Simplify Python Imports For Embedding

After the project split, shiboken exposed its own modules, and the
overall structure with shiboken2.support.signature and
PySide2.support.signature was already quite complicated.

When introducing embedding, it is necessary to have some support
folder that gets unpacked from a zipfile. That means, the shiboken2
root directory would be in the zip file in the embedding case.

This does not only increase the complexity, it further means
that we must make shiboken2.so available in the shiboken2
containing zipfile!

In order to avoid that, we stop the dependency from the two
support directories and use shibokensupport, instead. The
simplification of the loader and other modules is also significant.

Task-number: PYSIDE-510
Change-Id: Ic735a8d36f10f03698378f2ac9685a5955e40b0c
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@qt.io>

1 files changed, 195 insertions, 0 deletions

diff --git a/sources/shiboken2/shibokenmodule/files.dir/shibokensupport/signature/loader.py b/sources/shiboken2/shibokenmodule/files.dir/shibokensupport/signature/loader.py
new file mode 100644
index 000000000..3a8d614db
--- /dev/null
+++ b/sources/shiboken2/shibokenmodule/files.dir/shibokensupport/signature/loader.py
@@ -0,0 +1,195 @@
+#############################################################################
+##
+## Copyright (C) 2019 The Qt Company Ltd.
+## Contact: https://www.qt.io/licensing/
+##
+## This file is part of Qt for Python.
+##
+## $QT_BEGIN_LICENSE:LGPL$
+## Commercial License Usage
+## Licensees holding valid commercial Qt licenses may use this file in
+## accordance with the commercial license agreement provided with the
+## Software or, alternatively, in accordance with the terms contained in
+## a written agreement between you and The Qt Company. For licensing terms
+## and conditions see https://www.qt.io/terms-conditions. For further
+## information use the contact form at https://www.qt.io/contact-us.
+##
+## GNU Lesser General Public License Usage
+## Alternatively, this file may be used under the terms of the GNU Lesser
+## General Public License version 3 as published by the Free Software
+## Foundation and appearing in the file LICENSE.LGPL3 included in the
+## packaging of this file. Please review the following information to
+## ensure the GNU Lesser General Public License version 3 requirements
+## will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+##
+## GNU General Public License Usage
+## Alternatively, this file may be used under the terms of the GNU
+## General Public License version 2.0 or (at your option) the GNU General
+## Public license version 3 or any later version approved by the KDE Free
+## Qt Foundation. The licenses are as published by the Free Software
+## Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+## included in the packaging of this file. Please review the following
+## information to ensure the GNU General Public License requirements will
+## be met: https://www.gnu.org/licenses/gpl-2.0.html and
+## https://www.gnu.org/licenses/gpl-3.0.html.
+##
+## $QT_END_LICENSE$
+##
+#############################################################################
+
+from __future__ import print_function, absolute_import
+
+"""
+loader.py
+
+The loader has to lazy-load the signature module and also provides a few
+Python modules to support Python 2.7 .
+
+This version uses both a normal directory, but has also an embedded zip file
+as a fallback solution.
+"""
+
+import sys
+import os
+import traceback
+import types
+from contextlib import contextmanager
+
+"""
+A note on the import problem (solved):
+
+During the tests, the shiboken build structure has the layout
+
+    shiboken2/shibokenmodule/shiboken2.abi3.so
+
+and the name "shiboken2" in sys.modules points directly to the binary
+file, hiding the outer shiboken2 module.
+
+To fix that, we temporarily remove the binary from sys.path,
+do the needed imports and then restore the binary.
+This action was put into a context manager for readability.
+"""
+
+# On Python 2, we only have ImportError, which is way too coarse.
+# When problems occour, please use Python 3, because it has the finer
+# ModuleNotFoundError.
+
+try:
+    ModuleNotFoundError
+except NameError:
+    ModuleNotFoundError = ImportError
+
+@contextmanager
+def ensure_import_shibokensupport():
