Re: Behavior of dlopen in MacOSX

[Tony Finch <dot@...>]

Antonio Scuri <scuri@tecgraf.puc-rio.br> wrote:
>
>   Inspecting the code, I changed the following line:
>
> void *lib = dlopen(path, RTLD_NOW | (seeglb ? RTLD_GLOBAL : RTLD_LOCAL));
>
>   to (the same as it was in Lua 5.1):
>
> void *lib = dlopen(path, RTLD_NOW);
>
>   Then it works.

dlopen() without an explicit RTLD_GLOBAL or RTLD_LOCAL flag is not
portable. On Mac OS X the default is RTLD_GLOBAL but on many other systems
it is RTLD_LOCAL.

You need to arrange for the right value in the seeglb parameter. For
instance,

  package.loadlib (libname, funcname)

  Dynamically links the host program with the C library libname.

  If funcname is "*", then it only links with the library, making the
  symbols exported by the library available to other dynamically linked
  libraries. Otherwise, it looks for a function funcname inside the
  library and returns this function as a C function. (So, funcname must
  follow the prototype lua_CFunction).

The require() mechanism passes luaopen_<modname> as the function name,
so when loading modules in the usual way the RTLD_LOCAL flag is set.

Tony.
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