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problems embedding lua

nekoflux · 2004-02-06T17:51:01

Hi: I''ve been having trouble getting the libraries for lua integrated with my code. A little background information: My development environment is msvc++ version 6. I am trying to use lua v4.0.2 (yes, Im aware its a slightly older build, that is an intentional decision to avoid gpl licensing restrictions that lua 5 incurs) I have several questions I suppose: 1) where are the static libs? I''v visited lua.org and have been unable to procure the procompiled library for windows, or for that matter a msvc project that I can build from source with. 2) All the examples I''ve seen that embed lua involve a main() function....while this is fine for small test examples I may create in expirimenting with lua, this will not suffice in my codebase. Are there any peculiar things I need to do in order to embed lua in a file containing a class definition without any main() function declaration? So many questions, but those are the 2 major ones I can think of at the moment. Does anyone have an ultra simple example project in msvc that is a minimal example of how to embed lua in c++ that will compile when I unarchive it? I''m not a guru, but i''m fairly competent with c/c++, etc any help would be appreciated, thank you in advance!!

Engines and Middleware Programming

Started by nekoflux February 05, 2004 12:16 AM

40 comments, last by nekoflux 20 years, 5 months ago

JTippetts

13,308

February 05, 2004 01:58 AM

Perhaps, the loadstring() is defined in the liblualib library of basic functions. Are you linking that in as well?

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__ODIN__

479

February 05, 2004 01:59 AM

are you using lua_loadString (note : *lua_*loadString) ?

from your original code, you seemed to just use "loadstring(..)"

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nekoflux

173

Author

February 05, 2004 02:01 AM

That makes sense...

i added those files in src/lb to the project and rebuilt it. It prduced a new lua.lib file that was almost twice the size of the lua.lib I creaed before I added the files in src/lib...how do I tell it to create liblualib?

nekoflux

173

Author

February 05, 2004 02:04 AM

I tried both lua_loadstring(...) and loadstring(...); neither seems to work I keep getting an error:

error C2065: 'lua_loadstring' : undeclared identifier

*or*

error C2065: 'loadstring' : undeclared identifier

[edited by - nekoflux on February 5, 2004 3:32:51 AM]

nekoflux

Xerxes

133

February 05, 2004 02:32 AM

I had no problems incorporating LUA 5 to my applications (or more exactly I solved them all myself). I never actually used any kind of loadstring() - I needed to load files only. But I think you can use lua_dostring(), but don''t forget to include lauxlib.h , where it is defined! LUA 5 itself has pretty limited loading functions (only some lua_load(), which I never used) and more of them exist in the aux library.

Society's never gonna make any progress until we all learn to pretend to like each other.

nekoflux

173

Author

February 05, 2004 02:48 AM

Hey Xerxes:
cool name, is that a reference the the xml parser or system shock2? thats my favorite game...

anyways, yeah I include 3 files,

#include "lua.h"
#include "lualib.h"
#include "lauxlib.h"

ive tried loadfile(), lua_loadfile(), loadstring(..), dostring(..) none of them work, they all flag the same compile error.

I have both lua.lib and lualib.lib in the link options but still nothing
Its bizarre because I can call lua_open() lua_close(), lua_mathlibopen(), etc but none of the load functions seem to work..which leads me to believe that im missing a lib or didnt build those 2 libs correctly.

any clues whats up?

nekoflux

Kylotan

10,512

February 05, 2004 05:50 AM

quote: Original post by nekoflux
Hey Xerxes:
cool name, is that a reference the the xml parser or system shock2? thats my favorite game...

Xerxes

133

February 05, 2004 07:31 AM

Well, I actually tried lua_dostring(L, "something") with lauxlib.h included and it worked without any problem.

BTW, thanks, I originally started using Xerxes nickname when I saw it in System Shock 2 (my favourite game too), and THEN I learnt about Xerxes, the Persian king. And XML parser? Never heard of (maybe because I''m not using XML).

Society's never gonna make any progress until we all learn to pretend to like each other.

nekoflux

173

Author

February 05, 2004 08:58 AM

yes, I''ve tried various combinations. I have tried several permutations of loadstring, dostring, etc, but none of them work. Here is my code again:

#include "stdafx.h"extern "C"{#include "lua.h"#include "lualib.h"#include "lauxlib.h"}int main(int argc, char* argv[]){	lua_State* luaVM = lua_open();	if (NULL == luaVM)   {      printf("Error Initializing lua\n");      return -1;   }	lua_baselibopen(luaVM);   lua_iolibopen(luaVM);   lua_strlibopen(luaVM);   lua_mathlibopen(luaVM);       char* strLuaInput = "a = 1 + 1;\n";    //loadstring(luaVM, strLuaInput);   //lua_dostring("a = 1 + 1;\n");   //loadfile("a = 1 + 1;\n");	lua_close( luaVM );	return 0;}

the above code compiles fine, but as soon as I uncomment any of the above 4 lines, i get one of these errors:
error C2065: ''lua_loadstring'' : undeclared identifier
error C2065: ''loadstring'' : undeclared identifier
error C2065: ''lua_dostring'' : undeclared identifier
error C2065: ''loadfile'' : undeclared identifier

what perplexes me is, I can call lua_close(), lua_open(), lua_iolibopen(), etc but I can''t call any of the functions that are commented out. why does the compiler only see some functions and not others?

help please

nekoflux

Xerxes

133

February 05, 2004 11:42 AM

quote: //lua_dostring("a = 1 + 1;\n");

Why don''t use lua_dostring(luaVM, "something")? I think luaVM is missing. That code worked absolutely fine to me (I copy-pasted it to a new project), without any problem.

And I think I finally figured out what''s wrong with your code. Are you sure you are using right headers? Aren''t those you use some kind of leftover after LUA 4? Make sure you are using the right ones. Because in the right ones, there is a line declaring:

LUALIB_API int lua_dostring (lua_State *L, const char *str);

(Copy-pasted)

So I suggest you completely remove both LUAs, download the most recent version from www.lua.org and reinstall it, because that should work.

Society's never gonna make any progress until we all learn to pretend to like each other.