[Java.Interop] Improve ConstructorInfo lookup

Context: #1168 (comment)

> There is a remaining problem with this approach: there is no
> requirement of a 1:1 mapping between Java types and managed types.

A useful example of that is with arrays: a Java `int[]` array can be
treated as one of the following types, in various contexts:

  * C# `int[]`
  * `JavaArray<int>`
  * `JavaPrimitiveArray<int>`
  * `JavaInt32Array`

Update `JavaCallableExample` to demonstrate this:

	partial class JavaCallableExample {
	    [JavaCallableConstructor(SuperConstructorExpression="")]
	    public JavaCallableExample (int[] a, JavaInt32Array b);
	}

The intention is twofold:

 1. This should result in a Java Callable Wrapper constructor with
    signature `JavaCallableExample(int[] p0, int[] p1)`, and

 2. Java code should be able to invoke this constructor.

Turns out, neither of these worked when `Type.GetType()` is not used
for constructor argument lookup: `JavaCallableWrapperGenerator`
didn't fully support e.g. `[JniTypeSignature("I", ArrayRank=1)]`,
so didn't know what to do with `JavaInt32Array`.  Once (1) was fixed,
(2) would fail because
`JniRuntime.JniTypeManager.GetType(JniTypeSignature.Parse("[I"))`
would return `JavaPrimitiveArray<int>`, which wasn't used in
`JavaCallableExample`, resulting in:

	System.NotSupportedException : Unable to find constructor
	  Java.InteropTests.JavaCallableExample(Java.Interop.JavaPrimitiveArray`1[[System.Int32, System.Private.CoreLib, Version=7.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]], Java.Interop.JavaPrimitiveArray`1[[System.Int32, System.Private.CoreLib, Version=7.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]]).
	  Please provide the missing constructor.
	  ----> Java.Interop.JniLocationException : Exception of type 'Java.Interop.JniLocationException' was thrown.
	  Stack Trace:
	     at Java.Interop.ManagedPeer.GetConstructor(JniTypeManager typeManager, Type type, String signature, Type[]& parameterTypes)
	   at Java.Interop.ManagedPeer.Construct(IntPtr jnienv, IntPtr klass, IntPtr n_self, IntPtr n_constructorSignature, IntPtr n_constructorArguments)
	…
	  --- End of managed Java.Interop.JavaException stack trace ---
	java.lang.Throwable
		at net.dot.jni.ManagedPeer.construct(Native Method)
		at net.dot.jni.test.JavaCallableExample.<init>(JavaCallableExample.java:32)
		at net.dot.jni.test.UseJavaCallableExample.test(UseJavaCallableExample.java:8)

Intent (2) had two causes:

 1. Using `JniRuntime.JniTypeManager.GetType()` can only return a
    single type, but there are multiple possible matches.  Thus,
    we need to instead use `JniRuntime.JniTypeManager.GetTypes()`.

 2. `JniRuntime.JniTypeManager.GetTypes()` was incomplete, which is
    a longstanding limitation from f60906c: for `[I`, it would only
    return `JavaPrimitiveArray<int>` and `int[]`, in that order.

Fix both of these.
`JniRuntime.JniTypeManager.GetTypes(JniTypeSignature.Parse("[I"))`
will now include:

  * `JavaArray<int>`
  * `JavaPrimitiveArray<int>`
  * `JavaInt32Array`
  * `int[]`

This now allows the `JavaCallableExample` constructor to be invoked
from Java.

Because `ManagedPeer.Construct()` is now doing so much extra work
in order to find the `ConstructorInfo` to invoke, cache the lookups.
(Technically this is a "memory leak," as cache entries are never
removed.)

Author: jonpryor

src/Java.Interop.Tools.JavaCallableWrappers/Java.Interop.Tools.JavaCallableWrappers/JavaCallableWrapperGenerator.cs

@@ -387,6 +387,12 @@ void AddConstructor (MethodDefinition ctor, TypeDefinition type, string? outerTy
 				} else if (v.Name == "GenerateJavaPeer") {
 					r.DoNotGenerateAcw = ! (bool) v.Argument.Value;
 				}
+				var isKeyProp   = attr.Properties.FirstOrDefault (p => p.Name == "IsKeyword");
+				var isKeyword	= isKeyProp.Name != null && ((bool) isKeyProp.Argument.Value) == true;
+				var arrRankProp = attr.Properties.FirstOrDefault (p => p.Name == "ArrayRank");
+				if (arrRankProp.Name != null && arrRankProp.Argument.Value is int rank) {
+					r.Name = new string ('[', rank) + (isKeyword ? r.Name : "L" + r.Name + ";");
+				}
 			}
 			return r;
 		}

src/Java.Interop.Tools.TypeNameMappings/Java.Interop.Tools.TypeNameMappings/JavaNativeTypeManager.cs

