How to compile Lua scripts into a single executable, while still gaining the fast LuaJIT compiler?

Question

How can I compile my Lua scripts into a single executable file, while also gaining the super fast performance benefits of LuaJIT?

Background:

• My Lua scripts are for a web application I created (e.g. to host http://example.com)
• My current technology stack is NGINX (web server), Lua/LuaJIT (language to retrieve dynamic content)
• I have around 50+ .lua files that make up my web application (from Models/Views/Controllers)
• FreeBSD 9 operating system

For simplicity sake in deployment, I'd like to compile down all of my .lua scripts that run my web application down to a single executable.

1. Is this possible and how?

   It appears that Lua official comes with a library called SRLua

2. What are the negatives to compiling down my .lua to a single executable (e.g. would performance be worse, etc)?

Solution 1

Translate all of the Lua source code files to object files and put them in a static library:

for f in *.lua; do
    luajit -b $f `basename $f .lua`.o
done
ar rcus libmyluafiles.a *.o

Then link the libmyluafiles.a library into your main program using -Wl,--whole-archive -lmyluafiles -Wl,--no-whole-archive -Wl,-E.

This line forces the linker to include all object files from the archive and to export all symbols.

For example, a file named foo.lua can now be loaded with local foo = require("foo") from within your application.

Details about the -b option can be found on Running LuaJIT.

Solution 2

For a web app that you are currently deploying as a nest of related .lua files, your easiest answer will be to condense them into a single file. This can often be done for simple cases with luac. However, for complex applications with a mix of modules you want something smarter.

I personally use Mathew Wild's utility squish to do something similar.

After running squish, you will have a single .lua file containing all the Lua source code bundled up conveniently. You could just deploy that single file.

If you need to also bundle any binary modules, or the Lua or LuaJIT interpreter, then you can easily use SRLua to bundle it with the Lua interpreter, or similar techniques to bundle it with LuaJIT.

Comments

[nickb]

So, this isn't really compiling down to a single executable as in my original question but instead - merging all of my .lua files into a single .lua file?

[nickb]

Wahoo! Mike Pall from LuaJit answered this question :)

[nickb]

many thanks for all your work on LuaJIT! It's truly incredible what you have done.

[RBerteig]

Although you can go all the way to an executable, and can also use squish to simplify the collection of dependencies to link into that executable, you can also stop with just the single .lua file. Mike Pall has provided a good recipe for bundling LuaJIT with .lua files.

[hookenz]

That basename command doesn't work on Ubuntu 13.04. It ends up overwriting the original lua file with the bytecoded version

[hookenz]

I think what you want is something like: for f in *.lua; do luajit -b $f basename $f .lua.o; done

[Matt Fichman]

What should you do if you have two files with the same name, but they live in different directories? i.e., a/foo.lua and b/foo.lua. When I try to link the generated .o files, I get duplicate symbol errors (duplicated symbol _luaJIT_BC_foo)

[Josh S]

I have a luajit setup in windows32 built with gcc (tdm sjlj)... Would this recipe work for me?