"""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 __future__ import absolute_import, print_function

import re
import os

import SCons.Action
import SCons.Util
import SCons.Tool

#MAYBE:  from . import gnulink
from . import gnulink
from . import link

def _lib_generator(target, source, env, for_signature, **kw):
    try: cmd = kw['cmd']
    except KeyError: cmd = SCons.Util.CLVar(['$SHLINK'])

    try: vp = kw['varprefix']
    except KeyError: vp = 'SHLIB'

    dll = env.FindIxes(target, '%sPREFIX' % vp, '%sSUFFIX' % vp)
    if dll: cmd.extend(['-o', dll])

    cmd.extend(['$SHLINKFLAGS', '$__%sVERSIONFLAGS' % vp, '$__RPATH'])

    implib = env.FindIxes(target, 'IMPLIBPREFIX', 'IMPLIBSUFFIX')
    if implib:
        cmd.extend([
            '-Wl,--out-implib='+implib.get_string(for_signature),
            '-Wl,--export-all-symbols',
            '-Wl,--enable-auto-import',
            '-Wl,--whole-archive', '$SOURCES',
            '-Wl,--no-whole-archive', '$_LIBDIRFLAGS', '$_LIBFLAGS'
            ])
    else:
        cmd.extend(['$SOURCES', '$_LIBDIRFLAGS', '$_LIBFLAGS'])

    return [cmd]


def shlib_generator(target, source, env, for_signature):
    return _lib_generator(target, source, env, for_signature,
                          varprefix='SHLIB',
                          cmd = SCons.Util.CLVar(['$SHLINK']))

def ldmod_generator(target, source, env, for_signature):
    return _lib_generator(target, source, env, for_signature,
                          varprefix='LDMODULE',
                          cmd = SCons.Util.CLVar(['$LDMODULE']))

def _lib_emitter(target, source, env, **kw):
    Verbose = False

    if Verbose:
        print("_lib_emitter: target[0]=%r" % target[0].get_path())

    try: vp = kw['varprefix']
    except KeyError: vp = 'SHLIB'

    try: libtype = kw['libtype']
    except KeyError: libtype = 'ShLib'

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

    if Verbose:
        print("_lib_emitter: dll=%r" % dll.get_path())

    if not dll or len(target) > 1:
        raise SCons.Errors.UserError("A shared library should have exactly one target with the suffix: %s" % env.subst("$%sSUFFIX" % vp))

    # Remove any "lib" after the prefix
    pre = env.subst('$%sPREFIX' % vp)
    if dll.name[len(pre):len(pre)+3] == 'lib':
        dll.name = pre + dll.name[len(pre)+3:]

    if Verbose:
        print("_lib_emitter: dll.name=%r" % dll.name)

    orig_target = target
    target = [env.fs.File(dll)]
    target[0].attributes.shared = 1

    if Verbose:
        print("_lib_emitter: after target=[env.fs.File(dll)]: target[0]=%r" % target[0].get_path())

    # Append an import lib target
    if not no_import_lib:
        # Create list of target libraries as strings
        target_strings = env.ReplaceIxes(orig_target[0],
                                         '%sPREFIX' % vp, '%sSUFFIX' % vp,
                                         'IMPLIBPREFIX', 'IMPLIBSUFFIX')
        if Verbose:
            print("_lib_emitter: target_strings=%r" % target_strings)

        implib_target = env.fs.File(target_strings)
        if Verbose:
            print("_lib_emitter: implib_target=%r" % implib_target.get_path())
        implib_target.attributes.shared = 1
        target.append(implib_target)

    symlinks = SCons.Tool.ImpLibSymlinkGenerator(env, implib_target,
                                                 implib_libtype=libtype,
                                                 generator_libtype=libtype+'ImpLib')
    if Verbose:
        print("_lib_emitter: implib symlinks=%r" % SCons.Tool.StringizeLibSymlinks(symlinks))
    if symlinks:
        SCons.Tool.EmitLibSymlinks(env, symlinks, implib_target, clean_targets = target[0])
        implib_target.attributes.shliblinks = symlinks

    return (target, source)

def shlib_emitter(target, source, env):
    return _lib_emitter(target, source, env, varprefix='SHLIB', libtype='ShLib')

