str_checkname
label = str_checkname(ls);
new_localvar(ls, str_checkname(ls));
varname = str_checkname(ls); /* first variable name */
new_localvar(ls, str_checkname(ls)); /* new local variable */
new_localvar(ls, str_checkname(ls));
labelstat(ls, str_checkname(ls), line);
codestring(ls, e, str_checkname(ls));
TString *varname = str_checkname(ls);
new_localvar(ls, str_checkname(ls));