shiboken6: Split TargetToNativeConversion::sourceTypeCheck()

Make sourceTypeCheck() act like a normal property getter and add
sourceTypeCheckFallback() for cases in which the fallback logic is
desired.

Move additional special cases from CppGenerator into
sourceTypeCheckFallback().

Task-number: PYSIDE-3107
Change-Id: Iaebcac46a30302318bbaede373cd9dd4f50ac357
Reviewed-by: Cristian Maureira-Fredes <[email protected]>

3 files changed, 13 insertions, 8 deletions

diff --git a/sources/shiboken6/ApiExtractor/customconversion.cpp b/sources/shiboken6/ApiExtractor/customconversion.cpp
index 7b65bcf3a..b022cd692 100644
--- a/sources/shiboken6/ApiExtractor/customconversion.cpp
+++ b/sources/shiboken6/ApiExtractor/customconversion.cpp
@@ -96,6 +96,11 @@ QString TargetToNativeConversion::sourceTypeName() const
 
 QString TargetToNativeConversion::sourceTypeCheck() const
 {
+    return m_sourceTypeCheck;
+}
+
+QString TargetToNativeConversion::sourceTypeCheckFallback() const
+{
     if (!m_sourceTypeCheck.isEmpty())
         return m_sourceTypeCheck;
 
@@ -109,6 +114,10 @@ QString TargetToNativeConversion::sourceTypeCheck() const
         }
     }
 
+    if (m_sourceTypeName == "Py_None"_L1 || m_sourceTypeName == "PyNone"_L1)
+        return "%in == Py_None"_L1;
+    if (m_sourceTypeName == "SbkObject"_L1)
+        return "Shiboken::Object::checkType(%in)"_L1;
     return {};
 }
 
diff --git a/sources/shiboken6/ApiExtractor/customconversion.h b/sources/shiboken6/ApiExtractor/customconversion.h
index a75178846..9125d6705 100644
--- a/sources/shiboken6/ApiExtractor/customconversion.h
+++ b/sources/shiboken6/ApiExtractor/customconversion.h
@@ -25,7 +25,10 @@ public:
     void setSourceType(const TypeEntryCPtr &sourceType);
     bool isCustomType() const;
     QString sourceTypeName() const;
+    // Check as specified in the type system
     QString sourceTypeCheck() const;
+    // Check with fallback bases on sourceType
+    QString sourceTypeCheckFallback() const;
     QString conversion() const;
     void setConversion(const QString &conversion);
 
diff --git a/sources/shiboken6/generator/shiboken/cppgenerator.cpp b/sources/shiboken6/generator/shiboken/cppgenerator.cpp
index 9092768a3..f392eef38 100644
--- a/sources/shiboken6/generator/shiboken/cppgenerator.cpp
+++ b/sources/shiboken6/generator/shiboken/cppgenerator.cpp
@@ -3595,14 +3595,7 @@ void CppGenerator::writePythonToCppConversionFunctions(TextStream &s,
     writePythonToCppFunction(s, code, sourceTypeName, targetTypeName);
 
     // Python to C++ convertible check function.
-    QString typeCheck = toNative.sourceTypeCheck();
-    if (typeCheck.isEmpty()) {
-        QString pyTypeName = toNative.sourceTypeName();
-        if (pyTypeName == u"Py_None" || pyTypeName == u"PyNone")
-            typeCheck = u"%in == Py_None"_s;
-        else if (pyTypeName == u"SbkObject")
-            typeCheck = u"Shiboken::Object::checkType(%in)"_s;
-    }
+    QString typeCheck = toNative.sourceTypeCheckFallback();
     if (typeCheck.isEmpty()) {
         if (!toNative.sourceType() || toNative.sourceType()->isPrimitive()) {
             QString m;