[runtime] Remove ObjCRuntime.nfloat in favor of System.Runtime.Intero…

…pServices.NFloat. (xamarin#14197) * Remove ObjCRuntime.nfloat (in favor of System.Runtime.InteropServices.NFloat). * Automatically add a reference to the System.Runtime.InteropServices.Internal package, so that developers get the new NFloat API (with operators) we've added post .NET 6 (but don't do this for .NET 7). * Automatically add a global using alias for System.Runtime.InteropServices.NFloat -> nfloat. This is not behind the usual `ImplicitUsings` condition our other implicit usings are, because they're off by default for existing projects, and the main target for the global using alias for nfloat is upgraded projects. * Automatically generate a global using alias (like above) in the generator for all code the generator compiles. * Update xtro entries to reference System.Runtime.InteropServices.NFloat instead of ObjCRuntime.nfloat. * Add a workaround for a hopefully temporary issue with .NET/CoreCLR where the wrong runtime pack is selected otherwise (without the new NFloat API, so nothing works at runtime). Ref: xamarin#13087
tj-devel709 · Mar 8, 2022 · 5add8c5 · 5add8c5
1 parent 4eb430f
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diff --git a/Make.config b/Make.config
@@ -565,6 +565,14 @@ DOTNET6_DIR=$(abspath $(TOP)/builds/downloads/$(basename $(basename $(DOTNET6_TA
 DOTNET6=$(DOTNET6_DIR)/dotnet
 DOTNET6_BCL_DIR:=$(abspath $(TOP)/builds/downloads/microsoft.netcore.app.ref/$(DOTNET6_BCL_VERSION)/ref/net6.0)
 
+# Use the System.Runtime.InteropServices.NFloat.Internal package to get the System.Runtime.InteropServices.dll reference assembly for
+# .NET 6. This is no longer needed for .NET 7, when we can switch back to the usual BCL reference assemblies.
+ifeq ($(DOTNET_TFM),net6.0)
+DOTNET_SYSTEM_RUNTIME_INTEROPSERVICES_REF_ASSEMBLY_DIR:=$(abspath $(TOP)/builds/downloads/system.runtime.interopservices.nfloat.internal/6.0.1/ref/net6.0)
+else
+DOTNET_SYSTEM_RUNTIME_INTEROPSERVICES_REF_ASSEMBLY_DIR:=$(DOTNET6_BCL_DIR)
+endif
+
 # The sdk version band has the last two digits set to 0: https://github.com/dotnet/sdk/blob/22c4860dcb2cf6b123dd641cc4a87a50380759d5/src/Resolvers/Microsoft.NET.Sdk.WorkloadManifestReader/SdkDirectoryWorkloadManifestProvider.cs#L52-L53
 DOTNET_MANIFEST_VERSION_BAND=$(shell echo $(DOTNET6_VERSION_BAND) | sed 's/..$$/00/')
 # We must do the same for our version band: the last two digits must be set to 0.

diff --git a/builds/package-download/download-packages.proj b/builds/package-download/download-packages.proj
@@ -19,6 +19,9 @@
     <!-- download the reference assemblies -->
     <PackageDownload Include="microsoft.netcore.app.ref" Version="[$(ActualPackageVersion)]" />
 
+    <!-- download the nfloat reference assembly for .NET 6 (but only for .NET 6, once we switch to .NET 7 this can be removed) -->
+    <PackageDownload Include="System.Runtime.InteropServices.NFloat.Internal" Version="[6.0.1]" Condition="'$(ActualPackageVersion.Substring(0,1))' == '6'" />
+
     <!-- and get the mono workload as well -->
     <PackageDownload Include="Microsoft.NET.Workload.Mono.ToolChain.Manifest-$(ToolChainManifestVersionBand)" Version="[$(ActualPackageVersion)]" />
 

diff --git a/dotnet/BreakingChanges.md b/dotnet/BreakingChanges.md
@@ -40,25 +40,37 @@ favor of the C# 9 `nint` and `nuint` types (these map to `System.IntPtr` and
 
 Reference: https://github.com/xamarin/xamarin-macios/issues/10508
 
-## System.nfloat moved to ObjCRuntime.nfloat
+## Removed `System.nfloat`
 
-The `nfloat` type moved from the `System` namespace to the `ObjCRuntime` namespace.
+The `System.nfloat` type has been removed in favor of the
+`System.Runtime.InteropServices.NFloat` type.
 
