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[Export] Fix dynamic export array callbacks #11428

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Merged
jonathanpeppers merged 2 commits into from
May 22, 2026
+20 −22
Merged

[Export] Fix dynamic export array callbacks #11428

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9062efc
Fix dynamic export array callbacks
simonrozsival May 20, 2026
eabf089
Validate dynamic export array copy-back overload
simonrozsival May 20, 2026
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31 changes: 20 additions & 11 deletions src/Mono.Android.Export/CallbackCode.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -167,7 +167,7 @@ public CodeExpression PrepareCallback (CodeExpression arg)
return GetCallbackPrep (type, parameter_kind, arg);
}

public CodeExpression CleanupCallback (CodeExpression arg, CodeExpression orgArg)
public CodeItem CleanupCallback (CodeExpression arg, CodeExpression orgArg)
{
return GetCallbackCleanup (type, arg, orgArg);
}
Expand All @@ -190,7 +190,7 @@ public static CodeExpression GetCallbackPrep (Type type, ExportParameterKind pki
// ArraySymbol:
// return new string[] { String.Format ("{0}[] {1} = ({0}[]) JNIEnv.GetArray ({2}, JniHandleOwnership.DoNotTransfer, typeof ({3}));", ElementType, var_name, SymbolTable.GetNativeName (var_name), sym.FullName) };
case SymbolKind.Array:
return new CodeMethodCall (jnienv_getarray, arg, do_not_transfer_literal, new CodeLiteral (type)).CastTo (type);
return new CodeMethodCall (jnienv_getarray.MakeGenericMethod (type.GetElementType ()), arg).CastTo (type);

// CharSequenceSymbol:
// return new string[] { String.Format ("Java.Lang.ICharSequence {0} = Java.Lang.Object.GetObject<Java.Lang.ICharSequence> ({1}, JniHandleOwnership.DoNotTransfer);", var_name, SymbolTable.GetNativeName (var_name)) };
Expand Down Expand Up @@ -239,7 +239,7 @@ public static CodeExpression GetCallbackPrep (Type type, ExportParameterKind pki
return arg;
}

public static CodeExpression GetCallbackCleanup (Type type, CodeExpression arg, CodeExpression orgArg)
public static CodeItem GetCallbackCleanup (Type type, CodeExpression arg, CodeExpression orgArg)
{
switch (GetKind (type)) {
// ArraySymbol:
Expand All @@ -249,21 +249,28 @@ public static CodeExpression GetCallbackCleanup (Type type, CodeExpression arg,
// return result;
case SymbolKind.Array:
MethodInfo copyArrayMethod;
switch (Type.GetTypeCode (type)) {
Type elementType = type.GetElementType ();
switch (Type.GetTypeCode (elementType)) {
case TypeCode.Empty:
case TypeCode.DBNull:
throw new NotSupportedException ("Only primitive types and IJavaObject is supported in array type in callback method parameter or return value");
case TypeCode.Object:
if (typeof (IJavaObject).IsAssignableFrom (type))
copyArrayMethod = typeof (JNIEnv).GetMethod ("CopyArray", new Type [] { typeof (IJavaObject), typeof (IntPtr) });
if (typeof (IJavaObject).IsAssignableFrom (elementType))
copyArrayMethod = typeof (JNIEnv).GetMethod ("CopyArray", new Type [] { typeof (IJavaObject[]), typeof (IntPtr) });
else
goto case TypeCode.Empty;
break;
default:
copyArrayMethod = typeof (JNIEnv).GetMethod ("CopyArray", new Type [] { type, typeof (IntPtr) });
break;
}
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return new CodeWhen (arg.IsNull, arg, new CodeMethodCall (copyArrayMethod, arg, orgArg));
if (copyArrayMethod == null)
throw new NotSupportedException ($"JNIEnv.CopyArray does not support array type '{type}'.");
CodeBlock copyArrayBlock = new CodeBlock ();
copyArrayBlock.Add (new CodeMethodCall (copyArrayMethod, arg, orgArg));
return new CodeIf (CodeExpression.Not (arg.IsNull)) {
TrueBlock = copyArrayBlock,
};

