93 lines
2.4 KiB
Markdown
93 lines
2.4 KiB
Markdown
# Pepper kernel coding style
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This document describes the coding style for the Pepper kernel. It is used as a guideline across all source files.
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## Indentation
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Indentations should be 4 characters long.
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## Line length
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Lines should not be more than 100 characters long.
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## Variables
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Variables should be declared at most once per line.
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## Braces
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Non-function statement blocks should have an opening brace last on the line, and a closing brace first. Exception is made for `else`, `else if` statements and the like:
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```c
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if (something) {
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do_something();
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} else if (something_else) {
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do_something_else();
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}
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```
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Having no braces for a single statement structure is fine.
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Functions should have their opening brace on a separate line, and the same goes for the closing brace:
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```c
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void function()
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{
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do_something();
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}
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```
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## Spaces
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Use a space after `if, switch, case, for, do, while` keywords, but not for `sizeof, typeof, alignof, __attribute__` and the like.
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For pointers, the asterisk should always be placed adjacent to the type name, like `char* str;`.
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## Naming
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Functions should be named with whole words, beginning with the corresponding name of the module in the kernel (the parent folder). Words should be spaced with underscores, like so:
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```c
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serial_init(void* ptr, char* str, int foo);
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```
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Constants should be named in all caps, separated by underscores:
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```c
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#define MAX_HEAP_SIZE 0x1000
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```
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Global variables need to have descriptive names. Local variables can be kept short (especially for loop counters).
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## Typedefs
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Structures should not be `typedef`'d. However using `typedef` for an enumeration is fine.
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## Functions
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Functions should be short, simple, and only do one thing.
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Function prototypes should include parameter names and their data types.
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## Commenting
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Comments should describe what a function does and why, not how it does it. The preferred way of commenting functions is the following:
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```c
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/*
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* function_name - Function brief description
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* @arg1: Argument 1 description
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* @arg2: Argument 2 description
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*
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* A longer description can be featured here, explaining more
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* in detail what the function does and why it does it.
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*/
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```
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## Kernel messages
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When printing kernel messages with the `DEBUG` macro, they should start with a capital letter.
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### Resources
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Some of the elements here are inspired by the [Linux kernel coding style](https://www.kernel.org/doc/html/v4.10/process/coding-style.html). |