[generator] Use custom delegates instead of Func/Action.

tools/generator/CodeGenerationOptions.cs

@@ -3,7 +3,7 @@
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
-
+using System.Text;
 using Java.Interop.Tools.JavaCallableWrappers;
 
 using Xamarin.Android.Binder;
@@ -44,6 +44,9 @@ internal CodeGenerator CreateCodeGenerator (TextWriter writer)
 
 		public      SymbolTable             SymbolTable             { get; } = new SymbolTable ();
 
+		readonly SortedSet<string> jni_marshal_delegates = new SortedSet<string> ();
+		readonly object jni_marshal_delegates_lock = new object ();
+
 		public bool UseGlobal { get; set; }
 		public bool IgnoreNonPublicType { get; set; }
 		public string AssemblyName { get; set; }
@@ -129,9 +132,10 @@ public string GetNullForgiveness (Parameter symbol)
 			return string.Empty;
 		}
 
-		string GetNullable (string s)
+		string GetNullable(string s)
 		{
-			switch (s) {
+			switch (s)
+			{
 				case "void":
 				case "int":
 				//case "int[]":
@@ -156,6 +160,46 @@ string GetNullable (string s)
 			return NullableOperator;
 		}
 
+		// Encoding format:
+		// - Type name prefix: _JniMarshal_PP
+		// - Parameter types, using JNI encoding, e.g. Z is boolean, I is int, etc. Exception: Reference types, normally encoded as L…;, are instead just L.
+		// - Another _.
+		// - Return type, encoded as with parameters. A void return type is V.
+		internal string GetJniMarshalDelegate (Method method)
+		{
+			var sb = new StringBuilder ("_JniMarshal_PP");
+
+			foreach (var p in method.Parameters)
+				sb.Append (GetJniTypeCode (p.Symbol));
+
+			sb.Append ("_");
+
+			sb.Append (method.IsVoid ? "V" : GetJniTypeCode (method.RetVal.Symbol));
+
+			var result = sb.ToString ();
+
+			lock (jni_marshal_delegates_lock)
+				jni_marshal_delegates.Add (result);
+
+			return result;
+		}
+
+		string GetJniTypeCode (ISymbol symbol)
+		{
+			var jni_name = symbol.JniName;
+
+			if (jni_name.StartsWith ("L") || jni_name.StartsWith ("["))
+				return "L";
+
+			return symbol.JniName;
+		}
+
+		internal IEnumerable<string> GetJniMarshalDelegates ()
+		{
+			lock (jni_marshal_delegates_lock)
+				return jni_marshal_delegates;
+		}
+
 		public string GetOutputName (string s)
 		{
 			if (s == "System.Void")

tools/generator/CodeGenerator.cs

@@ -187,12 +187,12 @@ static void Run (CodeGeneratorOptions options, DirectoryAssemblyResolver resolve
 			if (mapping_file != null)
 				GenerateMappingReportFile (gens, mapping_file);
 
-			new NamespaceMapping (gens).Generate (opt, gen_info);
-
 			foreach (IGeneratable gen in gens)
 				if (gen.IsGeneratable)
 					gen.Generate (opt, gen_info);
 
+			new NamespaceMapping (gens).Generate (opt, gen_info);
+
 
 			ClassGen.GenerateTypeRegistrations (opt, gen_info);
 			ClassGen.GenerateEnumList (gen_info);

tools/generator/Java.Interop.Tools.Generator.CodeGeneration/CodeGenerator.cs

@@ -1090,7 +1090,7 @@ public virtual void WriteMethodCallback (Method method, string indent, GenBase t
 		{
 			var is_private = method.IsInterfaceDefaultMethod ? "private " : string.Empty;
 
-			string delegate_type = method.GetDelegateType ();
+			string delegate_type = method.GetDelegateType (opt);
 			writer.WriteLine ("{0}{2}static Delegate{3} {1};", indent, method.EscapedCallbackName, is_private, opt.NullableOperator);
 			writer.WriteLine ("#pragma warning disable 0169");
 			if (method.Deprecated != null)

tools/generator/Java.Interop.Tools.Generator.ObjectModel/Method.cs

@@ -128,15 +128,7 @@ internal string GetAdapterName (CodeGenerationOptions opt, string adapter)
 		// Connectors for DIM are defined on the interface, not the implementing type
 		public string GetConnectorNameFull (CodeGenerationOptions opt) => ConnectorName + (opt.SupportDefaultInterfaceMethods && IsInterfaceDefaultMethod ? $":{DeclaringType.FullName}, " + (AssemblyName ?? opt.AssemblyName) : string.Empty);
 
