Support help() using the Signature Module

The signature module will be used to generate automated
documentation by using the function signatures as docstrings.

This functionality should be low-hanging fruit. Actually, it was a
bit tricky to get this working. The crucial point was to use
PyType_Modified().

The function works fine on methods.
Supporting types needs some more effort.
It is not clear why the __signature__ attribute can be added,
but the change to __doc__ is not recognized. May be related to
the absence of Py_TPFLAGS_HAVE_VERSION_TAG ?
This will be addressed another time.

Task-number: PYSIDE-908
Change-Id: If8faa87927899f4c072d42b91eafd8f7658c6abc
Reviewed-by: Cristian Maureira-Fredes <cristian.maureira-fredes@qt.io>

2 files changed, 20 insertions, 0 deletions

diff --git a/sources/shiboken2/shibokenmodule/support/signature/errorhandler.py b/sources/shiboken2/shibokenmodule/support/signature/errorhandler.py
index 902bb05af..df24234e3 100644
--- a/sources/shiboken2/shibokenmodule/support/signature/errorhandler.py
+++ b/sources/shiboken2/shibokenmodule/support/signature/errorhandler.py
@@ -121,4 +121,20 @@ def seterror_argument(args, func_name):
     # We don't raise the error here, to avoid the loader in the traceback.
     return TypeError, msg
 
+
+def make_helptext(func):
+    existing_doc = func.__doc__
+    sigs = get_signature(func)
+    if not sigs:
+        return existing_doc
+    if type(sigs) != list:
+        sigs = [sigs]
+    try:
+        func_name = func.__name__
+    except AttribureError:
+        func_name = func.__func__.__name__
+    sigtext = "\n".join(func_name + str(sig) for sig in sigs)
+    msg = sigtext + "\n\n" + existing_doc if existing_doc else sigtext
+    return msg
+
 # end of file
diff --git a/sources/shiboken2/shibokenmodule/support/signature/loader.py b/sources/shiboken2/shibokenmodule/support/signature/loader.py
index be30483fe..8c7739d9a 100644
--- a/sources/shiboken2/shibokenmodule/support/signature/loader.py
+++ b/sources/shiboken2/shibokenmodule/support/signature/loader.py
@@ -201,4 +201,8 @@ def create_signature(props, key):
 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)
+
 # end of file