Imported Upstream version 4.6.0.125

Former-commit-id: a2155e9bd80020e49e72e86c44da02a8ac0e57a4

mcs/class/referencesource/XamlBuildTask/Microsoft/Build/Tasks/Xaml/ResolveAssemblyHelper.cs

@@ -0,0 +1,88 @@
+//------------------------------------------------------------
+// Copyright (c) Microsoft Corporation.  All rights reserved.
+//------------------------------------------------------------
+
+namespace Microsoft.Build.Tasks.Xaml
+{
+    using System;
+    using System.Collections.Generic;
+    using System.Linq;
+    using System.Text;
+    using System.Reflection;
+    using System.IO;
+    using System.Diagnostics.CodeAnalysis;
+    using System.Runtime;
+
+    internal class ResolveAssemblyHelper
+    {
+        static string fileNotfound = String.Empty;
+        IList<string> references;
+
+        public ResolveAssemblyHelper(IList<string> references)
+        {
+            this.references = references;
+        }
+
+        public Dictionary<string, Assembly> ReferencedAssemblies
+        { 
+            get;
+            internal set; 
+        }
+
+        // We are storing the file not found in this static variable so that
+        // later on we can print out the file name for the
+        // filenotfound exception thrown by CLR. 
+        // Ok to use static here as there will be only one instance of this 
+        // process per app domain.
+        internal static string FileNotFound
+        {
+            get { return fileNotfound; }
+        }
+
+        [SuppressMessage(FxCop.Category.Reliability, FxCop.Rule.AvoidCallingProblematicMethods,
+            Justification = "Using LoadFrom to avoid loading through Fusion and load from the exact path specified")]
+        public Assembly ResolveLocalProjectReferences(object sender, ResolveEventArgs args)
+        {
+            // Currently we are return the assembly just by matching the short name
+            // of the assembly. Filed bug 172138 to figure out whether we need
+            // to load the exact matching(version, culture, public key matches)
+            // assembly.
+
+            AssemblyName targetAssemblyName = new AssemblyName(args.Name);
+            string targetName = targetAssemblyName.Name;
+            Assembly targetAssembly = null;
+            if (this.ReferencedAssemblies != null)
+            {
+                this.ReferencedAssemblies.TryGetValue(targetName, out targetAssembly);
+            }
+
+            if (targetAssembly != null)
+            {
+                return targetAssembly;
+            }
+
+            foreach (string reference in this.references)
+            {
+                if (string.Equals(targetName, Path.GetFileNameWithoutExtension(reference), StringComparison.OrdinalIgnoreCase))
+                {
+                    Assembly assembly = Assembly.LoadFrom(reference);
+                    if (assembly != null)
+                    {
+                        targetAssembly = assembly;
+                        if (this.ReferencedAssemblies == null)
+                        {
+                            this.ReferencedAssemblies = new Dictionary<string, Assembly>(StringComparer.OrdinalIgnoreCase);
+                        }
+                        this.ReferencedAssemblies.Add(targetName, assembly);
+                    }
+                    break;
+                }
+            }
+            if (targetAssembly == null)
+            {
+                fileNotfound = targetName;
+            }
+            return targetAssembly;
+        }
+    }
+}