check in Auto as well, including generic structs

Author: VSadov

src/coreclr/tools/Common/TypeSystem/Common/MetadataFieldLayoutAlgorithm.cs

@@ -473,12 +473,6 @@ protected ComputedInstanceFieldLayout ComputeSequentialFieldLayout(MetadataType
 
             if (type.IsInlineArray)
             {
-                // inline array cannot have explicit instance size
-                if (layoutMetadata.Size != 0)
-                {
-                    ThrowHelper.ThrowTypeLoadException(ExceptionStringID.ClassLoadInlineArrayExplicitSize, type);
-                }
-
                 AdjustForInlineArray(type, numInstanceFields, ref instanceByteSizeAndAlignment, ref instanceSizeAndAlignment);
             }
 
@@ -516,6 +510,12 @@ private static void AdjustForInlineArray(
                 ThrowHelper.ThrowTypeLoadException(ExceptionStringID.ClassLoadInlineArrayFieldCount, type);
             }
 
+            var layoutMetadata = type.GetClassLayout();
+            if (layoutMetadata.Size != 0)
+            {
+                ThrowHelper.ThrowTypeLoadException(ExceptionStringID.ClassLoadInlineArrayExplicitSize, type);
+            }
+
             if (!instanceByteSizeAndAlignment.Size.IsIndeterminate)
             {
                 long size = instanceByteSizeAndAlignment.Size.AsInt;

src/coreclr/vm/methodtablebuilder.cpp

@@ -1771,6 +1771,12 @@ MethodTableBuilder::BuildMethodTableThrowing(
                 {
                     BuildMethodTableThrowException(IDS_CLASSLOAD_INLINE_ARRAY_EXPLICIT);
                 }
+
+                ULONG classSize;
+                if (SUCCEEDED(GetMDImport()->GetClassTotalSize(cl, &classSize)) && classSize != 0)
+                {
+                    BuildMethodTableThrowException(IDS_CLASSLOAD_INLINE_ARRAY_EXPLICIT_SIZE);
+                }
             }
         }
     }
@@ -1793,13 +1799,6 @@ MethodTableBuilder::BuildMethodTableThrowing(
     {
         if ((int)bmtFP->NumInstanceFieldBytes != (INT64)bmtFP->NumInstanceFieldBytes)
             BuildMethodTableThrowException(IDS_CLASSLOAD_FIELDTOOLARGE);
-
-        if (HasExplicitSize() &&
-            bmtLayout->layoutType == EEClassLayoutInfo::LayoutType::Sequential &&
-            GetHalfBakedClass()->IsInlineArray())
-        {
-            BuildMethodTableThrowException(IDS_CLASSLOAD_INLINE_ARRAY_EXPLICIT_SIZE);
-        }
     }
 
     if (CheckIfSIMDAndUpdateSize())

src/mono/mono/metadata/class-init.c

@@ -317,7 +317,7 @@ mono_class_setup_fields (MonoClass *klass)
 	if (explicit_size)
 		instance_size += real_size;
 
-	if (explicit_size && layout == TYPE_ATTRIBUTE_SEQUENTIAL_LAYOUT && m_class_is_inlinearray (klass)) {
+	if (explicit_size && real_size != 0 && m_class_is_inlinearray (klass)) {
 		if (mono_get_runtime_callbacks ()->mono_class_set_deferred_type_load_failure_callback)
 			mono_get_runtime_callbacks ()->mono_class_set_deferred_type_load_failure_callback (klass, "Inline array must not have explicit size.");
 		else

src/tests/Loader/classloader/InlineArray/InlineArrayInvalid.cs

@@ -23,18 +23,41 @@ public static void Explicit_Fails()
     }
 
     [Fact]
-    public static void ExplicitSize_Fails()
+    public static void ExplicitSize_FailsInSequential()
     {
-        Console.WriteLine($"{nameof(ExplicitSize_Fails)}...");
-
-        // .size is ignored for auto layout
-        Assert.True(sizeof(ExplicitSizeAuto) > 0);
+        Console.WriteLine($"{nameof(ExplicitSize_FailsInSequential)}...");
 
         Assert.Throws<TypeLoadException>(() => { var t = typeof(ExplicitSize); });
 
         Assert.Throws<TypeLoadException>(() =>
         {
-            return sizeof(ExplicitSize);
+            return new ExplicitSize();
+        });
+    }
+
+    [Fact]
+    public static void ExplicitSize_FailsInAuto()
+    {
+        Console.WriteLine($"{nameof(ExplicitSize_FailsInAuto)}...");
+
+        Assert.Throws<TypeLoadException>(() => { var t = typeof(ExplicitSizeAuto); });
+
+        Assert.Throws<TypeLoadException>(() =>
+        {
+            return sizeof(ExplicitSizeAuto);
+        });
+    }
+
+    [Fact]
+    public static void ExplicitSize_FailsInGeneric()
+    {
+        Console.WriteLine($"{nameof(ExplicitSize_FailsInGeneric)}...");
+
+        Assert.Throws<TypeLoadException>(() => { var t = typeof(ExplicitSizeGeneric<long>); });
+
+        Assert.Throws<TypeLoadException>(() =>
+        {
+            return new ExplicitSizeGeneric<int>();
         });
     }
 

src/tests/Loader/classloader/InlineArray/InvalidCSharpInlineArray.il

@@ -36,6 +36,17 @@
     .field [0] public valuetype [System.Runtime]System.Guid Guid
 }
 
+.class public auto ansi sealed beforefieldinit ExplicitSizeGeneric`1<T>
+    extends [System.Runtime]System.ValueType
+{
+    .custom instance void [System.Runtime]System.Runtime.CompilerServices.InlineArrayAttribute::.ctor(int32) = (
+        01 00 01 00 00 00 00 00
+    )
+
+    .size 256
+    .field [0] public valuetype [System.Runtime]System.Guid Guid
+}
+
 .class public sequential ansi sealed beforefieldinit ZeroLength
     extends [System.Runtime]System.ValueType
 {