@@ -192,7 +192,7 @@ public static string ToJniName (string jniType, int rank)
 			if (rank == 0)
 				return jniType;
 
-			if (jniType.Length > 1)
+			if (jniType.Length > 1 && jniType [0] != '[')
 				jniType = "L" + jniType + ";";
 			return new string ('[', rank) + jniType;
 		}
@@ -358,7 +358,9 @@ public static int GetArrayInfo (Type type, out Type elementType)
 			if (pJniName == null) {
 				return null;
 			}
-			return rank == 0 && pJniName.Length > 1 ? "L" + pJniName + ";" : ToJniName (pJniName, rank);
+			return (rank == 0 && pJniName.Length > 1 && pJniName[0] != '[')
+				? "L" + pJniName + ";"
+				: ToJniName (pJniName, rank);
 		}
 
 		static ExportParameterKind GetExportKind (System.Reflection.ICustomAttributeProvider p)
@@ -556,7 +558,15 @@ public static string ToJniName (TypeDefinition type, IMetadataResolver resolver)
 			var carg    = attr.ConstructorArguments.FirstOrDefault ();
 			if (carg.Type == null || carg.Type.FullName != "System.String")
 				return null;
-			return (string) carg.Value;
+			var jniType     = (string) carg.Value;
+			var isKeyProp   = attr.Properties.FirstOrDefault (p => p.Name == "IsKeyword");
+			var isKeyword   = isKeyProp.Name != null && ((bool) isKeyProp.Argument.Value) == true;
+			var arrRankProp = attr.Properties.FirstOrDefault (p => p.Name == "ArrayRank");
+			var arrayRank   = arrRankProp.Name != null && arrRankProp.Argument.Value is int rank ? rank : 0;
+			jniType = arrayRank == 0
+				? jniType
+				: new string ('[', arrayRank) + (isKeyword ? jniType : "L" + jniType + ";");
+			return jniType;
 		}
 
 		static string? ToJniNameFromAttributesForAndroid (TypeDefinition type, IMetadataResolver resolver)

src/Java.Interop/Java.Interop/JavaPrimitiveArrays.cs

@@ -1,4 +1,4 @@
-#nullable enable
+#nullable enable
 
 using System;
 using System.Collections.Generic;
@@ -12,50 +12,44 @@
 namespace Java.Interop {
 
