<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0//EN" "http://www.w3.org/TR/REC-html40/strict.dtd"><html><head><meta name="qrichtext" content="1" /><style type="text/css">p, li { white-space: pre-wrap; }</style></head><body style=" font-family:'Sans Serif'; font-size:10pt; font-weight:400; font-style:normal;">In compiz++ I've made few little changes that do not follow the our previous coding style: - allow variable definition in "for" loops: for (int i = 0; i < foo; i++) In the "C" version of compiz we've tried to follow the C89 rules, but this is not necessary anymore and should improve readability. - define variables not at the top of a function: For references we have to define a variable at the point where it gets initialised. I would like the keep the "define the variables at the top of a function" style, but we should allow "in body" variable definition, at places where it improves readability of the code. - indent "case" statements inside of "switch" statements: in the "C" version of compiz we aligned the case statements at the same level like its switch statement: switch (foo) { case foo1: break; case foo2 break; } I think that indenting the "case" statement is a better style here: switch (foo) { case foo1: break; case foo2: break; } Another style rule that I would like to add to our coding style is to provide a consistent system to mark differences between function local variables, function parameters, class member variables and global variables. I have already two possible solutions here: Solution 1: postfix member and global variables with a "_" prefix function parameter with a "_" Solution 2: prefix member variable with "m_" prefix global variables with "g_" For my diploma thesis I'm currently working on a C++ tool that already uses the first rule, and I've realized that it really improves readability of the code, because it's pretty clear where a variable is coming from. I would really like to get the opinions and solutions of other developers here. Dennis Am Dienstag 03 Februar 2009 16:46:27 schrieb Kristian Lyngstol: > I've been trying to come up with some good coding standards, but I've > realized that most of us already know most of this. So instead of trying to > define every aspect of how we code Compiz-code, I'll try to outline some of > the finer points. For a more complete list, you can review any of the many > coding-standard documents out there (For Linux, FreeBSD or any other > project). > > Part of this draft is designed to document the already undocumented code, > which means some additional work for developers working on existing code. > I hope the degree of work expected is acceptable. > > Note that this is a very rough draft. > > 1. Maintainability > > Your code will be used by thousands of users, and it will be used even if > you no longer find yourself working on Compiz. Design your code with this > in mind. Remember that if you can get 90% of the functionality with 10% of > the work, that's a good thing. > > Split your code into logical pieces. Ideally, functions span 1-3 screens > on a 80x25 terminal. Complex functions should strive for a smaller size, > while simple functions (like initialization of large structures) could be > quite long. If your function is one big if-elseif-elseif-...else- > statement, each block should be tiny or split out into separate functions. > Performance-wise, there's nothing stopping you from using an > inline-function to achieve the same performance with increased readability. > > To reduce complexity, clear and well defined interfaces are needed. The > fewer interfaces we need, the better. This goes for both core<->plugin > interaction, and interaction between different parts of core or a plugin. > > If you can't avoid complexity, attempt to separate it from the rest of the > code as much as possible, and make sure it's well-documented in-line in > your code. Any special exceptions you have to make should be documented in > the code. Which brings us to... > > 2. Document your code > > Note that from now on, it is your responsibility to document code you work > on, even if you aren't the original author. Commits that lack the necessary > documentation is likely to be revoked. There are exceptions to this, but > read on. > > This does not mean writing on the wiki, writing a seperate text file or > publishing a book. It means that you stick a little comment in each file > under the license explaining very briefly what the plugin does, and if > there are any special tricks used. And it means that if you work on any > non-trivial function, make sure you stick a comment on top of it explaining > what it does and how to use it, if it isn't evident. > > If in doubt, make a comment. > > There's a formula for when to do this, which is loosely based on > complexity, importance and how exposed your function is. This basically > means that ANY core function that is not declared static should be > documented. For core functions, you should also mention where you want this > function to be used, even if it might already be obvious from header-files. > This is specially important with functions that are only safe or valid in > certain contexts. > > As for exceptions: If you are only tweaking an existing function, for > instance to adjust it to an API change, it is not required to comment. If > you are in doubt about the code functionality, and don't wish to verify > with others, writing a FIXME: with a brief question/comment so somebody > else can pick it up, is acceptable. > > 3. Be consistent > > This applies to both within your own code, but also with regards to the > rest of the project. Use the same grammatical coding style (found on the > wiki), similar naming-conventions and so on. > > 4. Don't supply useless code or options > > Our job as developers is to create mechanism, not policy. Don't use your > plugin or core-code to change the world. Don't supply 5 different options > when you can supply one that allows for the same level of flexibility. > Think about Compiz' position in the bigger picture, not just the world you > live in. > > If you really really really want to change the world, at the very least, do > it as a warning, not an error! > > 5. Expect the unexpected > > Check return values. Check input-values for non-static code. It has a > negative development cost; Any time used now will be made up for down the > road. > > ----------------------------------------- > > That's it so far. I really hope someone can rip this apart, since I ended > up trashing my more detailed ideas and threw this together in a hurry. At > least it should get the discussion started. > > Specially since this is written with C, and not C++ in mind. > > - Kristian </body></html>