shiboken: Constify GeneratorContext

Pass around by const-ref and return a const pointer to the class.

In HeaderGenerator::generateClass(), make a copy of the context
passed in to prevent writing back via reference in the base
class loop.

Change-Id: I0338bd93b5a53c25ec18bc45b407ab67d8c7c91e
Reviewed-by: Christian Tismer <tismer@stackless.com>
Reviewed-by: Cristian Maureira-Fredes <cristian.maureira-fredes@qt.io>

8 files changed, 80 insertions, 77 deletions

diff --git a/sources/shiboken2/generator/generator.cpp b/sources/shiboken2/generator/generator.cpp
index bd56b1824..e997ef687 100644
--- a/sources/shiboken2/generator/generator.cpp
+++ b/sources/shiboken2/generator/generator.cpp
@@ -408,9 +408,9 @@ void Generator::setOutputDirectory(const QString &outDir)
     m_d->outDir = outDir;
 }
 
-bool Generator::generateFileForContext(GeneratorContext &context)
+bool Generator::generateFileForContext(const GeneratorContext &context)
 {
-    AbstractMetaClass *cls = context.metaClass();
+    const AbstractMetaClass *cls = context.metaClass();
 
     if (!shouldGenerate(cls))
         return true;
diff --git a/sources/shiboken2/generator/generator.h b/sources/shiboken2/generator/generator.h
index dde281f0e..136f0a5f0 100644
--- a/sources/shiboken2/generator/generator.h
+++ b/sources/shiboken2/generator/generator.h
@@ -148,7 +148,7 @@ private:
 class GeneratorContext {
 public:
     GeneratorContext() = default;
-    GeneratorContext(AbstractMetaClass *metaClass,
+    GeneratorContext(const AbstractMetaClass *metaClass,
                      const AbstractMetaType *preciseType = nullptr,
                      bool forSmartPointer = false)
         : m_metaClass(metaClass),
@@ -156,12 +156,12 @@ public:
         m_forSmartPointer(forSmartPointer) {}
 
 
-    AbstractMetaClass *metaClass() const { return m_metaClass; }
+    const AbstractMetaClass *metaClass() const { return m_metaClass; }
     bool forSmartPointer() const { return m_forSmartPointer; }
     const AbstractMetaType *preciseType() const { return m_preciseClassType; }
 
 private:
-    AbstractMetaClass *m_metaClass = nullptr;
+    const AbstractMetaClass *m_metaClass = nullptr;
     const AbstractMetaType *m_preciseClassType = nullptr;
     bool m_forSmartPointer = false;
 };
@@ -295,7 +295,7 @@ protected:
     const AbstractMetaEnum *findAbstractMetaEnum(const AbstractMetaType *metaType) const;
 
     /// Generates a file for given AbstractMetaClass or AbstractMetaType (smart pointer case).
-    bool generateFileForContext(GeneratorContext &context);
+    bool generateFileForContext(const GeneratorContext &context);
 
     /// Returns the file base name for a smart pointer.
     QString getFileNameBaseForSmartPointer(const AbstractMetaType *smartPointerType,
@@ -371,7 +371,7 @@ protected:
      *   \return the file name used to write the binding code for the class
      */
     virtual QString fileNameSuffix() const = 0;
-    virtual QString fileNameForContext(GeneratorContext &context) const = 0;
+    virtual QString fileNameForContext(const GeneratorContext &context) const = 0;
 
 
     virtual bool doSetup() = 0;
@@ -382,7 +382,7 @@ protected:
      *   \param  s   text stream to write the generated output
      *   \param  metaClass  the class that should be generated
      */
-    virtual void generateClass(QTextStream &s, GeneratorContext &classContext) = 0;
+    virtual void generateClass(QTextStream &s, const GeneratorContext &classContext) = 0;
     virtual bool finishGeneration() = 0;
 