-* Code that references the `nfloat` type might not compile unless the `ObjCRuntime` namespace is imported.
+In order to make existing code compile as much as possible, we're adding a
+global using directive to C# projects, so that using `nfloat` as a type name
+continues to work:
 
-  Fix: add `using ObjCRuntime` to the file in question.
+```csharp
+global using nfloat = System.Runtime.InteropServices.NFloat;
+```
+
+If this global using directive is undesirable, it can be turned off by setting
+a `NoNFloatUsing=true` property in the project file.
 
-* Code that references the full typename, `System.nfloat` won't compile.
+There are a few other source code incompatibilities:
 
-  Fix: use `ObjCRuntime.nfloat` instead.
+* Any code that refers to the full typename (`System.nfloat`) will have to be
+  modified to just use `nfloat`, or the new full typename
+  (`System.Runtime.InteropServices.NFloat`).
+* The `nfloat.CopyArray` methods don't exist in `NFloat`. The code needs to be
+  rewritten to use `Buffer.CopyMemory` instead.
 
 ## System.NMath moved to ObjCRuntime.NMath
 
 The `NMath` type moved from the `System` namespace to the `ObjCRuntime` namespace.
 
 * Code that uses the `NMath` type won't compile unless the `ObjCRuntime` namespace is imported.
 
-  Fix: add `using ObjCRuntime` to the file in question.
+  Fix: add `using ObjCRuntime` to the file in question, or as a global using directive.
 
 ## NSObject.Handle and INativeObject.Handle changed type from System.IntPtr to ObjCRuntime.NativeHandle
 

diff --git a/dotnet/targets/Microsoft.MacCatalyst.Sdk.ImplicitNamespaceImports.props b/dotnet/targets/Microsoft.MacCatalyst.Sdk.ImplicitNamespaceImports.props
@@ -27,4 +27,14 @@
 		<Using Include="Foundation" Platform="MacCatalyst" />
 		<Using Include="UIKit" Platform="MacCatalyst" />
 	</ItemGroup>
+
+	<!--
+		Add a 'global using nfloat = System.Runtime.InteropServices.NFloat' to ease migration from Xamarin.
+		This is not grouped with the other usings, because those are not enabled by default (ImplicitUsings is empty by default, but set in our templates).
+		However, the main target for this using is upgraded projects, which won't have ImplicitUsings set to anything, so we
+		use a different condition (NoNFloatUsing) to disable if desired.
+	-->
+	<ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'MacCatalyst' And '$(Language)' == 'C#' And '$(NoNFloatUsing)' != 'true'">
+		<Using Include="System.Runtime.InteropServices.NFloat" Platform="MacCatalyst" Alias="nfloat" />
+	</ItemGroup>
 </Project>
diff --git a/dotnet/targets/Microsoft.iOS.Sdk.ImplicitNamespaceImports.props b/dotnet/targets/Microsoft.iOS.Sdk.ImplicitNamespaceImports.props
@@ -27,4 +27,14 @@
 		<Using Include="Foundation" Platform="iOS" />
 		<Using Include="UIKit" Platform="iOS" />
 	</ItemGroup>
+
+	<!--
+		Add a 'global using nfloat = System.Runtime.InteropServices.NFloat' to ease migration from Xamarin.
+		This is not grouped with the other usings, because those are not enabled by default (ImplicitUsings is empty by default, but set in our templates).
+		However, the main target for this using is upgraded projects, which won't have ImplicitUsings set to anything, so we
+		use a different condition (NoNFloatUsing) to disable if desired.
+	-->
+	<ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'iOS' And '$(Language)' == 'C#' And '$(NoNFloatUsing)' != 'true'">
+		<Using Include="System.Runtime.InteropServices.NFloat" Platform="iOS" Alias="nfloat" />
+	</ItemGroup>
 </Project>
diff --git a/dotnet/targets/Microsoft.macOS.Sdk.ImplicitNamespaceImports.props b/dotnet/targets/Microsoft.macOS.Sdk.ImplicitNamespaceImports.props
@@ -27,4 +27,14 @@
 		<Using Include="CoreGraphics" Platform="macOS" />
 		<Using Include="Foundation" Platform="macOS" />
 	</ItemGroup>
+
+	<!--
+		Add a 'global using nfloat = System.Runtime.InteropServices.NFloat' to ease migration from Xamarin.
+		This is not grouped with the other usings, because those are not enabled by default (ImplicitUsings is empty by default, but set in our templates).
+		However, the main target for this using is upgraded projects, which won't have ImplicitUsings set to anything, so we
+		use a different condition (NoNFloatUsing) to disable if desired.
+	-->
+	<ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'macOS' And '$(Language)' == 'C#' And '$(NoNFloatUsing)' != 'true'">
+		<Using Include="System.Runtime.InteropServices.NFloat" Platform="macOS" Alias="nfloat" />
+	</ItemGroup>
 </Project>
diff --git a/dotnet/targets/Microsoft.tvOS.Sdk.ImplicitNamespaceImports.props b/dotnet/targets/Microsoft.tvOS.Sdk.ImplicitNamespaceImports.props
@@ -27,4 +27,14 @@
 		<Using Include="Foundation" Platform="tvOS" />
 		<Using Include="UIKit" Platform="tvOS" />
 	</ItemGroup>
+
+	<!--
+		Add a 'global using nfloat = System.Runtime.InteropServices.NFloat' to ease migration from Xamarin.
+		This is not grouped with the other usings, because those are not enabled by default (ImplicitUsings is empty by default, but set in our templates).
+		However, the main target for this using is upgraded projects, which won't have ImplicitUsings set to anything, so we
+		use a different condition (NoNFloatUsing) to disable if desired.
+	-->
+	<ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'tvOS' And '$(Language)' == 'C#' And '$(NoNFloatUsing)' != 'true'">
+		<Using Include="System.Runtime.InteropServices.NFloat" Platform="tvOS" Alias="nfloat" />
+	</ItemGroup>
 </Project>
diff --git a/dotnet/targets/Xamarin.Shared.Sdk.DefaultItems.targets b/dotnet/targets/Xamarin.Shared.Sdk.DefaultItems.targets
@@ -109,4 +109,36 @@
     <FrameworkReference Include="Microsoft.$(_PlatformName)" IsImplicitlyDefined="true" Pack="false" PrivateAssets="All" />
   </ItemGroup>
 
