From: Zoltan Varga <vargaz@gmail.com>
Date: Fri, 22 Sep 2017 22:44:10 +0000 (+0200)
Subject: [jit] Fix constrained calls from gsharedvt methods using an interface type to vtype... 
X-Git-Url: http://wien.tomnetworks.com/gitweb/?p=mono.git;a=commitdiff_plain;h=878b260edc6eefc7ec36244f8a30af6aa475fcf8

[jit] Fix constrained calls from gsharedvt methods using an interface type to vtype methods, the receiver is boxed, needs to be unboxed. Fixes #58507. (#5628)
---

diff --git a/mono/mini/gshared.cs b/mono/mini/gshared.cs
index 6b5bc95f134..75ea14aad6a 100644
--- a/mono/mini/gshared.cs
+++ b/mono/mini/gshared.cs
@@ -1823,6 +1823,19 @@ public class Tests
 		}
 	}
 
+	struct StructTest : IFaceTest {
+
+		int i;
+
+		public StructTest (int arg) {
+			i = arg;
+		}
+
+		public int iface_method () {
+			return i;
+		}
+	}
+
 	// Test constrained calls on an interface made from gsharedvt methods
 	public static int test_42_gsharedvt_constrained_iface () {
 		IFaceConstrainedIFace obj = new ConstrainedIFace ();
@@ -1830,6 +1843,12 @@ public class Tests
 		return obj.foo<IFaceTest, int> (ref t);
 	}
 
+	public static int test_42_gsharedvt_constrained_iface_vtype () {
+		IFaceConstrainedIFace obj = new ConstrainedIFace ();
+		IFaceTest t = new StructTest (42);
+		return obj.foo<IFaceTest, int> (ref t);
+	}
+
 	// Sign extension tests
 	// 0x55   == 85    == 01010101
 	// 0xAA   == 170   == 10101010
diff --git a/mono/mini/jit-icalls.c b/mono/mini/jit-icalls.c
index 56c7bc8169f..fa3d7a46819 100644
--- a/mono/mini/jit-icalls.c
+++ b/mono/mini/jit-icalls.c
@@ -1328,12 +1328,15 @@ constrained_gsharedvt_call_setup (gpointer mp, MonoMethod *cmethod, MonoClass *k
 {
 	MonoMethod *m;
 	int vt_slot, iface_offset;
+	gboolean is_iface = FALSE;
 
 	error_init (error);
 
 	if (mono_class_is_interface (klass)) {
 		MonoObject *this_obj;
 
+		is_iface = TRUE;
+
 		/* Have to use the receiver's type instead of klass, the receiver is a ref type */
 		this_obj = *(MonoObject**)mp;
 		g_assert (this_obj);
@@ -1359,21 +1362,33 @@ constrained_gsharedvt_call_setup (gpointer mp, MonoMethod *cmethod, MonoClass *k
 			m = mono_class_inflate_generic_method (m, mono_method_get_context (cmethod));
 	}
 
-	if (klass->valuetype && (m->klass == mono_defaults.object_class || m->klass == mono_defaults.enum_class->parent || m->klass == mono_defaults.enum_class))
+	if (klass->valuetype && (m->klass == mono_defaults.object_class || m->klass == mono_defaults.enum_class->parent || m->klass == mono_defaults.enum_class)) {
 		/*
 		 * Calling a non-vtype method with a vtype receiver, has to box.
 		 */
 		*this_arg = mono_value_box_checked (mono_domain_get (), klass, mp, error);
-	else if (klass->valuetype)
-		/*
-		 * Calling a vtype method with a vtype receiver
-		 */
-		*this_arg = mp;
-	else
+	} else if (klass->valuetype) {
+		if (is_iface) {
+			/*
+			 * The original type is an interface, so the receiver is a ref,
+			   the called method is a vtype method, need to unbox.
+			*/
+			MonoObject *this_obj = *(MonoObject**)mp;
+
+			*this_arg = mono_object_unbox (this_obj);
+		} else {
+			/*
+			 * Calling a vtype method with a vtype receiver
+			 */
+			*this_arg = mp;
+		}
+	} else {
 		/*
 		 * Calling a non-vtype method
 		 */
 		*this_arg = *(gpointer*)mp;
+	}
+
 	return m;
 }