# 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 os

import 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