def sstate_task_postfunc(d):
    shared_state = sstate_state_fromvars(d)

    for intercept in shared_state['interceptfuncs']:
        bb.build.exec_func(intercept, d, (d.getVar("WORKDIR"),))

    omask = os.umask(0o002)
    if omask != 0o002:
       bb.note("Using umask 0o002 (not %0o) for sstate packaging" % omask)
    sstate_package(shared_state, d)
    os.umask(omask)

    sstateinst = d.getVar("SSTATE_INSTDIR")
    d.setVar('SSTATE_FIXMEDIR', shared_state['fixmedir'])

    sstate_installpkgdir(shared_state, d)

    bb.utils.remove(d.getVar("SSTATE_BUILDDIR"), recurse=True)

sstate_task_postfunc(d)

def sstate_state_fromvars(d, task = None):
    if task is None:
        task = d.getVar('BB_CURRENTTASK')
        if not task:
            bb.fatal("sstate code running without task context?!")
        task = task.replace("_setscene", "")

    if task.startswith("do_"):
        task = task[3:]
    inputs = (d.getVarFlag("do_" + task, 'sstate-inputdirs') or "").split()
    outputs = (d.getVarFlag("do_" + task, 'sstate-outputdirs') or "").split()
    plaindirs = (d.getVarFlag("do_" + task, 'sstate-plaindirs') or "").split()
    lockfiles = (d.getVarFlag("do_" + task, 'sstate-lockfile') or "").split()
    lockfilesshared = (d.getVarFlag("do_" + task, 'sstate-lockfile-shared') or "").split()
    interceptfuncs = (d.getVarFlag("do_" + task, 'sstate-interceptfuncs') or "").split()
    fixmedir = d.getVarFlag("do_" + task, 'sstate-fixmedir') or ""
    if not task or len(inputs) != len(outputs):
        bb.fatal("sstate variables not setup correctly?!")

    if task == "populate_lic":
        d.setVar("SSTATE_PKGSPEC", "${SSTATE_SWSPEC}")
        d.setVar("SSTATE_EXTRAPATH", "")
        d.setVar('SSTATE_EXTRAPATHWILDCARD', "")

    ss = sstate_init(task, d)
    for i in range(len(inputs)):
        sstate_add(ss, inputs[i], outputs[i], d)
    ss['lockfiles'] = lockfiles
    ss['lockfiles-shared'] = lockfilesshared
    ss['plaindirs'] = plaindirs
    ss['interceptfuncs'] = interceptfuncs
    ss['fixmedir'] = fixmedir
    return ss

def sstate_installpkgdir(ss, d):
    import oe.path
    import subprocess

    sstateinst = d.getVar("SSTATE_INSTDIR")
    d.setVar('SSTATE_FIXMEDIR', ss['fixmedir'])

    for f in (d.getVar('SSTATEPOSTUNPACKFUNCS') or '').split():
        # All hooks should run in the SSTATE_INSTDIR
        bb.build.exec_func(f, d, (sstateinst,))

    def prepdir(dir):
        # remove dir if it exists, ensure any parent directories do exist
        if os.path.exists(dir):
            oe.path.remove(dir)
        bb.utils.mkdirhier(dir)
        oe.path.remove(dir)

    for state in ss['dirs']:
        prepdir(state[1])
        os.rename(sstateinst + state[0], state[1])
    sstate_install(ss, d)

    for plain in ss['plaindirs']:
        workdir = d.getVar('WORKDIR')
        src = sstateinst + "/" + plain.replace(workdir, '')
        dest = plain
        bb.utils.mkdirhier(src)
        prepdir(dest)
        os.rename(src, dest)

    return True

def sstate_package(ss, d):
    import oe.path

    tmpdir = d.getVar('TMPDIR')