 	partial class JniRuntime {
-		static JniTypeSignature __BooleanTypeArraySignature;
-		static JniTypeSignature __SByteTypeArraySignature;
-		static JniTypeSignature __CharTypeArraySignature;
-		static JniTypeSignature __Int16TypeArraySignature;
-		static JniTypeSignature __Int32TypeArraySignature;
-		static JniTypeSignature __Int64TypeArraySignature;
-		static JniTypeSignature __SingleTypeArraySignature;
-		static JniTypeSignature __DoubleTypeArraySignature;
-
-		static bool GetBuiltInTypeArraySignature (Type type, ref JniTypeSignature signature)
-		{
-			if (type == typeof (JavaArray<Boolean>) || type == typeof (JavaPrimitiveArray<Boolean>)) {
-				signature = GetCachedTypeSignature (ref __BooleanTypeArraySignature, "Z", arrayRank: 1, keyword: true);
-				return true;
-			}
-			if (type == typeof (JavaArray<SByte>) || type == typeof (JavaPrimitiveArray<SByte>)) {
-				signature = GetCachedTypeSignature (ref __SByteTypeArraySignature, "B", arrayRank: 1, keyword: true);
-				return true;
-			}
-			if (type == typeof (JavaArray<Char>) || type == typeof (JavaPrimitiveArray<Char>)) {
-				signature = GetCachedTypeSignature (ref __CharTypeArraySignature, "C", arrayRank: 1, keyword: true);
-				return true;
-			}
-			if (type == typeof (JavaArray<Int16>) || type == typeof (JavaPrimitiveArray<Int16>)) {
-				signature = GetCachedTypeSignature (ref __Int16TypeArraySignature, "S", arrayRank: 1, keyword: true);
-				return true;
-			}
-			if (type == typeof (JavaArray<Int32>) || type == typeof (JavaPrimitiveArray<Int32>)) {
-				signature = GetCachedTypeSignature (ref __Int32TypeArraySignature, "I", arrayRank: 1, keyword: true);
-				return true;
-			}
-			if (type == typeof (JavaArray<Int64>) || type == typeof (JavaPrimitiveArray<Int64>)) {
-				signature = GetCachedTypeSignature (ref __Int64TypeArraySignature, "J", arrayRank: 1, keyword: true);
-				return true;
-			}
-			if (type == typeof (JavaArray<Single>) || type == typeof (JavaPrimitiveArray<Single>)) {
-				signature = GetCachedTypeSignature (ref __SingleTypeArraySignature, "F", arrayRank: 1, keyword: true);
-				return true;
-			}
-			if (type == typeof (JavaArray<Double>) || type == typeof (JavaPrimitiveArray<Double>)) {
-				signature = GetCachedTypeSignature (ref __DoubleTypeArraySignature, "D", arrayRank: 1, keyword: true);
-				return true;
-			}
-			return false;
+
+		partial class JniTypeManager {
+
+			readonly struct JniPrimitiveArrayInfo {
+				public  readonly    JniTypeSignature    JniTypeSignature;
+				public  readonly    Type                PrimitiveType;
+				public  readonly    Type[]              ArrayTypes;
+
+				public JniPrimitiveArrayInfo (string jniSimpleReference, Type primitiveType, params Type[] arrayTypes)
+				{
+					JniTypeSignature    = new JniTypeSignature (jniSimpleReference, arrayRank: 1, keyword: true);
+					PrimitiveType       = primitiveType;
+					ArrayTypes          = arrayTypes;
+				}
+			}
+
+			static readonly JniPrimitiveArrayInfo[] JniPrimitiveArrayTypes = new JniPrimitiveArrayInfo[]{
+				new ("Z", typeof (Boolean), typeof (Boolean[]), typeof (JavaArray<Boolean>), typeof (JavaPrimitiveArray<Boolean>), typeof (JavaBooleanArray)),
+				new ("B", typeof (SByte), typeof (SByte[]), typeof (JavaArray<SByte>), typeof (JavaPrimitiveArray<SByte>), typeof (JavaSByteArray)),
+				new ("C", typeof (Char), typeof (Char[]), typeof (JavaArray<Char>), typeof (JavaPrimitiveArray<Char>), typeof (JavaCharArray)),
+				new ("S", typeof (Int16), typeof (Int16[]), typeof (JavaArray<Int16>), typeof (JavaPrimitiveArray<Int16>), typeof (JavaInt16Array)),
+				new ("I", typeof (Int32), typeof (Int32[]), typeof (JavaArray<Int32>), typeof (JavaPrimitiveArray<Int32>), typeof (JavaInt32Array)),
+				new ("J", typeof (Int64), typeof (Int64[]), typeof (JavaArray<Int64>), typeof (JavaPrimitiveArray<Int64>), typeof (JavaInt64Array)),
+				new ("F", typeof (Single), typeof (Single[]), typeof (JavaArray<Single>), typeof (JavaPrimitiveArray<Single>), typeof (JavaSingleArray)),
+				new ("D", typeof (Double), typeof (Double[]), typeof (JavaArray<Double>), typeof (JavaPrimitiveArray<Double>), typeof (JavaDoubleArray)),
+			};
+
+			static bool GetBuiltInTypeArraySignature (Type type, ref JniTypeSignature signature)
+			{
+				foreach (var e in JniPrimitiveArrayTypes) {
+					if (Array.IndexOf (e.ArrayTypes, type) < 0)
+						continue;
+					signature   = e.JniTypeSignature;
+					return true;
+				}
+				signature   = default;
+				return false;
+			}
 		}
 
 		static readonly Lazy<KeyValuePair<Type, JniValueMarshaler>[]> JniPrimitiveArrayMarshalers = new Lazy<KeyValuePair<Type, JniValueMarshaler>[]> (InitJniPrimitiveArrayMarshalers);

src/Java.Interop/Java.Interop/JavaPrimitiveArrays.tt

@@ -29,27 +29,43 @@ namespace Java.Interop {
 	};
 #>
 	partial class JniRuntime {
+
+		partial class JniTypeManager {
+
+			readonly struct JniPrimitiveArrayInfo {
+				public  readonly    JniTypeSignature    JniTypeSignature;
+				public  readonly    Type                PrimitiveType;
+				public  readonly    Type[]              ArrayTypes;
+
+				public JniPrimitiveArrayInfo (string jniSimpleReference, Type primitiveType, params Type[] arrayTypes)
+				{
+					JniTypeSignature    = new JniTypeSignature (jniSimpleReference, arrayRank: 1, keyword: true);
+					PrimitiveType       = primitiveType;
+					ArrayTypes          = arrayTypes;
+				}
+			}
+
+			static readonly JniPrimitiveArrayInfo[] JniPrimitiveArrayTypes = new JniPrimitiveArrayInfo[]{
 <#
 	foreach (var type in arrayTypeInfo) { 
 #>
-		static JniTypeSignature __<#= type.ManagedType #>TypeArraySignature;
+				new ("<#= type.JniType #>", typeof (<#= type.ManagedType #>), typeof (<#= type.ManagedType #>[]), typeof (JavaArray<<#= type.ManagedType #>>), typeof (JavaPrimitiveArray<<#= type.ManagedType #>>), typeof (Java<#= type.ManagedType #>Array)),
 <#
 	}
 #>
+			};
 
