Lua Dogfood

luacc.lua

-- Marc Balmer marc@msys.ch via lists.lua.org 
-- $ lua luacc.lua -o luacc luacc.lua

local outfile = 'luacc.out'
local strip = false

for k, v in pairs(arg) do
	if v == '-o' then
		outfile = arg[k + 1]
		arg[k] = ''
		arg[k + 1] = ''
	elseif v == '-s' then
		strip = true
		arg[k] = ''
	end
end

-- Load the chunks and keep the bytecodes
local bytecode = {}
for k, v in ipairs(arg) do
	if v ~= '' then
		bytecode[#bytecode + 1] = string.dump(loadfile(v), strip)
	end
end

-- Start the compiler that expects C code on standard input
-- local c = io.popen('cc -x c -o ' .. outfile .. ' -O3 -I/usr/local/include '
--    .. '-L/usr/local/lib -llua -', 'w')
    
-- Lua on Homebrew
local c = io.popen('cc -x c -o ' .. outfile .. ' -O3 -I/opt/homebrew/Cellar/lua/5.4.4_1/include/lua '
    .. '-L/opt/homebrew/Cellar/lua/5.4.4_1/lib -llua -', 'w')

-- Dump the bytecode to a const char array
c:write('static const char bytecode[] = {')

bytecode = table.concat(bytecode)
for n = 1, #bytecode do
	c:write(string.format('0x%02x,', string.byte(bytecode, n)))
end

c:write('}; static unsigned int bytecode_len = ' .. #bytecode .. ';\n')

-- Write the glue code
c:write([[
#include <stdlib.h>
#include <strings.h>

#include <lua.h>
#include <lualib.h>
#include <lauxlib.h>

int
main(int argc, char *argv[])
{
	lua_State *L;
	char *prognam;
	int n;

	/* Create a Lua state and provide the standard ibraries to it */
	if (!(L = luaL_newstate()))
		fprintf(stderr, "memory allocation error\n");

	luaL_openlibs(L);

	/* Create the arg table */
	lua_newtable(L);
	for (n = 1; n < argc; n++) {
		lua_pushinteger(L, n);
		lua_pushstring(L, argv[n]);
		lua_settable(L, -3);
	}
	/* Push the binary name last */
	prognam = rindex(argv[0], '/');
	if (!prognam)
		prognam = argv[0];
	else
		prognam++;
	lua_pushinteger(L, 0);
	lua_pushstring(L, prognam);
	lua_settable(L, -3);
	lua_setglobal(L, "arg");

	if (luaL_loadbuffer(L, bytecode, bytecode_len, "luac") != LUA_OK) {
		fprintf(stderr, "load error: %s\n", lua_tostring(L, 1));
		return -1;
	}
	if (lua_pcall(L, 0, LUA_MULTRET, 0) != LUA_OK) {
		fprintf(stderr, "runtime error: %s\n", lua_tostring(L, -1));
		return -1;
	}
	return 0;
}
]])

-- Finally close the pipe and let the compiler do it's work
c:close()