[generator] Add @managedOverride values none and reabstract. (#1000)

Fixes: #981
Context: 5a0e37e
Add support for `//class/method[@managedOverride = 'none']` and
`//interface/method[@managedOverride = 'reabstract']`.
Setting `@managedOverride` to `none` ensures that the member is not
marked with `virtual` or `override`. This is useful for `sealed`
classes, to avoid a [CS0549 error][0]. Previously, given the Java:
// Java
public final class MyClass {
public void doThing() {/* … */ }
}
The `class-parse` XML would specify that `MyClass.doThing()` was
"virtual" -- `@abstract` is false, `@final` is false:
<class name="MyClass …>
<method
abstract="false"
final="false"
name="doThing"
return="void"
… />
</class>
This would result in the C# binding:
// C#
public sealed partial class MyClass {
public virtual void DoThing() => …
}
which would error out with a CS0549:
error CS0549: 'MyClass.DoThing()' is a new virtual member in sealed type 'MyClass'
This can now be resolved by setting `@managedOverride` to `none`:
<attr path="//class[@name='MyClass']/method[@name='doThing']"
name="managedOverride">none</attr>
which will result in the compilable binding:
// C#
public sealed partial class MyClass {
public void DoThing() => …
}
Setting `@managedOverride` to `reabstract` is part of support for
re-abstracting interface members; see also a65d6fb. Currently in
`src/Java.Base`, we have Java:
// Java
public interface AnnotatedType {
default AnnotatedType getAnnotatedOwnerType() {…}
}
public interface AnnotatedArrayType implements AnnotatedType {
AnnotatedType getAnnotatedOwnerType(); // re-abstract interface default method
}
which results in the C# binding:
// C#
public partial interface IAnnotatedType {
virtual IAnnotatedType? AnnotatedOwnerType {
get => …
}
}
public partial interface IAnnotatedArrayType : IAnnotatedType {
IAnnotatedType? AnnotatedOwnerType { get; } // CS0108
}
which results in a [warning CS0108][1]:
warning CS0108: 'IAnnotatedArrayType.AnnotatedOwnerType' hides inherited member
'IAnnotatedType.AnnotatedOwnerType'. Use the new keyword if hiding was intended.
Fixing this requires two steps. First, we can now set
`//interface/method/@managedOverride` to `reabstract`:
<attr path="//interface[@name='AnnotatedArrayType']/method[@name='getAnnotatedOwnerType']"
name="managedOverride">reabstract</attr>
What we *also* need to do is make the member *explicitly qualified*.
This can be "forced" for *properties* by setting `@propertyName`:
<attr path="//interface[@name='AnnotatedArrayType']/method[@name='getAnnotatedOwnerType']"
name="propertyName">IAnnotatedType.AnnotatedOwnerType</attr>
`@managedOverride` and `@propertyName` work together to emit:
public partial interface IAnnotatedArrayType : IAnnotatedType {
abstract IAnnotatedType? IAnnotatedType.AnnotatedOwnerType {get;}
}
The problem is that this combination probably breaks Android output,
and it can't be used for *method* overrides, e.g. having
`java.io.Closeable.close()` re-abstract `java.lang.AutoCloseable.close()`.
TODO: complete the "interface reabstract" case, possibly via
`//interface/method[@explicitInterface='ManagedInterfaceName']`:
<attr path="//interface[@name='AnnotatedArrayType']/method[@name='getAnnotatedOwnerType']"
name="explicitInterface">IAnnotatedType</attr>
[0]: https://docs.microsoft.com/en-us/dotnet/csharp/misc/cs0549
[1]: https://docs.microsoft.com/en-us/dotnet/csharp/language-reference/compiler-messages/cs0108

Author: jpobst

tests/generator-Tests/Unit-Tests/CodeGeneratorTests.cs

@@ -147,6 +147,56 @@ public void ManagedOverrideMethod_Override ()
 Assert.True(writer.ToString().Contains("public override unsafe int DoStuff ()"),$"was: `{writer.ToString()}`");
 }
 