+  <ItemGroup>
+    <!-- Add a reference to our custom nfloat reference assembly for .NET 6 (but only for .NET 6, once we switch to .NET 7 this can be removed) -->
+    <PackageReference Include="System.Runtime.InteropServices.NFloat.Internal" Condition="'$(BundledNETCorePlatformsPackageVersion.Substring(0,1))' == '6'" Version="[6.0.1, )" />
+  </ItemGroup>
+
+  <!--
+
+    This a workaround for an issue with the Microsoft.NETCore.App runtime pack
+    selection. The Microsoft.NETCore.App known framework reference sets
+    LatestRuntimeFrameworkVersion=6.0.1, which means that when a project is
+    restored, the 6.0.1 packages (from NuGet) will be selected instead of the
+    bundled packages (which has version 6.0.3). The problem with this is that
+    the 6.0.1 packages don't have the new nfloat API. So we try to override
+    the LatestRuntimeFrameworkVersion=6.0.1 value on the
+    KnownFrameworkReference by explicitly setting the RuntimeFrameworkVersion
+    value on the FrameworkReference when LatestRuntimeFrameworkVersion<6.0.3.
+
+    Ref: https://github.com/dotnet/sdk/blob/31d4db7dc94bb2f1f4d0ef84ebf158d61f2a7c4f/src/Tasks/Microsoft.NET.Build.Tasks/ProcessFrameworkReferences.cs#L587-L594
+  -->
+  <ItemGroup Condition="'$(_PlatformName)' == 'macOS'">
+    <FrameworkReference
+        Update="Microsoft.NETCore.App"
+        Condition="
+        (
+          @(KnownFrameworkReference->AnyHaveMetadataValue('LatestRuntimeFrameworkVersion', '6.0.1')) Or
+          @(KnownFrameworkReference->AnyHaveMetadataValue('LatestRuntimeFrameworkVersion', '6.0.2'))
+        )
+        "
+        >
+      <RuntimeFrameworkVersion>6.0.3</RuntimeFrameworkVersion>
+    </FrameworkReference>
+  </ItemGroup>
 </Project>
diff --git a/dotnet/targets/Xamarin.Shared.Sdk.targets b/dotnet/targets/Xamarin.Shared.Sdk.targets
@@ -1030,6 +1030,11 @@
 			<_GeneratorAttributeAssembly>$(_XamarinSdkRootDirectory)/tools/lib/Xamarin.Apple.BindingAttributes.dll</_GeneratorAttributeAssembly>
 			<_DotNetCscCompiler>$(RoslynTargetsPath)/bincore/csc.dll</_DotNetCscCompiler>
 		</PropertyGroup>
+
+		<ItemGroup>
+			<_BTouchCompileCommand Include="$(DOTNET_HOST_PATH)" />
+			<_BTouchCompileCommand Include="$(RoslynTargetsPath)/bincore/csc.dll" />
+		</ItemGroup>
 	</Target>
 