     /**
diff --git a/sources/shiboken2/generator/qtdoc/qtdocgenerator.cpp b/sources/shiboken2/generator/qtdoc/qtdocgenerator.cpp
index 4fe6ecc7a..014cc948e 100644
--- a/sources/shiboken2/generator/qtdoc/qtdocgenerator.cpp
+++ b/sources/shiboken2/generator/qtdoc/qtdocgenerator.cpp
@@ -1523,7 +1523,7 @@ bool QtDocGenerator::shouldGenerate(const AbstractMetaClass *cls) const
         && cls->typeEntry()->type() != TypeEntry::SmartPointerType;
 }
 
-QString QtDocGenerator::fileNameForContext(GeneratorContext &context) const
+QString QtDocGenerator::fileNameForContext(const GeneratorContext &context) const
 {
     const AbstractMetaClass *metaClass = context.metaClass();
     if (!context.forSmartPointer()) {
@@ -1611,9 +1611,9 @@ static bool extractBrief(Documentation *sourceDoc, Documentation *brief)
     return true;
 }
 
-void QtDocGenerator::generateClass(QTextStream &s, GeneratorContext &classContext)
+void QtDocGenerator::generateClass(QTextStream &s, const GeneratorContext &classContext)
 {
-    AbstractMetaClass *metaClass = classContext.metaClass();
+    const AbstractMetaClass *metaClass = classContext.metaClass();
     qCDebug(lcShibokenDoc).noquote().nospace() << "Generating Documentation for " << metaClass->fullName();
 
     m_packages[metaClass->package()] << fileNameForContext(classContext);
diff --git a/sources/shiboken2/generator/qtdoc/qtdocgenerator.h b/sources/shiboken2/generator/qtdoc/qtdocgenerator.h
index 56cb9c4bb..e4067cc6f 100644
--- a/sources/shiboken2/generator/qtdoc/qtdocgenerator.h
+++ b/sources/shiboken2/generator/qtdoc/qtdocgenerator.h
@@ -238,8 +238,8 @@ public:
 protected:
     bool shouldGenerate(const AbstractMetaClass *) const override;
     QString fileNameSuffix() const override;
-    QString fileNameForContext(GeneratorContext &context) const override;
-    void generateClass(QTextStream &s, GeneratorContext &classContext) override;
+    QString fileNameForContext(const GeneratorContext &context) const override;
+    void generateClass(QTextStream &s, const GeneratorContext &classContext) override;
     bool finishGeneration() override;
 
     void writeFunctionArguments(QTextStream&, const AbstractMetaFunction*, Options) const override {}
diff --git a/sources/shiboken2/generator/shiboken2/cppgenerator.cpp b/sources/shiboken2/generator/shiboken2/cppgenerator.cpp
index c74f4b0a7..801bc83ec 100644
--- a/sources/shiboken2/generator/shiboken2/cppgenerator.cpp
+++ b/sources/shiboken2/generator/shiboken2/cppgenerator.cpp
@@ -195,7 +195,7 @@ QString CppGenerator::fileNameSuffix() const
     return QLatin1String("_wrapper.cpp");
 }
 
-QString CppGenerator::fileNameForContext(GeneratorContext &context) const
+QString CppGenerator::fileNameForContext(const GeneratorContext &context) const
 {
     const AbstractMetaClass *metaClass = context.metaClass();
     if (!context.forSmartPointer()) {
@@ -292,9 +292,9 @@ static inline bool canGenerateFieldSetter(const AbstractMetaField *field)
     \param s the output buffer
     \param metaClass the pointer to metaclass information
 */
-void CppGenerator::generateClass(QTextStream &s, GeneratorContext &classContext)
+void CppGenerator::generateClass(QTextStream &s, const GeneratorContext &classContext)
 {
-    AbstractMetaClass *metaClass = classContext.metaClass();
+    const AbstractMetaClass *metaClass = classContext.metaClass();
 
     // write license comment
     s << licenseComment() << Qt::endl;
@@ -1273,7 +1273,7 @@ void CppGenerator::writeEnumConverterFunctions(QTextStream &s, const TypeEntry *
 }
 
 void CppGenerator::writeConverterFunctions(QTextStream &s, const AbstractMetaClass *metaClass,
-                                           GeneratorContext &classContext)
+                                           const GeneratorContext &classContext)
 {
     s << "// Type conversion functions.\n\n";
 
