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diff --git a/docs/contributing.txt b/docs/contributing.txt new file mode 100644 index 000000000..696e63c2c --- /dev/null +++ b/docs/contributing.txt @@ -0,0 +1,390 @@ +Contributing To Busybox +======================= + +This document describes what you need to do to contribute to Busybox, where +you can help, guidelines on testing, and how to submit a well-formed patch +that is more likely to be accepted. + +The Busybox home page is at: http://busybox.lineo.com + + + +Pre-Contribution Checklist +-------------------------- + +So you want to contribute to Busybox, eh? Great, wonderful, glad you want to +help. However, before you dive in, headlong and hotfoot, there are some things +you need to do: + + +Checkout the Latest Code from CVS +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +This is a necessary first step. Please do not try to work with the last +released version, as there is a good chance that somebody has already worked +on the area you had in mind and your patch might already be obsolete. + +For information on how to check out Busybox from CVS, please look at the +following links: + + http://oss.lineo.com/cvs_anon.html + http://oss.lineo.com/cvs_howto.html + + +Read the Mailing List +~~~~~~~~~~~~~~~~~~~~~ + +No one is required to read the entire archives of the mailing list, but you +should at least read up on what people have been talking about lately. If +you've recently discovered a problem, chances are somebody else has too. If +you're the first to discover a problem, post a message and let the rest of us +know. + +Archives can be found here: + + http://opensource.lineo.com/lists/busybox/ + +If you have a serious interest in Busybox, i.e. you are using it day-to-day or +as part of an embedded project, it's a good idea to join the mailing list. + +A web-based sign-up form can be found here: + + http://opensource.lineo.com/mailman/listinfo/busybox + + +Coordinate with the Applet Maintainer +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Some (not all) of the applets in Busybox are "owned" by a maintainer who has +put significant effort into it and is probably more familiar with it than +others. To find the maintainer of an applet, look at the top of the .c file +for a name following the word 'Copyright' or 'Written by'. + +Before plunging ahead, it's a good idea to send a message to the mailing list +that says: "Hey, I was thinking about adding the 'transmogrify' feature to the +'foo' applet. Would this be useful? Is anyone else working on it?" You might +want to CC the maintainer (if any) with your question. + + + +Areas Where You Can Help +------------------------ + +Busybox can always use improvement! If you're looking for ways to help, there +there are a variety of areas where you could help. + + +What Busybox Doesn't Need +~~~~~~~~~~~~~~~~~~~~~~~~~ + +Before listing the areas where you _can_ help, it's worthwhile to mention the +areas where you shouldn't bother. While Busybox strives to be the "Swiss Army +Knife" of embedded Linux, there are some applets that will not be accepted: + + - Any filesystem manipulation tools: Busybox is filesystem independent and + we do not want to start adding mkfs/fsck tools for every (or any) + filesystem under the sun. (fsck_minix.c and mkfs_minix.c are living on + borrowed time.) There are far too many of these tools out there. Use + the upstream version. Not everything has to be part of Busybox. + + - Any partitioning tools: Partitioning a device is typically done once and + only once, and tools which do this generally do not need to reside on the + target device (esp a flash device). If you need a partitioning tool, grab + one (such as fdisk, sfdisk, or cfdisk from util-linux) and use that, but + don't try to merge it into busybox. These are nasty and complex and we + don't want to maintain them. + + - Any disk, device, or media-specific tools: Use the -utils or -tools package + that was designed for your device; don't try to shoehorn them into Busybox. + + - Any architecture specific tools: Busybox is (or should be) architecture + independent. Do not send us tools that cannot be used across multiple + platforms / arches. + + +Bug Reporting +~~~~~~~~~~~~~ + +If you find a bug in Busybox, you can send a bug report to our bug tracking +system (homepage: http://bugs.lineo.com). Instructions on how to send a bug +report to the tracking system can be found at: + + http://bugs.lineo.com/Reporting.html + +The README file that comes with Busybox also describes how to submit a bug. + +A well-written bug report will include a transcript of a shell session that +demonstrates the bad behavior and enables anyone else to duplicate the bug on +their own machine. + + +Bug Triage +~~~~~~~~~~ + +Validating and confirming bugs is nearly as important as reporting them in the +first place. It is valuable to know if a bug can be duplicated on a different +machine, on a different filesystem, on a different architecture, with a +different C library, and so forth. + +To see a listing of all the bugs currently filed against