Lua

This documentation is for LuaJIT 2.1. Please check the doc directory in each git branch for the version-specific documentation.

LuaJIT is only distributed as source code — get it from the git repository. This page explains how to build and install the LuaJIT binary and library for different operating systems.

For the impatient (on POSIX systems):

make && sudo make install

Requirements

LuaJIT currently builds out-of-the box on most systems. Please check the supported operating systems and CPU architectures on the status page.

Building LuaJIT requires a recent toolchain based on GCC, Clang/LLVM or MSVC++.

The Makefile-based build system requires GNU Make and supports cross-builds.

Batch files are provided for MSVC++ builds and console cross-builds.

Configuring LuaJIT

The standard configuration should work fine for most installations. Usually there is no need to tweak the settings. The following files hold all user-configurable settings:

Please read the instructions given in these files, before changing any settings.

All LuaJIT 64 bit ports use 64 bit GC objects by default (LJ_GC64). For x64, you can select the old 32-on-64 bit mode by adding XCFLAGS=-DLUAJIT_DISABLE_GC64 to the make command. Please check the note about the bytecode format differences, too.

POSIX Systems (Linux, macOS, *BSD etc.)

Prerequisites

Depending on your distribution, you may need to install a package for a compiler (GCC or Clang/LLVM), the development headers and/or a complete SDK. E.g. on a current Debian/Ubuntu, install build-essential with the package manager.

Building LuaJIT

The supplied Makefiles try to auto-detect the settings needed for your operating system and your compiler. They need to be run with GNU Make, which is probably the default on your system, anyway. Simply run:

make

This always builds a native binary, depending on the host OS you're running this command on. Check the section on cross-compilation for more options.

By default, modules are only searched under the prefix /usr/local. You can add an extra prefix to the search paths by appending the PREFIX option, e.g.:

make PREFIX=/home/myself/lj2

Note for macOS: you must set the MACOSX_DEPLOYMENT_TARGET environment variable to a value supported by your toolchain:

MACOSX_DEPLOYMENT_TARGET=XX.YY make

Installing LuaJIT

The top-level Makefile installs LuaJIT by default under /usr/local, i.e. the executable ends up in /usr/local/bin and so on. You need root privileges to write to this path. So, assuming sudo is installed on your system, run the following command and enter your sudo password:

sudo make install

Otherwise specify the directory prefix as an absolute path, e.g.:

make install PREFIX=/home/myself/lj2

Obviously the prefixes given during build and installation need to be the same.

Windows Systems

Prerequisites

Either install one of the open source SDKs (MinGW or Cygwin), which come with a modified GCC plus the required development headers. Or install Microsoft's Visual Studio (MSVC).

Building with MSVC

Open a "Visual Studio Command Prompt" (x86, x64 or ARM64), cd to the directory with the source code and run these commands:

cd src
msvcbuild

Check the msvcbuild.bat file for more options. Then follow the installation instructions below.

For an x64 to ARM64 cross-build run this first: vcvarsall.bat x64_arm64

Building with MinGW or Cygwin

Open a command prompt window and make sure the MinGW or Cygwin programs are in your path. Then cd to the directory of the git repository. Then run this command for MinGW:

mingw32-make

Or this command for Cygwin:

make

Then follow the installation instructions below.

Installing LuaJIT

Copy luajit.exe and lua51.dll (built in the src directory) to a newly created directory (any location is ok). Add lua and lua\jit directories below it and copy all Lua files from the src\jit directory of the distribution to the latter directory.

There are no hardcoded absolute path names — all modules are loaded relative to the directory where luajit.exe is installed (see src/luaconf.h).

Cross-compiling LuaJIT

First, let's clear up some terminology:

The GNU Makefile-based build system allows cross-compiling on any host for any supported target:

You need to specify TARGET_SYS whenever the host OS and the target OS differ, or you'll get assembler or linker errors:

Here are some examples where host and target have the same CPU:

# Cross-compile to a 32 bit binary on a multilib x64 OS
make CC="gcc -m32"

# Cross-compile on Debian/Ubuntu for Windows (mingw32 package)
make HOST_CC="gcc -m32" CROSS=i586-mingw32msvc- TARGET_SYS=Windows

The CROSS prefix allows specifying a standard GNU cross-compile toolchain (Binutils, GCC and a matching libc). The prefix may vary depending on the --target the toolchain was built for (note the CROSS prefix has a trailing "-"). The examples below use the canonical toolchain triplets for Linux.

Since there's often no easy way to detect CPU features at runtime, it's important to compile with the proper CPU or architecture settings:

Here are some examples for targets with a different CPU than the host:

# ARM soft-float
make HOST_CC="gcc -m32" CROSS=arm-linux-gnueabi- \
     TARGET_CFLAGS="-mfloat-abi=soft"

# ARM soft-float ABI with VFP (example for Cortex-A9)
make HOST_CC="gcc -m32" CROSS=arm-linux-gnueabi- \
     TARGET_CFLAGS="-mcpu=cortex-a9 -mfloat-abi=softfp"

# ARM hard-float ABI with VFP (armhf, most modern toolchains)
make HOST_CC="gcc -m32" CROSS=arm-linux-gnueabihf-

# ARM64
make CROSS=aarch64-linux-gnu-

# PPC
make HOST_CC="gcc -m32" CROSS=powerpc-linux-gnu-

# MIPS32 big-endian
make HOST_CC="gcc -m32" CROSS=mips-linux-gnu-
# MIPS32 little-endian
make HOST_CC="gcc -m32" CROSS=mipsel-linux-gnu-

# MIPS64 big-endian
make CROSS=mips-linux- TARGET_CFLAGS="-mips64r2 -mabi=64"
# MIPS64 little-endian
make CROSS=mipsel-linux- TARGET_CFLAGS="-mips64r2 -mabi=64"

You can cross-compile for Android using the Android NDK. Please adapt the environment variables to match the install locations and the desired target platform. E.g. Android 4.1 corresponds to ABI level 16.

