[generator] Explicitly load NSNumber from the api assembly for core builds. (#1676)

* [generator] Explicitly load NSNumber from the api assembly for core builds.

This fixes an issue where we'd run into a type comparison failure otherwise,
when using the `BindAs` attribute in the api definition for our platform
assemblies, because we end up with NSNumber loaded from two different
assemblies:

Foundation.NSNumber, **temp**, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null

Foundation.NSNumber, **core**, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null

* [generator] Explicitly load NSValue too from the api assembly for core builds.

src/btouch.cs

@@ -100,6 +100,8 @@ class BindingTouch {
 #endif
 	static char shellQuoteChar;
 
+	public static bool BindingThirdParty = true;
+
 	public static string ToolName {
 		get { return tool_name; }
 	}
@@ -155,6 +157,20 @@ class BindingTouch {
 			throw ErrorHelper.CreateError (70, "Invalid target framework: {0}. Valid target frameworks are: {1}.", target_framework.Value, string.Join (" ", TargetFramework.ValidFrameworks.Select ((v) => v.ToString ()).ToArray ()));
 	}
 
+	public static string NamespacePlatformPrefix {
+		get {
+			switch (CurrentPlatform) {
+			case PlatformName.MacOSX:
+				return Unified ? null : "MonoMac";
+			case PlatformName.iOS:
+				return Unified ? null : "MonoTouch";
+			default:
+				return null;
+			}
+
+		}
+	}
+
 	static int Main2 (string [] args)
 	{
 		bool show_help = false;
@@ -179,7 +195,6 @@ class BindingTouch {
 		var core_sources = new List<string> ();
 		var extra_sources = new List<string> ();
 		var defines = new List<string> ();
-		bool binding_third_party = true;
 		string generate_file_list = null;
 		bool process_enums = false;
 
@@ -200,7 +215,7 @@ class BindingTouch {
 			{ "sourceonly=", "Only generates the source", v => generate_file_list = v },
 			{ "ns=", "Sets the namespace for storing helper classes", v => ns = v },
 			{ "unsafe", "Sets the unsafe flag for the build", v=> unsafef = true },
-			{ "core", "Use this to build product assemblies", v => binding_third_party = false },
+			{ "core", "Use this to build product assemblies", v => BindingThirdParty = false },
 			{ "r=", "Adds a reference", v => references.Add (v) },
 			{ "lib=", "Adds the directory to the search path for the compiler", v => libs.Add (Quote (v)) },
 			{ "compiler=", "Sets the compiler to use", v => compiler = v },
@@ -357,6 +372,8 @@ class BindingTouch {
 			}
 			GC.KeepAlive (baselib); // Fixes a compiler warning (unused variable).
 				
+			TypeManager.Initialize (api);
+
 			foreach (object attr in AttributeManager.GetCustomAttributes (api, TypeManager.LinkWithAttribute, true)) {
 				LinkWithAttribute linkWith = (LinkWithAttribute) attr;
 				
@@ -389,19 +406,6 @@ class BindingTouch {
 					strong_dictionaries.Add (t);
 			}
 
-			string nsManagerPrefix;
-			switch (CurrentPlatform) {
-			case PlatformName.MacOSX:
-				nsManagerPrefix = Unified ? null : "MonoMac";
-				break;
-			case PlatformName.iOS:
-				nsManagerPrefix = Unified ? null : "MonoTouch";
-				break;
-			default:
-				nsManagerPrefix = null;
-				break;
-			}
-
 			if (CurrentPlatform == PlatformName.MacOSX && Unified) {
 				if (!target_framework.HasValue)
 					throw ErrorHelper.CreateError (86, "A target framework (--target-framework) must be specified when building for Xamarin.Mac.");
@@ -409,20 +413,20 @@ class BindingTouch {
 			}
 
 			var nsManager = new NamespaceManager (
-				nsManagerPrefix,
+				NamespacePlatformPrefix,
 				ns == null ? firstApiDefinitionName : ns,
 				skipSystemDrawing
 			);
 
 			var g = new Generator (nsManager, public_mode, external, debug, types.ToArray (), strong_dictionaries.ToArray ()){
-				BindThirdPartyLibrary = binding_third_party,
+				BindThirdPartyLibrary = BindingThirdParty,
 				CoreNSObject = CoreObject,
 				BaseDir = basedir != null ? basedir : tmpdir,
 				ZeroCopyStrings = zero_copy,
 				InlineSelectors = inline_selectors,
 			};
 