    sstatebuild = d.expand("${WORKDIR}/sstate-build-%s/" % ss['task'])
    sstatepkg = d.getVar('SSTATE_PKG') + '_'+ ss['task'] + ".tgz"
    bb.utils.remove(sstatebuild, recurse=True)
    bb.utils.mkdirhier(sstatebuild)
    bb.utils.mkdirhier(os.path.dirname(sstatepkg))
    for state in ss['dirs']:
        if not os.path.exists(state[1]):
            continue
        srcbase = state[0].rstrip("/").rsplit('/', 1)[0]
        # Find and error for absolute symlinks. We could attempt to relocate but its not
        # clear where the symlink is relative to in this context. We could add that markup
        # to sstate tasks but there aren't many of these so better just avoid them entirely.
        for walkroot, dirs, files in os.walk(state[1]):
            for file in files + dirs:
                srcpath = os.path.join(walkroot, file)
                if not os.path.islink(srcpath):
                    continue
                link = os.readlink(srcpath)
                if not os.path.isabs(link):
                    continue
                if not link.startswith(tmpdir):
                    continue
                bb.error("sstate found an absolute path symlink %s pointing at %s. Please replace this with a relative link." % (srcpath, link))
        bb.debug(2, "Preparing tree %s for packaging at %s" % (state[1], sstatebuild + state[0]))
        os.rename(state[1], sstatebuild + state[0])

    workdir = d.getVar('WORKDIR')
    for plain in ss['plaindirs']:
        pdir = plain.replace(workdir, sstatebuild)
        bb.utils.mkdirhier(plain)
        bb.utils.mkdirhier(pdir)
        os.rename(plain, pdir)

    d.setVar('SSTATE_BUILDDIR', sstatebuild)
    d.setVar('SSTATE_PKG', sstatepkg)
    d.setVar('SSTATE_INSTDIR', sstatebuild)

    if d.getVar('SSTATE_SKIP_CREATION') == '1':
        return

    for f in (d.getVar('SSTATECREATEFUNCS') or '').split() + \
             ['sstate_create_package', 'sstate_sign_package'] + \
             (d.getVar('SSTATEPOSTCREATEFUNCS') or '').split():
        # All hooks should run in SSTATE_BUILDDIR.
        bb.build.exec_func(f, d, (sstatebuild,))

    bb.siggen.dump_this_task(sstatepkg + ".siginfo", d)

    return

def sstate_init(task, d):
    ss = {}
    ss['task'] = task
    ss['dirs'] = []
    ss['plaindirs'] = []
    ss['lockfiles'] = []
    ss['lockfiles-shared'] = []
    return ss

def sstate_install(ss, d):
    import oe.path
    import oe.sstatesig
    import subprocess

    sharedfiles = []
    shareddirs = []
    bb.utils.mkdirhier(d.expand("${SSTATE_MANIFESTS}"))

    sstateinst = d.expand("${WORKDIR}/sstate-install-%s/" % ss['task'])

    manifest, d2 = oe.sstatesig.sstate_get_manifest_filename(ss['task'], d)

    if os.access(manifest, os.R_OK):
        bb.fatal("Package already staged (%s)?!" % manifest)

    d.setVar("SSTATE_INST_POSTRM", manifest + ".postrm")

    locks = []
    for lock in ss['lockfiles-shared']:
        locks.append(bb.utils.lockfile(lock, True))
    for lock in ss['lockfiles']:
        locks.append(bb.utils.lockfile(lock))

    for state in ss['dirs']:
        bb.debug(2, "Staging files from %s to %s" % (state[1], state[2]))
        for walkroot, dirs, files in os.walk(state[1]):
            for file in files:
                srcpath = os.path.join(walkroot, file)
                dstpath = srcpath.replace(state[1], state[2])
                #bb.debug(2, "Staging %s to %s" % (srcpath, dstpath))
                sharedfiles.append(dstpath)
            for dir in dirs:
                srcdir = os.path.join(walkroot, dir)
                dstdir = srcdir.replace(state[1], state[2])
                #bb.debug(2, "Staging %s to %s" % (srcdir, dstdir))
                if os.path.islink(srcdir):
                    sharedfiles.append(dstdir)
                    continue
                if not dstdir.endswith("/"):
                    dstdir = dstdir + "/"
                shareddirs.append(dstdir)

    # Check the file list for conflicts against files which already exist
    whitelist = (d.getVar("SSTATE_DUPWHITELIST") or "").split()
    match = []
    for f in sharedfiles:
        if os.path.exists(f) and not os.path.islink(f):
            f = os.path.normpath(f)
            realmatch = True
            for w in whitelist:
                w = os.path.normpath(w)
                if f.startswith(w):
                    realmatch = False
                    break
            if realmatch:
                match.append(f)
                sstate_search_cmd = "grep -rlF '%s' %s --exclude=master.list | sed -e 's:^.*/::'" % (f, d.expand("${SSTATE_MANIFESTS}"))
                search_output = subprocess.Popen(sstate_search_cmd, shell=True, stdout=subprocess.PIPE).communicate()[0]
                if search_output:
                    match.append("  (matched in %s)" % search_output.decode('utf-8').rstrip())
                else:
                    match.append("  (not matched to any task)")
    if match:
        bb.error("The recipe %s is trying to install files into a shared " \
          "area when those files already exist. Those files and their manifest " \
          "location are:\n  %s\nPlease verify which recipe should provide the " \
          "above files.\n\nThe build has stopped, as continuing in this scenario WILL " \
          "break things - if not now, possibly in the future (we've seen builds fail " \
          "several months later). If the system knew how to recover from this " \
          "automatically it would, however there are several different scenarios " \
          "which can result in this and we don't know which one this is. It may be " \
          "you have switched providers of something like virtual/kernel (e.g. from " \
          "linux-yocto to linux-yocto-dev), in that case you need to execute the " \
          "clean task for both recipes and it will resolve this error. It may be " \
          "you changed DISTRO_FEATURES from systemd to udev or vice versa. Cleaning " \
          "those recipes should again resolve this error, however switching " \
          "DISTRO_FEATURES on an existing build directory is not supported - you " \
          "should really clean out tmp and rebuild (reusing sstate should be safe). " \
          "It could be the overlapping files detected are harmless in which case " \
          "adding them to SSTATE_DUPWHITELIST may be the correct solution. It could " \
          "also be your build is including two different conflicting versions of " \
          "things (e.g. bluez 4 and bluez 5 and the correct solution for that would " \
          "be to resolve the conflict. If in doubt, please ask on the mailing list, " \
          "sharing the error and filelist above." % \
          (d.getVar('PN'), "\n  ".join(match)))
        bb.fatal("If the above message is too much, the simpler version is you're advised to wipe out tmp and rebuild (reusing sstate is fine). That will likely fix things in most (but not all) cases.")

    if ss['fixmedir'] and os.path.exists(ss['fixmedir'] + "/fixmepath.cmd"):
        sharedfiles.append(ss['fixmedir'] + "/fixmepath.cmd")
        sharedfiles.append(ss['fixmedir'] + "/fixmepath")

    # Write out the manifest
    f = open(manifest, "w")
    for file in sharedfiles:
        f.write(file + "\n")

    # We want to ensure that directories appear at the end of the manifest
    # so that when we test to see if they should be deleted any contents
    # added by the task will have been removed first.
    dirs = sorted(shareddirs, key=len)
    # Must remove children first, which will have a longer path than the parent
    for di in reversed(dirs):
        f.write(di + "\n")
    f.close()

    # Append to the list of manifests for this PACKAGE_ARCH

    i = d2.expand("${SSTATE_MANIFESTS}/index-${SSTATE_MANMACH}")
    l = bb.utils.lockfile(i + ".lock")
    filedata = d.getVar("STAMP") + " " + d2.getVar("SSTATE_MANFILEPREFIX") + " " + d.getVar("WORKDIR") + "\n"
    manifests = []
    if os.path.exists(i):
        with open(i, "r") as f:
            manifests = f.readlines()
    if filedata not in manifests:
        with open(i, "a+") as f:
            f.write(filedata)
    bb.utils.unlockfile(l)

    # Run the actual file install
    for state in ss['dirs']:
        if os.path.exists(state[1]):
            oe.path.copyhardlinktree(state[1], state[2])

    for postinst in (d.getVar('SSTATEPOSTINSTFUNCS') or '').split():
        # All hooks should run in the SSTATE_INSTDIR
        bb.build.exec_func(postinst, d, (sstateinst,))

    for lock in locks:
        bb.utils.unlockfile(lock)

def sstate_add(ss, source, dest, d):
    if not source.endswith("/"):
         source = source + "/"
    if not dest.endswith("/"):
         dest = dest + "/"
    source = os.path.normpath(source)
    dest = os.path.normpath(dest)
    srcbase = os.path.basename(source)
    ss['dirs'].append([srcbase, source, dest])
    return ss