Extend "auto tailcall" functionality similar to explicit tail.call.

configure.ac

@@ -40,7 +40,7 @@ MONO_VERSION_BUILD=`echo $VERSION | cut -d . -f 3`
 # This can be reset to 0 when Mono's version number is bumped
 # since it's part of the corlib version (the prefix '1' in the full
 # version number is to ensure the number isn't treated as octal in C)
-MONO_CORLIB_COUNTER=25
+MONO_CORLIB_COUNTER=31
 MONO_CORLIB_VERSION=`printf "1%02d%02d%02d%03d" $MONO_VERSION_MAJOR $MONO_VERSION_MINOR 0 $MONO_CORLIB_COUNTER`
 
 AC_DEFINE_UNQUOTED(MONO_CORLIB_VERSION,$MONO_CORLIB_VERSION,[Version of the corlib-runtime interface])

mcs/class/Mono.Debugger.Soft/Makefile

@@ -1,6 +1,14 @@
 thisdir = class/Mono.Debugger.Soft
 include ../../build/rules.make
 
+# FIXME Turn off tailcall optimizations for debugger tests.
+# Most of the tailcalls can be manually eliminated, however
+# there are two tests that check for a precise stack within the BCL,
+# and either we'd have to remove those tailcalls, or turn off tailcall like here,
+# or maybe split up the debugger tests into tailcall and non-tailcall versions,
+# where non-tailcall is quite small.
+TEST_RUNTIME_FLAGS += --optimize=-tailc
+
 LIBRARY = Mono.Debugger.Soft.dll
 LIBRARY_SNK = ../mono.snk
 

mcs/class/Mono.Debugger.Soft/Test/dtest-app.cs

@@ -1496,13 +1496,17 @@ internal static Delegate create_filter_delegate (Delegate dlg, MethodInfo filter
 
 		ig.Emit (OpCodes.Ldstr, "FOO");
 		ig.Emit (OpCodes.Call, typeof (Tests).GetMethod ("dyn_call"));
+		ig.Emit (OpCodes.Call, typeof (Tests).GetMethod ("NoTailcall"));
 		ig.Emit (OpCodes.Ret);
 
 		var del = (Action<int>)m.CreateDelegate (typeof (Action<int>));
 
 		del (0);
 	}
 
+	[MethodImplAttribute (MethodImplOptions.NoInlining)]
+	public static void NoTailcall () { }
+
 	public static void dyn_call (string s) {
 	}
 
@@ -1522,6 +1526,7 @@ internal static Delegate create_filter_delegate (Delegate dlg, MethodInfo filter
 		ILGenerator ig = mb.GetILGenerator ();
 		ig.Emit (OpCodes.Ldstr, "FOO");
 		ig.Emit (OpCodes.Call, typeof (Tests).GetMethod ("ref_emit_call"));
+		ig.Emit (OpCodes.Call, typeof (Tests).GetMethod ("NoTailcall"));
 		ig.Emit (OpCodes.Ret);
 
 		Type t = tb.CreateType ();

mcs/class/Mono.Debugger.Soft/Test/dtest-excfilter.il

@@ -12,8 +12,8 @@
 	{
 		.entrypoint
 		call void class ExceptionFilterTest::Test ()
-		ret
-	}
+		call void class ExceptionFilterTest::NoTailcall ()
+		ret }
 
 	.method public static int32 Filter ([mscorlib]System.Exception exc) cil managed noinlining
 	{
@@ -46,4 +46,10 @@
 	end:
 		ret
 	}
+
+	.method static void NoTailcall () noinlining
+	{
+		ret
+	}
+
 }

mcs/class/Mono.Debugger.Soft/Test/dtest.cs

@@ -3748,6 +3748,7 @@ Event step_out_await (string method, Event e)
 		// FIXME: This is racy
 		vm.Resume ();
 