Busybox, look here: + + http://bugs.lineo.com/db/pa/lbusybox.html + +If you have comments to add to a bug (can / can't duplicate, think a bug +should be closed / reopened), please send it to [bugnumber]@bugs.lineo.com. +The message you send will automatically be forwarded to the mailing list for +all to see. + + +Write Documentation +~~~~~~~~~~~~~~~~~~~ + +Chances are, documentation in Busybox is either missing or needs improvement. +Either way, help is welcome. + +Work is being done to automatically generate documentation from sources, +especially from the usage.h file. If you want to correct the documentation, +please make changes to the pre-generation parts, rather than the generated +documentation. [More to come on this later...] + +It is preferred that modifications to documentation be submitted in patch +format (more on this below), but we're a little more lenient when it comes to +docs. You could, for example, just say "after the listing of the mount +options, the following example would be helpful..." + + +Consult Existing Sources +~~~~~~~~~~~~~~~~~~~~~~~~ + +For a quick listing of "needs work" spots in the sources, cd into the Busybox +directory and run the following: + + for i in TODO FIXME XXX; do grep $i *.[ch]; done + +This will show all of the trouble spots or 'questionable' code. Pick a spot, +any spot, these are all invitations for you to contribute. + + +Consult The Bug-Tracking System +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Head to: http://bugs.lineo.com/db/pa/lBusybox.html and look at the bugs on +there. Pick one you think you can fix, and fix it. If it's a wishlist item and +someone's requesting a new feature, take a stab at adding it. Everything +previously said about "reading the mailing list" and "coordinating with the +applet maintainer" still applies. + + +Add a New Applet +~~~~~~~~~~~~~~~~ + +If you want to add a new applet to Busybox, we'd love to see it. However, +before you write any code, please ask beforehand on the mailing list something +like "Do you think applet 'foo' would be useful in Busybox?" or "Would you +guys accept applet 'foo' into Busybox if I were to write it?" If the answer is +"no" by the folks on the mailing list, then you've saved yourself some time. +Conversely, you could get some positive responses from folks who might be +interested in helping you implement it, or can recommend the best approach. +Perhaps most importantly, this is your way of calling "dibs" on something and +avoiding duplication of effort. + +Also, before you write a line of code, please read the 'new-applet-HOWTO.txt' +file in the docs/ directory. + + +Janitorial Work +~~~~~~~~~~~~~~~ + +These are dirty jobs, but somebody's gotta do 'em. + + - Security audits: + http://www.securityfocus.com/frames/?content=/forums/secprog/secure-programming.html + + - Synthetic code removal: http://www.perl.com/pub/2000/06/commify.html - This + is very Perl-specific, but the advice given in here applies equally well to + C. + + - C library funciton use audits: Verifying that functions are being used + properly (called with the right args), replacing unsafe library functions + with safer versions, making sure return codes are being checked, etc. + + - Where appropriate, replace preprocessor defined macros and values with + compile-time equivalents. + + - Makefile improvements: + http://www.canb.auug.org.au/~millerp/rmch/recu-make-cons-harm.html + (I think the recursive problems are pretty much taken care of at this point, non?) + + - "Ten Commandments" compliance: (this is a "maybe", certainly not as + important as any of the previous items.) + http://web.onetelnet.ch/~twolf/tw/c/ten_commandments.html + +Other useful links: + + - the comp.lang.c FAQ: http://web.onetelnet.ch/~twolf/tw/c/index.html#Sources + + + +Submitting Patches To Busybox +----------------------------- + +Here are some guidelines on how to submit a patch to Busybox. + + +Making A Patch +~~~~~~~~~~~~~~ + +If you've got anonymous CVS access set up, making a patch is simple. Just make +sure you're in the busybox/ directory and type 'cvs diff -bwu > mychanges.patch'. +You can send the resulting .patch file to the mailing list with a description +of what it does. (But not before you test it! See the next section for some +guidelines.) It is preferred that patches be sent as attachments, but it is +not required. + +Also, feel free to help test other people's patches and reply to them with +comments. You can apply a patch by saving it into your busybox/ directory and +typing 'patch < mychanges.patch'. Then you can recompile, see if it runs, test +if it works as advertised, and post your findings to the mailing list. + +NOTE: Please do not include extraneous or irrelevant changes in your patches. +Please do not try to "bundle" two patches together into one. Make single, +discreet changes on a per-patch basis. Sometimes you need to make a patch that +touches code in many places, but these kind of patches are rare and should be +coordinated with a maintainer. + + +Testing Guidelines +~~~~~~~~~~~~~~~~~~ + +It's considered good form to test your new