# Check for a module in a set of extension directories.# An extension directory should contain a Setup file# and one or more .o files or a lib.a file. import osimport parsesetup def checkextensions(unknown, extensions):    files = []    modules = []    edict = {}    for e in extensions:        setup = os.path.join(e, 'Setup')        liba = os.path.join(e, 'lib.a')        if not os.path.isfile(liba):            liba = None        edict[e] = parsesetup.getsetupinfo(setup), liba    for mod in unknown:        for e in extensions:            (mods, vars), liba = edict[e]            if not mods.has_key(mod):                continue            modules.append(mod)            if liba:                # If we find a lib.a, use it, ignore the                # .o files, and use *all* libraries for                # *all* modules in the Setup file                if liba in files:                    break                files.append(liba)                for m in mods.keys():                    files = files + select(e, mods, vars,                                           m, 1)                break            files = files + select(e, mods, vars, mod, 0)            break    return files, modules def select(e, mods, vars, mod, skipofiles):    files = []    for w in mods[mod]:        w = treatword(w)        if not w:            continue        w = expandvars(w, vars)        for w in w.split():            if skipofiles and w[-2:] == '.o':                continue            # Assume $var expands to absolute pathname            if w[0] not in ('-', '$') and w[-2:] in ('.o', '.a'):                w = os.path.join(e, w)            if w[:2] in ('-L', '-R') and w[2:3] != '$':                w = w[:2] + os.path.join(e, w[2:])            files.append(w)    return files cc_flags = ['-I', '-D', '-U']cc_exts = ['.c', '.C', '.cc', '.c++'] def treatword(w):    if w[:2] in cc_flags:        return None    if w[:1] == '-':        return w # Assume loader flag    head, tail = os.path.split(w)    base, ext = os.path.splitext(tail)    if ext in cc_exts:        tail = base + '.o'        w = os.path.join(head, tail)    return w def expandvars(str, vars):    i = 0    while i < len(str):        i = k = str.find('$', i)        if i < 0:            break        i = i+1        var = str[i:i+1]        i = i+1        if var == '(':            j = str.find(')', i)            if j < 0:                break            var = str[i:j]            i = j+1        if vars.has_key(var):            str = str[:k] + vars[var] + str[i:]            i = k    return str