-		internal string GetDelegateType ()
-		{
-			var parms = Parameters.DelegateTypeParams;
-
-			if (IsVoid)
-				return $"Action<IntPtr, IntPtr{parms}>";
-			else
-				return $"Func<IntPtr, IntPtr{parms}, {RetVal.NativeType}>";
-		}
+		internal string GetDelegateType (CodeGenerationOptions opt) => opt.GetJniMarshalDelegate (this);
 
 		public string GetMetadataXPathReference (GenBase declaringType) =>
 			$"{declaringType.MetadataXPathReference}/method[@name='{JavaName}'{Parameters.GetMethodXPathPredicate ()}]";

tools/generator/Java.Interop.Tools.Generator.ObjectModel/NamespaceMapping.cs

@@ -19,9 +19,54 @@ public NamespaceMapping (IEnumerable<GenBase> gens)
 		public void Generate (CodeGenerationOptions opt, GenerationInfo gen_info)
 		{
 			using (var sw = gen_info.OpenStream (opt.GetFileName ("__NamespaceMapping__"))) {
+				sw.WriteLine ("using System;");
+				sw.WriteLine ();
+
 				foreach (var p in mappings)
 					sw.WriteLine ("[assembly:global::Android.Runtime.NamespaceMapping (Java = \"{0}\", Managed=\"{1}\")]",
 					              p.Key, p.Value);
+
+				sw.WriteLine ();
+
+				// delegate bool _JniMarshal_PPL_Z (IntPtr jnienv, IntPtr klass, IntPtr a);
+				foreach (var jni in opt.GetJniMarshalDelegates ())
+					sw.WriteLine ($"delegate {FromJniType (jni[jni.Length - 1])} {jni} (IntPtr jnienv, IntPtr klass{GetDelegateParameters (jni)});");
+			}
+		}
+
+		string GetDelegateParameters (string jni)
+		{
+			var parameters = new List<string> ();
+
+			jni = jni.Substring ("_JniMarshal_PP".Length);
+
+			var index = 0;
+
+			while (jni[index] != '_') {
+				parameters.Add ($"{FromJniType (jni [index])} p{index}");
+				index++;
+			}
+
+			if (parameters.Count == 0)
+				return string.Empty;
+
+			return ", " + string.Join (", ", parameters);
+		}
+
+		string FromJniType (char c)
+		{
+			switch (c) {
+				case 'B': return "sbyte";
+				case 'C': return "char";
+				case 'D': return "double";
+				case 'F': return "float";
+				case 'I': return "int";
+				case 'J': return "long";
+				case 'S': return "short";
+				case 'Z': return "bool";
+				case 'V': return "void";
+				default:
+					return "IntPtr"; ;
 			}
 		}
 	}

tools/generator/generator.csproj

@@ -1,9 +1,10 @@
-<Project Sdk="Microsoft.NET.Sdk">
+<Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFrameworks>net472;netcoreapp3.1</TargetFrameworks>
+    <TargetFramework>net472</TargetFramework>
     <OutputType>Exe</OutputType>
     <DefineConstants>$(DefineConstants);GENERATOR;HAVE_CECIL;JCW_ONLY_TYPE_NAMES</DefineConstants>
+    <LangVersion>8.0</LangVersion>
   </PropertyGroup>
 
   <PropertyGroup>
@@ -35,6 +36,7 @@
   </ItemGroup>
 
   <ItemGroup>
+    <ProjectReference Include="..\..\src\Xamarin.SourceWriter\Xamarin.SourceWriter.csproj" />
     <ProjectReference Include="..\..\src\Xamarin.Android.Tools.AnnotationSupport\Xamarin.Android.Tools.AnnotationSupport.csproj" />
     <ProjectReference Include="..\..\src\Xamarin.Android.Tools.ApiXmlAdjuster\Xamarin.Android.Tools.ApiXmlAdjuster.csproj" />
     <ProjectReference Include="..\..\src\Java.Interop.Tools.Diagnostics\Java.Interop.Tools.Diagnostics.csproj" />

tools/generator/generator.sln

@@ -1,9 +1,12 @@
-
 Microsoft Visual Studio Solution File, Format Version 12.00
-# Visual Studio 2012
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "generator", "generator.csproj", "{D14A1B5C-2060-4930-92BE-F7190256C735}"
+# Visual Studio Version 16
+VisualStudioVersion = 16.0.30013.7
+MinimumVisualStudioVersion = 10.0.40219.1
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "generator", "generator.csproj", "{D14A1B5C-2060-4930-92BE-F7190256C735}"
 EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "generator-Tests", "..\..\tests\generator-Tests\generator-Tests.csproj", "{4EEAB1A7-99C1-4302-9C18-01A7B481409B}"
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "generator-Tests", "..\..\tests\generator-Tests\generator-Tests.csproj", "{4EEAB1A7-99C1-4302-9C18-01A7B481409B}"
+EndProject
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Xamarin.SourceWriter", "..\..\src\Xamarin.SourceWriter\Xamarin.SourceWriter.csproj", "{FD3882A4-2661-47C6-9C37-18FAFE5F7991}"
 EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
@@ -19,5 +22,15 @@ Global
 		{4EEAB1A7-99C1-4302-9C18-01A7B481409B}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{4EEAB1A7-99C1-4302-9C18-01A7B481409B}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{4EEAB1A7-99C1-4302-9C18-01A7B481409B}.Release|Any CPU.Build.0 = Release|Any CPU
+		{FD3882A4-2661-47C6-9C37-18FAFE5F7991}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{FD3882A4-2661-47C6-9C37-18FAFE5F7991}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{FD3882A4-2661-47C6-9C37-18FAFE5F7991}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{FD3882A4-2661-47C6-9C37-18FAFE5F7991}.Release|Any CPU.Build.0 = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(SolutionProperties) = preSolution
+		HideSolutionNode = FALSE
+	EndGlobalSection
+	GlobalSection(ExtensibilityGlobals) = postSolution
+		SolutionGuid = {EEBC7E77-8FA5-4C2C-8FFD-08F6CD0A5330}
 	EndGlobalSection
 EndGlobal