+[Test]
+publicvoidManagedOverrideMethod_None()
+{
+varxml=@"<api>
+ <package name='java.lang' jni-name='java/lang'>
+ <class abstract='false' deprecated='not deprecated' final='false' name='Object' static='false' visibility='public' jni-signature='Ljava/lang/Object;' />
+ </package>
+ <package name='com.xamarin.android' jni-name='com/xamarin/android'>
+ <class abstract='false' deprecated='not deprecated' extends='java.lang.Object' extends-generic-aware='java.lang.Object' jni-extends='Ljava/lang/Object;' final='false' name='MyClass' static='false' visibility='public' jni-signature='Lcom/xamarin/android/MyClass;'>
+ <method abstract='false' deprecated='not deprecated' final='false' name='DoStuff' jni-signature='()I' bridge='false' native='false' return='int' jni-return='I' static='false' synchronized='false' synthetic='false' visibility='public' managedOverride='none'></method>
+ </class>
+ </package>
+ </api>";
+
+vargens=ParseApiDefinition(xml);
+varklass=gens.Single(g =>g.Name=="MyClass");
+
+generator.Context.ContextTypes.Push(klass);
+generator.WriteType(klass,string.Empty,newGenerationInfo("","","MyAssembly"));
+generator.Context.ContextTypes.Pop();
+
+// This would contain 'virtual' if the 'managedOverride' was not working
+Assert.True(writer.ToString().Contains("public unsafe int DoStuff ()"),$"was: `{writer}`");
+}
+
+[Test]
+publicvoidManagedOverrideInterfaceMethod_Reabstract()
+{
+varxml=@"<api>
+ <package name='java.lang' jni-name='java/lang'>
+ <class abstract='false' deprecated='not deprecated' final='false' name='Object' static='false' visibility='public' jni-signature='Ljava/lang/Object;' />
+ </package>
+ <package name='com.xamarin.android' jni-name='com/xamarin/android'>
+ <interface abstract='false' deprecated='not deprecated' extends='java.lang.Object' extends-generic-aware='java.lang.Object' jni-extends='Ljava/lang/Object;' final='false' name='MyInterface' static='false' visibility='public' jni-signature='Lcom/xamarin/android/MyInterface;'>
+ <method abstract='true' deprecated='not deprecated' final='false' name='DoStuff' jni-signature='()I' bridge='false' native='false' return='int' jni-return='I' static='false' synchronized='false' synthetic='false' visibility='public' managedOverride='reabstract'></method>
+ </interface>
+ </package>
+ </api>";
+
+vargens=ParseApiDefinition(xml);
+variface=gens.Single(g =>g.Name=="IMyInterface");
+
+generator.Context.ContextTypes.Push(iface);
+generator.WriteType(iface,string.Empty,newGenerationInfo("","","MyAssembly"));
+generator.Context.ContextTypes.Pop();
+
+// This would not contain 'abstract' if the 'managedOverride' was not working
+Assert.True(writer.ToString().Contains("abstract int DoStuff ()"),$"was: `{writer}`");
+}
+
 [Test]
 publicvoidManagedOverrideProperty_Virtual()
 {
@@ -195,6 +245,56 @@ public void ManagedOverrideProperty_Override ()
 Assert.True(writer.ToString().Contains("public override unsafe int Name {"),$"was: `{writer.ToString()}`");
 }
 