@@ -1499,7 +1499,7 @@ void CppGenerator::writeCustomConverterFunctions(QTextStream &s, const CustomCon
 }
 
 void CppGenerator::writeConverterRegister(QTextStream &s, const AbstractMetaClass *metaClass,
-                                          GeneratorContext &classContext)
+                                          const GeneratorContext &classContext)
 {
     if (metaClass->isNamespace())
         return;
@@ -1626,7 +1626,7 @@ void CppGenerator::writeContainerConverterFunctions(QTextStream &s, const Abstra
 }
 
 void CppGenerator::writeMethodWrapperPreamble(QTextStream &s, OverloadData &overloadData,
-                                              GeneratorContext &context)
+                                              const GeneratorContext &context)
 {
     const AbstractMetaFunction *rfunc = overloadData.referenceFunction();
     const AbstractMetaClass *ownerClass = rfunc->ownerClass();
@@ -1703,7 +1703,7 @@ void CppGenerator::writeMethodWrapperPreamble(QTextStream &s, OverloadData &over
 }
 
 void CppGenerator::writeConstructorWrapper(QTextStream &s, const AbstractMetaFunctionList &overloads,
-                                           GeneratorContext &classContext)
+                                           const GeneratorContext &classContext)
 {
     ErrorCode errorCode(-1);
     OverloadData overloadData(overloads, this);
@@ -1863,7 +1863,7 @@ void CppGenerator::writeConstructorWrapper(QTextStream &s, const AbstractMetaFun
 }
 
 void CppGenerator::writeMethodWrapper(QTextStream &s, const AbstractMetaFunctionList &overloads,
-                                      GeneratorContext &classContext)
+                                      const GeneratorContext &classContext)
 {
     OverloadData overloadData(overloads, this);
     const AbstractMetaFunction *rfunc = overloadData.referenceFunction();
@@ -2074,7 +2074,7 @@ void CppGenerator::writeCppSelfConversion(QTextStream &s, const GeneratorContext
 }
 
 void CppGenerator::writeCppSelfDefinition(QTextStream &s,
-                                          GeneratorContext &context,
+                                          const GeneratorContext &context,
                                           bool hasStaticOverload,
                                           bool cppSelfAsReference)
 {
@@ -2123,7 +2123,7 @@ void CppGenerator::writeCppSelfDefinition(QTextStream &s,
 
 void CppGenerator::writeCppSelfDefinition(QTextStream &s,
                                           const AbstractMetaFunction *func,
-                                          GeneratorContext &context,
+                                          const GeneratorContext &context,
                                           bool hasStaticOverload)
 {
     if (!func->ownerClass() || func->isConstructor())
@@ -2692,7 +2692,7 @@ void CppGenerator::writeOverloadedFunctionDecisorEngine(QTextStream &s, const Ov
 }
 
 void CppGenerator::writeFunctionCalls(QTextStream &s, const OverloadData &overloadData,
-                                      GeneratorContext &context)
+                                      const GeneratorContext &context)
 {
     const OverloadData::MetaFunctionList &overloads = overloadData.overloadsWithoutRepetition();
     s << INDENT << "// Call function/method\n";
@@ -2727,7 +2727,7 @@ void CppGenerator::writeFunctionCalls(QTextStream &s, const OverloadData &overlo
 void CppGenerator::writeSingleFunctionCall(QTextStream &s,
                                            const OverloadData &overloadData,
                                            const AbstractMetaFunction *func,
-                                           GeneratorContext &context)
+                                           const GeneratorContext &context)
 {
     if (func->isDeprecated()) {
         s << INDENT << "Shiboken::warning(PyExc_DeprecationWarning, 1, \"Function: '"
@@ -3170,7 +3170,7 @@ static QStringList defaultExceptionHandling()
 }
 
 void CppGenerator::writeMethodCall(QTextStream &s, const AbstractMetaFunction *func,
-                                   GeneratorContext &context, int maxArgs)
+                                   const GeneratorContext &context, int maxArgs)
 {
     s << INDENT << "// " << func->minimalSignature() << (func->isReverseOperator() ? " [reverse operator]": "") << Qt::endl;
     if (func->isConstructor()) {
@@ -3891,7 +3891,7 @@ QTextStream &operator<<(QTextStream &str, const pyTypeSlotEntry &e)
 