 	<Target Name="_ComputeNativeExecutableInputs" DependsOnTargets="_ComputeVariables">

diff --git a/msbuild/Xamarin.MacDev.Tasks.Core/Tasks/BTouchTaskBase.cs b/msbuild/Xamarin.MacDev.Tasks.Core/Tasks/BTouchTaskBase.cs
@@ -55,6 +55,8 @@ public abstract class BTouchTaskBase : XamarinToolTask {
 
 		public string Namespace { get; set; }
 
+		public bool NoNFloatUsing { get; set; }
+
 		public ITaskItem[] NativeLibraries { get; set; }
 
 		public string OutputAssembly { get; set; }
@@ -156,6 +158,9 @@ protected override string GenerateCommandLineCommands ()
 
 			cmd.AddQuotedSwitchIfNotNull ("/ns:", Namespace);
 
+			if (NoNFloatUsing)
+				cmd.Add ("/no-nfloat-using:true");
+
 			if (!string.IsNullOrEmpty (DefineConstants)) {
 				var strv = DefineConstants.Split (new [] { ';' }, StringSplitOptions.RemoveEmptyEntries);
 				foreach (var str in strv)

diff --git a/msbuild/Xamarin.Shared/Xamarin.Shared.targets b/msbuild/Xamarin.Shared/Xamarin.Shared.targets
@@ -1584,6 +1584,7 @@ Copyright (C) 2018 Microsoft. All rights reserved.
 			GeneratedSourcesDir="$(GeneratedSourcesDir)"
 			GeneratedSourcesFileList="$(_GeneratedSourcesFileList)"
 			Namespace="$(Namespace)"
+			NoNFloatUsing="$(NoNFloatUsing)"
 			OutputAssembly="$(OutputAssembly)"
 			ProcessEnums="$(ProcessEnums)"
 			ProjectDir="$(MSBuildProjectDirectory)"

diff --git a/runtime/trampolines.m b/runtime/trampolines.m
@@ -1522,7 +1522,7 @@
 #endif
 		func = to_managed ? (void *) xamarin_nsnumber_to_nuint : (void *) xamarin_nuint_to_nsnumber;
 #if DOTNET
-	} else if (!strcmp (fullname, "ObjCRuntime.nfloat")) {
+	} else if (!strcmp (fullname, "System.Runtime.InteropServices.NFloat")) {
 #else
 	} else if (!strcmp (fullname, "System.nfloat")) {
 #endif

diff --git a/src/Makefile b/src/Makefile
@@ -52,7 +52,7 @@ DOTNET_REFERENCES = \
 	/r:$(DOTNET6_BCL_DIR)/System.Runtime.dll \
 	/r:$(DOTNET6_BCL_DIR)/System.Runtime.CompilerServices.Unsafe.dll \
 	/r:$(DOTNET6_BCL_DIR)/System.Runtime.Extensions.dll \
-	/r:$(DOTNET6_BCL_DIR)/System.Runtime.InteropServices.dll \
+	/r:$(DOTNET_SYSTEM_RUNTIME_INTEROPSERVICES_REF_ASSEMBLY_DIR)/System.Runtime.InteropServices.dll \
 	/r:$(DOTNET6_BCL_DIR)/System.Security.Cryptography.X509Certificates.dll \
 	/r:$(DOTNET6_BCL_DIR)/System.Text.RegularExpressions.dll \
 	/r:$(DOTNET6_BCL_DIR)/System.Threading.dll \

diff --git a/src/NativeTypes/Primitives.tt b/src/NativeTypes/Primitives.tt
@@ -32,10 +32,7 @@
 <#@ import namespace="System" #>
 <#@ import namespace="System.Collections.Generic" #>
 
