Add an option to disable implicit conversions

Add option and extract a helper to return the list of implicit
conversions depending on it.

[ChangeLog][shiboken6] An option to disable implicit conversions
has been added.

Task-number: PYSIDE-1669
Change-Id: Iaefbbf272a6c033bac10635f48057dd69fc83549
Reviewed-by: Christian Tismer <tismer@stackless.com>
(cherry picked from commit 78d929b957bfe200806602e1e1dfedd7e044cb20)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

4 files changed, 47 insertions, 21 deletions

diff --git a/sources/shiboken6/doc/shibokengenerator.rst b/sources/shiboken6/doc/shibokengenerator.rst
index ddc2c64a1..d42827c0e 100644
--- a/sources/shiboken6/doc/shibokengenerator.rst
+++ b/sources/shiboken6/doc/shibokengenerator.rst
@@ -124,6 +124,11 @@ Options
     If a class has an operator bool, it will be used to compute
     the value of boolean casts (see :ref:`bool-cast`).
 
+.. _no-implicit-conversions:
+
+``--no-implicit-conversions``
+    Do not generate implicit_conversions for function arguments.
+
 .. _api-version:
 
 ``--api-version=<version>``
diff --git a/sources/shiboken6/generator/shiboken/cppgenerator.cpp b/sources/shiboken6/generator/shiboken/cppgenerator.cpp
index 0a237ed8d..bc1f79e52 100644
--- a/sources/shiboken6/generator/shiboken/cppgenerator.cpp
+++ b/sources/shiboken6/generator/shiboken/cppgenerator.cpp
@@ -1550,17 +1550,9 @@ return result;)";
     s << '\n';
 
     // User provided implicit conversions.
-    CustomConversion *customConversion = metaClass->typeEntry()->customConversion();
-
+    auto *typeEntry = metaClass->typeEntry();
     // Implicit conversions.
-    AbstractMetaFunctionCList implicitConvs;
-    if (!customConversion || !customConversion->replaceOriginalTargetToNativeConversions()) {
-        const auto &allImplicitConvs = api().implicitConversions(metaClass->typeEntry());
-        for (const auto &func : allImplicitConvs) {
-            if (!func->isUserAdded())
-                implicitConvs << func;
-        }
-    }
+    const AbstractMetaFunctionCList implicitConvs = implicitConversions(typeEntry);
 
     if (!implicitConvs.isEmpty())
         s << "// Implicit conversions.\n";
@@ -1630,7 +1622,7 @@ return result;)";
         writePythonToCppConversionFunctions(s, sourceType, targetType, typeCheck, toCppConv, toCppPreConv);
     }
 
-    writeCustomConverterFunctions(s, customConversion);
+    writeCustomConverterFunctions(s, typeEntry->customConversion());
 }
 
 void CppGenerator::writeCustomConverterFunctions(TextStream &s,
@@ -1737,17 +1729,10 @@ void CppGenerator::writeConverterRegister(TextStream &s, const AbstractMetaClass
     writeAddPythonToCppConversion(s, QLatin1String("converter"), toCpp, isConv);
 
     // User provided implicit conversions.
-    CustomConversion *customConversion = metaClass->typeEntry()->customConversion();
+    auto *typeEntry = metaClass->typeEntry();
 
     // Add implicit conversions.
-    AbstractMetaFunctionCList implicitConvs;
-    if (!customConversion || !customConversion->replaceOriginalTargetToNativeConversions()) {
-        const auto &allImplicitConvs = api().implicitConversions(metaClass->typeEntry());
-        for (const auto &func : allImplicitConvs) {
-            if (!func->isUserAdded())
-                implicitConvs << func;
-        }
-    }
+    const AbstractMetaFunctionCList implicitConvs = implicitConversions(typeEntry);
 
     if (!implicitConvs.isEmpty())
         s << "// Add implicit conversions to type converter.\n";
@@ -1770,7 +1755,7 @@ void CppGenerator::writeConverterRegister(TextStream &s, const AbstractMetaClass
         writeAddPythonToCppConversion(s, QLatin1String("converter"), toCpp, isConv);
     }
 
-    writeCustomConverterRegister(s, customConversion, QLatin1String("converter"));
+    writeCustomConverterRegister(s, typeEntry->customConversion(), u"converter"_qs);
 }
 
 void CppGenerator::writeCustomConverterRegister(TextStream &s, const CustomConversion *customConversion,
diff --git a/sources/shiboken6/generator/shiboken/shibokengenerator.cpp b/sources/shiboken6/generator/shiboken/shibokengenerator.cpp
index 07c41b1c5..f3e7c1f6d 100644
--- a/sources/shiboken6/generator/shiboken/shibokengenerator.cpp
+++ b/sources/shiboken6/generator/shiboken/shibokengenerator.cpp
@@ -60,6 +60,7 @@ static const char DISABLE_VERBOSE_ERROR_MESSAGES[] = "disable-verbose-error-mess
 static const char USE_ISNULL_AS_NB_NONZERO[] = "use-isnull-as-nb_nonzero";
 static const char USE_OPERATOR_BOOL_AS_NB_NONZERO[] = "use-operator-bool-as-nb_nonzero";
 static const char WRAPPER_DIAGNOSTICS[] = "wrapper-diagnostics";
+static const char NO_IMPLICIT_CONVERSIONS[] = "no-implicit-conversions";
 
 const char *CPP_ARG = "cppArg";
 const char *CPP_ARG_REMOVED = "removed_cppArg";
@@ -241,6 +242,23 @@ bool ShibokenGenerator::shouldWriteVirtualMethodNative(const AbstractMetaFunctio
                  && !func->attributes().testFlag(AbstractMetaFunction::FinalCppMethod));
 }
 
