53e6e4b8f0
mesh-normal-scalar correctly fills sequential values in the output for triangle cone function, but mesh-normal-vector accidentally reuses the loop index, which results in writes to every third index of the array (1, 4, etc.). This is both slower (as the table turns into a hash map), and incorrect, especially as we have a scalar version of the benchmark that does the right thing. Note: there's a bunch of inefficiencies in the benchmark code that I have not fixed (around field access mostly, e.g. writing to `v.n` and then immediately reading it again). These are not ideal for performance, but they can be valuable to keep as is because this redundancy is common in real-world code, and it would be nice to see codegen optimizations eliminating most of that overhead. This one, however, is a straight up bug, and sparse arrays should not really be the thing this benchmark hits. |
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.github | ||
Analysis | ||
Ast | ||
bench | ||
CLI | ||
CodeGen | ||
Common/include/Luau | ||
Compiler | ||
Config | ||
EqSat | ||
extern | ||
fuzz | ||
tests | ||
tools | ||
VM | ||
.clang-format | ||
.gitignore | ||
CMakeLists.txt | ||
CMakePresets.json | ||
CONTRIBUTING.md | ||
LICENSE.txt | ||
lua_LICENSE.txt | ||
Makefile | ||
README.md | ||
SECURITY.md | ||
Sources.cmake |
Luau
Luau (lowercase u, /ˈlu.aʊ/) is a fast, small, safe, gradually typed embeddable scripting language derived from Lua.
It is designed to be backwards compatible with Lua 5.1, as well as incorporating some features from future Lua releases, but also expands the feature set (most notably with type annotations). Luau is largely implemented from scratch, with the language runtime being a very heavily modified version of Lua 5.1 runtime, with completely rewritten interpreter and other performance innovations. The runtime mostly preserves Lua 5.1 API, so existing bindings should be more or less compatible with a few caveats.
Luau is used by Roblox game developers to write game code, as well as by Roblox engineers to implement large parts of the user-facing application code as well as portions of the editor (Roblox Studio) as plugins. Roblox chose to open-source Luau to foster collaboration within the Roblox community as well as to allow other companies and communities to benefit from the ongoing language and runtime innovation. As a consequence, Luau is now also used by games like Alan Wake 2 and Warframe.
This repository hosts source code for the language implementation and associated tooling. Documentation for the language is available at https://luau.org/ and accepts contributions via site repository; the language is evolved through RFCs that are located in rfcs repository.
Usage
Luau is an embeddable language, but it also comes with two command-line tools by default, luau
and luau-analyze
.
luau
is a command-line REPL and can also run input files. Note that REPL runs in a sandboxed environment and as such doesn't have access to the underlying file system except for ability to require
modules.
luau-analyze
is a command-line type checker and linter; given a set of input files, it produces errors/warnings according to the file configuration, which can be customized by using --!
comments in the files or .luaurc
files. For details please refer to type checking and linting documentation.
Installation
You can install and run Luau by downloading the compiled binaries from a recent release; note that luau
and luau-analyze
binaries from the archives will need to be added to PATH or copied to a directory like /usr/local/bin
on Linux/macOS.
Alternatively, you can use one of the packaged distributions (note that these are not maintained by Luau development team):
- macOS: Install Homebrew and run
brew install luau
- Arch Linux: From the AUR (Arch Linux User Repository), install one of these packages via a AUR helper or manually (by cloning their repo and using
makepkg
): luau (manual build), luau-git (manual build by cloning this repo), or luau-bin (pre-built binaries from releases) - Alpine Linux: Enable community repositories and run
apk add luau
- Gentoo Linux: Luau is officially packaged by Gentoo and can be installed using
emerge dev-lang/luau
. You may have to unmask the package first before installing it (which can be done by including the--autounmask=y
option in theemerge
command).
After installing, you will want to validate the installation was successful by running the test case here.
Building
On all platforms, you can use CMake to run the following commands to build Luau binaries from source:
mkdir cmake && cd cmake
cmake .. -DCMAKE_BUILD_TYPE=RelWithDebInfo
cmake --build . --target Luau.Repl.CLI --config RelWithDebInfo
cmake --build . --target Luau.Analyze.CLI --config RelWithDebInfo
Alternatively, on Linux/macOS you can use make
:
make config=release luau luau-analyze
To integrate Luau into your CMake application projects as a library, at the minimum you'll need to depend on Luau.Compiler
and Luau.VM
projects. From there you need to create a new Luau state (using Lua 5.x API such as lua_newstate
), compile source to bytecode and load it into the VM like this:
// needs lua.h and luacode.h
size_t bytecodeSize = 0;
char* bytecode = luau_compile(source, strlen(source), NULL, &bytecodeSize);
int result = luau_load(L, chunkname, bytecode, bytecodeSize, 0);
free(bytecode);
if (result == 0)
return 1; /* return chunk main function */
For more details about the use of host API you currently need to consult Lua 5.x API. Luau closely tracks that API but has a few deviations, such as the need to compile source separately (which is important to be able to deploy VM without a compiler), or lack of __gc
support (use lua_newuserdatadtor
instead).
To gain advantage of many performance improvements it's highly recommended to use safeenv
feature, which sandboxes individual scripts' global tables from each other as well as protects builtin libraries from monkey-patching. For this to work you need to call luaL_sandbox
for the global state and luaL_sandboxthread
for each new script's execution thread.
Testing
Luau has an internal test suite; in CMake builds it is split into two targets, Luau.UnitTest
(for bytecode compiler and type checker/linter tests) and Luau.Conformance
(for VM tests). The unit tests are written in C++, whereas the conformance tests are largely written in Luau (see tests/conformance
).
Makefile builds combine both into a single target and can be ran via make test
.
Dependencies
Luau uses C++ as its implementation language. The runtime requires C++11, whereas the compiler and analysis components require C++17. It should build without issues using Microsoft Visual Studio 2017 or later, or gcc-7 or clang-7 or later.
Other than the STL/CRT, Luau library components don't have external dependencies. The test suite depends on doctest testing framework, and the REPL command-line depends on isocline.
License
Luau implementation is distributed under the terms of MIT License. It is based on Lua 5.x implementation that is MIT licensed as well.
When Luau is integrated into external projects, we ask to honor the license agreement and include Luau attribution into the user-facing product documentation. The attribution using Luau logo is also encouraged.