Re: Packaging issue: standalone interpreter requires dynamic linking

[Norman Ramsey <nr@...>]

 > 2008/5/8 Norman Ramsey <nr@eecs.harvard.edu>:
 > > This is really an issue for the Lua team, but I thought I would send to
 > >  the whole list to see how others are coping with this issue.
 > >
 > >  I work on a broken Unix system (sometimes called 'GNU/Linux') in which
 > >  critically important tools such as gprof do not work properly in the
 > >  presence of dynamically linked libraries...
 >
 > You can make a simple modification of lua.c to make use of the
 > package.preload table. First define a static array with all the
 > modules you want to use:
 > 
 > extern int luaopen_osbf3_core(lua_State *);
 > extern int luaopen_fastmime(lua_State *);
 > 
 > static struct luaL_Reg modules[] = {
 >     {"osbf3.core", luaopen_osbf3_core}, /* don't forget to replace the
 > underscores in module names with dots */
 >     {"fastmime", luaopen_fastmime},
 >     {0, 0},
 > };
 > 
 > Then just after luaL_openlibs, add the following lines:
 > 
 > lua_getglobal(L, "package");
 > lua_getfield(L, -1, "preload");
 > luaL_register(L, 0, modules);
 > lua_pop(L, 2); /* pop package and package.preload */
 > 
 > This will pre-register all your modules in one step. Then normal calls
 > to 'register' from your scripts in Lua will call the entry points just
 > like if they were loaded from a shared library.

You mean 'require' not 'register', right?

I like this suggestion for two reaons:

  1. It is much cleaner than my solution.

  2. If anybody is crazy enough to have side effects in the
     module-loading code, they will occur at the proper time (the
     first 'require' and not startup time.

However, the problem remains that I still have to edit the lua.c file.

Let me put forth a concrete suggestion to the Lua team:

  1. The auxiliary library should be extended with a function
       void luaL_openlibs_static(lua_State *L)
     which does nothing.

  2. This function should be called in lua.c immediately after
     luaL_openlibs.

  3. By defining my own .c file and linking the .o before -llua5.1
     on the link line, I can override this function with the code
     Jerome has suggested above.

With a change like this I could statically link my own libraries
without touching one line of distributed code.


Norman