Add generator model types and scanner enrichment for JCW/UCO generation

Add JniParameterInfo, JavaConstructorInfo, and additional properties to
MarshalMethodInfo and JavaPeerInfo that generators require (JniReturnType,
NativeCallbackName, Parameters, JavaConstructors, ManagedTypeNamespace,
ManagedTypeShortName). Extend JniSignatureHelper with raw type string
parsing. Enrich scanner output with these derived fields.

Author: simonrozsival

src/Microsoft.Android.Sdk.TrimmableTypeMap/Generator/JniSignatureHelper.cs

@@ -34,6 +34,26 @@ public static List<JniParamKind> ParseParameterTypes (string jniSignature)
 		return result;
 	}
 
+	/// <summary>Parses the raw JNI type descriptor strings from a JNI method signature.</summary>
+	public static List<string> ParseParameterTypeStrings (string jniSignature)
+	{
+		var result = new List<string> ();
+		int i = 1; // skip opening '('
+		while (i < jniSignature.Length && jniSignature [i] != ')') {
+			int start = i;
+			SkipSingleType (jniSignature, ref i);
+			result.Add (jniSignature.Substring (start, i - start));
+		}
+		return result;
+	}
+
+	/// <summary>Extracts the return type descriptor from a JNI method signature.</summary>
+	public static string ParseReturnTypeString (string jniSignature)
+	{
+		int i = jniSignature.IndexOf (')') + 1;
+		return jniSignature.Substring (i);
+	}
+
 	/// <summary>Parses the return type from a JNI method signature.</summary>
 	public static JniParamKind ParseReturnType (string jniSignature)
 	{
@@ -65,6 +85,25 @@ static JniParamKind ParseSingleType (string sig, ref int i)
 		}
 	}
 
+	static void SkipSingleType (string sig, ref int i)
+	{
+		switch (sig [i]) {
+		case 'V': case 'Z': case 'B': case 'C': case 'S':
+		case 'I': case 'J': case 'F': case 'D':
+			i++;
+			break;
+		case 'L':
+			i = sig.IndexOf (';', i) + 1;
+			break;
+		case '[':
+			i++;
+			SkipSingleType (sig, ref i);
+			break;
+		default:
+			throw new ArgumentException ($"Unknown JNI type character '{sig [i]}' in '{sig}' at index {i}");
+		}
+	}
+
 	/// <summary>Encodes the CLR type for a JNI parameter kind into a signature type encoder.</summary>
 	public static void EncodeClrType (SignatureTypeEncoder encoder, JniParamKind kind)
 	{

src/Microsoft.Android.Sdk.TrimmableTypeMap/Scanner/JavaPeerInfo.cs

@@ -28,6 +28,16 @@ sealed class JavaPeerInfo
 	/// </summary>
 	public string ManagedTypeName { get; set; } = "";
 
+	/// <summary>
+	/// Managed type namespace, e.g., "Android.App".
+	/// </summary>
+	public string ManagedTypeNamespace { get; set; } = "";
+
+	/// <summary>
+	/// Managed type short name (without namespace), e.g., "Activity".
+	/// </summary>
+	public string ManagedTypeShortName { get; set; } = "";
+
 	/// <summary>
 	/// Assembly name the type belongs to, e.g., "Mono.Android".
 	/// </summary>
@@ -70,6 +80,12 @@ sealed class JavaPeerInfo
 	/// </summary>
 	public IReadOnlyList<MarshalMethodInfo> MarshalMethods { get; set; } = Array.Empty<MarshalMethodInfo> ();
 
+	/// <summary>
+	/// Java constructors to emit in the JCW .java file.
+	/// Each has a JNI signature and an ordinal index for the nctor_N native method.
+	/// </summary>
+	public IReadOnlyList<JavaConstructorInfo> JavaConstructors { get; set; } = Array.Empty<JavaConstructorInfo> ();
+
 	/// <summary>
 	/// Information about the activation constructor for this type.
 	/// May reference a base type's constructor if the type doesn't define its own.
@@ -119,6 +135,33 @@ sealed class MarshalMethodInfo
 	/// </summary>
 	public string ManagedMethodName { get; set; } = "";
 
+	/// <summary>
+	/// Full name of the type that declares the managed method (may be a base type).
+	/// </summary>
+	public string DeclaringTypeName { get; set; } = "";
+
+	/// <summary>
+	/// Assembly name of the type that declares the managed method.
+	/// Needed for cross-assembly UCO wrapper generation.
+	/// </summary>
+	public string DeclaringAssemblyName { get; set; } = "";
+
+	/// <summary>
+	/// The native callback method name, e.g., "n_onCreate".
+	/// This is the actual method the UCO wrapper delegates to.
+	/// </summary>
+	public string NativeCallbackName { get; set; } = "";
+
+	/// <summary>
+	/// JNI parameter types for UCO generation.
+	/// </summary>
+	public IReadOnlyList<JniParameterInfo> Parameters { get; set; } = Array.Empty<JniParameterInfo> ();
+
+	/// <summary>
+	/// JNI return type descriptor, e.g., "V", "Landroid/os/Bundle;".
+	/// </summary>
+	public string JniReturnType { get; set; } = "";
+
 	/// <summary>
 	/// True if this is a constructor registration.
 	/// </summary>
@@ -137,6 +180,50 @@ sealed class MarshalMethodInfo
 	public string? SuperArgumentsString { get; set; }
 }
 
