6f739290ec
The various lists in the document are not quoted blocks. Don't indent them. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Acked-by: Jacopo Mondi <jacopo@jmondi.org> Acked-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
81 lines
3.3 KiB
ReStructuredText
81 lines
3.3 KiB
ReStructuredText
Coding Style Guidelines
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=======================
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The libcamera project has high standards of stability, efficiency and
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reliability. To achieve those, the project goes to great length to produce
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code that is as easy to read, understand and maintain as possible.
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These coding guidelines are meant to ensure code quality. As a contributor
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you are expected to follow them in all code submitted to the project. While
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strict compliance is desired, exceptions are tolerated when justified with
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good reasons. Please read the whole coding guidelines and use common sense
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to decide when departing from them is appropriate.
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libcamera is written in C++, a language that has seen many revisions and
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offers an extensive set of features that are easy to abuse. These coding
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guidelines establish the subset of C++ used by the project.
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Coding Style
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------------
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Even if the programming language in use is different, the project embraces the
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`Linux Kernel Coding Style`_ with a few exception and some C++ specificities.
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.. _Linux Kernel Coding Style: https://www.kernel.org/doc/html/latest/process/coding-style.html
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In particular, from the kernel style document, the following section are adopted:
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* 1 "Indentation"
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* 2 "Breaking Long Lines" striving to fit code within 80 columns and
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accepting up to 120 columns when necessary
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* 3 "Placing Braces and Spaces"
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* 3.1 "Spaces"
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* 8 "Commenting" with the exception that in-function comments are not
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always un-welcome.
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While libcamera uses the kernel coding style for all typographic matters, the
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project is a user space library, developed in a different programming language,
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and the kernel guidelines fall short for this use case.
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For this reason, rules and guidelines from the `Google C++ Style Guide`_ have
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been adopted as well as most coding principles specified therein, with a
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few exceptions and relaxed limitations on some subjects.
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.. _Google C++ Style Guide: https://google.github.io/styleguide/cppguide.html
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The following exceptions apply to the naming conventions specified in the
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document:
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* File names: libcamera uses the .cpp extensions for C++ source files and
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the .h extension for header files
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* Variables, function parameters, function names and class members use
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camel case style, with the first letter in lower-case (as in 'camelCase'
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and not 'CamelCase')
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* Types (classes, structs, type aliases, and type template parameters) use
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camel case, with the first letter in capital case (as in 'CamelCase' and
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not 'camelCase')
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* Enum members use 'CamelCase', while macros are in capital case with
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underscores in between
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* All formatting rules specified in the selected sections of the Linux kernel
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Code Style for indentation, braces, spacing, etc
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* Header guards are formatted as '__LIBCAMERA_FILE_NAME_H__'
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C++ Specific Rules
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------------------
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The code shall be implemented in C++03, extended with the following
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C++-11-specific features:
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* Initializer lists
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* Type inference (auto and decltype)
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Type inference shall be used with caution, to avoid drifting towards an
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untyped language.
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* Range-based for loop
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* Lambda functions
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* Explicit overrides and final
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* Null pointer constant
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* General-purpose smart pointers (std::unique_ptr), deprecating std::auto_ptr.
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Smart pointers, as well as shared pointers and weak pointers, shall not be
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overused.
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