-			if (!Unified && !binding_third_party) {
+			if (!Unified && !BindingThirdParty) {
 				foreach (var mi in baselib.GetType (nsManager.CoreObjCRuntime + ".Messaging").GetMethods ()){
 					if (mi.Name.IndexOf ("_objc_msgSend") != -1)
 						g.RegisterMethodName (mi.Name);

src/error.cs

@@ -72,6 +72,7 @@ using ProductException=BindingException;
 //		BI1049 Could not unbox type {0} from {1} container used on {2} member decorated with [BindAs].
 //		BI1050 [BindAs] cannot be used inside Protocol or Model types. Type: {0}
 //		BI1051 Internal error: Don't know how to get attributes for {0}. Please file a bug report (http://bugzilla.xamarin.com) with a test case.
+//		BI1052 Internal error: Could not find the type {0} in the assembly {1}. Please file a bug report (http://bugzilla.xamarin.com) with a test case.
 //	BI11xx	warnings
 //		BI1101 Trying to use a string as a [Target]
 //		BI1102 Using the deprecated EventArgs for a delegate signature in {0}.{1}, please use DelegateName instead

src/generator-typemanager.cs

@@ -60,6 +60,7 @@
 using System;
 using System.ComponentModel;
 using System.Diagnostics;
+using System.Reflection;
 using System.Runtime.InteropServices;
 
 using XamCore.CoreFoundation;
@@ -286,8 +287,33 @@ public static class TypeManager {
 	public static Type CoreGraphics_CGRect;
 	public static Type CoreGraphics_CGSize;
 
-	static TypeManager ()
+	static Assembly api_assembly;
+	static Assembly platform_assembly;
+
+	static Type Lookup (Assembly assembly, string @namespace, string @typename)
 	{
+		string fullname;
+		string nsManagerPrefix = BindingTouch.NamespacePlatformPrefix;
+		if (!string.IsNullOrEmpty (nsManagerPrefix))
+			nsManagerPrefix += ".";
+
+		if (string.IsNullOrEmpty (@namespace)) {
+			fullname = nsManagerPrefix + @typename;
+		} else {
+			fullname = nsManagerPrefix + @namespace + "." + @typename;
+		}
+
+		var rv = assembly.GetType (fullname);
+		if (rv == null)
+			throw new BindingException (1052, true, "Internal error: Could not find the type {0} in the assembly {1}. Please file a bug report (http://bugzilla.xamarin.com) with a test case.", fullname, assembly);
+		return rv;
+	}
+
+	public static void Initialize (Assembly api)
+	{
+		api_assembly = api;
+		platform_assembly = typeof (NSObject).Assembly;
+
 		/* corlib */
 		System_Attribute = typeof (System.Attribute);
 		System_Boolean = typeof (bool);
@@ -474,10 +500,10 @@ public static class TypeManager {
 	#if HAVE_AUDIOTOOLBOX_MUSICSEQUENCE
 		MusicSequence = typeof (MusicSequence);
 	#endif
-		NSNumber = typeof (NSNumber);
+		NSNumber = Lookup (BindingTouch.BindingThirdParty ? platform_assembly : api_assembly, "Foundation", "NSNumber");
 		NSRange = typeof (NSRange);
 		NSString = typeof (NSString);
-		NSValue = typeof (NSValue);
+		NSValue = Lookup (BindingTouch.BindingThirdParty ? platform_assembly : api_assembly, "Foundation", "NSValue");
 		NSZone = typeof (NSZone);
 		SCNMatrix4 = typeof (SCNMatrix4);
 		SCNVector3 = typeof (SCNVector3);