| # Helper functions for checking feature variables. | 
 |  | 
 | def df_enabled(d, feature, truevalue, falsevalue=""): | 
 |     return bb.utils.contains("DISTRO_FEATURES", feature, truevalue, falsevalue, d) | 
 |  | 
 |  | 
 | def mf_enabled(d, feature, truevalue, falsevalue=""): | 
 |     return bb.utils.contains("MACHINE_FEATURES", feature, truevalue, falsevalue, d) | 
 |  | 
 |  | 
 | def cf_enabled(d, feature, truevalue, falsevalue=""): | 
 |     return truevalue if df_enabled(d, feature, truevalue) \ | 
 |         and mf_enabled(d, feature, truevalue) \ | 
 |             else falsevalue | 
 |  | 
 |  | 
 | def set_append(d, var, val, sep=' '): | 
 |     values = (d.getVar(var, True) or '').split(sep) | 
 |     if filter(bool, values): | 
 |         d.appendVar(var, '%s%s' %(sep, val)) | 
 |     else: | 
 |         d.setVar(var, val) | 
 |  | 
 |  | 
 | def listvar_to_list(d, list_var, sep=' '): | 
 |     return list(filter(bool, (d.getVar(list_var, True) or '').split(sep))) | 
 |  | 
 |  | 
 | def compose_list(d, fmtvar, *listvars, **kw): | 
 |     import itertools | 
 |     fmt = d.getVar(fmtvar, True) | 
 |     lists = [listvar_to_list(d, x) for x in listvars] | 
 |     lst = [fmt.format(*x) for x in itertools.product(*lists)] | 
 |     return (kw.get('sep') or ' ').join(lst) | 
 |  | 
 |  | 
 | def compose_list_zip(d, fmtvar, *listvars, **kw): | 
 |     fmt = d.getVar(fmtvar, True) | 
 |     lists = [listvar_to_list(d, x) for x in listvars] | 
 |     lst = [fmt.format(*x) for x in zip(*lists)] | 
 |     return (kw.get('sep') or ' ').join(lst) | 
 |  | 
 |  | 
 | def append_suffix(val, suffix): | 
 |     words = val.split(' ') | 
 |     newval = [] | 
 |     for w in words: | 
 |         newval.append(w + suffix) | 
 |     return ' '.join(newval) |