 void CppGenerator::writeClassDefinition(QTextStream &s,
                                         const AbstractMetaClass *metaClass,
-                                        GeneratorContext &classContext)
+                                        const GeneratorContext &classContext)
 {
     QString tp_flags;
     QString tp_init;
@@ -4075,7 +4075,7 @@ void CppGenerator::writeClassDefinition(QTextStream &s,
 
 void CppGenerator::writeMappingMethods(QTextStream &s,
                                        const AbstractMetaClass *metaClass,
-                                       GeneratorContext &context)
+                                       const GeneratorContext &context)
 {
     for (auto it = m_mappingProtocol.cbegin(), end = m_mappingProtocol.cend(); it != end; ++it) {
         const AbstractMetaFunction *func = metaClass->findFunction(it.key());
@@ -4099,7 +4099,7 @@ void CppGenerator::writeMappingMethods(QTextStream &s,
 
 void CppGenerator::writeSequenceMethods(QTextStream &s,
                                         const AbstractMetaClass *metaClass,
-                                        GeneratorContext &context)
+                                        const GeneratorContext &context)
 {
     bool injectedCode = false;
 
@@ -4285,7 +4285,7 @@ void CppGenerator::writeTpClearFunction(QTextStream &s, const AbstractMetaClass
     s << "}\n";
 }
 
-void CppGenerator::writeCopyFunction(QTextStream &s, GeneratorContext &context)
+void CppGenerator::writeCopyFunction(QTextStream &s, const GeneratorContext &context)
 {
     const AbstractMetaClass *metaClass = context.metaClass();
     const QString className = chopType(cpythonTypeName(metaClass));
@@ -4308,7 +4308,7 @@ void CppGenerator::writeCopyFunction(QTextStream &s, GeneratorContext &context)
 
 void CppGenerator::writeGetterFunction(QTextStream &s,
                                        const AbstractMetaField *metaField,
-                                       GeneratorContext &context)
+                                       const GeneratorContext &context)
 {
     ErrorCode errorCode(QString::fromLatin1(NULL_PTR));
     s << "static PyObject *" << cpythonGetterFunctionName(metaField) << "(PyObject *self, void *)\n";
@@ -4390,7 +4390,7 @@ void CppGenerator::writeGetterFunction(QTextStream &s,
 
 void CppGenerator::writeSetterFunction(QTextStream &s,
                                        const AbstractMetaField *metaField,
-                                       GeneratorContext &context)
+                                       const GeneratorContext &context)
 {
     ErrorCode errorCode(0);
     s << "static int " << cpythonSetterFunctionName(metaField) << "(PyObject *self, PyObject *pyIn, void *)\n";
@@ -4453,7 +4453,7 @@ void CppGenerator::writeSetterFunction(QTextStream &s,
     s << "}\n";
 }
 
-void CppGenerator::writeRichCompareFunction(QTextStream &s, GeneratorContext &context)
+void CppGenerator::writeRichCompareFunction(QTextStream &s, const GeneratorContext &context)
 {
     const AbstractMetaClass *metaClass = context.metaClass();
     QString baseName = cpythonBaseName(metaClass);
@@ -4958,7 +4958,7 @@ QString CppGenerator::getSimpleClassInitFunctionName(const AbstractMetaClass *me
     return initFunctionName;
 }
 
-QString CppGenerator::getInitFunctionName(GeneratorContext &context) const
+QString CppGenerator::getInitFunctionName(const GeneratorContext &context) const
 {
     return !context.forSmartPointer()
         ? getSimpleClassInitFunctionName(context.metaClass())
@@ -4967,7 +4967,7 @@ QString CppGenerator::getInitFunctionName(GeneratorContext &context) const
 
 void CppGenerator::writeClassRegister(QTextStream &s,
                                       const AbstractMetaClass *metaClass,
-                                      GeneratorContext &classContext,
+                                      const GeneratorContext &classContext,
                                       QTextStream &signatureStream)
 {
     const ComplexTypeEntry *classTypeEntry = metaClass->typeEntry();
@@ -5175,7 +5175,7 @@ void CppGenerator::writeClassRegister(QTextStream &s,
     s << "}\n";
 }
 
