Function findloader

libraries/AP_Scripting/lua/src/loadlib.c:575–619

#endif

static void findloader (lua_State *L, const char *name) {
  luaL_Buffer msg;  /* to build error message */
  luaL_buffinit(L, &msg);
  lua_pushstring(L, name);
#if defined(ARDUPILOT_BUILD)
  // since we only use lua modules there's no point
  // in searching for C or other types of modules
  // so we just call the lua searcher
  searcher_Lua(L);
  if (lua_isfunction(L, -2)) {  /* module loader found? */
    return;  /* module loader already on stack */
  } else if (lua_isstring(L, -2)) {  /* searcher returned error message? */
    lua_pop(L, 1);  /* remove extra return */
    luaL_addvalue(&msg);  /* concatenate error message */
  } else {
    lua_pop(L, 2);  /* remove both returns */
  }
  // module not found
  lua_pop(L, 1);  /* remove nil */
  luaL_pushresult(&msg);  /* create error message */
  luaL_error(L, "module '%s' not found:%s", name, lua_tostring(L, -1));
#else
  /* push 'package.searchers' to index 3 in the stack */
  if (lua_getfield(L, lua_upvalueindex(1), "searchers") != LUA_TTABLE)
    luaL_error(L, "'package.searchers' must be a table");
  /*  iterate over available searchers to find a loader */
  for (i = 1; ; i++) {
    if (lua_rawgeti(L, 3, i) == LUA_TNIL) {  /* no more searchers? */
      lua_pop(L, 1);  /* remove nil */
      luaL_pushresult(&msg);  /* create error message */
      luaL_error(L, "module '%s' not found:%s", name, lua_tostring(L, -1));
    }
    lua_pushstring(L, name);
    lua_call(L, 1, 2);  /* call it */
    if (lua_isfunction(L, -2))  /* did it find a loader? */
      return;  /* module loader found */
    else if (lua_isstring(L, -2)) {  /* searcher returned error message? */
      lua_pop(L, 1);  /* remove extra return */
      luaL_addvalue(&msg);  /* concatenate error message */
    }
    else
      lua_pop(L, 2);  /* remove both returns */
  }
#endif
}


static int ll_require (lua_State *L) {