# Android/ARM64, aarch64, Android 5.0+ (L)
NDKDIR=/opt/android/ndk
NDKBIN=$NDKDIR/toolchains/llvm/prebuilt/linux-x86_64/bin
NDKCROSS=$NDKBIN/aarch64-linux-android-
NDKCC=$NDKBIN/aarch64-linux-android21-clang
make CROSS=$NDKCROSS \
     STATIC_CC=$NDKCC DYNAMIC_CC="$NDKCC -fPIC" \
     TARGET_LD=$NDKCC TARGET_AR="$NDKBIN/llvm-ar rcus" \
     TARGET_STRIP=$NDKBIN/llvm-strip

# Android/ARM, armeabi-v7a (ARMv7 VFP), Android 4.1+ (JB)
NDKDIR=/opt/android/ndk
NDKBIN=$NDKDIR/toolchains/llvm/prebuilt/linux-x86_64/bin
NDKCROSS=$NDKBIN/arm-linux-androideabi-
NDKCC=$NDKBIN/armv7a-linux-androideabi16-clang
make HOST_CC="gcc -m32" CROSS=$NDKCROSS \
     STATIC_CC=$NDKCC DYNAMIC_CC="$NDKCC -fPIC" \
     TARGET_LD=$NDKCC TARGET_AR="$NDKBIN/llvm-ar rcus" \
     TARGET_STRIP=$NDKBIN/llvm-strip

You can cross-compile for iOS 3.0+ (iPhone/iPad) using the iOS SDK:

Note: the JIT compiler is disabled for iOS, because regular iOS Apps are not allowed to generate code at runtime. You'll only get the performance of the LuaJIT interpreter on iOS. This is still faster than plain Lua, but much slower than the JIT compiler. Please complain to Apple, not me. Or use Android. :-p

# iOS/ARM64
ISDKP=$(xcrun --sdk iphoneos --show-sdk-path)
ICC=$(xcrun --sdk iphoneos --find clang)
ISDKF="-arch arm64 -isysroot $ISDKP"
make DEFAULT_CC=clang CROSS="$(dirname $ICC)/" \
     TARGET_FLAGS="$ISDKF" TARGET_SYS=iOS

Cross-compiling for consoles

Building LuaJIT for consoles requires both a supported host compiler (x86 or x64) and a cross-compiler from the official console SDK.

Due to restrictions on consoles, the JIT compiler is disabled and only the fast interpreter is built. This is still faster than plain Lua, but much slower than the JIT compiler. The FFI is disabled, too, since it's not very useful in such an environment.

The following commands build a static library libluajit.a, which can be linked against your game, just like the Lua library.

To cross-compile for PS3 from a Linux host (requires 32 bit GCC, i.e. multilib Linux/x64) or a Windows host (requires 32 bit MinGW), run this command:

make HOST_CC="gcc -m32" CROSS=ppu-lv2-

To cross-compile for the other consoles from a Windows host, open a "Native Tools Command Prompt for VS". You need to choose either the 32 or the 64 bit version of the host compiler to match the target. Then cd to the src directory below the source code and run the build command given in the table:

Console Bits Build Command
PS4 64 ps4build
PS5 64 ps5build
PS Vita 32 psvitabuild
Xbox 360 32 xedkbuild
Xbox One 64 xb1build
Nintendo Switch NX32 32 nxbuild
Nintendo Switch NX64 64 nxbuild

Please check out the comments in the corresponding *.bat file for more options.

Embedding LuaJIT

LuaJIT is API-compatible with Lua 5.1. If you've already embedded Lua into your application, you probably don't need to do anything to switch to LuaJIT, except link with a different library:

Additional hints for initializing LuaJIT using the C API functions:

Hints for Distribution Maintainers

The LuaJIT build system has extra provisions for the needs of most POSIX-based distributions. If you're a package maintainer for a distribution, please make use of these features and avoid patching, subverting, autotoolizing or messing up the build system in unspeakable ways.

There should be absolutely no need to patch luaconf.h or any of the Makefiles. And please do not hand-pick files for your packages — simply use whatever make install creates. There's a reason for all the files and directories it creates.

The build system uses GNU make and auto-detects most settings based on the host you're building it on. This should work fine for native builds, even when sandboxed. You may need to pass some of the following flags to both the make and the make install command lines for a regular distribution build:

The build system has a special target for an amalgamated build, i.e. make amalg. This compiles the LuaJIT core as one huge C file and allows GCC to generate faster and shorter code. Alas, this requires lots of memory during the build. This may be a problem for some users, that's why it's not enabled by default. But it shouldn't be a problem for most build farms. It's recommended that binary distributions use this target for their LuaJIT builds.

The tl;dr version of the above:

make amalg PREFIX=/usr && \
make install PREFIX=/usr DESTDIR=/tmp/buildroot

Finally, if you encounter any difficulties, please contact me first, instead of releasing a broken package onto unsuspecting users. Because they'll usually gonna complain to me (the upstream) and not you (the package maintainer), anyway.