Signature: re-implement error messages for generic types

Correct error messages for generic types are a
non-trivial problem that was a long-standing FIXME.

For typing.Union, typing.Iterable and typing.Sequence
this is now implemented. Other generic cases will follow.

The problem is the isinstance function which does not work
for indexed generic types. It must be implemented by hand,
broken up and handled recursively with `any` and `all`
expressions.

[ChangeLog][PySide6] Error message are more correct now when indexed
generic types are involved like Union, Sequence and Iterable.

Task-number: PYSIDE-1675
Change-Id: Idb9546bcc9dc02801c19a95f51cdbc8ca5427fbb
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@qt.io>
Reviewed-by: Cristian Maureira-Fredes <cristian.maureira-fredes@qt.io>
(cherry picked from commit d7357265bed4ab1fff539957df0ec7dbe6b954b2)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

1 files changed, 15 insertions, 9 deletions

diff --git a/sources/shiboken6/shibokenmodule/files.dir/shibokensupport/signature/errorhandler.py b/sources/shiboken6/shibokenmodule/files.dir/shibokensupport/signature/errorhandler.py
index 71f2ffbab..0c1b72644 100644
--- a/sources/shiboken6/shibokenmodule/files.dir/shibokensupport/signature/errorhandler.py
+++ b/sources/shiboken6/shibokenmodule/files.dir/shibokensupport/signature/errorhandler.py
@@ -54,8 +54,10 @@ enough to produce a useful ValueError.
 This matter will be improved in a later version.
 """
 
+import collections.abc
 import inspect
 import sys
+import typing
 
 from shibokensupport.signature import get_signature
 from shibokensupport.signature.mapping import update_mapping, namespace
@@ -64,11 +66,21 @@ from textwrap import dedent
 
 def qt_isinstance(inst, the_type):
     if the_type == float:
-        return isinstance(inst, int) or isinstance(int, float)
+        # Qt thinks differently about int and float - simply keep it.
+        return isinstance(inst, int) or isinstance(inst, float)
+    if the_type.__module__ == "typing":
+        if the_type.__origin__ is typing.Union:
+            return any(qt_isinstance(inst, _) for _ in the_type.__args__)
+        if the_type.__origin__ in (collections.abc.Sequence,
+                                   collections.abc.Iterable):
+            try:
+                return all(qt_isinstance(_, the_type.__args__[0]) for _ in inst)
+            except TypeError:
+                return False
     try:
         return isinstance(inst, the_type)
     except TypeError as e:
-        print("FIXME", e)
+        print(f"FIXME qt_isinstance({inst}, {the_type}):", e)
         return False
 
 
@@ -82,13 +94,7 @@ def matched_type(args, sigs):
             if params[k].default is params[k].empty:
                 # this is a necessary parameter, so it fails.
                 continue
-        ok = True
-        for arg, param in zip(args, params):
-            ann = param.annotation
-            if qt_isinstance(arg, ann):
-                continue
-            ok = False
-        if ok:
+        if all(qt_isinstance(arg, param.annotation) for arg, param in zip(args, params)):
             return sig
     return None