lua2exe.lua

local format, pack = string.format, string.pack
local print, loadfile = print, loadfile
local open, stderr, exit = io.open, io.stderr, os.exit
local dirsep, pathsep, pathmark = package.config:match('(.-)\n(.-)\n(.-)\n')
local luapath, cpath, pathgm = package.path, package.cpath, '[^' .. pathsep .. ']+'

local lfs = require('lfs')
local attributes, currentdir, mkdir = lfs.attributes, lfs.currentdir, lfs.mkdir

local haslz4, lz4 = pcall(require, 'minilz4')

local options = {
base = 'lbase.exe',
dest = 'out.exe',
compile = false,
strip = false,
sources = {},
dlls = {}
}

local function printHelpAndExit ()
print(format([[
Pack lua script into a standalone executable.
Syntax: %s [options] scripts...
Options:
-b <base>, --base <base>
  Define the base lua VM executable to use. Default: %s
-o <outfile>, --output <outfile>
  Define where to put the compiled executable. Default: %s
-s, --strip
  Strip debug information in compiled executable. Default: false
scripts...
  Define lua scripts to compile into the executable. 
  The first one is run when launching the executable.
  Other scripts are compiled in but not run. They stay available with require().
]], arg and arg[0], options.base, options.dest))
exit(0)
end

local function fail (...)
stderr:write(string.format(...))
exit(1)
end

local function nextarg (args, i)
return args[i], i+1
end

local function parseArgs (args, t)
local i, n, opt = 1, #args
while i<=n do
opt, i = nextarg(args, i)
if opt == '-b' or opt == '--base' then t.base, i = nextarg(args, i) 
elseif opt == '-o' or opt == '--output' then t.dest, i = nextarg(args, i)
elseif opt == '-c' or opt == '--compile' then t.compile = true
elseif opt == '-C' or opt == '--no-compile' then t.compile = false
elseif opt == '-s' or opt == '--strip' then t.strip = true
elseif opt == '-g' or opt == '--debug' then t.strip = false
elseif opt == '-h' or opt == '--help' or opt == '-?' then printHelpAndExit()
elseif opt:sub(1,1)=='-' and opt~='-' then warn(format('Unknown option: %s', opt))
else table.insert(t.sources, { name=opt, file=opt })
end end
end

local function checkoptions (options) 
if not options.sources or #options.sources<1 then fail('No sources given')
elseif not options.base then fail('No base executable given')
elseif not options.dest then fail('No output file given')
elseif options.strip and not options.compile then fail('Sources must be compiled in order to be striped')
end end

local function readall (fn)
local fp <close>, err = open(fn, 'rb')
return fp and fp:read('a'), err
end

local function dirname (fn)
return fn:match('^(.-)[^' .. dirsep ..']-' .. dirsep .. '?$')
end

local function isdir (fn)
return attributes(fn, 'mode') == 'directory'
end

local function isfile (fn)
return attributes(fn, 'mode') == 'file'
end

local function getoutdir (dest)
local outdir = dirname(dest)
if not outdir or outdir=='' then outdir = currentdir() end
if outdir:sub(-1)~=dirsep then outdir = outdir .. dirsep end
return outdir
end

local function checkinc (sources, pathlist, modname)
if sources[modname] then return true end
for path in pathlist:gmatch(pathgm) do
local fn = path:gsub(pathmark, (modname:gsub('%.', dirsep))) 
if isfile(fn) then 
local inc = fn:sub(path:find(pathmark), -1)
table.insert(sources, { name=inc, file=fn })
sources[modname] = true
return true
end end
end

local function checkrequire (sources, dlls, modname)
local unused = checkinc(sources, luapath, modname) or checkinc(dlls, cpath, modname)
end

local function checkrequires (sources, dlls)
local i = 1
while sources[i] do
local data = readall(sources[i].file)
for modname in data:gmatch[[require%s*%(?['"]([^'"]+)['"]%)?]] do
checkrequire(sources, dlls, modname)
end
i = i+1
end end

local function copybase (base, dest)
local fp = open(dest, 'wb')
fp:write((readall(base)))
return fp
end

local function packsources (fp, sources, compile, strip)
local read = compile and loadfile or readall
local dump = compile and string.dump or function (x) return x end
for i, source in ipairs(sources) do
local func, err = read(source.file, 'bt') 
if not func then
error('Compilation error:\n' .. err)
end
local bin = dump(func, strip)
local out = haslz4 and lz4 and lz4.compress and lz4.compress(bin) or bin
source.offset = fp:seek('cur', 0)
fp:write(string.pack('I4I4I1', #out, #bin, haslz4 and 1 or 0))
fp:write(out)
print(format('Packed %s in %s, size=%d, stored=%d, compressed=%s', source.file, source.name, #bin, #out, haslz4))
end 
end


local function writefiletable (fp, sources)
local fileTableOffset = fp:seek('cur', 0)
for i, source in ipairs(sources) do
fp:write(pack('s4I4', source.name, source.offset))
end
fp:write(pack('I4c8', fileTableOffset, 'lua2exe1'))
end

local function getdirs (dir)
local dirs = {}
while dir do
dir = dirname(dir)
if not dir or dir=='' then break end
table.insert(dirs, dir)
end
return dirs
end

local function mkdirs (fn)
local dirs = getdirs(fn)
for i = #dirs, 1, -1 do
local dir = dirs[i]
if not isdir(dir) then 
local re, err = mkdir(dir)
end end end

local function copyfile (src, dst)
local da, sa, err = attributes(dst), attributes(src)
if sa and da and sa.modification<=da.modification and sa.size==da.size then return false end -- no need to copy if dst is more recent than src and if they have same size
local data = readall(src)
local fp <close>, err = open(dst, 'wb')
return fp and data and fp:write(data)
end

local function copydlls (dlls, dest)
local outdir = getoutdir(dest)
for i, dll in ipairs(dlls) do
local src, dst = dll.file, outdir..dll.name
mkdirs(dst)
if copyfile(src, dst) then
print(format('Copied %s to %s', src, dst))
end end end

parseArgs(arg or {...}, options)
checkoptions(options)
checkrequires(options.sources, options.dlls)
local fp <close> = copybase(options.base, options.dest)
packsources(fp, options.sources, options.compile, options.strip)
writefiletable(fp, options.sources)
copydlls(options.dlls, options.dest)
print(format('Successfully compiled %s (%d bytes)', options.dest, fp:seek('cur', 0)))