// CharSequenceSymbol:
// return new string[] { String.Format ("Java.Lang.ICharSequence {0} = Java.Lang.Object.GetObject<Java.Lang.ICharSequence> ({1}, JniHandleOwnership.DoNotTransfer);", var_name, SymbolTable.GetNativeName (var_name)) };
Expand Down Expand Up @@ -711,10 +718,12 @@ CodeMethod GenerateNativeCallbackDelegate (string generatedMethodName)
// sw.WriteLine ("{0}\t{1} {2};", indent, Parameters.HasCleanup ? RetVal.NativeType + " __ret =" : "return", RetVal.ToNative (opt, call));
var callArgs = new List<CodeExpression> ();
for (int i = 0; i < parameter_type_infos.Count; i++) {
if (parameter_type_infos [i].NeedsPrep)
callArgs.Add (parameter_type_infos [i].PrepareCallback (mgen.GetArg (i + 2)));
else
if (parameter_type_infos [i].NeedsPrep) {
var preparedArg = parameter_type_infos [i].PrepareCallback (mgen.GetArg (i + 2));
callArgs.Add (builder.DeclareVariable (method.GetParameters () [i].ParameterType, preparedArg));
} else {
callArgs.Add (parameter_type_infos [i].FromNative (mgen.GetArg (i + 2)));
}
}
CodeMethodCall call;
if (method.IsStatic)
Expand All @@ -740,7 +749,7 @@ CodeMethod GenerateNativeCallbackDelegate (string generatedMethodName)
// sw.WriteLine ("{0}\t{1}", indent, cleanup);
var callbackCleanup = new List<CodeStatement> ();
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🤖 💡 Code organization — callbackCleanup is declared but never used (pre-existing). Now that this area is being touched, consider removing it to reduce noise.

Rule: Remove unused code

for (int i = 0; i < parameter_type_infos.Count; i++)
builder.CurrentBlock.Add (parameter_type_infos [i].CleanupCallback (callArgs [i], mgen.GetArg (i)));
builder.CurrentBlock.Add (parameter_type_infos [i].CleanupCallback (callArgs [i], mgen.GetArg (i + 2)));

//if (!IsVoid && Parameters.HasCleanup)
// sw.WriteLine ("{0}\treturn __ret;", indent);
Expand Down
11 changes: 0 additions & 11 deletions tests/Mono.Android-Tests/Mono.Android-Tests/Java.Interop/ExportTests.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -99,8 +99,6 @@ public void Export_Method_PeerArg_NullArg_HandledGracefully ()
[Test, Category ("Export")]
public void Export_Method_IntArray_RoundTrip_AndCopyBack ()
{
AssumeTrimmableExportArrayMarshalling ();

using var e = new ExportIntArray ();
var m = JNIEnv.GetMethodID (e.Class.Handle, "DoubleArray", "([I)[I");
Assert.AreNotEqual (IntPtr.Zero, m, "JNI method id for DoubleArray not found");
Expand Down Expand Up @@ -135,8 +133,6 @@ public void Export_Method_IntArray_RoundTrip_AndCopyBack ()
[Test, Category ("Export")]
public void Export_Method_PeerArray_RoundTrip ()
{
AssumeTrimmableExportArrayMarshalling ();

using var e = new ExportPeerArray ();
using var a = new Java.Lang.Integer (1);
using var b = new Java.Lang.Integer (2);
Expand Down Expand Up @@ -263,13 +259,6 @@ static void AssumeTrimmableExportExceptionRouting ()
}
}

static void AssumeTrimmableExportArrayMarshalling ()
{
if (!RuntimeFeature.TrimmableTypeMap) {
Assert.Ignore ("[Export] array marshalling coverage is enabled in the Mono.Android.Export stacked PR.");
}
}

// ---------------------------------------------------------------
// Group D — [ExportField] runtime visibility from Java
// ---------------------------------------------------------------
Expand Down