Add support for __repr__ in QObject derived classes

Currently shiboken generates classes without __repr__ for QObject
derived classes. However for all non-QObject classes that have an
operator<<() for QDebug, it *does* add a valid repr implementation.
Extend this behavior to QObject classes as well.

In order for this to become more useful, also check for the indirection
of operator<<(): If operator<<(QDebug, Foo*) is available, use the
current non-value-type behavior, (i.e. provide cppSelf to operator<<()),
but if operator<<(QDebug, const Foo&) is available instead, use the same
behavior as for value-types, i.e. provide *cppSelf.

This greatly increases the number of classes where operator<<() provides
useful results.

Also make sure to check for operator<<() in namespaces (recursively),
not just at global scope.

Change-Id: Ief9158455a25e332f07169f09692cafb8097078b
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@qt.io>

5 files changed, 28 insertions, 12 deletions

diff --git a/sources/shiboken2/ApiExtractor/abstractmetabuilder.cpp b/sources/shiboken2/ApiExtractor/abstractmetabuilder.cpp
index 4b31dbb05..6aafe68be 100644
--- a/sources/shiboken2/ApiExtractor/abstractmetabuilder.cpp
+++ b/sources/shiboken2/ApiExtractor/abstractmetabuilder.cpp
@@ -248,6 +248,15 @@ void AbstractMetaBuilderPrivate::registerHashFunction(const FunctionModelItem &f
     }
 }
 
+void AbstractMetaBuilderPrivate::registerToStringCapabilityIn(const NamespaceModelItem &nsItem)
+{
+    const FunctionList &streamOps = nsItem->findFunctions(QLatin1String("operator<<"));
+    for (const FunctionModelItem &item : streamOps)
+        registerToStringCapability(item, nullptr);
+    for (const NamespaceModelItem &ni : nsItem->namespaces())
+        registerToStringCapabilityIn(ni);
+}
+
 /**
  * Check if a class has a debug stream operator that can be used as toString
  */
@@ -261,7 +270,7 @@ void AbstractMetaBuilderPrivate::registerToStringCapability(const FunctionModelI
             const ArgumentModelItem &arg = arguments.at(1);
             if (AbstractMetaClass *cls = argumentToClass(arg, currentClass)) {
                 if (arg->type().indirections() < 2)
-                    cls->setToStringCapability(true);
+                    cls->setToStringCapability(true, arg->type().indirections());
             }
         }
     }
@@ -591,11 +600,7 @@ void AbstractMetaBuilderPrivate::traverseDom(const FileModelItem &dom)
             registerHashFunction(item, nullptr);
     }
 
-    {
-        const FunctionList &streamOps = dom->findFunctions(QLatin1String("operator<<"));
-        for (const FunctionModelItem &item : streamOps)
-            registerToStringCapability(item, nullptr);
-    }
+    registerToStringCapabilityIn(dom);
 
     {
         FunctionList binaryOperators = dom->findFunctions(QStringLiteral("operator=="));
diff --git a/sources/shiboken2/ApiExtractor/abstractmetabuilder_p.h b/sources/shiboken2/ApiExtractor/abstractmetabuilder_p.h
index fec2eddb9..9b1b181cc 100644
--- a/sources/shiboken2/ApiExtractor/abstractmetabuilder_p.h
+++ b/sources/shiboken2/ApiExtractor/abstractmetabuilder_p.h
@@ -106,6 +106,7 @@ public:
     void checkFunctionModifications();
     void registerHashFunction(const FunctionModelItem &functionItem,
                               AbstractMetaClass *currentClass);
+    void registerToStringCapabilityIn(const NamespaceModelItem &namespaceItem);
     void registerToStringCapability(const FunctionModelItem &functionItem,
                                     AbstractMetaClass *currentClass);
 
diff --git a/sources/shiboken2/ApiExtractor/abstractmetalang.h b/sources/shiboken2/ApiExtractor/abstractmetalang.h
index afb4e5fbd..91ca4d7a9 100644
--- a/sources/shiboken2/ApiExtractor/abstractmetalang.h
+++ b/sources/shiboken2/ApiExtractor/abstractmetalang.h
@@ -1691,9 +1691,10 @@ public:
         return m_stream;
     }
 