+		// FIXME This test does not allow for tailcall optimization in Sleep.
 		Thread.Sleep (100);
 
 		vm.Suspend ();
@@ -4252,6 +4253,8 @@ Event step_out_await (string method, Event e)
 		vm.Suspend ();
 		Assert.AreEqual (ThreadState.WaitSleepJoin, thread.ThreadState, "#6");
 
+		// FIXME This test is deeply tied to BCL internals.
+		// FIXME This test does not allow for tailcall optimizations therein.
 		frames = thread.GetFrames ();
 		Assert.AreEqual (8, frames.Length, "#7");
 		Assert.AreEqual ("Wait_internal", frames [0].Method.Name, "#8.0");

mcs/class/Mono.Profiler.Log/Test/ProfilerTestRun.cs

@@ -58,7 +58,8 @@ void RunTest ()
 				proc.StartInfo = new ProcessStartInfo {
 					UseShellExecute = false,
 					FileName = Path.GetFullPath (Path.Combine ("..", "..", "..", "runtime", "mono-wrapper")),
-					Arguments = $"--debug --profile=log:nodefaults,output={_output},{Options} log-profiler-test.exe {Name}",
+					// FIXME profiler test is broken by tailcall optimization
+					Arguments = $"--optimize=-tailc --debug --profile=log:nodefaults,output={_output},{Options} log-profiler-test.exe {Name}",
 				};
 
 				proc.Start ();

mcs/class/System.Runtime.Serialization/Test/System.Runtime.Serialization/DataContractResolverTest.cs

@@ -44,6 +44,7 @@
 using System.Xml.Schema;
 using System.Xml.Serialization;
 using NUnit.Framework;
+using System.Runtime.CompilerServices;
 
 namespace MonoTests.System.Runtime.Serialization
 {
@@ -75,6 +76,9 @@ public void UseCase1 ()
 
 	public class MyResolver : DataContractResolver
 	{
+		[MethodImplAttribute (MethodImplOptions.NoInlining)]
+		static void NoTailcall () { }
+
 		public override bool TryResolveType (Type type, Type declaredType, DataContractResolver knownTypeResolver, out XmlDictionaryString typeName, out XmlDictionaryString typeNamespace)
 		{
 			//Console.WriteLine ("TryResolveType: {0} {1}", type, declaredType);
@@ -96,7 +100,9 @@ bool SafeResolveType (Type type, out XmlDictionaryString name, out XmlDictionary
 		public override Type ResolveName (string typeName, string typeNamespace, Type declaredType, DataContractResolver knownTypeResolver)
 		{
 			//Console.WriteLine ("ResolveName: {0} {1} {2}", typeName, typeNamespace, declaredType);
-			return knownTypeResolver.ResolveName (typeName, typeNamespace, declaredType, null) ?? RecoveringResolveName (typeName, typeNamespace);
+			var a = knownTypeResolver.ResolveName (typeName, typeNamespace, declaredType, null) ?? RecoveringResolveName (typeName, typeNamespace);
+			NoTailcall ();
+			return a;
 		}
 
 		Type RecoveringResolveName (string typeName, string typeNamespace)

mcs/class/System.Web.Extensions/Test/System.Web.UI.WebControls/DataPagerFieldCollectionTest.cs

@@ -33,6 +33,7 @@
 using System.Reflection;
 using System.Web.UI;
 using System.Web.UI.WebControls;
+using System.Runtime.CompilerServices;
 
 using NUnit.Framework;
 
@@ -42,12 +43,16 @@ class DataPagerFieldCollectionPoker : DataPagerFieldCollection
 	{
 		EventRecorder recorder;
 
