre>
382
383<p>
384Some touch testing should also be performed at this point, (run glxgears or
385more involved OpenGL programs against the installed Mesa).
386</p>
387
388<p>
389Create detached GPG signatures for each of the archive files created above:
390</p>
391
392<pre>
393 gpg --sign --detach MesaLib-X.Y.Z.tar.gz
394 gpg --sign --detach MesaLib-X.Y.Z.tar.bz2
395 gpg --sign --detach MesaLib-X.Y.Z.zip
396</pre>
397
398<p>
399Tag the commit used for the build:
400</p>
401
402<pre>
403 git tag -s mesa-X.Y.X -m "Mesa X.Y.Z release"
404</pre>
405
406<p>
407Note: It would be nice to investigate and fix the issue that causes the
408tarballs target to fail with multiple build process, such as with "-j4". It
409would also be nice to incorporate all of the above commands into a single
410makefile target. And instead of a custom "tarballs" target, we should
411incorporate things into the standard "make dist" and "make distcheck" targets.
412</p>
413
414<h3>Add the sha256sums to the release notes</h3>
415
416<p>
417Edit docs/relnotes/X.Y.Z.html to add the sha256sums printed as part of "make
418tarballs" in the previous step. Commit this change.
419</p>
420
421<h3>Push all commits and the tag creates above</h3>
422
423<p>
424This is the first step that cannot easily be undone. The release is going
425forward from this point:
426</p>
427
428<pre>
429 git push origin X.Y --tags
430</pre>
431
432<h3>Install the release files and signatures on the distribution server</h3>
433
434<p>
435The following commands can be used to copy the release archive files and
436signatures to the freedesktop.org server:
437</p>
438
439<pre>
440 scp MesaLib-X.Y.Z* people.freedesktop.org:
441 ssh people.freedesktop.org
442 cd /srv/ftp.freedesktop.org/pub/mesa
443 mkdir X.Y.Z
444 cd X.Y.Z
445 mv ~/MesaLib-X.Y.Z* .
446</pre>
447
448<h3>Back on mesa master, andd the new release notes into the tree</h3>
449
450<p>
451Something like the following steps will do the trick:
452</p>
453
454<pre>
455 cp docs/relnotes/X.Y.Z.html /tmp
456 git checkout master
457 cp /tmp/X.Y.Z.html docs/relnotes
458 git add docs/relnotes/X.Y.Z.html
459</pre>
460
461<p>
462Also, edit docs/relnotes.html to add a link to the new release notes, and edit
463docs/index.html to add a news entry. Then commit and push:
464</p>
465
466<pre>
467 git commit -a -m "docs: Import X.Y.Z release notes, add news item."
468 git push origin
469</pre>
470
471<h3>Update the mesa3d.org website</h3>
472
473<p>
474NOTE: The recent release managers have not been performing this step
475themselves, but leaving this to Brian Paul, (who has access to the
476sourceforge.net hosting for mesa3d.org). Brian is more than willing to grant
477the permission necessary to future release managers to do this step on their
478own.
Brian Paul84c5e482009-06-23 19:21:04 -0600479</p>
480
481<p>
Brian Paul65b79052004-11-22 17:49:15 +0000482Update the web site by copying the docs/ directory's files to
Brian Paul84c5e482009-06-23 19:21:04 -0600483/home/users/b/br/brianp/mesa-www/htdocs/ with:
484<br>
485<code>
486sftp USERNAME,mesa3d@web.sourceforge.net
487</code>
Brian Paul0b27ace2003-03-08 17:38:57 +0000488</p>
489
Carl Worth619505a2014-08-21 10:44:35 -0700490
491<h3>Announce the release</h3>
Brian Paul0b27ace2003-03-08 17:38:57 +0000492<p>
Brian Paulefe56712003-03-19 19:15:28 +0000493Make an announcement on the mailing lists:
Ian Romanick8f32c642010-06-16 14:28:08 -0700494
Kenneth Graunke7d24d1b2013-07-25 11:42:38 -0700495<em>mesa-dev@lists.freedesktop.org</em>,
Brian Paulefe56712003-03-19 19:15:28 +0000496and
Kenneth Graunke7d24d1b2013-07-25 11:42:38 -0700497<em>mesa-announce@lists.freedesktop.org</em>
Carl Worth619505a2014-08-21 10:44:35 -0700498
499Follow the template of previously-sent release announcements. The following
500command can be used to generate the log of changes to be included in the
501release announcement:
502
503<pre>
504 git shortlog mesa-X.Y.Z-1..mesa-X.Y.Z
505</pre>
Brian Paul0b27ace2003-03-08 17:38:57 +0000506</p>
507
Brian Paul98f2f472015-05-25 09:13:09 -0600508
509<h2 id="extensions">Adding Extensions</h2>
510
511<p>
512To add a new GL extension to Mesa you have to do at least the following.
513
514<ul>
515<li>
516 If glext.h doesn't define the extension, edit include/GL/gl.h and add
517 code like this:
518 <pre>
519 #ifndef GL_EXT_the_extension_name
520 #define GL_EXT_the_extension_name 1
521 /* declare the new enum tokens */
522 /* prototype the new functions */
523 /* TYPEDEFS for the new functions */
524 #endif
525 </pre>
526</li>
527<li>
528 In the src/mapi/glapi/gen/ directory, add the new extension functions and
529 enums to the gl_API.xml file.
530 Then, a bunch of source files must be regenerated by executing the
531 corresponding Python scripts.
532</li>
533<li>
534 Add a new entry to the <code>gl_extensions</code> struct in mtypes.h
535</li>
536<li>
537 Update the <code>extensions.c</code> file.
538</li>
539<li>
540 From this point, the best way to proceed is to find another extension,
541 similar to the new one, that's already implemented in Mesa and use it
542 as an example.
543</li>
544<li>
545 If the new extension adds new GL state, the functions in get.c, enable.c
546 and attrib.c will most likely require new code.
547</li>
548<li>
549 The dispatch tests check_table.cpp and dispatch_sanity.cpp
550 should be updated with details about the new extensions functions. These
551 tests are run using 'make check'
552</li>
553</ul>
554
555
556
557
Andreas Bollb5da52a2012-09-18 18:57:02 +0200558</div>
Brian Paul0b27ace2003-03-08 17:38:57 +0000559</body>
560</html>