-void CppGenerator::writeInitQtMetaTypeFunctionBody(QTextStream &s, GeneratorContext &context) const
+void CppGenerator::writeInitQtMetaTypeFunctionBody(QTextStream &s, const GeneratorContext &context) const
 {
     const AbstractMetaClass *metaClass = context.metaClass();
     // Gets all class name variants used on different possible scopes
@@ -5303,7 +5303,7 @@ inline void CppGenerator::writeSetattroDefaultReturn(QTextStream &s) const
 }
 
 void CppGenerator::writeSetattroFunction(QTextStream &s, AttroCheck attroCheck,
-                                         GeneratorContext &context)
+                                         const GeneratorContext &context)
 {
     Q_ASSERT(!context.forSmartPointer());
     const AbstractMetaClass *metaClass = context.metaClass();
@@ -5343,7 +5343,7 @@ void CppGenerator::writeSetattroFunction(QTextStream &s, AttroCheck attroCheck,
     writeSetattroDefaultReturn(s);
 }
 
-void CppGenerator::writeSmartPointerSetattroFunction(QTextStream &s, GeneratorContext &context)
+void CppGenerator::writeSmartPointerSetattroFunction(QTextStream &s, const GeneratorContext &context)
 {
     Q_ASSERT(context.forSmartPointer());
     writeSetattroDefinition(s, context.metaClass());
@@ -5389,7 +5389,7 @@ QString CppGenerator::qObjectGetAttroFunction() const
 }
 
 void CppGenerator::writeGetattroFunction(QTextStream &s, AttroCheck attroCheck,
-                                         GeneratorContext &context)
+                                         const GeneratorContext &context)
 {
     Q_ASSERT(!context.forSmartPointer());
     const AbstractMetaClass *metaClass = context.metaClass();
@@ -5462,7 +5462,7 @@ void CppGenerator::writeGetattroFunction(QTextStream &s, AttroCheck attroCheck,
     s << INDENT << "return " << getattrFunc << ";\n}\n\n";
 }
 
-void CppGenerator::writeSmartPointerGetattroFunction(QTextStream &s, GeneratorContext &context)
+void CppGenerator::writeSmartPointerGetattroFunction(QTextStream &s, const GeneratorContext &context)
 {
     Q_ASSERT(context.forSmartPointer());
     const AbstractMetaClass *metaClass = context.metaClass();
@@ -6035,7 +6035,7 @@ void CppGenerator::writeReturnValueHeuristics(QTextStream &s, const AbstractMeta
     }
 }
 
-void CppGenerator::writeHashFunction(QTextStream &s, GeneratorContext &context)
+void CppGenerator::writeHashFunction(QTextStream &s, const GeneratorContext &context)
 {
     const AbstractMetaClass *metaClass = context.metaClass();
     s << "static Py_hash_t " << cpythonBaseName(metaClass) << "_HashFunc(PyObject *self) {\n";
@@ -6045,7 +6045,7 @@ void CppGenerator::writeHashFunction(QTextStream &s, GeneratorContext &context)
     s<< "}\n\n";
 }
 
-void CppGenerator::writeStdListWrapperMethods(QTextStream &s, GeneratorContext &context)
+void CppGenerator::writeStdListWrapperMethods(QTextStream &s, const GeneratorContext &context)
 {
     const AbstractMetaClass *metaClass = context.metaClass();
     ErrorCode errorCode(0);
@@ -6111,7 +6111,7 @@ void CppGenerator::writeIndexError(QTextStream &s, const QString &errorMsg)
 }
 
