Add test coverage for unsupported marshal scenarios (dotnet/coreclr#2…

…7393)

* Pointers to non-blittable structs are not supported
* SizeParamIndex could be bogus

Commit migrated from dotnet/coreclr@f1a900d

src/coreclr/tests/src/Interop/PInvoke/Primitives/Pointer/PInvokePointerTest.cs

@@ -0,0 +1,28 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System;
+using System.Runtime.InteropServices;
+using TestLibrary;
+
+unsafe class Program
+{
+    [StructLayout(LayoutKind.Sequential)]
+    struct NonBlittable
+    {
+        bool _nonBlittable;
+    }
+
+    // the "string unused" parameter is just so that we don't hit https://github.com/dotnet/coreclr/issues/27408 that
+    // makes this p/invoke actually work.
+    [DllImport("Unused")]
+    private static extern void PointerToNonBlittableType(NonBlittable* pNonBlittable, string unused);
+
+    static int Main()
+    {
+        Assert.Throws<MarshalDirectiveException>(() => PointerToNonBlittableType(null, null));
+
+        return 100;
+    }
+}

src/coreclr/tests/src/Interop/PInvoke/Primitives/Pointer/PInvokePointerTest.csproj

@@ -0,0 +1,11 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <DefineConstants>$(DefineConstants);STATIC</DefineConstants>
+    <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
+  </PropertyGroup>
+  <ItemGroup>
+    <Compile Include="PInvokePointerTest.cs" />
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), Interop.settings.targets))\Interop.settings.targets" />
+</Project>

src/coreclr/tests/src/Interop/PInvoke/SizeParamIndex/PInvoke/Invalid/InvalidParamIndex.cs

@@ -0,0 +1,26 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System;
+using System.Runtime.InteropServices;
+using TestLibrary;
+
+class Program
+{
+    [DllImport("Unused")]
+    static extern void SizeParamIndexTooBig(
+        out byte arrSize, [MarshalAs(UnmanagedType.LPArray, SizeParamIndex = 20)] out byte[] arrByte);
+
+    [DllImport("Unused")]
+    public static extern void SizeParamIndexWrongType(
+        out string arrSize, [MarshalAs(UnmanagedType.LPArray, SizeParamIndex = 0)] out byte[] arrByte);
+
+    static int Main()
+    {
+        Assert.Throws<MarshalDirectiveException>(() => SizeParamIndexTooBig(out var _, out var _));
+        Assert.Throws<MarshalDirectiveException>(() => SizeParamIndexWrongType(out var _, out var _));
+
+        return 100;
+    }
+}

src/coreclr/tests/src/Interop/PInvoke/SizeParamIndex/PInvoke/Invalid/InvalidParamIndex.csproj

@@ -0,0 +1,10 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <DefineConstants>$(DefineConstants);STATIC</DefineConstants>
+  </PropertyGroup>
+  <ItemGroup>
+    <Compile Include="InvalidParamIndex.cs" />
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), Interop.settings.targets))\Interop.settings.targets" />
+</Project>