-#if NET
-#define SKIP_nint
-#define SKIP_nuint
-#endif
+#if !NET
 
 using System;
 using System.ComponentModel;
@@ -454,3 +451,5 @@ namespace System
 #endif // !SKIP_<#= type.NSName #>
 }
 <# } #>
+
+#endif // !NET
diff --git a/src/ObjCRuntime/NFloat.cs b/src/ObjCRuntime/NFloat.cs
@@ -0,0 +1,7 @@
+#if NET
+
+#if !(MTOUCH || MMP || BUNDLER)
+global using nfloat = System.Runtime.InteropServices.NFloat;
+#endif
+
+#endif // NET
diff --git a/src/ObjCRuntime/Registrar.cs b/src/ObjCRuntime/Registrar.cs
@@ -89,9 +89,9 @@ abstract partial class Registrar {
 #endif
 
 #if MMP || MTOUCH || BUNDLER
-		static string NFloatTypeName { get => Driver.IsDotNet ? "ObjCRuntime.nfloat" : "System.nfloat"; }
+		static string NFloatTypeName { get => Driver.IsDotNet ? "System.Runtime.InteropServices.NFloat" : "System.nfloat"; }
 #elif NET
-		const string NFloatTypeName = "ObjCRuntime.nfloat";
+		const string NFloatTypeName = "System.Runtime.InteropServices.NFloat";
 #else
 		const string NFloatTypeName = "System.nfloat";
 #endif

diff --git a/src/ObjCRuntime/Stret.cs b/src/ObjCRuntime/Stret.cs
@@ -229,12 +229,18 @@ static bool IsBuiltInType (Type type, bool is_64_bits, out int type_size)
 #if NET
 			if (type.Namespace == "ObjCRuntime") {
 				switch (type.Name) {
-				case "nfloat":
 				case "NativeHandle":
 					type_size = is_64_bits ? 8 : 4;
 					return true;
 				}
 				return false;
+			} else if (type.Namespace == "System.Runtime.InteropServices") {
+				switch (type.Name) {
+				case "NFloat":
+					type_size = is_64_bits ? 8 : 4;
+					return true;
+				}
+				return false;
 			}
 #endif
 

diff --git a/src/README.md b/src/README.md
@@ -106,8 +106,9 @@ We have introduced 6 new types to make this possible:
 | `CGRect`      | `System.Drawing.RectangleF` | `CoreGraphics.CGRect`    |
 
 In the Classic assembly, the `System.Drawing` types are backed by the 32-bit
-`System.Single` type. In the Unified assemblies, the `CoreGraphics` types
-are backed by 32/64-bit `System.nfloat` type (`ObjCRuntime.nfloat` in .NET).
+`System.Single` type. In the Unified assemblies, the `CoreGraphics` types are
+backed by 32/64-bit `System.nfloat` type
+(`System.Runtime.InteropServices.NFloat` in .NET).
 
 #### Enums ####
 

diff --git a/src/SceneKit/SCNMatrix4_dotnet.cs b/src/SceneKit/SCNMatrix4_dotnet.cs
@@ -45,7 +45,7 @@ OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 #if PFLOAT_SINGLE
 using pfloat = System.Single;
 #else
-using pfloat = ObjCRuntime.nfloat;
+using pfloat = System.Runtime.InteropServices.NFloat;
 #endif
 