feature before you submit a patch +to the mailing list, and especially before you commit a change to CVS. Here +are some guidelines on how to test your changes. + + - Always test Busybox applets against GNU counterparts and make sure the + behavior / output is identical between the two. + + - Try several different permutations and combinations of the features you're + adding (i.e. different combinations of command-line switches) and make sure + they all work; make sure one feature does not interfere with another. + + - Make sure you test compiling against the source both with the feature + turned on and turned off in Config.h and make sure Busybox compiles cleanly + both ways. + + - Run the multibuild.pl script in the tests directory and make sure + everything checks out OK. (Do this from within the busybox/ directory by + typing: 'tests/multibuild.pl'.) + + +Making Sure Your Patch Doesn't Get Lost +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +If you don't want your patch to be lost or forgotten, send it to the bug +tracking system (http://bugs.lineo.com). You do this by emailing your patch in +a message to submit@bugs.lineo.com with a subject line something like this: + + [PATCH] - Adds "transmogrify" feature to "foo" + +In the body, you should have a pseudo-header that looks like the following: + + Package: busybox + Version: v0.50pre (or whatever the current version is) + Severity: wishlist + +The remainder of the body should read along these lines: + + This patch adds the "transmogrify" feature to the "foo" applet. I have + tested this on [arch] system(s) and it works. I have tested it against the + GNU counterparts and the outputs are identical. I have run the scripts in + the 'tests' directory and nothing breaks. + +Detailed instructions on how to submit a bug to the tracking system are at: + + http://bugs.lineo.com/Reporting.html + + + +Improving Your Chances of Patch Acceptance +------------------------------------------ + +Even after you send a brilliant patch to the mailing list, sometimes it can go +unnoticed, un-replied-to, and sometimes (sigh) even lost. This is an +unfortunate fact of life, but there are steps you can take to help your patch +get noticed and convince a maintainer that it should be added: + + +Be Succinct +~~~~~~~~~~~ + +A patch that includes small, isolated, obvious changes is more likely to be +accepted than a patch that touches code in lots of different places or makes +sweeping, dubious changes. + + +Back It Up +~~~~~~~~~~ + +Hard facts on why your patch is better than the existing code will go a long +way toward convincing maintainers that your patch should be included. +Specifically, patches are more likely to be accepted if they are provably more +correct, smaller, faster, simpler, or more maintainable than the existing +code. + +Conversely, any patch that is supported with nothing more than "I think this +would be cool" or "this patch is good because I say it is and I've got a Phd +in Computer Science" will likely be ignored. + + +Follow The Style Guide +~~~~~~~~~~~~~~~~~~~~~~ + +It's considered good form to abide by the established coding style used in a +project; Busybox is no exception. We have gone so far as to delineate the +"elements of Busybox style" in the file docs/style-guide.txt. Please follow +them. + + +Work With Someone Else +~~~~~~~~~~~~~~~~~~~~~~ + +Working on a patch in isolation is less effective than working with someone +else for a variety of reasons. If another Busybox user is interested in what +you're doing, then it's two (or more) voices instead of one that can petition +for inclusion of the patch. You'll also have more people that can test your +changes, or even offer suggestions on better approaches you could take. + +Getting other folks interested follows as a natural course if you've received +responses from queries to applet maintainer or positive responses from folks +on the mailing list. + +We've made strident efforts to put a useful "collaboration" infrastructure in +place in the form of mailing lists, the bug tracking system, and CVS. Please +use these resources. + + +Be Polite +~~~~~~~~~ + +The old saying "You'll catch more flies with honey than you will with vinegar" +applies when submitting patches to the mailing list for approval. The way you +present your patch is sometimes just as important as the actual patch itself +(if not more so). Being rude to the maintainers is not an effective way to +convince them that your patch should be included; it will likely have the +opposite effect. + + + +Final Words +----------- + +If all of this seems complicated, don't panic, it's really not that tough. If +you're having difficulty following some of the steps outlined in this +document don't worry, the folks on the Busybox mailing list are a fairly +good-natured bunch and will work with you to help get your patches into shape +or help you make contributions. + +If you submit several patches that demonstrate that you are a skilled and wise +coder, you may be invited to become a committer, thus enabling you to commit +changes directly to CVS. + + |