+    # Make sure that we always have the shibokensupport containing package first.
+    # Also remove any prior loaded module of this name, just in case.
+    sbk_support_dir = os.path.abspath(os.path.join(__file__, "..", "..", ".."))
+    assert os.path.basename(sbk_support_dir) == "files.dir"
+    sys.path.insert(0, sbk_support_dir)
+
+    sbk = "shibokensupport"
+    if sbk in sys.modules:
+        del sys.modules[sbk]
+    for key in list(key for key in sys.modules if key.startswith(sbk + ".")):
+        del sys.modules[key]
+    try:
+        import shibokensupport
+        yield
+    except Exception as e:
+        print("Problem importing shibokensupport:")
+        print(e)
+        traceback.print_exc()
+        sys.stdout.flush()
+        sys.exit(-1)
+    sys.path.remove(sbk_support_dir)
+
+
+# patching inspect's formatting to keep the word "typing":
+def formatannotation(annotation, base_module=None):
+    # if getattr(annotation, '__module__', None) == 'typing':
+    #     return repr(annotation).replace('typing.', '')
+    if isinstance(annotation, type):
+        if annotation.__module__ in ('builtins', base_module):
+            return annotation.__qualname__
+        return annotation.__module__ + '.' + annotation.__qualname__
+    return repr(annotation)
+
+# patching __repr__ to disable the __repr__ of typing.TypeVar:
+"""
+    def __repr__(self):
+        if self.__covariant__:
+            prefix = '+'
+        elif self.__contravariant__:
+            prefix = '-'
+        else:
+            prefix = '~'
+        return prefix + self.__name__
+"""
+def _typevar__repr__(self):
+    return "typing." + self.__name__
+
+# Note also that during the tests we have a different encoding that would
+# break the Python license decorated files without an encoding line.
+
+# name used in signature.cpp
+def create_signature(props, key):
+    return layout.create_signature(props, key)
+
+# name used in signature.cpp
+def seterror_argument(args, func_name):
+    return errorhandler.seterror_argument(args, func_name)
+
+# name used in signature.cpp
+def make_helptext(func):
+    return errorhandler.make_helptext(func)
+
+with ensure_import_shibokensupport():
+    import signature_loader
+    import shibokensupport.signature
+    shibokensupport.signature.get_signature = signature_loader.get_signature
+    del signature_loader  # protect this dir, too?
+
+    if sys.version_info >= (3,):
+        import typing
+        import inspect
+        inspect.formatannotation = formatannotation
+    else:
+        import inspect
+        namespace = inspect.__dict__
+        from shibokensupport.signature import typing27 as typing
+        typing.__name__ = "typing"
+        # Fix the module names in typing if possible. This is important since
+        # the typing names should be I/O compatible, so that typing.Dict
+        # shows itself as "typing.Dict".
+        for name, obj in typing.__dict__.items():
+            if hasattr(obj, "__module__"):
+                try:
+                    obj.__module__ = "typing"
+                except (TypeError, AttributeError):
+                    pass
+        from shibokensupport.signature import backport_inspect as inspect
+        _doc = inspect.__doc__
+        inspect.__dict__.update(namespace)
+        inspect.__doc__ += _doc
+        # force inspect to find all attributes. See "heuristic" in pydoc.py!
+        inspect.__all__ = list(x for x in dir(inspect) if not x.startswith("_"))
+    typing.TypeVar.__repr__ = _typevar__repr__
+
+    def put_into_package(module, package):
+        # take the last component of the module name
+        name = module.__name__.rsplit(".", 1)[-1]
+        # allow access as {package}.typing
+        setattr(package, name, module)
+        # put into sys.modules as a package to allow all import options
+        fullname = "{}.{}".format(package.__name__, name)
+        sys.modules[fullname] = module
+
+    put_into_package(typing, shibokensupport.signature)
+    put_into_package(inspect, shibokensupport.signature)
+    from shibokensupport.signature import mapping
+    from shibokensupport.signature import errorhandler
+    from shibokensupport.signature import layout
+    from shibokensupport.signature.lib import enum_sig
+    from shibokensupport.signature.parser import pyside_type_init
+
+# end of file