[cinvoke-dev] Lua / VC++ 2005 / passing struct to callback

[Dean C. Davis]

First time user here.  I built cinvoke (0.9) and the Lua (5.1.1) binding
on a Windows XP system with MS VC++ 2005 Express.  I had to make four
changes to cinvoke_lua.c to get this to work (well, the change to
luaopen_ is a matter of taste).

To learn about the binding, I am attempting to invoke functions from
Simple HTTPD (http://shttpd.sourceforce.net) built "EMBEDDED" into a
DLL.  However, I'm stumped by the callback functions because they expect
to be passed a struct (specifically, "struct shttpd_arg *").  Passing a
plain Cptr is a partial solution, but to actually be useful it is
necessary to manipulate some of the shttpd_arg struct members.

I'm a bit naive on the implementation details, so I'm wondering, is the
restriction on passing a struct to a callback function a limitation of
the Lua binding or of C/Invoke in general?  Is there an alternate
approach that I'm overlooking?  I'm willing to post my
shttpd.[lua|h|dll] if anyone is willing to take a look.

Thanks,
Dean.

34a35,38
> #ifdef _MSC_VER
> #define snprintf _snprintf
> #endif
>  
384,386c388,392
<               lua_Integer charid = tointeger(l, -1);
<               lua_pop(l, 1);
<               return (char)charid;
---
>               {
>                       lua_Integer charid = tointeger(l, -1);
>                       lua_pop(l, 1);
>                       return (char)charid;
>               }
506c512
<               ret = (void *)strtol(pstr, &endptr, 10);
---
>               ret = (void *)strtol(pstr, &endptr, 16);
1484c1490
< int luaopen_cinvoke_lua(lua_State *l) {
---
> LUALIB_API int luaopen_cinvoke(lua_State *l) {