ARM64_32 Debug Mode (#7012)

* [builds] add arm64_32 cross compiler

* [mtouch] force --interpreter on arm64_32 debug mode build

* [mtouch] include debug check for arm64_32 and reflect error codes in documentation

builds/Makefile

@@ -958,6 +958,7 @@ install-local:: install-cross
 $(MONO_IOS_SDK_DESTDIR)/ios-cross32-release/bin/arm-darwin-mono-sgen: .stamp-$(MONO_BUILD_MODE)
 $(MONO_IOS_SDK_DESTDIR)/ios-cross64-release/bin/aarch64-darwin-mono-sgen: .stamp-$(MONO_BUILD_MODE)
 $(MONO_IOS_SDK_DESTDIR)/ios-crosswatch-release/bin/armv7k-unknown-darwin-mono-sgen: .stamp-$(MONO_BUILD_MODE)
+$(MONO_IOS_SDK_DESTDIR)/ios-crosswatch-release/bin/aarch64-apple-darwin10_ilp32-mono-sgen: .stamp-$(MONO_BUILD_MODE)
 
 $(PREFIX)/bin/arm-darwin-mono-sgen: $(MONO_IOS_SDK_DESTDIR)/ios-cross32-release/bin/arm-darwin-mono-sgen | $(PREFIX)/bin
 	$(call Q_2,INSTALL ,[CROSS]) install -c -m 0755 $(INSTALL_STRIP_FLAG) $^ $@
@@ -968,11 +969,14 @@ $(PREFIX)/bin/arm64-darwin-mono-sgen: $(MONO_IOS_SDK_DESTDIR)/ios-cross64-releas
 $(PREFIX)/bin/armv7k-unknown-darwin-mono-sgen: $(MONO_IOS_SDK_DESTDIR)/ios-crosswatch-release/bin/armv7k-unknown-darwin-mono-sgen | $(PREFIX)/bin
 	$(call Q_2,INSTALL ,[CROSS]) install -c -m 0755 $(INSTALL_STRIP_FLAG) $^ $@
 
+$(PREFIX)/bin/arm64_32-darwin-mono-sgen: $(MONO_IOS_SDK_DESTDIR)/ios-crosswatch64_32-release/bin/aarch64-apple-darwin10_ilp32-mono-sgen | $(PREFIX)/bin
+	$(call Q_2,INSTALL ,[CROSS]) install -c -m 0755 $(INSTALL_STRIP_FLAG) $^ $@
+
 $(PREFIX)/bin:
 	$(Q) mkdir -p $@
 
 .PHONY: install-cross
-install-cross: $(PREFIX)/bin/arm-darwin-mono-sgen $(PREFIX)/bin/arm64-darwin-mono-sgen $(PREFIX)/bin/armv7k-unknown-darwin-mono-sgen
+install-cross: $(PREFIX)/bin/arm-darwin-mono-sgen $(PREFIX)/bin/arm64-darwin-mono-sgen $(PREFIX)/bin/armv7k-unknown-darwin-mono-sgen $(PREFIX)/bin/arm64_32-darwin-mono-sgen
 
 #
 # LLVM

docs/website/mtouch-errors.md

@@ -966,6 +966,18 @@ This warning is shown if the assemblies names given to the `--interpreter` optio
 
 <!-- 0143-0144: used by mmp -->
 
+<a name="MT0145" />
+
+### MT0145: Please use device builds on WatchOS.
+
+This error occurs if you use combined device builds for a Watch extension project. Per device builds are default in new projects.
+
+<a name="MT0146" />
+
+### MT0146: ARM64_32 Debug mode requires --interpreter[=all], forcing it.
+
+This warning is shown when `--interpreter` isn't specified explicitly for ARM64_32 Debug builds. The AOT compiler can't be used because it doesn't support ARM64_32.
+
 # MT1xxx: Project related error messages
 
 ### MT10xx: Installer / mtouch

tools/mtouch/Assembly.cs

@@ -281,7 +281,7 @@ public void CreateAOTTask (Abi abi)
 				aotInfo.AsmFiles.Add (asm_output);
 			aotInfo.AotDataFiles.Add (data);
 
