"""SCons.Tool.cyglink

Customization of gnulink for Cygwin (http://www.cygwin.com/)

There normally shouldn't be any need to import this module directly.
It will usually be imported through the generic SCons.Tool.Tool()
selection method.

"""

from SCons.Tool.linkCommon import StringizeLibSymlinks, EmitLibSymlinks
from SCons.Util import CLVar, is_String
from . import gnulink


def cyglink_lib_emitter(target, source, env, **kw):
    verbose = True

    if 'variable_prefix' in kw:
        var_prefix = kw['variable_prefix']
    else:
        var_prefix = 'SHLIB'

    no_import_lib = env.get('no_import_lib', False)

    if verbose:
        print("cyglink_lib_emitter: target[0]={!r}".format(target[0].get_path()))

    if not no_import_lib:
        # Specify import lib and add to targets

        import_lib = env.subst('$%s_IMPLIBNAME' % var_prefix, target=target, source=source)
        import_lib_target = env.fs.File(import_lib)
        import_lib_target.attributes.shared = 1
        target.append(import_lib_target)

        if verbose:
            print("cyglink_lib_emitter: import_lib={}".format(import_lib))
            print("cyglink_lib_emitter: target=%s" % target)

    for tgt in target:
        if is_String(tgt):
            tgt = env.File(tgt)
        tgt.attributes.shared = 1

    return target, source


def cyglink_ldmodule_emitter(target, source, env, **kw):
    return cyglink_lib_emitter(target, source, env, variable_prefix='LDMODULE')


def cyglink_shlib_symlink_emitter(target, source, env, **kw):
    """
    On cygwin, we only create a symlink from the non-versioned implib to the versioned implib.
    We don't version the shared library itself.
    :param target:
    :param source:
    :param env:
    :param kw:
    :return:
    """
    verbose = True

    if 'variable_prefix' in kw:
        var_prefix = kw['variable_prefix']
    else:
        var_prefix = 'SHLIB'

    no_import_lib = env.get('no_import_lib', False)
    if no_import_lib in ['1', 'True', 'true', True]:
        if verbose:
            print("cyglink_shlib_symlink_emitter: no_import_lib=%s" % no_import_lib)
        return target, source

    no_symlinks = env.subst('$%sNOVERSIONSYMLINKS' % var_prefix)
    if no_symlinks in ['1', 'True', 'true', True]:
        return target, source

    shlibversion = env.subst('$%sVERSION' % var_prefix)
    if shlibversion:
        if verbose:
            print("cyglink_shlib_symlink_emitter: %sVERSION=%s" % (var_prefix, shlibversion))

        # The implib (added by the cyglink_lib_emitter)
        imp_lib_node = target[1]
        shlib_noversion_symlink = env.subst('$%s_NOVERSION_SYMLINK' % var_prefix, target=target[0], source=source)

        if verbose:
            print("cyglink_shlib_symlink_emitter: shlib_noversion_symlink :%s" % shlib_noversion_symlink)
            print("cyglink_shlib_symlink_emitter: imp_lib_node            :%s" % imp_lib_node)

        symlinks = [(env.File(shlib_noversion_symlink), imp_lib_node)]

        if verbose:
            print("cyglink_shlib_symlink_emitter: symlinks={!r}".format(
                ', '.join(["%r->%r" % (k, v) for k, v in StringizeLibSymlinks(symlinks)])
            ))

        if symlinks:
            # This does the actual symlinking
            EmitLibSymlinks(env, symlinks, target[0])

            # This saves the information so if the versioned shared library is installed
            # it can faithfully reproduce the correct symlinks
            target[0].attributes.shliblinks = symlinks

    return target, source


def cyglink_ldmod_symlink_emitter(target, source, env, **kw):
    return cyglink_shlib_symlink_emitter(target, source, env, variable_prefix='LDMODULE')


def cyglink_shlibversion(target, source, env, for_signature):
    var_prefix = 'SHLIB'
    var = '%sVERSION' % var_prefix
    if var not in env:
        return ''

    version = env.subst("$%s" % var, target=target, source=source)
    version = version.replace('.', '-')
    return "." + version


def cyglink_ldmodule_version(target, source, env, for_signature):
    var_prefix = 'LDMODULE'
    var = '%sVERSION' % var_prefix
    if var not in env:
        return ''

    version = env.subst("$%s" % var, target=target, source=source)
    version = version.replace('.', '-')
    return "." + version