def ldmod_emitter(target, source, env):
    return _lib_emitter(target, source, env, varprefix='LDMODULE', libtype='LdMod')

def _versioned_lib_suffix(env, suffix, version):
    """Generate versioned shared library suffix from a unversioned one.
       If suffix='.dll', and version='0.1.2', then it returns '-0-1-2.dll'"""
    Verbose = False
    if Verbose:
        print("_versioned_lib_suffix: suffix= ", suffix)
        print("_versioned_lib_suffix: version= ", version)
    cygversion = re.sub('\.', '-', version)
    if not suffix.startswith('-' + cygversion):
        suffix = '-' + cygversion + suffix
    if Verbose:
        print("_versioned_lib_suffix: return suffix= ", suffix)
    return suffix

def _versioned_implib_name(env, libnode, version, prefix, suffix, **kw):
    return link._versioned_lib_name(env, libnode, version, prefix, suffix,
                                    SCons.Tool.ImpLibPrefixGenerator,
                                    SCons.Tool.ImpLibSuffixGenerator,
                                    implib_libtype=kw['libtype'])

def _versioned_implib_symlinks(env, libnode, version, prefix, suffix, **kw):
    """Generate link names that should be created for a versioned shared library.
       Returns a list in the form [ (link, linktarget), ... ]
    """
    Verbose = False

    if Verbose:
        print("_versioned_implib_symlinks: libnode=%r" % libnode.get_path())
        print("_versioned_implib_symlinks: version=%r" % version)

    try: libtype = kw['libtype']
    except KeyError: libtype = 'ShLib'


    linkdir = os.path.dirname(libnode.get_path())
    if Verbose:
        print("_versioned_implib_symlinks: linkdir=%r" % linkdir)

    name = SCons.Tool.ImpLibNameGenerator(env, libnode,
                                          implib_libtype=libtype,
                                          generator_libtype=libtype+'ImpLib')
    if Verbose:
        print("_versioned_implib_symlinks: name=%r" % name)

    major = version.split('.')[0]

    link0 = env.fs.File(os.path.join(linkdir, name))
    symlinks = [(link0, libnode)]

    if Verbose:
        print("_versioned_implib_symlinks: return symlinks=%r" % SCons.Tool.StringizeLibSymlinks(symlinks))

    return symlinks

shlib_action = SCons.Action.Action(shlib_generator, generator=1)
ldmod_action = SCons.Action.Action(ldmod_generator, generator=1)

def generate(env):
    """Add Builders and construction variables for cyglink to an Environment."""
    gnulink.generate(env)

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

    env['SHLINKCOM'] = shlib_action
    env['LDMODULECOM'] = ldmod_action
    env.Append(SHLIBEMITTER = [shlib_emitter])
    env.Append(LDMODULEEMITTER = [ldmod_emitter])

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

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

    # Variables used by versioned shared libraries
    env['_SHLIBVERSIONFLAGS']      = '$SHLIBVERSIONFLAGS'
    env['_LDMODULEVERSIONFLAGS']   = '$LDMODULEVERSIONFLAGS'

    # SHLIBVERSIONFLAGS and LDMODULEVERSIONFLAGS are same as in gnulink...

    # LINKCALLBACKS are NOT inherited from gnulink
    env['LINKCALLBACKS'] = {
        'VersionedShLibSuffix'          : _versioned_lib_suffix,
        'VersionedLdModSuffix'          : _versioned_lib_suffix,
        'VersionedImpLibSuffix'         : _versioned_lib_suffix,
        'VersionedShLibName'            : link._versioned_shlib_name,
        'VersionedLdModName'            : link._versioned_ldmod_name,
        'VersionedShLibImpLibName'      : lambda *args: _versioned_implib_name(*args, libtype='ShLib'),
        'VersionedLdModImpLibName'      : lambda *args: _versioned_implib_name(*args, libtype='LdMod'),
        'VersionedShLibImpLibSymlinks'  : lambda *args: _versioned_implib_symlinks(*args, libtype='ShLib'),
        'VersionedLdModImpLibSymlinks'  : lambda *args: _versioned_implib_symlinks(*args, libtype='LdMod'),
    }

    # these variables were set by gnulink but are not used in cyglink
    try: del env['_SHLIBSONAME']
    except KeyError: pass
    try: del env['_LDMODULESONAME']
    except KeyError: pass

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


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