Bump to xamarin/java.interop@99897b2 #5262
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Context: 855b7e9 Context: dotnet/android#5251 Context: dotnet/android#5262 When an Java interface contains a `static` method in API-30+, we use C# 8.0's Default Interface Methods support to place corresponding `static` methods in the C# interface binding: // Java public /* partial */ interface Comparator<T> {} int compare(T o1, T o2); static <T> Comparator<T> comparingDouble(ToDoubleFunction<? super T> keyExtractor) {…} // … } // C# binding public partial interface IComparator { [Register ("compare", "(Ljava/lang/Object;Ljava/lang/Object;)I", "GetCompare_Ljava_lang_Object_Ljava_lang_Object_Handler:Java.Util.IComparatorInvoker, Mono.Android, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null")] int Compare (Java.Lang.Object? o1, Java.Lang.Object? o2); [Register ("comparingDouble", "(Ljava/util/function/ToDoubleFunction;)Ljava/util/Comparator;", "", ApiSince = 24)] [global::Java.Interop.JavaTypeParameters (new string [] {"T"})] public static unsafe Java.Util.IComparator? ComparingDouble (Java.Util.Functions.IToDoubleFunction? keyExtractor) {…} } This works until you (1) attempt to implement the C# interface: public partial class CompareSizesByArea : Java.Lang.Object, Java.Util.IComparator { public int Compare (Java.Lang.Object lhs, Java.Lang.Object rhs) {…} } and then (2) *instantiate* that class: var comparator = new CompareSizesByArea(); The result is an `ArgumentException`: System.ArgumentException: Couldn't bind to method ''. at System.Delegate.GetCandidateMethod (System.Type type, System.Type target, System.String method, System.Reflection.BindingFlags bflags, System.Boolean ignoreCase, System.Boolean throwOnBindFailure) at System.Delegate.CreateDelegate (System.Type type, System.Type target, System.String method, System.Boolean ignoreCase, System.Boolean throwOnBindFailure) at System.Delegate.CreateDelegate (System.Type type, System.Type target, System.String method) at Android.Runtime.AndroidTypeManager.RegisterNativeMembers (Java.Interop.JniType nativeClass, System.Type type, System.String methods) at Android.Runtime.JNIEnv.RegisterJniNatives (System.IntPtr typeName_ptr, System.Int32 typeName_len, System.IntPtr jniClass, System.IntPtr methods_ptr, System.Int32 methods_len) /* missing stack entries */ at (wrapper managed-to-native) Java.Interop.NativeMethods.java_interop_jnienv_alloc_object(intptr,intptr&,intptr) at Java.Interop.JniEnvironment+Object.AllocObject (Java.Interop.JniObjectReference type) at Java.Interop.JniType.AllocObject () at Java.Interop.JniPeerMembers+JniInstanceMethods.StartCreateInstance (System.String constructorSignature, System.Type declaringType, Java.Interop.JniArgumentValue* parameters) at Java.Lang.Object..ctor () at App16.MainActivity+CompareSizesByArea..ctor () Why this fails is because of the intermediate Java Callable Wrapper, which emits a method override for every method in the interface, *including `static` methods*: // Java callable wrapper public /* partial */ class CompareSizesByArea extends java.lang.Object, implements java.util.Comparator { public static final String __md_methods; static { __md_methods = "n_compare:(Ljava/lang/Object;Ljava/lang/Object;)I:GetCompare_Ljava_lang_Object_Ljava_lang_Object_Handler:Java.Util.IComparatorInvoker, Mono.Android, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null\n" + … + "n_comparingDouble:(Ljava/util/function/ToDoubleFunction;)Ljava/util/Comparator;:\n" + … mono.android.Runtime.register ("CompareSizesByArea, …", CompareSizesByArea.class, __md_methods); } public int compare (java.lang.Object p0, java.lang.Object p1) { return n_compare (p0, p1); } private native int n_compare (java.lang.Object p0, java.lang.Object p1); public java.util.Comparator comparingDouble (java.util.function.ToDoubleFunction p0) { return n_comparingDouble (p0); } private native java.util.Comparator n_comparingDouble (java.util.function.ToDoubleFunction p0); } (Note: The `/* missing stack entries */` line (above) is from the Java-side `CompareSizesByArea` static constructor execution, which calls `Runtime.register()`, which in turn calls `JNIEnv.RegisterJniNatives()`.) The `Runtime.register()` invocation eventually hits [`AndroidTypeManager.RegisterNativeMembers()`][0], which "splits" `__md_methods` into lines, and each line into `:`-separated values. One of those values is expected to be a "connector method", obtainable via Reflection. In the case of `n_comparingDouble`, the connector method *is not specified*: note that the line ends with `:`, unlike the entry for `n_compare`, which lists `GetCompare_…`. This "missing" connector method is the cause of the `ArgumentException`. Fix the problem by *skipping* `static` methods found from interfaces when emitting Java Callable Wrappers. This ensures that `__md_methods` won't contain entries with missing "connector" methods. An integration test is part of dotnet/android#5262, as we're not currently able to use C#8 Default Interface Methods in a `net472` target framework for unit testing within the xamarin/Java.Interop repo. [0]: https://github.com/xamarin/xamarin-android/blob/15b37758e9d65c82aebe1a327747b285f38ce791/src/Mono.Android/Android.Runtime/AndroidRuntime.cs#L394-L413
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Context: #5251
Context: dotnet/java-interop#745
dotnet/java-interop@c3c3575...99897b2
Adds a test for
staticmethods on an interface that is implemented by a class. Our existingstatictest was an interface that only containedstaticmembers, and thus we did not try to implement the interface. Implementing the interface exposed a JCW error.