 #nullable enable

diff --git a/src/SceneKit/SCNQuaternion.cs b/src/SceneKit/SCNQuaternion.cs
@@ -39,7 +39,7 @@ OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 
 #if MONOMAC
 #if NET
-using pfloat = ObjCRuntime.nfloat;
+using pfloat = System.Runtime.InteropServices.NFloat;
 #else
 using pfloat = System.nfloat;
 #endif

diff --git a/src/SceneKit/SCNVector3.cs b/src/SceneKit/SCNVector3.cs
@@ -42,7 +42,7 @@ OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 
 #if MONOMAC
 #if NET
-using pfloat = ObjCRuntime.nfloat;
+using pfloat = System.Runtime.InteropServices.NFloat;
 #else
 using pfloat = System.nfloat;
 #endif

diff --git a/src/SceneKit/SCNVector4.cs b/src/SceneKit/SCNVector4.cs
@@ -43,7 +43,7 @@ OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 
 #if MONOMAC
 #if NET
-using pfloat = ObjCRuntime.nfloat;
+using pfloat = System.Runtime.InteropServices.NFloat;
 #else
 using pfloat = System.nfloat;
 #endif

diff --git a/src/btouch.cs b/src/btouch.cs
@@ -229,6 +229,7 @@ int Main3 (string [] args)
 		var defines = new List<string> ();
 		string? generate_file_list = null;
 		bool process_enums = false;
+		bool noNFloatUsing = false;
 
 		ErrorHelper.ClearWarningLevels ();
 
@@ -316,6 +317,10 @@ int Main3 (string [] args)
 					}
 				}
 			},
+			{ "no-nfloat-using:", "If a global using alias directive for 'nfloat = System.Runtime.InteropServices.NFloat' should automatically be created.", (v) => {
+					noNFloatUsing = string.Equals ("true", v, StringComparison.OrdinalIgnoreCase) || string.IsNullOrEmpty (v);
+				}
+			},
 			new Mono.Options.ResponseFileSource (),
 		};
 
@@ -466,6 +471,14 @@ int Main3 (string [] args)
 			if (!string.IsNullOrEmpty (Path.GetDirectoryName (baselibdll)))
 				cargs.Add ("-lib:" + Path.GetDirectoryName (baselibdll));
 
+#if NET
+			var tmpusing = Path.Combine (tmpdir, "GlobalUsings.g.cs");
+			if (!noNFloatUsing) {
+				File.WriteAllText (tmpusing, "global using nfloat = global::System.Runtime.InteropServices.NFloat;\n");
+				cargs.Add (tmpusing);
+			}
+#endif
+
 			Compile (cargs, 2);
 
 			universe = new MetadataLoadContext (
@@ -592,6 +605,11 @@ int Main3 (string [] args)
 			if (!string.IsNullOrEmpty (Path.GetDirectoryName (baselibdll)))
 				cargs.Add ("-lib:" + Path.GetDirectoryName (baselibdll));
 
+#if NET
+			if (!noNFloatUsing)
+				cargs.Add (tmpusing);
+#endif
+
 			Compile (cargs, 1000);
 		} finally {
 			if (delete_temp)

diff --git a/src/frameworks.sources b/src/frameworks.sources
@@ -1859,6 +1859,7 @@ SHARED_CORE_SOURCES = \
 	ObjCRuntime/LinkWithAttribute.cs \
 	ObjCRuntime/NativeAttribute.cs \
 	ObjCRuntime/NativeHandle.cs \
+	ObjCRuntime/NFloat.cs \
 	ObjCRuntime/ObsoleteConstants.cs \
 	ObjCRuntime/PlatformAvailability.cs \
 	ObjCRuntime/PlatformAvailability2.cs \

diff --git a/src/generator-typemanager.cs b/src/generator-typemanager.cs
@@ -194,7 +194,8 @@ public void Initialize (BindingTouch binding_touch, Assembly api, Assembly corli
 #if NET
 		System_nint = Lookup (corlib_assembly, "System", "IntPtr");
 		System_nuint = Lookup (corlib_assembly, "System", "UIntPtr");
-		System_nfloat = Lookup (platform_assembly, "ObjCRuntime", "nfloat");
+		var interop_assembly = binding_touch.universe.LoadFromAssemblyName ("System.Runtime.InteropServices");
+		System_nfloat = Lookup (interop_assembly, "System.Runtime.InteropServices", "NFloat");
 #else
 		System_nint = Lookup (platform_assembly, "System", "nint");
 		System_nuint = Lookup (platform_assembly, "System", "nuint");