 QString CppGenerator::writeReprFunction(QTextStream &s,
-                                        GeneratorContext &context,
+                                        const GeneratorContext &context,
                                         uint indirections)
 {
     const AbstractMetaClass *metaClass = context.metaClass();
diff --git a/sources/shiboken2/generator/shiboken2/cppgenerator.h b/sources/shiboken2/generator/shiboken2/cppgenerator.h
index 583066c7a..97864135b 100644
--- a/sources/shiboken2/generator/shiboken2/cppgenerator.h
+++ b/sources/shiboken2/generator/shiboken2/cppgenerator.h
@@ -43,10 +43,10 @@ public:
 
 protected:
     QString fileNameSuffix() const override;
-    QString fileNameForContext(GeneratorContext &context) const override;
+    QString fileNameForContext(const GeneratorContext &context) const override;
     QVector<AbstractMetaFunctionList> filterGroupedOperatorFunctions(const AbstractMetaClass *metaClass,
                                                                      uint query);
-    void generateClass(QTextStream &s, GeneratorContext &classContext) override;
+    void generateClass(QTextStream &s, const GeneratorContext &classContext) override;
     bool finishGeneration() override;
 
 private:
@@ -66,29 +66,29 @@ private:
     void writeEnumConverterFunctions(QTextStream &s, const TypeEntry *enumType);
     void writeEnumConverterFunctions(QTextStream &s, const AbstractMetaEnum *metaEnum);
     void writeConverterFunctions(QTextStream &s, const AbstractMetaClass *metaClass,
-                                 GeneratorContext &classContext);
+                                 const GeneratorContext &classContext);
     void writeCustomConverterFunctions(QTextStream &s, const CustomConversion *customConversion);
     void writeConverterRegister(QTextStream &s, const AbstractMetaClass *metaClass,
-                                GeneratorContext &classContext);
+                                const GeneratorContext &classContext);
     void writeCustomConverterRegister(QTextStream &s, const CustomConversion *customConversion, const QString &converterVar);
 
     void writeContainerConverterFunctions(QTextStream &s, const AbstractMetaType *containerType);
 
     void writeMethodWrapperPreamble(QTextStream &s, OverloadData &overloadData,
-                                    GeneratorContext &context);
+                                    const GeneratorContext &context);
     void writeConstructorWrapper(QTextStream &s, const AbstractMetaFunctionList &overloads,
-                                 GeneratorContext &classContext);
+                                 const GeneratorContext &classContext);
     void writeMethodWrapper(QTextStream &s, const AbstractMetaFunctionList &overloads,
-                            GeneratorContext &classContext);
+                            const GeneratorContext &classContext);
     void writeArgumentsInitializer(QTextStream &s, OverloadData &overloadData);
     void writeCppSelfConversion(QTextStream &s, const GeneratorContext &context,
                                 const QString &className, bool useWrapperClass);
     void writeCppSelfDefinition(QTextStream &s,
                                 const AbstractMetaFunction *func,
-                                GeneratorContext &context,
+                                const GeneratorContext &context,
                                 bool hasStaticOverload = false);
     void writeCppSelfDefinition(QTextStream &s,
-                                GeneratorContext &context,
+                                const GeneratorContext &context,
                                 bool hasStaticOverload = false,
                                 bool cppSelfAsReference = false);
 
@@ -107,11 +107,13 @@ private:
 
     void writeSetattroDefinition(QTextStream &s, const AbstractMetaClass *metaClass) const;
     void writeSetattroDefaultReturn(QTextStream &s) const;
-    void writeSmartPointerSetattroFunction(QTextStream &s, GeneratorContext &context);
-    void writeSetattroFunction(QTextStream &s, AttroCheck attroCheck, GeneratorContext &context);
+    void writeSmartPointerSetattroFunction(QTextStream &s, const GeneratorContext &context);
+    void writeSetattroFunction(QTextStream &s, AttroCheck attroCheck,
+                               const GeneratorContext &context);
     static void writeGetattroDefinition(QTextStream &s, const AbstractMetaClass *metaClass);
-    void writeSmartPointerGetattroFunction(QTextStream &s, GeneratorContext &context);
-    void writeGetattroFunction(QTextStream &s, AttroCheck attroCheck, GeneratorContext &context);
+    void writeSmartPointerGetattroFunction(QTextStream &s, const GeneratorContext &context);
+    void writeGetattroFunction(QTextStream &s, AttroCheck attroCheck,
+                               const GeneratorContext &context);
     QString writeSmartPointerGetterCast();
     QString qObjectGetAttroFunction() const;
 
