error: cannot pass object of non-trivial type 'QtJniTypes::Context' through variadic constructor

Dmitriano

The following code stopped compiling for Android with QT 6.7.2:

    m_javaObject = QJniObject("org/qtproject/qt/android/purchasing/InAppPurchase",
                              "(Landroid/content/Context;J)V",
                              QNativeInterface::QAndroidApplication::context(),
                              this);

The error is:

error: cannot pass object of non-trivial type 'QtJniTypes::Context' through variadic constructor; call will abort at runtime [-Wnon-pod-varargs]
                              QNativeInterface::QAndroidApplication::context(),

As far as I can guess, Context type is not trivial anymore and can't be passed as an argument of a function with three dots in its signature like

QJniObject(const char *className, const char *signature, ...);

What is the workaround?

gregory109

Hello, @Dmitriano

The issue you’re encountering is related to passing a non-trivial type (specifically, QtJniTypes::Context) through a variadic constructor. In Qt 6.7.2, the QJniObject constructor expects a variadic argument list, but passing non-trivial types directly can cause problems.

To work around this, you can use the following approach:

Create a Local Variable:
Instead of passing QNativeInterface::QAndroidApplication::context() directly, create a local variable of type QtJniTypes::Context.
Then pass that local variable to the QJniObject constructor.
Here’s an example of how you can modify your code:

// Create a local variable of type QtJniTypes::Context
QtJniTypes::Context androidContext = QNativeInterface::QAndroidApplication::context();

// Pass the local variable to the QJniObject constructor
m_javaObject = QJniObject("org/qtproject/qt/android/purchasing/InAppPurchase",
"(Landroid/content/Context;J)V",
androidContext,
this);

By using a local variable, you avoid passing non-trivial types directly through the variadic constructor, and it should compile without issues.

Remember to adjust the variable names and context as needed for your specific use case.

I hope this info is helpful to you.

Best Regard,
Gregory Chavez

@Dmitriano Official Site said in error: cannot pass object of non-trivial type 'QtJniTypes::Context' through variadic constructor:

The following code stopped compiling for Android with QT 6.7.2:
    m_javaObject = QJniObject("org/qtproject/qt/android/purchasing/InAppPurchase",
                              "(Landroid/content/Context;J)V",
                              QNativeInterface::QAndroidApplication::context(),
                              this);
The error is:
error: cannot pass object of non-trivial type 'QtJniTypes::Context' through variadic constructor; call will abort at runtime [-Wnon-pod-varargs]
                              QNativeInterface::QAndroidApplication::context(),
As far as I can guess, Context type is not trivial anymore and can't be passed as an argument of a function with three dots in its signature like
QJniObject(const char *className, const char *signature, ...);
What is the workaround?

Dmitriano

@gregory109 I tried:

QtJniTypes::Context context = QNativeInterface::QAndroidApplication::context();

    m_javaObject = QJniObject("org/qtproject/qt/android/purchasing/InAppPurchase",
                              "(Landroid/content/Context;J)V",
                              context,
                              this);

but it did not help. Looks like QtJniTypes::Context is not a trivial type defined with Q_DECLARE_JNI_CLASS(Context, "android/content/Context").