-    void setToStringCapability(bool value)
+    void setToStringCapability(bool value, uint indirections = 0)
     {
         m_hasToStringCapability = value;
+        m_toStringCapabilityIndirections = indirections;
     }
 
     bool hasToStringCapability() const
@@ -1701,6 +1702,11 @@ public:
         return m_hasToStringCapability;
     }
 
+    uint toStringCapabilityIndirections() const
+    {
+        return m_toStringCapabilityIndirections;
+    }
+
     bool deleteInMainThread() const;
 
     static AbstractMetaClass *findClass(const AbstractMetaClassList &classes,
@@ -1753,6 +1759,7 @@ private:
 //     FunctionModelItem m_qDebugStreamFunction;
 
     bool m_stream = false;
+    uint m_toStringCapabilityIndirections = 0;
 };
 
 Q_DECLARE_OPERATORS_FOR_FLAGS(AbstractMetaClass::FunctionQueryOptions)
diff --git a/sources/shiboken2/generator/shiboken2/cppgenerator.cpp b/sources/shiboken2/generator/shiboken2/cppgenerator.cpp
index 7de0cfc09..61429b383 100644
--- a/sources/shiboken2/generator/shiboken2/cppgenerator.cpp
+++ b/sources/shiboken2/generator/shiboken2/cppgenerator.cpp
@@ -3933,9 +3933,10 @@ void CppGenerator::writeClassDefinition(QTextStream &s,
             m_tpFuncs[func->name()] = cpythonFunctionName(func);
     }
     if (m_tpFuncs.value(QLatin1String("__repr__")).isEmpty()
-        && !metaClass->isQObject()
         && metaClass->hasToStringCapability()) {
-        m_tpFuncs[QLatin1String("__repr__")] = writeReprFunction(s, classContext);
+        m_tpFuncs[QLatin1String("__repr__")] = writeReprFunction(s,
+                classContext,
+                metaClass->toStringCapabilityIndirections());
     }
 
     // class or some ancestor has multiple inheritance
@@ -6006,7 +6007,9 @@ void CppGenerator::writeIndexError(QTextStream &s, const QString &errorMsg)
     s << INDENT << '}' << endl;
 }
 
-QString CppGenerator::writeReprFunction(QTextStream &s, GeneratorContext &context)
+QString CppGenerator::writeReprFunction(QTextStream &s,
+                                        GeneratorContext &context,
+                                        uint indirections)
 {
     const AbstractMetaClass *metaClass = context.metaClass();
     QString funcName = cpythonBaseName(metaClass) + QLatin1String("__repr__");
@@ -6019,7 +6022,7 @@ QString CppGenerator::writeReprFunction(QTextStream &s, GeneratorContext &contex
     s << INDENT << "buffer.open(QBuffer::ReadWrite);" << endl;
     s << INDENT << "QDebug dbg(&buffer);" << endl;
     s << INDENT << "dbg << ";
-    if (metaClass->typeEntry()->isValue())
+    if (metaClass->typeEntry()->isValue() || indirections == 0)
          s << '*';
     s << CPP_SELF_VAR << ';' << endl;
     s << INDENT << "buffer.close();" << endl;
diff --git a/sources/shiboken2/generator/shiboken2/cppgenerator.h b/sources/shiboken2/generator/shiboken2/cppgenerator.h
index ae6da9582..005518f96 100644
--- a/sources/shiboken2/generator/shiboken2/cppgenerator.h
+++ b/sources/shiboken2/generator/shiboken2/cppgenerator.h
@@ -336,7 +336,7 @@ private:
     /// Helper function for writeStdListWrapperMethods.
     void writeIndexError(QTextStream &s, const QString &errorMsg);
 
-    QString writeReprFunction(QTextStream &s, GeneratorContext &context);
+    QString writeReprFunction(QTextStream &s, GeneratorContext &context, uint indirections);
 
     const AbstractMetaFunction *boolCast(const AbstractMetaClass *metaClass) const;
     bool hasBoolCast(const AbstractMetaClass *metaClass) const