@@ -182,13 +184,13 @@ private:
     /// Writes calls to all the possible method/function overloads.
     void writeFunctionCalls(QTextStream &s,
                             const OverloadData &overloadData,
-                            GeneratorContext &context);
+                            const GeneratorContext &context);
 
     /// Writes the call to a single function usually from a collection of overloads.
     void writeSingleFunctionCall(QTextStream &s,
                                  const OverloadData &overloadData,
                                  const AbstractMetaFunction *func,
-                                 GeneratorContext &context);
+                                 const GeneratorContext &context);
 
     /// Returns the name of a C++ to Python conversion function.
     static QString cppToPythonFunctionName(const QString &sourceTypeName, QString targetTypeName = QString());
@@ -241,48 +243,48 @@ private:
     /// Returns a string containing the name of an argument for the given function and argument index.
     QString argumentNameFromIndex(const AbstractMetaFunction *func, int argIndex, const AbstractMetaClass **wrappedClass);
     void writeMethodCall(QTextStream &s, const AbstractMetaFunction *func,
-                         GeneratorContext &context, int maxArgs = 0);
+                         const GeneratorContext &context, int maxArgs = 0);
 
-    QString getInitFunctionName(GeneratorContext &context) const;
+    QString getInitFunctionName(const GeneratorContext &context) const;
     QString getSimpleClassInitFunctionName(const AbstractMetaClass *metaClass) const;
 
     void writeClassRegister(QTextStream &s,
                             const AbstractMetaClass *metaClass,
-                            GeneratorContext &classContext,
+                            const GeneratorContext &classContext,
                             QTextStream &signatureStream);
     void writeClassDefinition(QTextStream &s,
                               const AbstractMetaClass *metaClass,
-                              GeneratorContext &classContext);
+                              const GeneratorContext &classContext);
     void writeMethodDefinitionEntry(QTextStream &s, const AbstractMetaFunctionList &overloads);
     void writeMethodDefinition(QTextStream &s, const AbstractMetaFunctionList &overloads);
     void writeSignatureInfo(QTextStream &s, const AbstractMetaFunctionList &overloads);
     /// Writes the implementation of all methods part of python sequence protocol
     void writeSequenceMethods(QTextStream &s,
                               const AbstractMetaClass *metaClass,
-                              GeneratorContext &context);
+                              const GeneratorContext &context);
     void writeTypeAsSequenceDefinition(QTextStream &s, const AbstractMetaClass *metaClass);
 
     /// Writes the PyMappingMethods structure for types that supports the python mapping protocol.
     void writeTypeAsMappingDefinition(QTextStream &s, const AbstractMetaClass *metaClass);
     void writeMappingMethods(QTextStream &s,
                              const AbstractMetaClass *metaClass,
-                             GeneratorContext &context);
+                             const GeneratorContext &context);
 
     void writeTypeAsNumberDefinition(QTextStream &s, const AbstractMetaClass *metaClass);
 
     void writeTpTraverseFunction(QTextStream &s, const AbstractMetaClass *metaClass);
     void writeTpClearFunction(QTextStream &s, const AbstractMetaClass *metaClass);
 
-    void writeCopyFunction(QTextStream &s, GeneratorContext &context);
+    void writeCopyFunction(QTextStream &s, const GeneratorContext &context);
 
     void writeGetterFunction(QTextStream &s,
                              const AbstractMetaField *metaField,
-                             GeneratorContext &context);
+                             const GeneratorContext &context);
     void writeSetterFunction(QTextStream &s,
                              const AbstractMetaField *metaField,
-                             GeneratorContext &context);
+                             const GeneratorContext &context);
 
