LUALIB_API void luaL_openlib(lua_State *L, const char *libname,
const luaL_Reg *l, int nup)
{
lj_lib_checkfpu(L);
if (libname) {
int size = libsize(l);
/* check whether lib already exists */
luaL_findtable(L, LUA_REGISTRYINDEX, "_LOADED", 16);
lua_getfield(L, -1, libname); /* get _LOADED[libname] */
if (!lua_istable(L, -1)) { /* not found? */
lua_pop(L, 1); /* remove previous result */
/* try global variable (and create one if it does not exist) */
if (luaL_findtable(L, LUA_GLOBALSINDEX, libname, size) != NULL)
lj_err_callerv(L, LJ_ERR_BADMODN, libname);
lua_pushvalue(L, -1);
lua_setfield(L, -3, libname); /* _LOADED[libname] = new table */
}
lua_remove(L, -2); /* remove _LOADED table */
lua_insert(L, -(nup+1)); /* move library table to below upvalues */
}
for (; l->name; l++) {
int i;
for (i = 0; i < nup; i++) /* copy upvalues to the top */
lua_pushvalue(L, -nup);
lua_pushcclosure(L, l->func, nup);
lua_setfield(L, -(nup+2), l->name);
}
lua_pop(L, nup); /* remove upvalues */
}
static int lj_cf_package_require(lua_State *L)
{
const char *name = luaL_checkstring(L, 1);
int i;
lua_settop(L, 1); /* _LOADED table will be at index 2 */
lua_getfield(L, LUA_REGISTRYINDEX, "_LOADED");
lua_getfield(L, 2, name);
if (lua_toboolean(L, -1)) { /* is it there? */
if (lua_touserdata(L, -1) == sentinel) /* check loops */
luaL_error(L, "loop or previous error loading module " LUA_QS, name);
return 1; /* package is already loaded */
}
/* else must load it; iterate over available loaders */
lua_getfield(L, LUA_ENVIRONINDEX, "loaders");
if (!lua_istable(L, -1))
luaL_error(L, LUA_QL("package.loaders") " must be a table");
lua_pushliteral(L, ""); /* error message accumulator */
for (i = 1; ; i++) {
lua_rawgeti(L, -2, i); /* get a loader */
if (lua_isnil(L, -1))
luaL_error(L, "module " LUA_QS " not found:%s",
name, lua_tostring(L, -2));
lua_pushstring(L, name);
lua_call(L, 1, 1); /* call it */
if (lua_isfunction(L, -1)) /* did it find module? */
break; /* module loaded successfully */
else if (lua_isstring(L, -1)) /* loader returned error message? */
lua_concat(L, 2); /* accumulate it */
else
lua_pop(L, 1);
}
lua_pushlightuserdata(L, sentinel);
lua_setfield(L, 2, name); /* _LOADED[name] = sentinel */
lua_pushstring(L, name); /* pass name as argument to module */
lua_call(L, 1, 1); /* run loaded module */
if (!lua_isnil(L, -1)) /* non-nil return? */
lua_setfield(L, 2, name); /* _LOADED[name] = returned value */
lua_getfield(L, 2, name);
if (lua_touserdata(L, -1) == sentinel) { /* module did not set a value? */
lua_pushboolean(L, 1); /* use true as result */
lua_pushvalue(L, -1); /* extra copy to be returned */
lua_setfield(L, 2, name); /* _LOADED[name] = true */
}
lj_lib_checkfpu(L);
return 1;
}
