Obsolete AssemblyName.CodeBase, AssemblyName.EscapedCodeBase

src/coreclr/System.Private.CoreLib/src/System/Reflection/RuntimeAssembly.cs

@@ -134,9 +134,10 @@ public override AssemblyName GetName(bool copiedName)
 
             an.RawFlags = GetFlags() | AssemblyNameFlags.PublicKey;
 
-#pragma warning disable IL3000 // System.Reflection.AssemblyName.CodeBase' always returns an empty string for assemblies embedded in a single-file app.
+#pragma warning disable IL3000, SYSLIB0044 // System.Reflection.AssemblyName.CodeBase' always returns an empty string for assemblies embedded in a single-file app.
+                                           // AssemblyName.CodeBase and AssemblyName.EscapedCodeBase are obsolete. Using them for loading an assembly is not supported.
             an.CodeBase = GetCodeBase();
-#pragma warning restore IL3000
+#pragma warning restore IL3000, SYSLIB0044
 
 #pragma warning disable SYSLIB0037 // AssemblyName.HashAlgorithm is obsolete
             an.HashAlgorithm = GetHashAlgorithm();

src/libraries/Common/src/System/Obsoletions.cs

@@ -141,5 +141,8 @@ internal static class Obsoletions
 
         internal const string EcDhPublicKeyBlobMessage = "ECDiffieHellmanPublicKey.ToByteArray() and the associated constructor do not have a consistent and interoperable implementation on all platforms. Use ECDiffieHellmanPublicKey.ExportSubjectPublicKeyInfo() instead.";
         internal const string EcDhPublicKeyBlobDiagId = "SYSLIB0043";
+
+        internal const string AssemblyNameCodeBaseMessage = "AssemblyName.CodeBase and AssemblyName.EscapedCodeBase are obsolete. Using them for loading an assembly is not supported.";
+        internal const string AssemblyNameCodeBaseDiagId = "SYSLIB0044";
     }
 }

src/libraries/System.ComponentModel.Composition/src/System/ComponentModel/Composition/Hosting/AssemblyCatalog.cs

@@ -558,7 +558,9 @@ private static Assembly LoadAssembly(string codeBase)
             catch (ArgumentException)
             {
                 assemblyName = new AssemblyName();
+#pragma warning disable SYSLIB0044 // AssemblyName.CodeBase and AssemblyName.EscapedCodeBase are obsolete. Using them for loading an assembly is not supported.
                 assemblyName.CodeBase = codeBase;
+#pragma warning restore SYSLIB0044
             }
 
             try

src/libraries/System.Private.CoreLib/src/System/Reflection/AssemblyName.cs

@@ -82,13 +82,15 @@ public string? CultureName
             set => _cultureInfo = (value == null) ? null : new CultureInfo(value);
         }
 
+        [Obsolete(Obsoletions.AssemblyNameCodeBaseMessage, DiagnosticId = Obsoletions.AssemblyNameCodeBaseDiagId, UrlFormat = Obsoletions.SharedUrlFormat)]
         public string? CodeBase
         {
             [RequiresAssemblyFiles("The code will return an empty string for assemblies embedded in a single-file app")]
             get => _codeBase;
             set => _codeBase = value;
         }
 
+        [Obsolete(Obsoletions.AssemblyNameCodeBaseMessage, DiagnosticId = Obsoletions.AssemblyNameCodeBaseDiagId, UrlFormat = Obsoletions.SharedUrlFormat)]
         [RequiresAssemblyFiles("The code will return an empty string for assemblies embedded in a single-file app")]
         public string? EscapedCodeBase
         {

src/libraries/System.Private.Xml/src/System/Xml/Serialization/Compilation.cs

@@ -162,7 +162,6 @@ internal void InitAssemblyMethods(XmlMapping[] xmlMappings)
                     serializerName = Compiler.GetTempAssemblyName(name, defaultNamespace);
                     // use strong name
                     name.Name = serializerName;
-                    name.CodeBase = null;
                     name.CultureInfo = CultureInfo.InvariantCulture;
 
                     try

src/libraries/System.Reflection/tests/AssemblyNameTests.cs

@@ -235,7 +235,7 @@ public void Verify_CultureName()
             AssemblyName an = new AssemblyName("MyAssemblyName");
             Assert.Null(an.CultureName);
         }
-
+#pragma warning disable SYSLIB0044 // AssemblyName.CodeBase .AssemblyName.EscapedCodeBase are obsolete
         [Fact]
         public void Verify_CodeBase()
         {
@@ -259,6 +259,7 @@ public static void Verify_EscapedCodeBase()
             n.CodeBase = @"file:///c:/program files/MyAssemblyName.dll";
             Assert.Equal(n.EscapedCodeBase, Uri.EscapeUriString(n.CodeBase));
         }
+#pragma warning restore SYSLIB0044
 