+/// <summary>
+/// Describes a JNI parameter for UCO method generation.
+/// </summary>
+sealed class JniParameterInfo
+{
+	/// <summary>
+	/// JNI type descriptor, e.g., "Landroid/os/Bundle;", "I", "Z".
+	/// </summary>
+	public string JniType { get; set; } = "";
+
+	/// <summary>
+	/// Managed parameter type name, e.g., "Android.OS.Bundle", "System.Int32".
+	/// </summary>
+	public string ManagedType { get; set; } = "";
+}
+
+/// <summary>
+/// Describes a Java constructor to emit in the JCW .java source file.
+/// </summary>
+sealed class JavaConstructorInfo
+{
+	/// <summary>
+	/// JNI constructor signature, e.g., "(Landroid/content/Context;)V".
+	/// </summary>
+	public string JniSignature { get; set; } = "";
+
+	/// <summary>
+	/// Ordinal index for the native constructor method (nctor_0, nctor_1, ...).
+	/// </summary>
+	public int ConstructorIndex { get; set; }
+
+	/// <summary>
+	/// JNI parameter types parsed from the signature.
+	/// Used to generate the Java constructor parameter list.
+	/// </summary>
+	public IReadOnlyList<JniParameterInfo> Parameters { get; set; } = Array.Empty<JniParameterInfo> ();
+
+	/// <summary>
+	/// For [Export] constructors: super constructor arguments string.
+	/// Null for [Register] constructors.
+	/// </summary>
+	public string? SuperArgumentsString { get; set; }
+}
+
 /// <summary>
 /// Describes how to call the activation constructor for a Java peer type.
 /// </summary>

src/Microsoft.Android.Sdk.TrimmableTypeMap/Scanner/JavaPeerScanner.cs

@@ -214,6 +214,8 @@ void ScanAssembly (AssemblyIndex index, Dictionary<string, JavaPeerInfo> results
 				JavaName = jniName,
 				CompatJniName = compatJniName,
 				ManagedTypeName = fullName,
+				ManagedTypeNamespace = ExtractNamespace (fullName),
+				ManagedTypeShortName = ExtractShortName (fullName),
 				AssemblyName = index.AssemblyName,
 				BaseJavaName = baseJavaName,
 				ImplementedInterfaceJavaNames = implementedInterfaces,
@@ -222,6 +224,7 @@ void ScanAssembly (AssemblyIndex index, Dictionary<string, JavaPeerInfo> results
 				DoNotGenerateAcw = doNotGenerateAcw,
 				IsUnconditional = isUnconditional,
 				MarshalMethods = marshalMethods,
+				JavaConstructors = BuildJavaConstructors (marshalMethods),
 				ActivationCtor = activationCtor,
 				InvokerTypeName = invokerTypeName,
 				IsGenericDefinition = isGenericDefinition,
@@ -276,6 +279,9 @@ static void AddMarshalMethod (List<MarshalMethodInfo> methods, RegisterInfo regi
 			JniSignature = registerInfo.Signature ?? "()V",
 			Connector = registerInfo.Connector,
 			ManagedMethodName = index.Reader.GetString (methodDef.Name),
+			NativeCallbackName = "n_" + index.Reader.GetString (methodDef.Name),
+			JniReturnType = JniSignatureHelper.ParseReturnTypeString (registerInfo.Signature ?? "()V"),
+			Parameters = ParseJniParameters (registerInfo.Signature ?? "()V"),
 			IsConstructor = registerInfo.JniName == "<init>" || registerInfo.JniName == ".ctor",
 			ThrownNames = registerInfo.ThrownNames,
 			SuperArgumentsString = registerInfo.SuperArgumentsString,
@@ -741,4 +747,45 @@ static string GetCrc64PackageName (string ns, string assemblyName)
 		var hash = System.IO.Hashing.Crc64.Hash (data);
 		return "crc64" + BitConverter.ToString (hash).Replace ("-", "").ToLowerInvariant ();
 	}
+
+	static string ExtractNamespace (string fullName)
+	{
+		int lastDot = fullName.LastIndexOf ('.');
+		return lastDot >= 0 ? fullName.Substring (0, lastDot) : "";
+	}
+
+	static string ExtractShortName (string fullName)
+	{
+		int lastDot = fullName.LastIndexOf ('.');
+		return lastDot >= 0 ? fullName.Substring (lastDot + 1) : fullName;
+	}
+
+	static List<JniParameterInfo> ParseJniParameters (string jniSignature)
+	{
+		var typeStrings = JniSignatureHelper.ParseParameterTypeStrings (jniSignature);
+		var result = new List<JniParameterInfo> (typeStrings.Count);
+		foreach (var t in typeStrings) {
+			result.Add (new JniParameterInfo { JniType = t });
+		}
+		return result;
+	}
+
+	static List<JavaConstructorInfo> BuildJavaConstructors (List<MarshalMethodInfo> marshalMethods)
+	{
+		var ctors = new List<JavaConstructorInfo> ();
+		int ctorIndex = 0;
+		foreach (var mm in marshalMethods) {
+			if (!mm.IsConstructor) {
+				continue;
+			}
+			ctors.Add (new JavaConstructorInfo {
+				JniSignature = mm.JniSignature,
+				ConstructorIndex = ctorIndex,
+				Parameters = mm.Parameters,
+				SuperArgumentsString = mm.SuperArgumentsString,
+			});
+			ctorIndex++;
+		}
+		return ctors;
+	}
 }