+		[MethodImplAttribute (MethodImplOptions.NoInlining)]
+		static void NoTailcall () { }
+
 		void RecordEvent (string suffix)
 		{
 			if (recorder == null)
 				return;
 
 			recorder.Record (suffix);
+			NoTailcall ();
 		}
 
 		public DataPagerFieldCollectionPoker ()
@@ -79,6 +84,7 @@ public object DoCreateKnownType (int index)
 		public void DoOnValidate (object value)
 		{
 			OnValidate (value);
+			NoTailcall ();
 		}
 
 		public void CatchFieldsChangedEvent ()
@@ -91,33 +97,38 @@ protected override void OnValidate (object o)
 			RecordEvent ("Enter");
 			base.OnValidate (o);
 			RecordEvent ("Leave");
+			NoTailcall ();
 		}
 
 		protected override void OnClearComplete ()
 		{
 			RecordEvent ("Enter");
 			base.OnClearComplete ();
 			RecordEvent ("Leave");
+			NoTailcall ();
 		}
 
 		protected override void OnInsertComplete (int index, object value)
 		{
 			RecordEvent ("Enter");
 			base.OnInsertComplete (index, value);
 			RecordEvent ("Leave");
+			NoTailcall ();
 		}
 
 		protected override void OnRemoveComplete (int index, object value)
 		{
 			RecordEvent ("Enter");
 			base.OnRemoveComplete (index, value);
 			RecordEvent ("Leave");
+			NoTailcall ();
 		}
 
 		void OnFieldsChanged (object sender, EventArgs args)
 		{
 			RecordEvent ("Enter");
 			RecordEvent ("Leave");
+			NoTailcall ();
 		}
 	}
 

mcs/class/System.Web.Extensions/Test/System.Web.UI.WebControls/ListViewTest.cs

@@ -36,6 +36,7 @@
 using System.Web.UI;
 using System.Web.UI.HtmlControls;
 using System.Web.UI.WebControls;
+using System.Runtime.CompilerServices;
 
 using NUnit.Framework;
 using MonoTests.SystemWeb.Framework;
@@ -50,13 +51,17 @@ public sealed class ListViewPoker : ListView
 		public StateBag StateBag {
 			get { return base.ViewState; }
 		}
-
+
+		[MethodImplAttribute (MethodImplOptions.NoInlining)]
+		static void NoTailcall () { }
+
 		void RecordEvent (string suffix)
 		{
 			if (recorder == null)
 				return;
 
 			recorder.Record (suffix);
+			NoTailcall ();
 		}
 
 		public ListViewPoker ()
@@ -86,132 +91,151 @@ protected override void OnItemCanceling (ListViewCancelEventArgs e)
 			RecordEvent ("Enter");
 			base.OnItemCanceling (e);
 			RecordEvent ("Leave");
+			NoTailcall ();
 		}
 
 		protected override void OnItemCommand (ListViewCommandEventArgs e)
 		{
 			RecordEvent ("Enter");
 			base.OnItemCommand (e);
 			RecordEvent ("Leave");
+			NoTailcall ();
 		}
 
 		protected override void OnItemCreated (ListViewItemEventArgs e)
 		{
 			RecordEvent ("Enter");
 			base.OnItemCreated (e);
 			RecordEvent ("Leave");
+			NoTailcall ();
 		}
 
 		protected override void OnItemDataBound (ListViewItemEventArgs e)
 		{
 			RecordEvent ("Enter");
 			base.OnItemDataBound (e);
 			RecordEvent ("Leave");
+			NoTailcall ();
 		}
 
 		protected override void OnItemDeleted (ListViewDeletedEventArgs e)
 		{
 			RecordEvent ("Enter");
 			base.OnItemDeleted (e);
 			RecordEvent ("Leave");
+			NoTailcall ();
 		}
 
 		protected override void OnItemDeleting (ListViewDeleteEventArgs e)
 		{
 			RecordEvent ("Enter");
 			base.OnItemDeleting (e);
 			RecordEvent ("Leave");
+			NoTailcall ();
 		}
 
 		protected override void OnItemEditing (ListViewEditEventArgs e)
 		{
 			RecordEvent ("Enter");
 			base.OnItemEditing (e);
 			RecordEvent ("Leave");
+			NoTailcall ();
 		}
 
