Re: lua to native linux binary

[Axel Kittenberger <axkibe@...>]

Thats the Lua script I'm using. I'm waving any copyright claims of that:

------------------------------
if #arg < 3 then
        error("Usage: "..arg[0].." [infile] [varname] [outfile]")
end

fin, err = io.open(arg[1], "rb")
if fin == nil then
        error("Cannot open '"..arg[1].."' for reading: "..err)
end

fout, err = io.open(arg[3], "w")
if fout == nil then
        error("Cannot open '"..arg[3].."'for writing: "..err)
end

fout:write("/* created by "..arg[0].." from file "..arg[1].." */\n")
fout:write("#include <stddef.h>\n")
fout:write("const char "..arg[2].."_out[] = {\n")
while true do
        local block = fin:read(16)
        if block == nil then
                break
        end
        for i = 1, #block do
                local val = string.format("%x", block:byte(i))
                if #val < 2 then
                        val = "0" ..val
                end
                fout:write("0x",val,",")
        end
        fout:write("\n")
end
fout:write("};\n\nsize_t "..arg[2].."_size = sizeof("..arg[2].."_out);\n");

fin:close();
fout:close();
------------------------------
In my case with following Makefile rules:
------------------------------
luac.o: luac.c

luac.c: luac.out bin2carray.lua
	lua ./bin2carray.lua luac.out luac luac.c

luac.out: lsyncd.lua
	luac $<
------------------------------


In the past I've been using "objcopy", its theoretically quite an
effective way to store any binary data into an executable or library.
However, I've moved back to standard c-file-array-generation since a)
its really Linux only b) had some complains about some stack bits not
correctly set or something like that, so if you arent into
rocketscience thats binary formats and linking better stay away from
it - like I eventually decided to. I just wished the people within
this craft would make the tools simpler to directly link in arbitrary
data. Thats what I had before:
------------------------------
objarch: | lsyncd.o
	objdump -f lsyncd.o | grep architecture | \
		sed -e "s/,.*$$//" -e "s/[^ ]* \(.*\)/\1/" > $@ || rm $@

objtarget: | lsyncd.o
	objdump -f lsyncd.o | grep "file format" | \
		sed -e "s/.* \(.*\)/\1/" > $@ || rm $@

luac.o: luac.out objarch objtarget
	objcopy --input-target=binary \
		--output-target=`cat objtarget` \
		--binary-architecture=`cat objarch` $< $@

luac.out: lsyncd.lua
	luac $<