+AbstractMetaFunctionCList ShibokenGenerator::implicitConversions(const TypeEntry *t) const
+{
+    if (!generateImplicitConversions())
+        return {};
+    auto *customConversion = t->customConversion();
+    if (customConversion && customConversion->replaceOriginalTargetToNativeConversions())
+        return {};
+
+    auto result = api().implicitConversions(t);
+    auto end = std::remove_if(result.begin(), result.end(),
+                              [](const AbstractMetaFunctionCPtr &f) {
+                                  return f->isUserAdded();
+                              });
+    result.erase(end, result.end());
+    return result;
+}
+
 QString ShibokenGenerator::wrapperName(const AbstractMetaClass *metaClass) const
 {
     Q_ASSERT(shouldGenerateCppWrapper(metaClass));
@@ -2383,6 +2401,8 @@ Generator::OptionDescriptions ShibokenGenerator::options() const
         {QLatin1String(USE_OPERATOR_BOOL_AS_NB_NONZERO),
          QLatin1String("If a class has an operator bool, it will be used to compute\n"
                        "the value of boolean casts")},
+        {QLatin1String(NO_IMPLICIT_CONVERSIONS),
+         u"Do not generate implicit_conversions for function arguments."_qs},
         {QLatin1String(WRAPPER_DIAGNOSTICS),
          QLatin1String("Generate diagnostic code around wrappers")}
     });
@@ -2405,6 +2425,10 @@ bool ShibokenGenerator::handleOption(const QString &key, const QString &value)
         return (m_useOperatorBoolAsNbNonZero = true);
     if (key == QLatin1String(AVOID_PROTECTED_HACK))
         return (m_avoidProtectedHack = true);
+    if (key == QLatin1String(NO_IMPLICIT_CONVERSIONS)) {
+        return m_generateImplicitConversions = false;
+        return true;
+    }
     if (key == QLatin1String(WRAPPER_DIAGNOSTICS))
         return (m_wrapperDiagnostics = true);
     return false;
@@ -2515,6 +2539,11 @@ bool ShibokenGenerator::avoidProtectedHack() const
     return m_avoidProtectedHack;
 }
 
+bool ShibokenGenerator::generateImplicitConversions() const
+{
+    return m_generateImplicitConversions;
+}
+
 QString ShibokenGenerator::moduleCppPrefix(const QString &moduleName)
  {
     QString result = moduleName.isEmpty() ? packageName() : moduleName;
diff --git a/sources/shiboken6/generator/shiboken/shibokengenerator.h b/sources/shiboken6/generator/shiboken/shibokengenerator.h
index 35374b843..645d09121 100644
--- a/sources/shiboken6/generator/shiboken/shibokengenerator.h
+++ b/sources/shiboken6/generator/shiboken/shibokengenerator.h
@@ -195,6 +195,9 @@ protected:
     /// Condition to call WriteVirtualMethodNative. Was extracted because also used to count these calls.
     bool shouldWriteVirtualMethodNative(const AbstractMetaFunctionCPtr &func) const;
 
+    // Return a list of implicit conversions if generation is enabled.
+    AbstractMetaFunctionCList implicitConversions(const TypeEntry *t) const;
+
     QString wrapperName(const AbstractMetaClass *metaClass) const;
 
     static QString fullPythonClassName(const AbstractMetaClass *metaClass);
@@ -314,6 +317,8 @@ protected:
     bool useOperatorBoolAsNbNonZero() const;
     /// Returns true if the generated code should use the "#define protected public" hack.
     bool avoidProtectedHack() const;
+    /// Generate implicit conversions of function arguments
+    bool generateImplicitConversions() const;
     static QString cppApiVariableName(const QString &moduleName = QString());
     static QString pythonModuleObjectName(const QString &moduleName = QString());
     static QString convertersVariableName(const QString &moduleName = QString());
@@ -475,6 +480,8 @@ private:
     bool m_useIsNullAsNbNonZero = false;
     bool m_useOperatorBoolAsNbNonZero = false;
     bool m_avoidProtectedHack = false;
+    // FIXME PYSIDE 7 Flip generateImplicitConversions default or remove?
+    bool m_generateImplicitConversions = true;
     bool m_wrapperDiagnostics = false;
 
     /// Type system converter variable replacement names and regular expressions.