Split The Signature Module After The Project Split

The PySide project has been split into three pieces, including
Shiboken. This had far-reaching consequences for the signature project.

Shiboken can be run together with PySide or alone,
with tests or without. In every configuration, the signature
module has to work correctly.

During tests, the shiboken binary also hides the shiboken module,
and we had to use extra efforts to always guarantee the accessibility
of all signature modules.

This commit is the preparation for typeerrors implemented with the
signature module. It has been split off because the splitting
is not directly related, besides these unawaited consequences.

I re-added and corrected voidptr_test and simplified the calls.
Remark.. We should rename shiboken to Shiboken in all imports.

I also simplified initialization. After "from PySide2 import QtCore",
now a simple access like "type.__signature__" triggers initialization.

Further, I removed all traces of "signature_loader" and allowed
loading everything from PySide2.support.signature, again. The
loader is now needed internally, only.

Also, moved the type patching into FinishSignatureInitialization
to support modules with no classes at all.

The "testbinding" problem was finally identified as a name clash
when the same function is also a signal. A further investigation
showed that there exists also a regular PySide method with
that problem. The test was extended to all methods, and it
maps now all these cases to "{name}.overload".

Updated the included typing27.py from https://pypi.org/project/typing/
from version 3.6.2 to version 3.6.6 .

Task-number: PYSIDE-749
Change-Id: Ie33b8c6b0df5640212f8991539088593a041a05c
Reviewed-by: Cristian Maureira-Fredes <cristian.maureira-fredes@qt.io>

