70 lines
2.3 KiB
Plaintext
70 lines
2.3 KiB
Plaintext
Every project has its coding style, and kmod is not an exception. This
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document describes the preferred coding style for kmod code, in order to keep
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some level of consistency among developers so that code can be easily
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understood and maintained, and also to help your code survive under
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maintainer's fastidious eyes so that you can get a passport for your patch
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ASAP.
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First of all, kmod coding style must follow every rule for Linux kernel
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(http://www.kernel.org/doc/Documentation/CodingStyle). There also exists a tool
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named checkpatch.pl to help you check the compliance with it. Just type
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"checkpatch.pl --no-tree patch_name" to check your patch. In theory, you need
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to clean up all the warnings and errors except this one: "ERROR: Missing
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Signed-off-by: line(s)". kmod does not used Signed-Off lines, so including
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them is actually an error. In certain circumstances one can ignore the 80
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character per line limit. This is generally only allowed if the alternative
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would make the code even less readable.
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Besides the kernel coding style above, kmod coding style is heavily based on
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oFono's and BlueZ's. Below some basic rules:
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1) Wrap line at 80 char limit.
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There are a few exceptions:
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- Headers may or may not wrap
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- If it's a string that is hitting the limit, it's preferred not to break
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in order to be able to grep for that string. E.g:
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err = my_function(ctx, "this is a long string that will pass the 80chr limit");
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- If code would become unreadable if line is wrapped
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- If there's only one argument to the function, don't put it alone in a
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new line.
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Align the wrapped line either with tabs (BlueZ, oFono, etc) or tab + spaces
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(kernel), at your discretion. Kernel's is preferred.
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2) It's better to return/exit early in a function than having a really long
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"if (...) { }". Example:
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if (x) { // worse | if (!x) // better
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... | return b;
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... |
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... | ...
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... | ...
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... | ...
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... | ...
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... | ...
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... | ...
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} else { | ...
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return b; | return a;
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} |
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return a; |
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3) Don't initialize variable unnecessarily
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When declaring a variable, try not to initialize it unless necessary.
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Example:
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int i = 1; // wrong
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for (i = 0; i < 3; i++) {
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}
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4) Let the includes in the following order, separated by a new line:
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< system headers >
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< shared/* >
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< libkmod >
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< tool >
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"local headers"
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