Mark LoadFrom overload that always throws as obsolete

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

@@ -177,5 +177,8 @@ internal static class Obsoletions
 
         internal const string ArmIntrinsicPerformsUnsignedOperationMessage = "The underlying hardware instruction does not perform a signed saturate narrowing operation, and it always returns an unsigned result. Use the unsigned overload instead.";
         internal const string ArmIntrinsicPerformsUnsignedOperationDiagId = "SYSLIB0055";
+
+        internal const string LoadFromHashAlgorithmMessage = "LoadFrom with a custom AssemblyHashAlgorithm is obsolete. Use overloads without an AssemblyHashAlgorithm.";
+        internal const string LoadFromHashAlgorithmDiagId = "SYSLIB0056";
     }
 }

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

@@ -385,6 +385,7 @@ public static Assembly LoadFrom(string assemblyFile)
         }
 
         [RequiresUnreferencedCode("Types and members the loaded assembly depends on might be removed")]
+        [Obsolete(Obsoletions.LoadFromHashAlgorithmMessage, DiagnosticId = Obsoletions.LoadFromHashAlgorithmDiagId, UrlFormat = Obsoletions.SharedUrlFormat)]
         public static Assembly LoadFrom(string assemblyFile, byte[]? hashValue, AssemblyHashAlgorithm hashAlgorithm)
         {
             throw new NotSupportedException(SR.NotSupported_AssemblyLoadFromHash);

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

@@ -11139,6 +11139,7 @@ public virtual void GetObjectData(System.Runtime.Serialization.SerializationInfo
         [System.Diagnostics.CodeAnalysis.RequiresUnreferencedCodeAttribute("Types and members the loaded assembly depends on might be removed")]
         public static System.Reflection.Assembly LoadFrom(string assemblyFile) { throw null; }
         [System.Diagnostics.CodeAnalysis.RequiresUnreferencedCodeAttribute("Types and members the loaded assembly depends on might be removed")]
+        [System.ObsoleteAttribute("LoadFrom with a custom AssemblyHashAlgorithm is obsolete. Use overloads without an AssemblyHashAlgorithm.", DiagnosticId = "SYSLIB0056", UrlFormat = "https://aka.ms/dotnet-warnings/{0}")]
         public static System.Reflection.Assembly LoadFrom(string assemblyFile, byte[]? hashValue, System.Configuration.Assemblies.AssemblyHashAlgorithm hashAlgorithm) { throw null; }
         [System.Diagnostics.CodeAnalysis.RequiresUnreferencedCodeAttribute("Types and members the loaded module depends on might be removed")]
         public System.Reflection.Module LoadModule(string moduleName, byte[]? rawModule) { throw null; }

src/libraries/System.Runtime/tests/System.Reflection.Tests/AssemblyTests.cs

@@ -442,12 +442,20 @@ public void LoadFile_ValidPEBadIL_ThrowsBadImageFormatExceptionWithPath_ByInitia
             AssertExtensions.ThrowsContains<BadImageFormatException>(() => Assembly.LoadFile(path), path);
         }
 
+#pragma warning disable SYSLIB0056 // AssemblyHashAlgorithm overload is not supported and throws NotSupportedException.
         [ConditionalFact(typeof(PlatformDetection), nameof(PlatformDetection.IsAssemblyLoadingSupported))]
         public void LoadFromUsingHashValue()
         {
             Assert.Throws<NotSupportedException>(() => Assembly.LoadFrom("abc", null, System.Configuration.Assemblies.AssemblyHashAlgorithm.SHA1));
         }
 
+        [ConditionalFact(typeof(PlatformDetection), nameof(PlatformDetection.IsAssemblyLoadingSupported))]
+        public void LoadFrom_WithHashValue_ThrowsNotSupportedException()
+        {
+            Assert.Throws<NotSupportedException>(() => Assembly.LoadFrom(DestTestAssemblyPath, new byte[0], Configuration.Assemblies.AssemblyHashAlgorithm.None));
+        }
+#pragma warning restore SYSLIB0056 // AssemblyHashAlgorithm overload is not supported and throws NotSupportedException.
+
         [ConditionalFact(typeof(PlatformDetection), nameof(PlatformDetection.IsAssemblyLoadingSupported))]
         public void LoadFrom_SamePath_ReturnsEqualAssemblies()
         {
@@ -496,12 +504,6 @@ public void UnsafeLoadFrom_SamePath_ReturnsEqualAssemblies()
             Assert.Equal(assembly1, assembly2);
         }
 
-        [ConditionalFact(typeof(PlatformDetection), nameof(PlatformDetection.IsAssemblyLoadingSupported))]
-        public void LoadFrom_WithHashValue_ThrowsNotSupportedException()
-        {
-            Assert.Throws<NotSupportedException>(() => Assembly.LoadFrom(DestTestAssemblyPath, new byte[0], Configuration.Assemblies.AssemblyHashAlgorithm.None));
-        }
-
         [ConditionalFact(typeof(PlatformDetection), nameof(PlatformDetection.IsAssemblyLoadingSupported))]
         public void LoadModule()
         {

src/mono/System.Private.CoreLib/CompatibilitySuppressions.xml

@@ -32,4 +32,4 @@
     <DiagnosticId>CP0015</DiagnosticId>
     <Target>M:System.Diagnostics.Tracing.EventSource.WriteEventWithRelatedActivityIdCore(System.Int32,System.Guid*,System.Int32,System.Diagnostics.Tracing.EventSource.EventData*):[T:System.Diagnostics.CodeAnalysis.RequiresUnreferencedCodeAttribute]</Target>
   </Suppression>
-</Suppressions>
+</Suppressions>