Add QtCore.Slot.__signature__ and much more manually

The signature of QtCore.Slot and other classes could not automatically
be generated because the function is not generated by cppgenerator.cpp .
We add it manually in the C++ code into the generation process.

The case of QtCore.Slot had diverse follow-up issues to be solved:

- Classes which did not inherit from Shiboken were not generated.
  This is a long-standing omission and creates very many new
  simple types.

- The arity of Slot has default arguments after the varargs parameter
  "*types". This needed an extended Python parser analysis that fixes
  the arguments given to the inspect module, accordingly.

- The signature generation was completely new implemented and
  relies no longer on the restricted syntax of a Python (2) function
  but generates signatures directly as Parameter instances.

Implemented classes with hand-made signatures:

    QtCore.ClassInfo
    QtCore.MetaFunction,
    QtCore.MetaSignal
    QtCore.Property
    QtCore.Signal
    QtCore.SignalInstance
    QtCore.Slot
    QtQml.ListProperty
    QtQml.VolatileBool

As a side effect, many more subtypes were published.
Enums are done, which concludes this work.

Fixes: PYSIDE-945
Fixes: PYSIDE-1052
Change-Id: Ic09f02ece3a90325519e42e4e39719beb0c27ae9
Reviewed-by: Christian Tismer <tismer@stackless.com>

2 files changed, 23 insertions, 5 deletions

diff --git a/sources/pyside2/PySide2/QtQml/pysideqmlregistertype.cpp b/sources/pyside2/PySide2/QtQml/pysideqmlregistertype.cpp
index db297db7c..6427e5198 100644
--- a/sources/pyside2/PySide2/QtQml/pysideqmlregistertype.cpp
+++ b/sources/pyside2/PySide2/QtQml/pysideqmlregistertype.cpp
@@ -41,6 +41,7 @@
 
 // shiboken
 #include <shiboken.h>
+#include <signature.h>
 
 // pyside
 #include <pyside.h>
@@ -469,12 +470,22 @@ PyTypeObject *QtQml_VolatileBoolTypeF(void)
     return type;
 }
 
+static const char *PropertyList_SignatureStrings[] = {
+    "PySide2.QtQml.ListProperty(type:type,append:typing.Callable,"
+        "at:typing.Callable=None,clear:typing.Callable=None,count:typing.Callable=None)",
+    nullptr}; // Sentinel
+
+static const char *VolatileBool_SignatureStrings[] = {
+    "PySide2.QtQml.VolatileBool.get()->bool",
+    "PySide2.QtQml.VolatileBool.set(a:object)",
+    nullptr}; // Sentinel
+
 void PySide::initQmlSupport(PyObject *module)
 {
     ElementFactory<PYSIDE_MAX_QML_TYPES - 1>::init();
 
     // Export QmlListProperty type
-    if (PyType_Ready(PropertyListTypeF()) < 0) {
+    if (SbkSpecial_Type_Ready(module, PropertyListTypeF(), PropertyList_SignatureStrings) < 0) {
         PyErr_Print();
         qWarning() << "Error initializing PropertyList type.";
         return;
@@ -484,7 +495,7 @@ void PySide::initQmlSupport(PyObject *module)
     PyModule_AddObject(module, PepType_GetNameStr(PropertyListTypeF()),
                        reinterpret_cast<PyObject *>(PropertyListTypeF()));
 
-    if (PyType_Ready(QtQml_VolatileBoolTypeF()) < 0) {
+    if (SbkSpecial_Type_Ready(module, QtQml_VolatileBoolTypeF(), VolatileBool_SignatureStrings) < 0) {
         PyErr_Print();
         qWarning() << "Error initializing VolatileBool type.";
         return;
diff --git a/sources/pyside2/PySide2/support/generate_pyi.py b/sources/pyside2/PySide2/support/generate_pyi.py
index c732227f4..8aa69c983 100644
--- a/sources/pyside2/PySide2/support/generate_pyi.py
+++ b/sources/pyside2/PySide2/support/generate_pyi.py
@@ -141,7 +141,7 @@ class Formatter(Writer):
             self.outfile.seek(here)
             self.outfile.truncate()
             # Note: we cannot use class_str when we have no body.
-            self.print("{spaces}class {class_name}: ...".format(**locals()))
+            self.print("{spaces}class {class_str}: ...".format(**locals()))
         if "<" in class_name:
             # This is happening in QtQuick for some reason:
             ## class QSharedPointer<QQuickItemGrabResult >:
@@ -168,6 +168,13 @@ class Formatter(Writer):
             self.print('{spaces}@staticmethod'.format(**locals()))
         self.print('{spaces}def {func_name}{signature}: ...'.format(**locals()))
 
+    @contextmanager
+    def enum(self, class_name, enum_name, value):
+        spaces = self.spaces
+        hexval = hex(value)
+        self.print("{spaces}{enum_name:20}: {class_name} = ... # {hexval}".format(**locals()))
+        yield
+
 
 def get_license_text():
     with io.open(sourcepath) as f:
@@ -247,10 +254,10 @@ def generate_all_pyi(outpath, options):
         os.environ["PYTHONPATH"] = pypath
 
     # now we can import
-    global PySide2, inspect, HintingEnumerator
+    global PySide2, inspect, HintingEnumerator, EnumType
     import PySide2
     from PySide2.support.signature import inspect
-    from PySide2.support.signature.lib.enum_sig import HintingEnumerator
+    from PySide2.support.signature.lib.enum_sig import HintingEnumerator, EnumType
 
     # propagate USE_PEP563 to the mapping module.
     # Perhaps this can be automated?