Imported Upstream version 5.4.0.167

Former-commit-id: 5624ac747d633e885131e8349322922b6a59baaa

external/linker/corebuild/integration/ILLink.Tasks/Microsoft.NET.Build.Tasks/BuildErrorException.cs

@@ -0,0 +1,33 @@
+// 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.Globalization;
+
+namespace Microsoft.NET.Build.Tasks
+{
+	/// <summary>
+	/// Represents an error that is neither avoidable in all cases nor indicative of a bug in this library.
+	/// It will be logged as a plain build error without the exception type or stack.
+	/// </summary>
+	internal class BuildErrorException : Exception
+	{
+		public BuildErrorException()
+		{
+		}
+
+		public BuildErrorException(string message) : base(message)
+		{
+		}
+
+		public BuildErrorException(string message, Exception innerException) : base(message, innerException)
+		{
+		}
+
+		public BuildErrorException(string format, params string[] args)
+			: this(string.Format(CultureInfo.CurrentCulture, format, args))
+		{
+		}
+	}
+}

external/linker/corebuild/integration/ILLink.Tasks/Microsoft.NET.Build.Tasks/LockFileCache.cs

@@ -0,0 +1,62 @@
+// Copyright (c) .NET Foundation and contributors. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
+using System;
+using System.IO;
+using Microsoft.Build.Framework;
+using NuGet.Common;
+using NuGet.ProjectModel;
+
+namespace Microsoft.NET.Build.Tasks
+{
+	internal class LockFileCache
+	{
+		private IBuildEngine4 _buildEngine;
+
+		public LockFileCache(IBuildEngine4 buildEngine)
+		{
+			_buildEngine = buildEngine;
+		}
+
+		public LockFile GetLockFile(string path)
+		{
+			if (!Path.IsPathRooted(path))
+			{
+				throw new BuildErrorException("Assets file path '{0}' is not rooted. Only full paths are supported.", path);
+			}
+
+			string lockFileKey = GetTaskObjectKey(path);
+
+			LockFile result;
+			object existingLockFileTaskObject = _buildEngine.GetRegisteredTaskObject(lockFileKey, RegisteredTaskObjectLifetime.Build);
+			if (existingLockFileTaskObject == null)
+			{
+				result = LoadLockFile(path);
+
+				_buildEngine.RegisterTaskObject(lockFileKey, result, RegisteredTaskObjectLifetime.Build, true);
+			}
+			else
+			{
+				result = (LockFile)existingLockFileTaskObject;
+			}
+
+			return result;
+		}
+
+		private static string GetTaskObjectKey(string lockFilePath)
+		{
+			return $"{nameof(LockFileCache)}:{lockFilePath}";
+		}
+
+		private LockFile LoadLockFile(string path)
+		{
+			if (!File.Exists(path))
+			{
+				throw new BuildErrorException("Assets file '{0}' not found. Run a NuGet package restore to generate this file.", path);
+			}
+
+			// TODO - https://github.com/dotnet/sdk/issues/18 adapt task logger to Nuget Logger
+			return LockFileUtilities.GetLockFile(path, NullLogger.Instance);
+		}
+	}
+}