5 \___|\___/|_| \_\_____|
7 When Contributing Source Code
9 This document is intended to offer guidelines that can be useful to keep in
10 mind when you decide to contribute to the project. This concerns new features
11 as well as corrections to existing flaws or bugs.
14 1.1 Join the Community
18 2. cURL Coding Standards
24 2.6 Non-clobbering All Over
25 2.7 Platform Dependent Code
26 2.8 Write Separate Patches
27 2.9 Patch Against Recent Sources
31 3. Pushing Out Your Changes
32 3.1 Write Access to git Repository
33 3.2 How To Make a Patch with git
34 3.3 How To Make a Patch without git
35 3.4 How to get your changes into the main sources
36 3.5 Write good commit messages
38 ==============================================================================
42 1.1 Join the Community
44 Skip over to http://curl.haxx.se/mail/ and join the appropriate mailing
45 list(s). Read up on details before you post questions. Read this file before
46 you start sending patches! We prefer patches and discussions being held on
47 the mailing list(s), not sent to individuals.
49 Before posting to one of the curl mailing lists, please read up on the mailing
50 list etiquette: http://curl.haxx.se/mail/etiquette.html
52 We also hang out on IRC in #curl on irc.freenode.net
56 When contributing with code, you agree to put your changes and new code under
57 the same license curl and libcurl is already using unless stated and agreed
60 If you add a larger piece of code, you can opt to make that file or set of
61 files to use a different license as long as they don't enforce any changes to
62 the rest of the package and they make sense. Such "separate parts" can not be
63 GPL licensed (as we don't want copyleft to affect users of libcurl) but they
64 must use "GPL compatible" licenses (as we want to allow users to use libcurl
65 properly in GPL licensed environments).
67 When changing existing source code, you do not alter the copyright of the
68 original file(s). The copyright will still be owned by the original
69 creator(s) or those who have been assigned copyright by the original
72 By submitting a patch to the curl project, you are assumed to have the right
73 to the code and to be allowed by your employer or whatever to hand over that
74 patch/code to us. We will credit you for your changes as far as possible, to
75 give credit but also to keep a trace back to who made what changes. Please
76 always provide us with your full real name when contributing!
80 Source code, the man pages, the INTERNALS document, TODO, KNOWN_BUGS, the
81 most recent CHANGES. Just lurking on the libcurl mailing list is gonna give
82 you a lot of insights on what's going on right now. Asking there is a good
85 2. cURL Coding Standards
89 Try using a non-confusing naming scheme for your new functions and variable
90 names. It doesn't necessarily have to mean that you should use the same as in
91 other places of the code, just that the names should be logical,
92 understandable and be named according to what they're used for. File-local
93 functions should be made static. We like lower case names.
95 See the INTERNALS document on how we name non-exported library-global
100 Please try using the same indenting levels and bracing method as all the
101 other code already does. It makes the source code a lot easier to follow if
102 all of it is written using the same style. We don't ask you to like it, we
103 just ask you to follow the tradition! ;-) This mainly means: 2-level indents,
104 using spaces only (no tabs) and having the opening brace ({) on the same line
105 as the if() or while().
107 Also note that we use if() and while() with no space before the parenthesis.
111 Comment your source code extensively using C comments (/* comment */), DO NOT
112 use C++ comments (// this style). Commented code is quality code and enables
113 future modifications much more. Uncommented code risk having to be completely
114 replaced when someone wants to extend things, since other persons' source
115 code can get quite hard to read.
119 We write source lines shorter than 80 columns.
123 Keep your functions small. If they're small you avoid a lot of mistakes and
124 you don't accidentally mix up variables etc.
126 2.6 Non-clobbering All Over
128 When you write new functionality or fix bugs, it is important that you don't
129 fiddle all over the source files and functions. Remember that it is likely
130 that other people have done changes in the same source files as you have and
131 possibly even in the same functions. If you bring completely new
132 functionality, try writing it in a new source file. If you fix bugs, try to
133 fix one bug at a time and send them as separate patches.
135 2.7 Platform Dependent Code
137 Use #ifdef HAVE_FEATURE to do conditional code. We avoid checking for
138 particular operating systems or hardware in the #ifdef lines. The
139 HAVE_FEATURE shall be generated by the configure script for unix-like systems
140 and they are hard-coded in the config-[system].h files for the others.
