LUALIB_API const char *luaL_findtable (lua_State *L, int idx,
const char *fname, int szhint) {
const char *e;
lua_pushvalue(L, idx);
do {
e = c_strchr(fname, '.');
if (e == NULL) e = fname + c_strlen(fname);
lua_pushlstring(L, fname, e - fname);
lua_rawget(L, -2);
if (lua_isnil(L, -1)) {
/* If looking for a global variable, check the rotables too */
void *ptable = luaR_findglobal(fname, e - fname);
if (ptable) {
lua_pop(L, 1);
lua_pushrotable(L, ptable);
}
}
if (lua_isnil(L, -1)) { /* no such field? */
lua_pop(L, 1); /* remove this nil */
lua_createtable(L, 0, (*e == '.' ? 1 : szhint)); /* new table for field */
lua_pushlstring(L, fname, e - fname);
lua_pushvalue(L, -2);
lua_settable(L, -4); /* set new table into field */
}
else if (!lua_istable(L, -1) && !lua_isrotable(L, -1)) { /* field has a non-table value? */
lua_pop(L, 2); /* remove table and value */
return fname; /* return problematic part of the name */
}
lua_remove(L, -2); /* remove previous table */
fname = e + 1;
} while (*e == '.');
return NULL;
}
static int traceback (lua_State *L) {
if (!lua_isstring(L, 1)) /* 'message' not a string? */
return 1; /* keep it intact */
lua_getfield(L, LUA_GLOBALSINDEX, "debug");
if (!lua_istable(L, -1) && !lua_isrotable(L, -1)) {
lua_pop(L, 1);
return 1;
}
lua_getfield(L, -1, "traceback");
if (!lua_isfunction(L, -1) && !lua_islightfunction(L, -1)) {
lua_pop(L, 2);
return 1;
}
lua_pushvalue(L, 1); /* pass error message */
lua_pushinteger(L, 2); /* skip this function and traceback */
lua_call(L, 2, 1); /* call debug.traceback */
return 1;
}