4 Contributing
zqpvr01 edited this page 2024-03-22 12:39:40 +01:00

Reporting Issues

The issue tracker is not a support forum. Unless you can provide precise technical information regarding an issue, you should not post in it. If you need support, first read the FAQ and then either visit our Discord server, or ask in a general emulation forum such as /r/emulation. If you post support questions, generic messages to the developers or vague reports without technical details, they will be closed and locked.

If you believe you have a valid issue report, please post text or a screenshot from the log (the console window that opens alongside suyu) and build version (hex string visible in the titlebar and zip filename), as well as your hardware and software information if applicable.


suyu is a brand new project, so we have a great opportunity to keep things clean and well organized early on. As such, coding style is very important when making commits. We run clang-format on our CI to check the code. Please use it to format your code when contributing. However, it doesn't cover all the rules below. Some of them aren't very strict rules since we want to be flexible and we understand that under certain circumstances some of them can be counterproductive. Just try to follow as many of them as possible.

Using clang-format

A custom build target, that updates the formatting of all C++ source files when executed, is added only if clang format is found by cmake. Before running cmake, please install clang format.


Version should be 10 or above.

  • Windows: do nothing; cmake will download a pre built binary for MSVC and MINGW. MSVC users can additionally install a clang format Visual Studio extension to add features like format on save.
  • macOS: run brew install clang-format
  • Linux: use your package manager to get an appropriate binary. e.g.:
    • Fedora: sudo dnf install clang-tools-extra
    • Ubuntu: sudo apt install clang-format


You should format before making a pull request so that the reviewers can spend more time reviewing the code logic instead of the style.

  • Windows with MSVC: build the clang-format project in the solution
  • macOS: either use make clang-format or build the 'clang-format' target in XCode
  • Linux: run ninja clang-format

Style guidelines

General Rules

  • A lot of code was taken from other projects (e.g. Dolphin, PPSSPP, Gekko). In general, when editing other people's code, follow the style of the module you're in (or better yet, fix the style if it drastically differs from our guide).
  • Line width is typically 100 characters. Please do not use 80-characters.
  • Don't ever introduce new external dependencies into Core
  • Don't use any platform specific code in Core
  • Use namespaces often
  • Avoid the use of C-style casts and instead prefer C++-style static_cast and reinterpret_cast. Try to avoid using dynamic_cast. Never use const_cast except for when dealing with external const-incorrect APIs.

Naming Rules

  • Functions: PascalCase
  • Variables: lower_case_underscored. Prefix with g_ if global.
  • Classes: PascalCase
  • Files and Directories: lower_case_underscored
  • Namespaces: PascalCase, _ may also be used for clarity (e.g. ARM_InitCore)

Indentation/Whitespace Style

Follow the indentation/whitespace style shown below. Do not use tabs, use 4-spaces instead.


  • For regular comments, use C++ style (//) comments, even for multi-line ones.
  • For doc-comments (Doxygen comments), use /// if it's a single line, else use the /** */ style featured in the example. Start the text on the second line, not the first containing /**.
  • For items that are both defined and declared in two separate files, put the doc-comment only next to the associated declaration. (In a header file, usually.) Otherwise, put it next to the implementation. Never duplicate doc-comments in both places.
// Includes should be sorted lexicographically
// STD includes first
#include <array>
#include <map>
#include <memory>

// then, library includes
#include <nihstro/shared_binary.h>

// finally, suyu includes
#include "common/math_util.h"
#include "common/vector_math.h"

// each major module is separated
#include "video_core/pica.h"
#include "video_core/video_core.h"

namespace Example {

// Namespace contents are not indented

// Declare globals at the top (better yet, don't use globals at all!)
int g_foo{}; // {} can be used to initialize types as 0, false, or nullptr
char* g_some_pointer{}; // Pointer * and reference & stick to the type name, and make sure to initialize as nullptr!

/// A colorful enum.
enum class SomeEnum {
    Red,   ///< The color of fire.
    Green, ///< The color of grass.
    Blue,  ///< Not actually the color of water.

 * Very important struct that does a lot of stuff.
 * Note that the asterisks are indented by one space to align to the first line.
struct Position {
    // Always intitialize member variables!
    int x{};
    int y{};

// Use "typename" rather than "class" here
template <typename T>
void FooBar() {
    const std::string some_string{"prefer uniform initialization"};

    const std::array<int, 4> some_array{

    if (note == the_space_after_the_if) {
    } else {
        // Use a space after the // when commenting

    // Place a single space after the for loop semicolons, prefer pre-increment
    for (int i = 0; i != 25; ++i) {
        // This is how we write loops

    DoStuff(this, function, call, takes, up, multiple,
            lines, like, this);

    if (this || condition_takes_up_multiple &&
        lines && like && this || everything ||
        alright || then) {

        // Leave a blank space before the if block body if the condition was continued across
        // several lines.

    // No indentation for case labels
    switch (var) {
    case 1: {
        const int case_var{var + 3};
    case 3:
        // Yes, even break for the last case

} // namespace Example