 		protected override void OnItemInserted (ListViewInsertedEventArgs e)
 		{
 			RecordEvent ("Enter");
 			base.OnItemInserted (e);
 			RecordEvent ("Leave");
+			NoTailcall ();
 		}
 
 		protected override void OnItemInserting (ListViewInsertEventArgs e)
 		{
 			RecordEvent ("Enter");
 			base.OnItemInserting (e);
 			RecordEvent ("Leave");
+			NoTailcall ();
 		}
 
 		protected override void OnItemUpdated (ListViewUpdatedEventArgs e)
 		{
 			RecordEvent ("Enter");
 			base.OnItemUpdated (e);
 			RecordEvent ("Leave");
+			NoTailcall ();
 		}
 
 		protected override void OnItemUpdating (ListViewUpdateEventArgs e)
 		{
 			RecordEvent ("Enter");
 			base.OnItemUpdating (e);
 			RecordEvent ("Leave");
+			NoTailcall ();
 		}
 
 		protected override void OnLayoutCreated (EventArgs e)
 		{
 			RecordEvent ("Enter");
 			base.OnLayoutCreated (e);
 			RecordEvent ("Leave");
+			NoTailcall ();
 		}
 
 		protected override void OnPagePropertiesChanged (EventArgs e)
 		{
 			RecordEvent ("Enter");
 			base.OnPagePropertiesChanged (e);
 			RecordEvent ("Leave");
+			NoTailcall ();
 		}
-	
+
 		protected override void OnPagePropertiesChanging (PagePropertiesChangingEventArgs e)
 		{
 			RecordEvent ("Enter");
 			base.OnPagePropertiesChanging (e);
 			RecordEvent ("Leave");
+			NoTailcall ();
 		}
 
 		protected override void OnSelectedIndexChanged (EventArgs e)
 		{
 			RecordEvent ("Enter");
 			base.OnSelectedIndexChanged (e);
 			RecordEvent ("Leave");
+			NoTailcall ();
 		}
 
 		protected override void OnSelectedIndexChanging (ListViewSelectEventArgs e)
 		{
 			RecordEvent ("Enter");
 			base.OnSelectedIndexChanging (e);
 			RecordEvent ("Leave");
+			NoTailcall ();
 		}
 
 		protected override void OnSorted (EventArgs e)
 		{
 			RecordEvent ("Enter");
 			base.OnSorted (e);
 			RecordEvent ("Leave");
+			NoTailcall ();
 		}
 
 		protected override void OnSorting (ListViewSortEventArgs e)
 		{
 			RecordEvent ("Enter");
 			base.OnSorting (e);
 			RecordEvent ("Leave");
+			NoTailcall ();
 		}
 
 		protected override void OnTotalRowCountAvailable (PageEventArgs e)
 		{
 			RecordEvent ("Enter");
 			base.OnTotalRowCountAvailable (e);
 			RecordEvent ("Leave");
+			NoTailcall ();
 		}
 
 		public void DoSetPageProperties (int startRowIndex, int maximumRows, bool databind)

mcs/class/System.Web/Makefile

@@ -2,6 +2,10 @@ thisdir = class/System.Web
 SUBDIRS = Test
 include ../../build/rules.make
 
+# FIXME This tests for precise stack traces, which tailcall optimization breaks.
+# The exact tailcall has not been determined.
+TEST_RUNTIME_FLAGS += --optimize=-tailc
+
 LIBRARY = System.Web.dll
 
 RESOURCE_FILES_1= \

mcs/class/corlib/System.Runtime.InteropServices/ExtensibleClassFactory.cs

@@ -51,7 +51,7 @@ internal static ObjectCreationDelegate GetObjectCreationCallback (Type t)
 		}
 
 		public static void RegisterObjectCreationCallback (ObjectCreationDelegate callback) {
-			int i = 1;
+			int i = 0;
 			StackTrace trace = new StackTrace (false);
 			while (i < trace.FrameCount) {
 				StackFrame frame = trace.GetFrame (i);