Dogfood ComInterfaceGenerator in crossgen2

src/coreclr/tools/aot/ILCompiler.Diagnostics/AssemblyInfo.cs

@@ -2,6 +2,9 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 
 using System;
+using System.Runtime.CompilerServices;
+
+[assembly: DisableRuntimeMarshalling]
 
 namespace ILCompiler.Diagnostics
 {

src/coreclr/tools/aot/ILCompiler.Diagnostics/ISymNGenWriter.cs

@@ -4,6 +4,7 @@
 using System;
 using System.Collections.Generic;
 using System.Runtime.InteropServices;
+using System.Runtime.InteropServices.Marshalling;
 using System.Security;
 using System.Text;
 
@@ -38,10 +39,10 @@ namespace Microsoft.DiaSymReader
     /// };
     /// </code>
     /// </remarks>
-    internal interface ISymNGenWriter
+    [GeneratedComInterface]
+    [Guid("D682FD12-43dE-411C-811B-BE8404CEA126")]
+    internal partial interface ISymNGenWriter
     {
-        public static readonly Guid IID = new Guid("D682FD12-43dE-411C-811B-BE8404CEA126");
-
         // Add a new public symbol to the NGEN PDB.
         void AddSymbol([MarshalAs(UnmanagedType.BStr)] string pSymbol,
                         ushort iSection,
@@ -110,21 +111,10 @@ internal enum OMF : ushort
     /// };
     /// </remarks>
     /// </code>
-    internal interface ISymNGenWriter2 : ISymNGenWriter
+    [GeneratedComInterface]
+    [Guid("B029E51B-4C55-4fe2-B993-9F7BC1F10DB4")]
+    internal partial interface ISymNGenWriter2 : ISymNGenWriter
     {
-        public readonly static new Guid IID = new Guid("B029E51B-4C55-4fe2-B993-9F7BC1F10DB4");
-
-        // Add a new public symbol to the NGEN PDB.
-        new void AddSymbol([MarshalAs(UnmanagedType.BStr)] string pSymbol,
-                        ushort iSection,
-                        ulong rva);
-
-        // Adds a new section to the NGEN PDB.
-        new void AddSection(ushort iSection,
-                        OMF flags,
-                        int offset,
-                        int cb);
-
         void OpenModW([MarshalAs(UnmanagedType.LPWStr)] string wszModule,
                       [MarshalAs(UnmanagedType.LPWStr)] string wszObjFile,
                       out UIntPtr ppmod);
@@ -143,7 +133,8 @@ void ModAddSecContribEx(
             uint dwRelocCrc);
 
         void QueryPDBNameExW(
-            [MarshalAs(UnmanagedType.LPWStr)] char[] pdb,
+            [MarshalUsing(CountElementName = nameof(cchMax))]
+            char[] pdb,
             IntPtr cchMax);
     }
 }

src/coreclr/tools/aot/ILCompiler.Diagnostics/PdbWriter.cs

@@ -7,6 +7,7 @@
 using System.Reflection;
 using System.Reflection.PortableExecutable;
 using System.Runtime.InteropServices;
+using System.Runtime.InteropServices.Marshalling;
 using System.Text;
 
 using Internal.TypeSystem;
@@ -73,7 +74,7 @@ public bool Equals(SymDocument other)
         }
     }
 
-    public class PdbWriter
+    public partial class PdbWriter
     {
         private const string DiaSymReaderLibrary = "Microsoft.DiaSymReader.Native";
 
@@ -89,7 +90,7 @@ public class PdbWriter
         Dictionary<SymDocument,int> _documentToChecksumOffsetMapping;
 
         UIntPtr _pdbMod;
-        SymNgenWriterWrapper _ngenWriter;
+        ISymNGenWriter2 _ngenWriter;
 
         static PdbWriter()
         {
@@ -112,10 +113,10 @@ private static IntPtr DllImportResolver(string libraryName, Assembly assembly, D
         }
 
         [DefaultDllImportSearchPaths(DllImportSearchPath.AssemblyDirectory | DllImportSearchPath.SafeDirectories)]
-        [DllImport(DiaSymReaderLibrary, PreserveSig = false)]
-        private extern static void CreateNGenPdbWriter(
-            [MarshalAs(UnmanagedType.LPWStr)] string ngenImagePath,
-            [MarshalAs(UnmanagedType.LPWStr)] string pdbPath,
+        [LibraryImport(DiaSymReaderLibrary, StringMarshalling = StringMarshalling.Utf16)]
+        private static partial void CreateNGenPdbWriter(
+            string ngenImagePath,
+            string pdbPath,
             out IntPtr ngenPdbWriterPtr);
 
         public PdbWriter(string pdbPath, PDBExtraData pdbExtraData, TargetDetails target)
@@ -145,7 +146,6 @@ public void WritePDBData(string dllPath, IEnumerable<MethodInfo> methods)
                     if ((_ngenWriter != null) && (_pdbMod != UIntPtr.Zero))
                     {
                         _ngenWriter.CloseMod(_pdbMod);
-                        _ngenWriter?.Dispose();
                     }
                 }
 
@@ -208,9 +208,9 @@ private void WritePDBDataHelper(string dllPath, IEnumerable<MethodInfo> methods)
             // Delete any preexisting PDB file upfront, otherwise CreateNGenPdbWriter silently opens it
             File.Delete(_pdbFilePath);
 
-            var comWrapper = new ILCompilerComWrappers();
+            var comWrapper = new StrategyBasedComWrappers();
             CreateNGenPdbWriter(dllPath, _pdbFilePath, out var pdbWriterInst);
-            _ngenWriter = (SymNgenWriterWrapper)comWrapper.GetOrCreateObjectForComInstance(pdbWriterInst, CreateObjectFlags.UniqueInstance);
+            _ngenWriter = (ISymNGenWriter2)comWrapper.GetOrCreateObjectForComInstance(pdbWriterInst, CreateObjectFlags.UniqueInstance);
 
             {
                 // PDB file is now created. Get its path and update _pdbFilePath so the PDB file