Lake - a Lua-based Build Tool

lake is a build engine written in Lua, similar to Ruby's rake. It is not a makefile generator, but evaluates dependencies directly - that is, it is an interpreter of dependency rules, not a makefile compiler. This is a sensible design decision because lake is small (about 70K pure Lua, 250K together with Lua and LuaFileSystem) enough to carry around.

Much of the inspiration for lake comes from Martin Fowler's article on dependency-driven programming in rake.

There is one file, lake, which only depends on LuaFileSystem. On Unix, you can simply make it executable and put it on your path.

Or for Windows:

rem lake.bat
lua \path\to\lake %*

Apart from being quick & compact, these are the features of interest:

• it is an embedded DSL (Domain Specific Language) - all the normal functionality of Lua is available
• it knows about both GCC and Microsoft Visual C++ compilers, and does cross-platform builds
• it knows about building Lua extensions in C or C++

For example, a lakefile for building a GTK application can be as simple as:

c.program{'hello',needs='gtk'}

Creating a binary Lua extension:

c.shared{'mylib',needs='lua'}

lake can be used to automate other tools as well. This will convert all JPEG files in the current directory to PNG, but only if the PNG file does not exist or the JPEG file has changed.

to_png = rule('.jpg','.png',
  'convert $(INPUT) $(TARGET)'
)

default(to_png '*')

Here is a lakefile for building Lua itself:

LUA='lua'
LUAC='luac print'
as_dll = WINDOWS
if as_dll then
  defs = 'LUA_BUILD_AS_DLL'
end
if not WINDOWS then
  defs = 'LUA_USE_LINUX'
end

-- build the static library
lib,ll=c.library{'lua',src='*',exclude={LUA,LUAC},defines=defs}

-- build the shared library
if as_dll then
  libl = c.shared{'lua',rules=ll,dynamic=true}
else
  libl = lib
end

-- build the executables
lua = c.program{'lua',libl,src=LUA,needs='dl math readline',export=not as_dll}
luac = c.program{'luac',lib,src=LUAC,needs='math'}

default {lua,luac}

More details can be found in doc/index.md

Released under the MIT/X11 licence, Steve Donovan, 2010-2013