1 files changed, 245 insertions, 0 deletions

diff --git a/sources/shiboken2/shibokenmodule/support/signature/layout.py b/sources/shiboken2/shibokenmodule/support/signature/layout.py
new file mode 100644
index 000000000..47f97fc2b
--- /dev/null
+++ b/sources/shiboken2/shibokenmodule/support/signature/layout.py
@@ -0,0 +1,245 @@
+#############################################################################
+##
+## Copyright (C) 2018 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
+
+"""
+layout.py
+
+The signature module now has the capability to configure
+differently formatted versions of signatures. The default
+layout is known from the "__signature__" attribute.
+
+The function "get_signature(ob, modifier=None)" produces the same
+signatures by default. By passing different modifiers, you
+can select different layouts.
+
+This module configures the different layouts which can be used.
+It also implements them in this file. The configurations are
+used literally as strings like "signature", "existence", etc.
+"""
+
+from textwrap import dedent
+from signature_loader import inspect
+
+
+class SimpleNamespace(object):
+    # From types.rst, because the builtin is implemented in Python 3, only.
+    def __init__(self, **kwargs):
+        self.__dict__.update(kwargs)
+
+    def __repr__(self):
+        keys = sorted(self.__dict__)
+        items = ("{}={!r}".format(k, self.__dict__[k]) for k in keys)
+        return "{}({})".format(type(self).__name__, ", ".join(items))
+
+    def __eq__(self, other):
+        return self.__dict__ == other.__dict__
+
+
+class SignatureLayout(SimpleNamespace):
+    """
+    Configure a signature.
+
+    The layout of signatures can have different layouts which are
+    controlled by keyword arguments:
+
+    definition=True         Determines if self will generated.
+    defaults=True
+    ellipsis=False          Replaces defaults by "...".
+    return_annotation=True
+    parameter_names=True    False removes names before ":".
+    """
+    allowed_keys = SimpleNamespace(definition=True,
+                                   defaults=True,
+                                   ellipsis=False,
+                                   return_annotation=True,
+                                   parameter_names=True)
+    allowed_values = True, False
+
+    def __init__(self, **kwds):
+        args = SimpleNamespace(**self.allowed_keys.__dict__)
+        args.__dict__.update(kwds)
+        self.__dict__.update(args.__dict__)
+        err_keys = list(set(self.__dict__) - set(self.allowed_keys.__dict__))
+        if err_keys:
+            self._attributeerror(err_keys)
+        err_values = list(set(self.__dict__.values()) - set(self.allowed_values))
+        if err_values:
+            self._valueerror(err_values)
+
+    def __setattr__(self, key, value):
+        if key not in self.allowed_keys.__dict__:
+            self._attributeerror([key])
+        if value not in self.allowed_values:
+            self._valueerror([value])
+        self.__dict__[key] = value
+
+    def _attributeerror(self, err_keys):
+        err_keys = ", ".join(err_keys)
+        allowed_keys = ", ".join(self.allowed_keys.__dict__.keys())
+        raise AttributeError(dedent("""\
+            Not allowed: '{err_keys}'.
+            The only allowed keywords are '{allowed_keys}'.
+            """.format(**locals())))
+
+    def _valueerror(self, err_values):
+        err_values = ", ".join(map(str, err_values))
+        allowed_values = ", ".join(map(str, self.allowed_values))
+        raise ValueError(dedent("""\
+            Not allowed: '{err_values}'.
+            The only allowed values are '{allowed_values}'.
+            """.format(**locals())))
+
+# The following names are used literally in this module.
+# This way, we avoid the dict hashing problem.
+signature = SignatureLayout()
+
+existence = SignatureLayout(definition=False,
+                            defaults=False,
+                            return_annotation=False,
+                            parameter_names=False)
+
+hintingstub = SignatureLayout(ellipsis=True)
+
+typeerror = SignatureLayout(definition=False,
+                            return_annotation=False,
+                            parameter_names=False)
+
+
+def define_nameless_parameter():
+    """
+    Create Nameless Parameters
+
+    A nameless parameter has a reduced string representation.
+    This is done by cloning the parameter type and overwriting its
+    __str__ method. The inner structure is still a valid parameter.
+    """
+    def __str__(self):
+        # for Python 2, we must change self to be an instance of P
+        klass = self.__class__
+        self.__class__ = P
+        txt = P.__str__(self)
+        self.__class__ = klass
+        txt = txt[txt.index(":") + 1:].strip() if ":" in txt else txt
+        return txt
+
+    P = inspect.Parameter
+    newname = "NamelessParameter"
+    bases = P.__bases__
+    body = dict(P.__dict__) # get rid of mappingproxy
+    if "__slots__" in body:
+        # __slots__ would create duplicates
+        for name in body["__slots__"]:
+            del body[name]
+    body["__str__"] = __str__
+    return type(newname, bases, body)
+
+
+NamelessParameter = define_nameless_parameter()
+
+
+def make_signature_nameless(signature):
+    """
+    Make a Signature Nameless
+
+    We use an existing signature and change the type of its parameters.
+    The signature looks different, but is totally intact.
+    """
+    for key in signature.parameters.keys():
+        signature.parameters[key].__class__ = NamelessParameter
+
+
+def create_signature(props, key):
+    if not props:
+        # empty signatures string
+        return
+    if isinstance(props["multi"], list):
+        # multi sig: call recursively
+        return list(create_signature(elem, key)
+                    for elem in props["multi"])
+    if type(key) is tuple:
+        sig_kind, modifier = key
+    else:
+        sig_kind, modifier = key, "signature"
+
+    layout = globals()[modifier]  # lookup of the modifier in this module
+    if not isinstance(layout, SignatureLayout):
+        raise SystemError("Modifiers must be names of a SignatureLayout "
+                          "instance")
+
+    # this is the basic layout of a signature
+    varnames = props["varnames"]
+    if layout.definition:
+        if sig_kind == "function":
+            pass
+        elif sig_kind == "method":
+            varnames = ("self",) + varnames
+        elif sig_kind == "staticmethod":
+            pass
+        elif sig_kind == "classmethod":
+            varnames = ("klass",) + varnames
+        else:
+            raise SystemError("Methods must be function, method, staticmethod or "
+                              "classmethod")
+    # calculate the modifications
+    defaults = props["defaults"][:]
+    if not layout.defaults:
+        defaults = ()
+    if layout.ellipsis:
+        defaults = ("...",) * len(defaults)
+    annotations = props["annotations"].copy()
+    if not layout.return_annotation and "return" in annotations:
+        del annotations["return"]
+
+    # attach parameters to a fake function and build a signature
+    argstr = ", ".join(varnames)
+    fakefunc = eval("lambda {}: None".format(argstr))
+    fakefunc.__name__ = props["name"]
+    fakefunc.__defaults__ = defaults
+    fakefunc.__kwdefaults__ = props["kwdefaults"]
+    fakefunc.__annotations__ = annotations
+    sig = inspect._signature_from_function(inspect.Signature, fakefunc)
+
+    # the special case of nameless parameters
+    if not layout.parameter_names:
+        make_signature_nameless(sig)
+    return sig
+
+# end of file