def _implib_pre_flags(target, source, env, for_signature) -> str:
    no_import_lib = env.get('no_import_lib', False)
    if no_import_lib in ['1', 'True', 'true', True]:
        return ''
    else:
        return '-Wl,--out-implib=${TARGETS[1]} -Wl,--export-all-symbols -Wl,--enable-auto-import -Wl,--whole-archive'


def _implib_post_flags(target, source, env, for_signature) -> str:
    no_import_lib = env.get('no_import_lib', False)
    if no_import_lib in ['1', 'True', 'true', True]:
        return ''
    else:
        return '-Wl,--no-whole-archive'


def generate(env) -> None:
    """Add Builders and construction variables for cyglink to an Environment."""
    gnulink.generate(env)

    env['LINKFLAGS'] = CLVar('-Wl,-no-undefined')

    env['SHLIBPREFIX'] = 'cyg'
    env['SHLIBSUFFIX'] = '.dll'

    env['IMPLIBPREFIX'] = 'lib'
    env['IMPLIBSUFFIX'] = '.dll.a'

    # Variables used by versioned shared libraries
    # SHLIBVERSIONFLAGS and LDMODULEVERSIONFLAGS are same as in gnulink...
    env['_SHLIBVERSIONFLAGS'] = '$SHLIBVERSIONFLAGS'
    env['_LDMODULEVERSIONFLAGS'] = '$LDMODULEVERSIONFLAGS'

    env['_IMPLIB_PRE_SOURCES'] = _implib_pre_flags
    env['_IMPLIB_POST_SOURCES'] = _implib_post_flags
    env['SHLINKCOM'] = '$SHLINK -o $TARGET $SHLINKFLAGS $__SHLIBVERSIONFLAGS $__RPATH ' \
                       '$_IMPLIB_PRE_SOURCES $SOURCES  $_IMPLIB_POST_SOURCES $_LIBDIRFLAGS $_LIBFLAGS'
    env['LDMODULECOM'] = '$LDMODULE -o $TARGET $SHLINKFLAGS $__LDMODULEVERSIONFLAGS $__RPATH ' \
                         '$_IMPLIB_PRE_SOURCES $SOURCES $_IMPLIB_POST_SOURCES $_LIBDIRFLAGS  $_LIBFLAGS'

    # Overwrite emitters. Cyglink does things differently when creating symlinks
    env['SHLIBEMITTER'] = [cyglink_lib_emitter, cyglink_shlib_symlink_emitter]
    env['LDMODULEEMITTER'] = [cyglink_ldmodule_emitter, cyglink_ldmod_symlink_emitter]

    # This is the non versioned shlib filename
    # If SHLIBVERSION is defined then this will symlink to $SHLIBNAME
    env['SHLIB_NOVERSION_SYMLINK'] = '${IMPLIBPREFIX}$_get_shlib_stem${IMPLIBSUFFIX}'
    env['LDMODULE_NOVERSION_SYMLINK'] = '${IMPLIBPREFIX}$_get_ldmodule_stem${IMPLIBSUFFIX}'

    env['SHLIB_IMPLIBNAME'] = '${IMPLIBPREFIX}$_get_shlib_stem${_SHLIB_IMPLIBSUFFIX}'
    env['LDMODULE_IMPLIBNAME'] = '${IMPLIBPREFIX}$_get_ldmodule_stem${_LDMODULE_IMPLIBSUFFIX}'

    env['_cyglink_shlibversion'] = cyglink_shlibversion
    env['_SHLIB_IMPLIBSUFFIX'] = '${_cyglink_shlibversion}${IMPLIBSUFFIX}'
    env['_SHLIBSUFFIX'] = '${_cyglink_shlibversion}${SHLIBSUFFIX}'

    env['_cyglink_ldmodule_version'] = cyglink_ldmodule_version

    env['_LDMODULESUFFIX'] = '${_cyglink_ldmodule_version}${LDMODULESUFFIX}'
    env['_LDMODULE_IMPLIBSUFFIX'] = '${_cyglink_ldmodule_version}${IMPLIBSUFFIX}'

    # Remove variables set by default initialization which aren't needed/used by cyglink
    # these variables were set by gnulink but are not used in cyglink
    for rv in ['_SHLIBSONAME', '_LDMODULESONAME']:
        if rv in env:
            del env[rv]


def exists(env):
    return gnulink.exists(env)

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