142 2.8 Write Separate Patches
144 It is annoying when you get a huge patch from someone that is said to fix 511
145 odd problems, but discussions and opinions don't agree with 510 of them - or
146 509 of them were already fixed in a different way. Then the patcher needs to
147 extract the single interesting patch from somewhere within the huge pile of
148 source, and that gives a lot of extra work. Preferably, all fixes that
149 correct different problems should be in their own patch with an attached
150 description exactly what they correct so that all patches can be selectively
151 applied by the maintainer or other interested parties.
153 2.9 Patch Against Recent Sources
155 Please try to get the latest available sources to make your patches
156 against. It makes the life of the developers so much easier. The very best is
157 if you get the most up-to-date sources from the git repository, but the
158 latest release archive is quite OK as well!
162 Writing docs is dead boring and one of the big problems with many open source
163 projects. Someone's gotta do it. It makes it a lot easier if you submit a
164 small description of your fix or your new features with every contribution so
165 that it can be swiftly added to the package documentation.
167 The documentation is always made in man pages (nroff formatted) or plain
168 ASCII files. All HTML files on the web site and in the release archives are
169 generated from the nroff/ASCII versions.
173 Since the introduction of the test suite, we can quickly verify that the main
174 features are working as they're supposed to. To maintain this situation and
175 improve it, all new features and functions that are added need to be tested
176 in the test suite. Every feature that is added should get at least one valid
177 test case that verifies that it works as documented. If every submitter also
178 posts a few test cases, it won't end up as a heavy burden on a single person!
180 3. Pushing Out Your Changes
182 3.1 Write Access to git Repository
184 If you are a frequent contributor, or have another good reason, you can of
185 course get write access to the git repository and then you'll be able to push
186 your changes straight into the git repo instead of sending changes by mail as
187 patches. Just ask if this is what you'd want. You will be required to have
188 posted a few quality patches first, before you can be granted push access.
190 3.2 How To Make a Patch with git
192 You need to first checkout the respository:
194 git clone git://github.com/bagder/curl.git
196 You then proceed and edit all the files you like and you commit them to your
201 As usual, group your commits so that you commit all changes that at once that
202 constitutes a logical change. See also section "3.5 Write good commit
205 Once you have done all your commits and you're happy with what you see, you
206 can make patches out of your changes that are suitable for mailing:
208 git format-patch remotes/origin/master
210 This creates files in your local directory named NNNN-[name].patch for each
213 Now send those patches off to the curl-library list. You can of course opt to
214 do that with the 'get send-email' command.
216 3.3 How To Make a Patch without git
218 Keep a copy of the unmodified curl sources. Make your changes in a separate
219 source tree. When you think you have something that you want to offer the
220 curl community, use GNU diff to generate patches.
222 If you have modified a single file, try something like:
224 diff -u unmodified-file.c my-changed-one.c > my-fixes.diff
226 If you have modified several files, possibly in different directories, you
227 can use diff recursively:
229 diff -ur curl-original-dir curl-modified-sources-dir > my-fixes.diff
231 The GNU diff and GNU patch tools exist for virtually all platforms, including
232 all kinds of Unixes and Windows:
234 For unix-like operating systems:
236 http://www.gnu.org/software/patch/patch.html
237 http://www.gnu.org/directory/diffutils.html
241 http://gnuwin32.sourceforge.net/packages/patch.htm
242 http://gnuwin32.sourceforge.net/packages/diffutils.htm
244 3.4 How to get your changes into the main sources
246 1. Submit your patch to the curl-library mailing list
248 2. Make the patch against as recent sources as possible.
250 3. Make sure your patch adheres to the source indent and coding style of
251 already existing source code. Failing to do so just adds more work for me.
253 4. Respond to replies on the list about the patch and answer questions and/or
254 fix nits/flaws. This is very important. I will take lack of replies as a
255 sign that you're not very anxious to get your patch accepted and I tend to
256 simply drop such patches from my TODO list.
258 5. If you've followed the above mentioned paragraphs and your patch still
259 hasn't been incorporated after some weeks, consider resubmitting it to the
262 3.5 Write good commit messages
264 A short guide to how to do fine commit messages in the curl project.
267 [area]: [short line describing the main effect]
269 [separate the above single line from the rest with an empty line]
271 [full description, no wider than 72 columns that describe as much as
272 possible as to why this change is made, and possibly what things
273 it fixes and everything else that is related]
276 Don't forget to use commit --author="" if you commit someone else's work,
277 and make sure that you have your own user and email setup correctly in git