Add new output DebugSymbolsFiles to ResolvePackageAssets

DebugSymbolsFiles outputs the list of absolute path to symbols files
for runtime assemblies which can be either pdb and/or xml.

The change:
ResolvePackagesAssets was modified to read/write DebugSymbolsFiles
from/to the cache file and it was inserted after ContentFilesToProcess
because the list of Item groups is ordered alphabetically.

Since we need to copy this debug symbols to the output director,
the task parameter output for DebugSymbolsFiles is appended to
ReferenceCopyLocalPaths.

There is some minor code cleanup not related to this bug.

Author: ocalles

src/Tasks/Common/MetadataKeys.cs

@@ -131,5 +131,12 @@ internal static class MetadataKeys
         public const string IsVersion5 = "IsVersion5";
         public const string CreateCompositeImage = "CreateCompositeImage";
         public const string PerfmapFormatVersion = "PerfmapFormatVersion";
+
+        // Debug symbols
+        public const string RelatedProperty = "related";
+        public const string XmlExtension = ".xml";
+        public const string XmlFilePath = "XmlFilePath";
+        public const string PdbExtension = ".pdb";
+        public const string PdbFilePath = "PdbFilePath";
     }
 }

src/Tasks/Microsoft.NET.Build.Tasks/ResolvePackageAssets.cs

@@ -156,6 +156,9 @@ public sealed class ResolvePackageAssets : TaskBase
         [Required]
         public string DotNetAppHostExecutableNameWithoutExtension { get; set; }
 
+        /// <summary>
+        /// True indicates we are doing a design-time build. Otherwise we are in a build.
+        /// </summary>
         public bool DesignTimeBuild { get; set; }
 
         /// <summary>
@@ -231,6 +234,15 @@ public sealed class ResolvePackageAssets : TaskBase
         [Output]
         public ITaskItem[] PackageDependencies { get; private set; }
 
+        /// <summary>
+        /// List of file symbols pdb and xml related to NuGet packages
+        /// </summary>
+        /// <remarks>
+        /// This is the list of files to be copied to the output directory
+        /// </remarks>
+        [Output]
+        public ITaskItem[] DebugSymbolsFiles { get; private set;}
+
         /// <summary>
         /// Messages from the assets file.
         /// These are logged directly and therefore not returned to the targets (note private here).
@@ -311,6 +323,7 @@ private void ReadItemGroups()
                 ApphostsForShimRuntimeIdentifiers = reader.ReadItemGroup();
                 CompileTimeAssemblies = reader.ReadItemGroup();
                 ContentFilesToPreprocess = reader.ReadItemGroup();
+                DebugSymbolsFiles = reader.ReadItemGroup();
                 FrameworkAssemblies = reader.ReadItemGroup();
                 FrameworkReferences = reader.ReadItemGroup();
                 NativeLibraries = reader.ReadItemGroup();
@@ -510,7 +523,7 @@ private static BinaryReader CreateReaderFromDisk(ResolvePackageAssets task, byte
                 BinaryReader reader = null;
                 try
                 {
-                    if (File.GetLastWriteTimeUtc(task.ProjectAssetsCacheFile) > File.GetLastWriteTimeUtc(task.ProjectAssetsFile))
+                    if (IsCacheFileUpToDate())
                     {
                         reader = OpenCacheFile(task.ProjectAssetsCacheFile, settingsHash);
                     }
@@ -537,6 +550,8 @@ private static BinaryReader CreateReaderFromDisk(ResolvePackageAssets task, byte
                 }
 
                 return reader;
+
+                bool IsCacheFileUpToDate() => File.GetLastWriteTimeUtc(task.ProjectAssetsCacheFile) > File.GetLastWriteTimeUtc(task.ProjectAssetsFile);
             }
 
             private static BinaryReader OpenCacheStream(Stream stream, byte[] settingsHash)
@@ -651,6 +666,8 @@ internal sealed class CacheWriter : IDisposable
 
             private const string NetCorePlatformLibrary = "Microsoft.NETCore.App";
 
+            private const char RelatedPropertySeparator = ';';
+
             public CacheWriter(ResolvePackageAssets task)
             {
                 _targetFramework = task.TargetFramework;
@@ -776,6 +793,7 @@ private void WriteItemGroups()
                 WriteItemGroup(WriteApphostsForShimRuntimeIdentifiers);
                 WriteItemGroup(WriteCompileTimeAssemblies);
                 WriteItemGroup(WriteContentFilesToPreprocess);
+                WriteItemGroup(WriteDebugSymbolsFiles);
                 WriteItemGroup(WriteFrameworkAssemblies);
                 WriteItemGroup(WriteFrameworkReferences);
                 WriteItemGroup(WriteNativeLibraries);
@@ -1091,6 +1109,42 @@ private void WriteContentFilesToPreprocess()
                     });
             }
 
+            private void WriteDebugSymbolsFiles()
+            {
+                foreach (LockFileTargetLibrary library in _runtimeTarget.Libraries)
+                {
+                    if (!library.IsPackage())
+                    {
+                        continue;
+                    }
+
+                    foreach (var asset in library.RuntimeAssemblies)
+                    {
+                        if (asset.IsPlaceholderFile() || !asset.Properties.ContainsKey(MetadataKeys.RelatedProperty))
+                        {
+                            continue;
+                        }
+
+                        string itemSpec = _packageResolver.ResolvePackageAssetPath(library, asset.Path);
+
+                        asset.Properties.TryGetValue(MetadataKeys.RelatedProperty, out string relatedExtensions);
+
+                        foreach (string fileExtension in relatedExtensions.Split(RelatedPropertySeparator))
+                        {
+                            switch (fileExtension.ToLower())
+                            {
+                                case MetadataKeys.PdbExtension:
+                                    WriteItem(Path.ChangeExtension(itemSpec, MetadataKeys.PdbExtension), library);
+                                    break;
+                                case MetadataKeys.XmlExtension:
+                                    WriteItem(Path.ChangeExtension(itemSpec, MetadataKeys.XmlExtension), library);
+                                    break;
+                            }
+                        }
+                    }
+                }
+            }
+
             private void WriteFrameworkAssemblies()
             {
                 if (_task.DisableFrameworkAssemblies)

src/Tasks/Microsoft.NET.Build.Tasks/targets/Microsoft.PackageDependencyResolution.targets

@@ -297,6 +297,7 @@ Copyright (c) .NET Foundation. All rights reserved.
       <Output TaskParameter="Analyzers" ItemName="ResolvedAnalyzers" />
       <Output TaskParameter="ApphostsForShimRuntimeIdentifiers" ItemName="_ApphostsForShimRuntimeIdentifiersResolvePackageAssets" />
       <Output TaskParameter="ContentFilesToPreprocess" ItemName="_ContentFilesToPreprocess" />
+      <Output TaskParameter="DebugSymbolsFiles" ItemName="ReferenceCopyLocalPaths" />
       <Output TaskParameter="FrameworkAssemblies" ItemName="ResolvedFrameworkAssemblies" />
       <Output TaskParameter="FrameworkReferences" ItemName="TransitiveFrameworkReference" />
       <Output TaskParameter="NativeLibraries" ItemName="NativeCopyLocalItems" />