Embedding C in Lua

[LucasTheDuck]

Hello, As a contribution, I present this method to create libraries for AMS without compiling anything, using c code.

The only drawback for that work, dependency of MinGW compiler that must be installed and the LUA libraries created, but, you can create a cache of compiled or simply copy the return .so file and run them in any application

This sample may be help the explanation

Code=[[
#include <lua.h>
#include <lauxlib.h>
#include <stdio.h>
#include <stdlib.h>


int start(lua_State * L) {
    luaL_checkstring(L,1);
    lua_pushstring(L, "hello ");
    lua_pushvalue(L, 1);
    lua_concat(L, 2);
    return 1;
  }
  
int l_funcion(lua_State * L) {
    int n = lua_tonumber(L,1);
    int ret = n + 38;
    lua_pushnumber(L,ret);
    return 1;
}

int l_do(lua_State * L) {
    lua_dostring(L,"Dialog.Message(l_funcion(5), start(\"world\"))");
    return 1;
}

]]

bOk          =CC.Compile(Code)
start        =CC.Register("start")
l_funcion    =CC.Register("l_funcion")
RunLib       =CC.Register("l_do")


RunLib() 

This returns this



The posibilities for this are big, you can compile with some libraries such as mysql, soket, winapi...

You can use any compiler, i used MinGW but I tested the compiler of VisualStudio2005 and work perfect

I think that this functions are self explicative

CC={}
function CC.Compile(code)
TextFile.WriteFromString("F:\\cee.c", Code, false);
return File.Run("F:\\MinGW\\bin\\gcc.exe", "-O2 -shared -o f:/cee.so f:/cee.c -llua -llualib", "", SW_MINIMIZE, true);
end

function CC.Register(cfunc)
return loadlib("f://cee.so",cfunc)
end 

This is all you need.

PS. Remember to put lua.h lualib.h luaxlib.h in /includes and liblua.a liblualib.a in /lib, i put the files for testing

[Sakuya]

I'd better check this out, Maybe this can fix a fatal flaw in password protection with AMS.

[Sakuya]

Nevermind..

[LucasTheDuck]

shhhh... it's secret

[LucasTheDuck]

A simple callback system

Code=[[
#include <lua.h>
#include <lauxlib.h>
#include <stdio.h>
#include <stdlib.h>

int l_callback(lua_State * L) {
    lua_getglobal(L,"LuaFunction");
    lua_pushstring(L,"hello");
    lua_pushstring(L,"world");
    if(lua_pcall(L,2,1,0) != 0){
        //ERROR
    }
    return 1;
}


]]
function LuaFunction (arg1,arg2)
Dialog.Message(arg1,arg2)
end
bOk          =CC.Compile(Code)
l_callback   =CC.Register("l_callback")

l_callback() 

The lua C api is cool

[Dermot]

Very interesting but when you close the app, you get the Vista crash message. 'This app has stopped working...."

[LucasTheDuck]

I use xp but i think that you may use the clasic closing method

OnClose

Handle = Application.GetWndHandle();
Window.Close(Handle, CLOSEWND_TERMINATE); 

or any dllunload method... I think that there are more methods to register funcs same as

 Code=[[
  #include <windows.h>
  #include <lua.h>
  #include <lauxlib.h>
  #include <stdio.h>
  #include <stdlib.h>

  int lua_msgbox(lua_State* L)
  {
    const char* message = luaL_checkstring(L, 1);
    const char* caption = luaL_optstring(L, 2, "");
    int result = MessageBox(NULL, message, caption, MB_OK);
    lua_pushnumber(L, result);
    return 1;
  }

  int libinit (lua_State* L)
  {
   lua_register(L, "msgbox",  lua_msgbox);
   return 0;
  }
]]
bOk         =CC.Compile(Code)
LoadLib     =CC.Register("libinit")
LoadLib()
msgbox('mytext') 

Automaticly lua_msgbox is registered in L, you can aso use a Lual_reg to register more funcs

const luaL_reg tab_funcs[] = {
        {"Test", irExample_test},
        {"Demo", irExample_demo},
        {NULL, NULL}
    };
luaL_openlib(L, "Example", tab_funcs, 0); 

Now functions Example.Test and Example.Demo are registered and working

[Dermot]

No crash using that method of registering.

[LucasTheDuck]

Right! This is the proper method to do...

if anyone can test on deferent OS and architecture could be a great testing, i will test with w7 x32 but i don't have any x64

I'm looking for do this embeddable in an actions plugin and a cache system based on hash of code, i'm triying to use CINT but he needs precompiled lua and other libs... for this raeson it's very difficult and ineficient, i prefer use mingw that have very much optons and libraries