-		static bool GetBuiltInTypeArraySignature (Type type, ref JniTypeSignature signature)
-		{
-<#
-	foreach (var info in arrayTypeInfo) {
-#>
-			if (type == typeof (JavaArray<<#= info.ManagedType #>>) || type == typeof (JavaPrimitiveArray<<#= info.ManagedType #>>)) {
-				signature = GetCachedTypeSignature (ref __<#= info.ManagedType #>TypeArraySignature, "<#= info.JniType #>", arrayRank: 1, keyword: true);
-				return true;
+			static bool GetBuiltInTypeArraySignature (Type type, ref JniTypeSignature signature)
+			{
+				foreach (var e in JniPrimitiveArrayTypes) {
+					if (Array.IndexOf (e.ArrayTypes, type) < 0)
+						continue;
+					signature   = e.JniTypeSignature;
+					return true;
+				}
+				signature   = default;
+				return false;
 			}
-<#
-	}
-#>
-			return false;
 		}
 
 		static readonly Lazy<KeyValuePair<Type, JniValueMarshaler>[]> JniPrimitiveArrayMarshalers = new Lazy<KeyValuePair<Type, JniValueMarshaler>[]> (InitJniPrimitiveArrayMarshalers);

src/Java.Interop/Java.Interop/JniRuntime.JniTypeManager.cs

@@ -79,7 +79,7 @@ public override string ToString ()
 		}
 #endif  // NET
 
-		public class JniTypeManager : IDisposable, ISetRuntime {
+		public partial class JniTypeManager : IDisposable, ISetRuntime {
 
 			JniRuntime?             runtime;
 			bool                    disposed;
@@ -294,13 +294,16 @@ IEnumerable<Type> CreateGetTypesEnumerator (JniTypeSignature typeSignature)
 						continue;
 					}
 
+					if (typeSignature.IsKeyword) {
+						foreach (var t in GetPrimitiveArrayTypesForSimpleReference (typeSignature, type)) {
+							yield return t;
+						}
+						continue;
+					}
+
 					if (typeSignature.ArrayRank > 0) {
 						var rank        = typeSignature.ArrayRank;
 						var arrayType   = type;
-						if (typeSignature.IsKeyword) {
-							arrayType   = typeof (JavaPrimitiveArray<>).MakeGenericType (arrayType);
-							rank--;
-						}
 						while (rank-- > 0) {
 							arrayType   = typeof (JavaObjectArray<>).MakeGenericType (arrayType);
 						}
@@ -318,6 +321,35 @@ IEnumerable<Type> CreateGetTypesEnumerator (JniTypeSignature typeSignature)
 				}
 			}
 
+			IEnumerable<Type> GetPrimitiveArrayTypesForSimpleReference (JniTypeSignature typeSignature, Type type)
+			{
+				int index   = -1;
+				for (int i = 0; i < JniPrimitiveArrayTypes.Length; ++i) {
+					if (JniPrimitiveArrayTypes [i].PrimitiveType == type) {
+						index   = i;
+						break;
+					}
+				}
+				if (index == -1) {
+					throw new InvalidOperationException ($"Should not be reached; Could not find JniPrimitiveArrayInfo for {type}");
+				}
+				foreach (var t in JniPrimitiveArrayTypes [index].ArrayTypes) {
+					var rank        = typeSignature.ArrayRank-1;
+					var arrayType   = t;
+					while (rank-- > 0) {
+						arrayType   = typeof (JavaObjectArray<>).MakeGenericType (arrayType);
+					}
+					yield return arrayType;
+
+					rank            = typeSignature.ArrayRank-1;
+					arrayType       = t;
+					while (rank-- > 0) {
+						arrayType   = arrayType.MakeArrayType ();
+					}
+					yield return arrayType;
+				}
+			}
+
 			protected virtual IEnumerable<Type> GetTypesForSimpleReference (string jniSimpleReference)
 			{
 				AssertValid ();