-			var aotCompiler = Driver.GetAotCompiler (App, Target.Is64Build);
+			var aotCompiler = Driver.GetAotCompiler (App, abi, Target.Is64Build);
 			var aotArgs = Driver.GetAotArguments (App, assembly_path, abi, build_dir, asm_output ?? other_output, llvm_aot_ofile, data);
 			var task = new AOTTask
 			{

tools/mtouch/BuildTasks.mtouch.cs

@@ -218,7 +218,8 @@ public override IEnumerable<string> FileDependencies {
 					if (Assembly.HasDependencyMap)
 						inputs.AddRange (Assembly.DependencyMap);
 					inputs.Add (AssemblyName);
-					inputs.Add (Driver.GetAotCompiler (Assembly.App, Assembly.Target.Is64Build));
+					foreach (var abi in Assembly.Target.Abis)
+						inputs.Add (Driver.GetAotCompiler (Assembly.App, abi, Assembly.Target.Is64Build));
 					var mdb = Assembly.FullPath + ".mdb";
 					if (File.Exists (mdb))
 						inputs.Add (mdb);

tools/mtouch/mtouch.cs

@@ -362,7 +362,7 @@ public static int XcodeRun (string command, string args, StringBuilder output =
 			return ret;
 		}
 
-		public static string GetAotCompiler (Application app, bool is64bits)
+		public static string GetAotCompiler (Application app, Abi abi, bool is64bits)
 		{
 			switch (app.Platform) {
 			case ApplePlatform.iOS:
@@ -372,7 +372,12 @@ public static string GetAotCompiler (Application app, bool is64bits)
 					return Path.Combine (cross_prefix, "bin", "arm-darwin-mono-sgen");
 				}
 			case ApplePlatform.WatchOS:
-				return Path.Combine (cross_prefix, "bin", "armv7k-unknown-darwin-mono-sgen");
+				/* Use arm64_32 cross only for Debug mode */
+				if (abi == Abi.ARM64_32 && !app.EnableLLVMOnlyBitCode) {
+					return Path.Combine (cross_prefix, "bin", "arm64_32-darwin-mono-sgen");
+				} else {
+					return Path.Combine (cross_prefix, "bin", "armv7k-unknown-darwin-mono-sgen");
+				}
 			case ApplePlatform.TVOS:
 				return Path.Combine (cross_prefix, "bin", "arm64-darwin-mono-sgen");
 			default:
@@ -1339,14 +1344,24 @@ static int Main2 (string[] args)
 					app.UseInterpreter = false;
 				}
 
-				// FIXME: the interpreter only supports ARM64 right now
+				// FIXME: the interpreter only supports ARM64{,_32} right now
 				// temporary - without a check here the error happens when deploying
-				if (!app.IsSimulatorBuild && !app.IsArchEnabled (Abi.ARM64))
+				if (!app.IsSimulatorBuild && (!app.IsArchEnabled (Abi.ARM64) && !app.IsArchEnabled (Abi.ARM64_32)))
 					throw ErrorHelper.CreateError (99, "Internal error: The interpreter is currently only available for 64 bits.");
 
 				// needs to be set after the argument validations
 				// interpreter can use some extra code (e.g. SRE) that is not shipped in the default (AOT) profile
 				app.EnableRepl = true;
+			} else {
+				if (app.Platform == ApplePlatform.WatchOS && app.IsArchEnabled (Abi.ARM64_32) && app.BitCodeMode != BitCodeMode.LLVMOnly) {
+					if (app.IsArchEnabled (Abi.ARMv7k)) {
+						throw ErrorHelper.CreateError (145, "Please use device builds on WatchOS.");
+					} else {
+						ErrorHelper.Warning (146, "ARM64_32 Debug mode requires --interpreter[=all], forcing it.");
+						app.UseInterpreter = true;
+						app.InterpretedAssemblies.Clear ();
+					}
+				}
 			}
 
 			if (cross_prefix == null)