-    void writeRichCompareFunction(QTextStream &s, GeneratorContext &context);
+    void writeRichCompareFunction(QTextStream &s, const GeneratorContext &context);
 
     void writeEnumsInitialization(QTextStream &s, AbstractMetaEnumList &enums);
     void writeEnumInitialization(QTextStream &s, const AbstractMetaEnum *metaEnum);
@@ -313,7 +315,7 @@ private:
     void writeParentChildManagement(QTextStream &s, const AbstractMetaFunction *func, bool userHeuristicForReturn);
     bool writeParentChildManagement(QTextStream &s, const AbstractMetaFunction *func, int argIndex, bool userHeuristicPolicy);
     void writeReturnValueHeuristics(QTextStream &s, const AbstractMetaFunction *func);
-    void writeInitQtMetaTypeFunctionBody(QTextStream &s, GeneratorContext &context) const;
+    void writeInitQtMetaTypeFunctionBody(QTextStream &s, const GeneratorContext &context) const;
 
     /**
      *   Returns the multiple inheritance initializer function for the given class.
@@ -338,14 +340,14 @@ private:
     /// Returns true if generator should produce getters and setters for the given class.
     bool shouldGenerateGetSetList(const AbstractMetaClass *metaClass);
 
-    void writeHashFunction(QTextStream &s, GeneratorContext &context);
+    void writeHashFunction(QTextStream &s, const GeneratorContext &context);
 
     /// Write default implementations for sequence protocol
-    void writeStdListWrapperMethods(QTextStream &s, GeneratorContext &context);
+    void writeStdListWrapperMethods(QTextStream &s, const GeneratorContext &context);
     /// Helper function for writeStdListWrapperMethods.
     void writeIndexError(QTextStream &s, const QString &errorMsg);
 
-    QString writeReprFunction(QTextStream &s, GeneratorContext &context, uint indirections);
+    QString writeReprFunction(QTextStream &s, const GeneratorContext &context, uint indirections);
 
     const AbstractMetaFunction *boolCast(const AbstractMetaClass *metaClass) const;
     bool hasBoolCast(const AbstractMetaClass *metaClass) const
diff --git a/sources/shiboken2/generator/shiboken2/headergenerator.cpp b/sources/shiboken2/generator/shiboken2/headergenerator.cpp
index 70a24bd3c..235ea003d 100644
--- a/sources/shiboken2/generator/shiboken2/headergenerator.cpp
+++ b/sources/shiboken2/generator/shiboken2/headergenerator.cpp
@@ -45,7 +45,7 @@ QString HeaderGenerator::fileNameSuffix() const
     return QLatin1String("_wrapper.h");
 }
 
-QString HeaderGenerator::fileNameForContext(GeneratorContext &context) const
+QString HeaderGenerator::fileNameForContext(const GeneratorContext &context) const
 {
     const AbstractMetaClass *metaClass = context.metaClass();
     if (!context.forSmartPointer()) {
@@ -91,9 +91,10 @@ void HeaderGenerator::writeProtectedFieldAccessors(QTextStream &s, const Abstrac
       << " { " << fieldName << " = value; }\n";
 }
 
-void HeaderGenerator::generateClass(QTextStream &s, GeneratorContext &classContext)
+void HeaderGenerator::generateClass(QTextStream &s, const GeneratorContext &classContextIn)
 {
-    AbstractMetaClass *metaClass = classContext.metaClass();
+    GeneratorContext classContext = classContextIn;
+    const AbstractMetaClass *metaClass = classContext.metaClass();
     m_inheritedOverloads.clear();
     Indentation indent(INDENT);
 
diff --git a/sources/shiboken2/generator/shiboken2/headergenerator.h b/sources/shiboken2/generator/shiboken2/headergenerator.h
index 5f59dd13a..30ce06636 100644
--- a/sources/shiboken2/generator/shiboken2/headergenerator.h
+++ b/sources/shiboken2/generator/shiboken2/headergenerator.h
@@ -47,8 +47,8 @@ public:
 
 protected:
     QString fileNameSuffix() const override;
-    QString fileNameForContext(GeneratorContext &context) const override;
-    void generateClass(QTextStream &s, GeneratorContext &classContext) override;
+    QString fileNameForContext(const GeneratorContext &context) const override;
+    void generateClass(QTextStream &s, const GeneratorContext &classContext) override;
     bool finishGeneration() override;
 
 private: