def _dllEmitter(target, source, env, paramtp):
    """Common implementation of dll emitter."""
    SCons.Tool.msvc.validate_vars(env)

    extratargets = []
    extrasources = []

    dll = env.FindIxes(target, '%sPREFIX' % paramtp, '%sSUFFIX' % paramtp)
    no_import_lib = env.get('no_import_lib', 0)

    if not dll:
        raise SCons.Errors.UserError('A shared library should have exactly one target with the suffix: %s' % env.subst('$%sSUFFIX' % paramtp))

    insert_def = env.subst("$WINDOWS_INSERT_DEF")
    if not insert_def in ['', '0', 0] and \
       not env.FindIxes(source, "WINDOWSDEFPREFIX", "WINDOWSDEFSUFFIX"):

        # append a def file to the list of sources
        extrasources.append(
            env.ReplaceIxes(dll,
                            '%sPREFIX' % paramtp, '%sSUFFIX' % paramtp,
                            "WINDOWSDEFPREFIX", "WINDOWSDEFSUFFIX"))

    version_num, suite = SCons.Tool.msvs.msvs_parse_version(env.get('MSVS_VERSION', '6.0'))
    if version_num >= 8.0 and \
            (env.get('WINDOWS_INSERT_MANIFEST', 0) or env.get('WINDOWS_EMBED_MANIFEST', 0)):
        # MSVC 8 and above automatically generate .manifest files that must be installed
        extratargets.append(
            env.ReplaceIxes(dll,
                            '%sPREFIX' % paramtp, '%sSUFFIX' % paramtp,
                            "WINDOWSSHLIBMANIFESTPREFIX", "WINDOWSSHLIBMANIFESTSUFFIX"))

    if 'PDB' in env and env['PDB']:
        pdb = env.arg2nodes('$PDB', target=target, source=source)[0]
        extratargets.append(pdb)
        target[0].attributes.pdb = pdb

    if version_num >= 11.0 and env.get('PCH', 0):
        # MSVC 11 and above need the PCH object file to be added to the link line,
        # otherwise you get link error LNK2011.
        pchobj = SCons.Util.splitext(str(env['PCH']))[0] + '.obj'
        # print "prog_emitter, version %s, appending pchobj %s"%(version_num, pchobj)
        if pchobj not in extrasources:
            extrasources.append(pchobj)

    if not no_import_lib and \
       not env.FindIxes(target, "LIBPREFIX", "LIBSUFFIX"):
        # Append an import library to the list of targets.
        extratargets.append(
            env.ReplaceIxes(dll,
                            '%sPREFIX' % paramtp, '%sSUFFIX' % paramtp,
                            "LIBPREFIX", "LIBSUFFIX"))
        # and .exp file is created if there are exports from a DLL
        extratargets.append(
            env.ReplaceIxes(dll,
                            '%sPREFIX' % paramtp, '%sSUFFIX' % paramtp,
                            "WINDOWSEXPPREFIX", "WINDOWSEXPSUFFIX"))

    return (target+extratargets, source+extrasources)
Common implementation of dll emitter.