[WIP][TrimmableTypeMap] Add marshal method scanning infrastructure

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

@@ -0,0 +1,58 @@
+using System;
+using System.Collections.Generic;
+
+namespace Microsoft.Android.Sdk.TrimmableTypeMap;
+
+/// <summary>
+/// Helpers for parsing JNI method signatures.
+/// </summary>
+static class JniSignatureHelper
+{
+	/// <summary>
+	/// Parses the JNI parameter type descriptors from a JNI method signature
+	/// and returns them as <see cref="JniParameterInfo"/> records.
+	/// </summary>
+	public static List<JniParameterInfo> ParseParameterTypes (string jniSignature)
+	{
+		var result = new List<JniParameterInfo> ();
+		int i = 1; // skip opening '('
+		while (i < jniSignature.Length && jniSignature [i] != ')') {
+			int start = i;
+			SkipSingleType (jniSignature, ref i);
+			result.Add (new JniParameterInfo { JniType = 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);
+	}
+
+	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':
+			int end = sig.IndexOf (';', i);
+			if (end < 0) {
+				throw new ArgumentException ($"Malformed JNI signature: missing ';' after 'L' at index {i} in '{sig}'");
+			}
+			i = end + 1;
+			break;
+		case '[':
+			i++;
+			SkipSingleType (sig, ref i);
+			break;
+		default:
+			throw new ArgumentException ($"Unknown JNI type character '{sig [i]}' in '{sig}' at index {i}");
+		}
+	}
+}

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

@@ -280,6 +280,15 @@ sealed record RegisterInfo
 	public bool DoNotGenerateAcw { get; init; }
 }
 
+/// <summary>
+/// Parsed [Export] attribute data for a method.
+/// </summary>
+sealed record ExportInfo
+{
+	public IReadOnlyList<string>? ThrownNames { get; init; }
+	public string? SuperArgumentsString { get; init; }
+}
+
 class TypeAttributeInfo (string attributeName)
 {
 	public string AttributeName { get; } = attributeName;

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

@@ -1,3 +1,4 @@
+using System;
 using System.Collections.Generic;
 
 namespace Microsoft.Android.Sdk.TrimmableTypeMap;
@@ -15,6 +16,13 @@ sealed record JavaPeerInfo
 	/// </summary>
 	public required string JavaName { get; init; }
 
+	/// <summary>
+	/// Compat JNI type name, e.g., "myapp.namespace/MyType" for user types (uses raw namespace, not CRC64).
+	/// For MCW binding types (with [Register]), this equals <see cref="JavaName"/>.
+	/// Used by acw-map.txt to support legacy custom view name resolution in layout XMLs.
+	/// </summary>
+	public required string CompatJniName { get; init; }
+
 	/// <summary>
 	/// Full managed type name, e.g., "Android.App.Activity".
 	/// </summary>
@@ -50,6 +58,14 @@ sealed record JavaPeerInfo
 	/// </summary>
 	public bool IsUnconditional { get; init; }
 
+	/// <summary>
+	/// Marshal methods: methods with [Register(name, sig, connector)], [Export], or
+	/// constructor registrations ([Register(".ctor", sig, "")] / [JniConstructorSignature]).
+	/// Constructors are identified by <see cref="MarshalMethodInfo.IsConstructor"/>.
+	/// Ordered — the index in this list is the method's ordinal for RegisterNatives.
+	/// </summary>
+	public IReadOnlyList<MarshalMethodInfo> MarshalMethods { get; init; } = Array.Empty<MarshalMethodInfo> ();
+
 	/// <summary>
 	/// Information about the activation constructor for this type.
 	/// May reference a base type's constructor if the type doesn't define its own.
@@ -79,6 +95,99 @@ sealed record JavaPeerInfo
 	public bool IsGenericDefinition { get; init; }
 }
 
+/// <summary>
+/// Describes a marshal method (a method with [Register] or [Export]) on a Java peer type.
+/// Contains all data needed to generate a UCO wrapper, a JCW native declaration,
+/// and a RegisterNatives call.
+/// </summary>
+sealed record MarshalMethodInfo
+{
+	/// <summary>
+	/// JNI method name, e.g., "onCreate".
+	/// This is the Java method name (without n_ prefix).
+	/// </summary>
+	public required string JniName { get; init; }
+
+	/// <summary>
+	/// JNI method signature, e.g., "(Landroid/os/Bundle;)V".
+	/// Contains both parameter types and return type.
+	/// </summary>
+	public required string JniSignature { get; init; }
+
+	/// <summary>
+	/// The connector string from [Register], e.g., "GetOnCreate_Landroid_os_Bundle_Handler".
+	/// Null for [Export] methods.
+	/// </summary>
+	public string? Connector { get; init; }
+
+	/// <summary>
+	/// Name of the managed method this maps to, e.g., "OnCreate".
+	/// </summary>
+	public required string ManagedMethodName { get; init; }
+
+	/// <summary>
+	/// Full name of the type that declares the managed method (may be a base type).
+	/// Empty when the declaring type is the same as the peer type.
+	/// </summary>
+	public string DeclaringTypeName { get; init; } = "";
+
+	/// <summary>
+	/// Assembly name of the type that declares the managed method.
+	/// Needed for cross-assembly UCO wrapper generation.
+	/// Empty when the declaring type is the same as the peer type.
+	/// </summary>
+	public string DeclaringAssemblyName { get; init; } = "";
+
+	/// <summary>
+	/// The native callback method name, e.g., "n_onCreate".
+	/// This is the actual method the UCO wrapper delegates to.
+	/// </summary>
+	public required string NativeCallbackName { get; init; }
+
+	/// <summary>
+	/// JNI parameter types for UCO generation.
+	/// </summary>
+	public IReadOnlyList<JniParameterInfo> Parameters { get; init; } = Array.Empty<JniParameterInfo> ();
+
+	/// <summary>
+	/// JNI return type descriptor, e.g., "V", "Landroid/os/Bundle;".
+	/// </summary>
+	public required string JniReturnType { get; init; }
+
+	/// <summary>
+	/// True if this is a constructor registration.
+	/// </summary>
+	public bool IsConstructor { get; init; }
+
+	/// <summary>
+	/// For [Export] methods: Java exception types that the method declares it can throw.
+	/// Null for [Register] methods.
+	/// </summary>
+	public IReadOnlyList<string>? ThrownNames { get; init; }
+
+	/// <summary>
+	/// For [Export] methods: super constructor arguments string.
+	/// Null for [Register] methods.
+	/// </summary>
+	public string? SuperArgumentsString { get; init; }
+}
+
+/// <summary>
+/// Describes a JNI parameter for UCO method generation.
+/// </summary>
+sealed record JniParameterInfo
+{
+	/// <summary>
+	/// JNI type descriptor, e.g., "Landroid/os/Bundle;", "I", "Z".
+	/// </summary>
+	public required string JniType { get; init; }
+
+	/// <summary>
+	/// Managed parameter type name, e.g., "Android.OS.Bundle", "System.Int32".
+	/// </summary>
+	public string ManagedType { get; init; } = "";
+}
+
 /// <summary>
 /// Describes how to call the activation constructor for a Java peer type.
 /// </summary>