ComInterfaceGenerator does not allocate an array to pass as [Out] parameter in CCW

[jtschuster]

By value out CCW does not allocate an array to pass to the interface method. Instead it passes a null pointer.

public void ByValueOutParam([MarshalUsing(ConstantElementCount = 10)][Out] string[] value);

Generated:

internal static int ABI_ByValueOutParam(System.Runtime.InteropServices.ComWrappers.ComInterfaceDispatch* __this_native, nint* __value_native)
    {
        global::SharedTypes.ComInterfaces.MarshallingFails.IStringArrayMarshallingFails @this = default;
        string[] value = default;
        int __retVal = default;
        // Setup - Perform required setup.
        int __value_native__numElements;
        System.Runtime.CompilerServices.Unsafe.SkipInit(out __value_native__numElements);
        try
        {
            // Unmarshal - Convert native data to managed data.
            __retVal = 0; // S_OK
            global::System.Runtime.InteropServices.Marshalling.ArrayMarshaller<string, nint>.GetManagedValuesDestination(value).Clear();
            @this = System.Runtime.InteropServices.ComWrappers.ComInterfaceDispatch.GetInstance<global::SharedTypes.ComInterfaces.MarshallingFails.IStringArrayMarshallingFails>(__this_native);
            // Call method on null parameter
            @this.ByValueOutParam(value);
            // Marshal - Convert managed data to native data.
            {
                __value_native__numElements = global::System.Runtime.InteropServices.Marshalling.ArrayMarshaller<string, nint>.GetManagedValuesDestination(value).Length;
                System.Span<nint> __value_native__nativeSpan = System.Runtime.InteropServices.MemoryMarshal.CreateSpan(ref System.Runtime.CompilerServices.Unsafe.AsRef(in global::System.Runtime.InteropServices.Marshalling.ArrayMarshaller<string, nint>.GetUnmanagedValuesSource(__value_native, __value_native__numElements).GetPinnableReference()), __value_native__numElements);
                System.Span<string> __value_native__managedSpan = global::System.Runtime.InteropServices.Marshalling.ArrayMarshaller<string, nint>.GetManagedValuesDestination(value);
                for (int __i0 = 0; __i0 < __value_native__numElements; ++__i0)
                {
                    nint __value_native__nativeSpan____i0__original = __value_native__nativeSpan[__i0];
                    __value_native__nativeSpan[__i0] = global::SharedTypes.ComInterfaces.MarshallingFails.StringMarshallingFails.ConvertToUnmanaged(__value_native__managedSpan[__i0]);
                }
            }
        }
        catch (System.Exception __exception)
        {
            __retVal = System.Runtime.InteropServices.Marshalling.ExceptionAsHResultMarshaller<int>.ConvertToUnmanaged(__exception);
        }

 

        return __retVal;
    }

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Issue Details

---

By value out CCW does not allocate an array to pass to the interface method. Instead it passes a null pointer.

public void ByValueOutParam([MarshalUsing(ConstantElementCount = 10)][Out] string[] value);

Generated:

internal static int ABI_ByValueOutParam(System.Runtime.InteropServices.ComWrappers.ComInterfaceDispatch* __this_native, nint* __value_native)
    {
        global::SharedTypes.ComInterfaces.MarshallingFails.IStringArrayMarshallingFails @this = default;
        string[] value = default;
        int __retVal = default;
        // Setup - Perform required setup.
        int __value_native__numElements;
        System.Runtime.CompilerServices.Unsafe.SkipInit(out __value_native__numElements);
        try
        {
            // Unmarshal - Convert native data to managed data.
            __retVal = 0; // S_OK
            global::System.Runtime.InteropServices.Marshalling.ArrayMarshaller<string, nint>.GetManagedValuesDestination(value).Clear();
            @this = System.Runtime.InteropServices.ComWrappers.ComInterfaceDispatch.GetInstance<global::SharedTypes.ComInterfaces.MarshallingFails.IStringArrayMarshallingFails>(__this_native);
            // Call method on null parameter
            @this.ByValueOutParam(value);
            // Marshal - Convert managed data to native data.
            {
                __value_native__numElements = global::System.Runtime.InteropServices.Marshalling.ArrayMarshaller<string, nint>.GetManagedValuesDestination(value).Length;
                System.Span<nint> __value_native__nativeSpan = System.Runtime.InteropServices.MemoryMarshal.CreateSpan(ref System.Runtime.CompilerServices.Unsafe.AsRef(in global::System.Runtime.InteropServices.Marshalling.ArrayMarshaller<string, nint>.GetUnmanagedValuesSource(__value_native, __value_native__numElements).GetPinnableReference()), __value_native__numElements);
                System.Span<string> __value_native__managedSpan = global::System.Runtime.InteropServices.Marshalling.ArrayMarshaller<string, nint>.GetManagedValuesDestination(value);
                for (int __i0 = 0; __i0 < __value_native__numElements; ++__i0)
                {
                    nint __value_native__nativeSpan____i0__original = __value_native__nativeSpan[__i0];
                    __value_native__nativeSpan[__i0] = global::SharedTypes.ComInterfaces.MarshallingFails.StringMarshallingFails.ConvertToUnmanaged(__value_native__managedSpan[__i0]);
                }
            }
        }
        catch (System.Exception __exception)
        {
            __retVal = System.Runtime.InteropServices.Marshalling.ExceptionAsHResultMarshaller<int>.ConvertToUnmanaged(__exception);
        }

 

        return __retVal;
    }

Author:	jtschuster
Assignees:	-
Labels:	area-System.Runtime.InteropServices
Milestone:	-