From 35e6156c20a006c8201b3b427466e4492c3988bd Mon Sep 17 00:00:00 2001
From: Giuseppe Lippolis <spaccabit@gmail.com>
Date: Fri, 3 Feb 2023 22:01:57 +0100
Subject: [PATCH] fix: Sourcelink Avalonia.Build.Tasks

---
 nukebuild/BuildTasksPatcher.cs | 104 +++++++++++++++++++++++++++++----
 1 file changed, 93 insertions(+), 11 deletions(-)

diff --git a/nukebuild/BuildTasksPatcher.cs b/nukebuild/BuildTasksPatcher.cs
index 5fd331035a..f2dd217657 100644
--- a/nukebuild/BuildTasksPatcher.cs
+++ b/nukebuild/BuildTasksPatcher.cs
@@ -4,9 +4,58 @@ using System.IO.Compression;
 using System.Linq;
 using ILRepacking;
 using Mono.Cecil;
+using Mono.Cecil.Cil;
 
 public class BuildTasksPatcher
 {
+    /// <summary>
+    /// This helper class, avoid argument null exception
+    /// when cecil write AssemblyNameDefinition on MemoryStream.
+    /// </summary>
+    private class Wrapper : ISymbolWriterProvider
+    {
+        readonly ISymbolWriterProvider _provider;
+        readonly string _filename;
+
+        public Wrapper(ISymbolWriterProvider provider, string filename)
+        {
+            _provider = provider;
+            _filename = filename;
+        }
+
+        public ISymbolWriter GetSymbolWriter(ModuleDefinition module, string fileName) =>
+            _provider.GetSymbolWriter(module, string.IsNullOrWhiteSpace(fileName) ? _filename : fileName);
+
+        public ISymbolWriter GetSymbolWriter(ModuleDefinition module, Stream symbolStream) =>
+            _provider.GetSymbolWriter(module, symbolStream);
+    }
+
+    private static string GetSourceLinkInfo(string path)
+    {
+        try
+        {
+            using (var asm = AssemblyDefinition.ReadAssembly(path,
+                new ReaderParameters
+                {
+                    ReadWrite = true,
+                    InMemory = true,
+                    ReadSymbols = true,
+                    SymbolReaderProvider = new DefaultSymbolReaderProvider(false),
+                }))
+            {
+                if (asm.MainModule.CustomDebugInformations?.OfType<SourceLinkDebugInformation>()?.FirstOrDefault() is { } sli)
+                {
+                    return sli.Content;
+                }
+            }
+        }
+        catch
+        {
+
+        }
+        return null;
+    }
+
     public static void PatchBuildTasksInPackage(string packagePath)
     {
         using (var archive = new ZipArchive(File.Open(packagePath, FileMode.Open, FileAccess.ReadWrite),
@@ -19,7 +68,7 @@ public class BuildTasksPatcher
                 {
                     var tempDir = Path.Combine(Path.GetTempPath(), Guid.NewGuid().ToString());
                     Directory.CreateDirectory(tempDir);
-                    var temp = Path.Combine(tempDir, Guid.NewGuid() + ".dll");
+                    var temp = Path.Combine(tempDir, entry.Name);
                     var output = temp + ".output";
                     File.Copy(typeof(Microsoft.Build.Framework.ITask).Assembly.GetModules()[0].FullyQualifiedName,
                         Path.Combine(tempDir, "Microsoft.Build.Framework.dll"));
@@ -27,41 +76,74 @@ public class BuildTasksPatcher
                     try
                     {
                         entry.ExtractToFile(temp, true);
+                        // Get Original SourceLinkInfo Content
+                        var sourceLinkInfoContent = GetSourceLinkInfo(temp);
                         var repack = new ILRepacking.ILRepack(new RepackOptions()
                         {
                             Internalize = true,
                             InputAssemblies = new[]
                             {
-                                temp, typeof(Mono.Cecil.AssemblyDefinition).Assembly.GetModules()[0]
-                                    .FullyQualifiedName,
+                                temp,
+                                typeof(Mono.Cecil.AssemblyDefinition).Assembly.GetModules()[0].FullyQualifiedName,
                                 typeof(Mono.Cecil.Rocks.MethodBodyRocks).Assembly.GetModules()[0].FullyQualifiedName,
                                 typeof(Mono.Cecil.Pdb.PdbReaderProvider).Assembly.GetModules()[0].FullyQualifiedName,
-                                typeof(Mono.Cecil.Mdb.MdbReaderProvider).Assembly.GetModules()[0].FullyQualifiedName
-                                
+                                typeof(Mono.Cecil.Mdb.MdbReaderProvider).Assembly.GetModules()[0].FullyQualifiedName,
                             },
-                            SearchDirectories = new string[0],
+                            SearchDirectories = Array.Empty<string>(),
+                            DebugInfo = true, // Allowed read debug info
                             OutputFile = output
                         });
                         repack.Repack();
 
-
                         // 'hurr-durr assembly with the same name is already loaded' prevention
                         using (var asm = AssemblyDefinition.ReadAssembly(output,
-                            new ReaderParameters { ReadWrite = true, InMemory = true, }))
+                            new ReaderParameters
+                            {
+                                ReadWrite = true,
+                                InMemory = true,
+                                ReadSymbols = true,
+                                SymbolReaderProvider = new DefaultSymbolReaderProvider(false),
+                            }))
                         {
                             asm.Name = new AssemblyNameDefinition(
                                 "Avalonia.Build.Tasks."
                                 + Guid.NewGuid().ToString().Replace("-", ""),
                                 new Version(0, 0, 0));
-                            asm.Write(patched);
+
+                            var mainModule = asm.MainModule;
+
+                            // If we have SourceLink info copy to patched assembly.
+                            if (!string.IsNullOrEmpty(sourceLinkInfoContent))
+                            {
+                                mainModule.CustomDebugInformations.Add(new SourceLinkDebugInformation(sourceLinkInfoContent));
+                            }
+
+                            // Try to get SymbolWriter if it has it
+                            var reader = mainModule.SymbolReader;
+                            var hasDebugInfo = reader is not null;
+                            var proivder = reader?.GetWriterProvider() is ISymbolWriterProvider p
+                                ? new Wrapper(p, "Avalonia.Build.Tasks.dll")
+                                : default(ISymbolWriterProvider);
+
+                            var parameters = new WriterParameters
+                            {
+#if ISNETFULLFRAMEWORK
+                                StrongNameKeyPair = signingStep.KeyPair,
+#endif
+                                WriteSymbols = hasDebugInfo,
+                                SymbolWriterProvider = proivder,
+                                DeterministicMvid = hasDebugInfo,
+                            };
+                            asm.Write(patched, parameters);
                             patched.Position = 0;
                         }
+
                     }
                     finally
                     {
                         try
                         {
-                            if(Directory.Exists(tempDir))
+                            if (Directory.Exists(tempDir))
                                 Directory.Delete(tempDir, true);
                         }
                         catch
@@ -79,4 +161,4 @@ public class BuildTasksPatcher
             }
         }
     }
-}
\ No newline at end of file
+}