+[Test]
+publicvoidManagedOverrideProperty_None()
+{
+varxml=@"<api>
+ <package name='java.lang' jni-name='java/lang'>
+ <class abstract='false' deprecated='not deprecated' final='false' name='Object' static='false' visibility='public' jni-signature='Ljava/lang/Object;' />
+ </package>
+ <package name='com.xamarin.android' jni-name='com/xamarin/android'>
+ <class abstract='false' deprecated='not deprecated' extends='java.lang.Object' extends-generic-aware='java.lang.Object' jni-extends='Ljava/lang/Object;' final='false' name='MyClass' static='false' visibility='public' jni-signature='Lcom/xamarin/android/MyClass;'>
+ <method abstract='false' deprecated='not deprecated' final='false' name='getName' jni-signature='()I' bridge='false' native='false' return='int' jni-return='I' static='false' synchronized='false' synthetic='false' visibility='public' managedOverride='none'></method>
+ </class>
+ </package>
+ </api>";
+
+vargens=ParseApiDefinition(xml);
+varklass=gens.Single(g =>g.Name=="MyClass");
+
+generator.Context.ContextTypes.Push(klass);
+generator.WriteType(klass,string.Empty,newGenerationInfo("","","MyAssembly"));
+generator.Context.ContextTypes.Pop();
+
+// This would contain 'virtual' if the 'managedOverride' was not working
+Assert.True(writer.ToString().Contains("public unsafe int Name {"),$"was: `{writer}`");
+}
+
+[Test]
+publicvoidManagedOverrideInterfaceProperty_Reabstract()
+{
+varxml=@"<api>
+ <package name='java.lang' jni-name='java/lang'>
+ <class abstract='false' deprecated='not deprecated' final='false' name='Object' static='false' visibility='public' jni-signature='Ljava/lang/Object;' />
+ </package>
+ <package name='com.xamarin.android' jni-name='com/xamarin/android'>
+ <interface abstract='false' deprecated='not deprecated' extends='java.lang.Object' extends-generic-aware='java.lang.Object' jni-extends='Ljava/lang/Object;' final='false' name='MyInterface' static='false' visibility='public' jni-signature='Lcom/xamarin/android/MyInterface;'>
+ <method abstract='true' deprecated='not deprecated' final='false' name='getName' jni-signature='()I' bridge='false' native='false' return='int' jni-return='I' static='false' synchronized='false' synthetic='false' visibility='public' managedOverride='reabstract'></method>
+ </interface>
+ </package>
+ </api>";
+
+vargens=ParseApiDefinition(xml);
+variface=gens.Single(g =>g.Name=="IMyInterface");
+
+generator.Context.ContextTypes.Push(iface);
+generator.WriteType(iface,string.Empty,newGenerationInfo("","","MyAssembly"));
+generator.Context.ContextTypes.Pop();
+
+// This would not contain 'abstract' if the 'managedOverride' was not working
+Assert.True(writer.ToString().Contains("abstract int Name {"),$"was: `{writer}`");
+}
+
 [Test]
 publicvoidWriteDuplicateInterfaceEventArgs()
 {

tools/generator/SourceWriters/BoundInterfaceMethodDeclaration.cs

@@ -25,6 +25,10 @@ public BoundInterfaceMethodDeclaration (Method method, string adapter, CodeGener
 ReturnType=newTypeReferenceWriter(opt.GetTypeReferenceName(method.RetVal));
 IsDeclaration=true;
 
+// Allow user to force adding the 'abstract' keyword for "reabstraction"
+if(method.ManagedOverride?.ToLowerInvariant()=="reabstract")
+IsAbstract=true;
+
 if(method.DeclaringType.IsGeneratable)
 Comments.Add($"// Metadata.xml XPath method reference: path=\"{method.GetMetadataXPathReference(method.DeclaringType)}\"");
 if(method.Deprecated!=null)

tools/generator/SourceWriters/BoundInterfacePropertyDeclaration.cs

@@ -20,6 +20,10 @@ public BoundInterfacePropertyDeclaration (GenBase gen, Property property, string
 PropertyType=newTypeReferenceWriter(opt.GetTypeReferenceName(property));
 IsAutoProperty=true;
 
+// Allow user to force adding the 'abstract' keyword for "reabstraction"
+if((property.Getter??property.Setter).ManagedOverride?.ToLowerInvariant()=="reabstract")
+IsAbstract=true;
+
 if(property.Getter!=null){
 HasGet=true;
 

tools/generator/SourceWriters/BoundMethod.cs

@@ -58,6 +58,9 @@ public BoundMethod (GenBase type, Method method, CodeGenerationOptions opt, bool
 }elseif(method.ManagedOverride?.ToLowerInvariant()=="override"){
 IsVirtual=false;
 IsOverride=true;
+}elseif(method.ManagedOverride?.ToLowerInvariant()=="none"){
+IsVirtual=false;
+IsOverride=false;
 }
 
 ReturnType=newTypeReferenceWriter(opt.GetTypeReferenceName(method.RetVal));

tools/generator/SourceWriters/BoundProperty.cs

@@ -66,6 +66,9 @@ public BoundProperty (GenBase gen, Property property, CodeGenerationOptions opt,
 }elseif(!forceOverride&&(property.Getter??property.Setter).ManagedOverride?.ToLowerInvariant()=="override"){
 IsVirtual=false;
 IsOverride=true;
+}elseif(!forceOverride&&(property.Getter??property.Setter).ManagedOverride?.ToLowerInvariant()=="none"){
+IsVirtual=false;
+IsOverride=false;
 }
 
 // Unlike [Register], [Obsolete] cannot be put on property accessors, so we can apply them only under limited condition...