         [Fact]
         public static void Verify_HashAlgorithm()

src/libraries/System.Runtime.Extensions/tests/System/AppDomainTests.cs

@@ -254,7 +254,6 @@ public void ExecuteAssemblyByName()
                 Assert.Equal(10, AppDomain.CurrentDomain.ExecuteAssemblyByName(assembly.FullName, new string[2] { "2", "3" }));
                 Assert.Throws<FormatException>(() => AppDomain.CurrentDomain.ExecuteAssemblyByName(assembly.FullName, new string[1] { "a" }));
                 AssemblyName assemblyName = assembly.GetName();
-                assemblyName.CodeBase = null;
                 Assert.Equal(105, AppDomain.CurrentDomain.ExecuteAssemblyByName(assemblyName, new string[3] { "50", "25", "25" }));
             }).Dispose();
         }
@@ -358,7 +357,6 @@ public void Unload()
         public void Load()
         {
             AssemblyName assemblyName = typeof(AppDomainTests).Assembly.GetName();
-            assemblyName.CodeBase = null;
             Assert.NotNull(AppDomain.CurrentDomain.Load(assemblyName));
             Assert.NotNull(AppDomain.CurrentDomain.Load(typeof(AppDomainTests).Assembly.FullName));
         }

src/libraries/System.Runtime.Loader/tests/AssemblyLoadContextTest.cs

@@ -115,7 +115,6 @@ public static void LoadFromAssemblyName_AssemblyNotFound()
         public static void LoadFromAssemblyName_ValidTrustedPlatformAssembly()
         {
             var asmName = typeof(System.Linq.Enumerable).Assembly.GetName();
-            asmName.CodeBase = null;
             var loadContext = new CustomTPALoadContext();
 
             // We should be able to override (and thus, load) assemblies that were
@@ -131,7 +130,6 @@ public static void LoadFromAssemblyName_ValidTrustedPlatformAssembly()
         public static void LoadFromAssemblyName_FallbackToDefaultContext()
         {
             var asmName = typeof(System.Linq.Enumerable).Assembly.GetName();
-            asmName.CodeBase = null;
             var loadContext = new AssemblyLoadContext("FallbackToDefaultContextTest");
 
             // This should not have any special handlers, so it should just find the version in the default context

src/libraries/System.Runtime/ref/System.Runtime.cs

@@ -10828,11 +10828,13 @@ public sealed partial class AssemblyName : System.ICloneable, System.Runtime.Ser
     {
         public AssemblyName() { }
         public AssemblyName(string assemblyName) { }
+        [System.ObsoleteAttribute("AssemblyName.CodeBase and AssemblyName.EscapedCodeBase are obsolete. Using them for loading an assembly is not supported.", DiagnosticId = "SYSLIB0044", UrlFormat = "https://aka.ms/dotnet-warnings/{0}")]
         public string? CodeBase { [System.Diagnostics.CodeAnalysis.RequiresAssemblyFilesAttribute("The code will return an empty string for assemblies embedded in a single-file app")] get { throw null; } set { } }
         public System.Reflection.AssemblyContentType ContentType { get { throw null; } set { } }
         public System.Globalization.CultureInfo? CultureInfo { get { throw null; } set { } }
         public string? CultureName { get { throw null; } set { } }
         [System.Diagnostics.CodeAnalysis.RequiresAssemblyFilesAttribute("The code will return an empty string for assemblies embedded in a single-file app")]
+        [System.ObsoleteAttribute("AssemblyName.CodeBase and AssemblyName.EscapedCodeBase are obsolete. Using them for loading an assembly is not supported.", DiagnosticId = "SYSLIB0044", UrlFormat = "https://aka.ms/dotnet-warnings/{0}")]
         public string? EscapedCodeBase { get { throw null; } }
         public System.Reflection.AssemblyNameFlags Flags { get { throw null; } set { } }
         public string FullName { get { throw null; } }