1 files changed, 49 insertions, 0 deletions
diff --git a/src/SMAPI/Framework/ModLoading/Finders/LegacyAssemblyFinder.cs b/src/SMAPI/Framework/ModLoading/Finders/LegacyAssemblyFinder.cs
new file mode 100644
index 00000000..d3437b05
--- /dev/null
+++ b/src/SMAPI/Framework/ModLoading/Finders/LegacyAssemblyFinder.cs
@@ -0,0 +1,49 @@
+using Mono.Cecil;
+using StardewModdingAPI.Framework.ModLoading.Framework;
+
+namespace StardewModdingAPI.Framework.ModLoading.Finders
+{
+    /// <summary>Detects assembly references which will break in SMAPI 4.0.0.</summary>
+    internal class LegacyAssemblyFinder : BaseInstructionHandler
+    {
+        /*********
+        ** Public methods
+        *********/
+        /// <summary>Construct an instance.</summary>
+        public LegacyAssemblyFinder()
+            : base(defaultPhrase: "legacy assembly references") { }
+
+
+        /// <inheritdoc />
+        public override bool Handle(ModuleDefinition module)
+        {
+            foreach (AssemblyNameReference assembly in module.AssemblyReferences)
+            {
+                InstructionHandleResult flag = this.GetFlag(assembly);
+                if (flag is InstructionHandleResult.None)
+                    continue;
+
+                this.MarkFlag(flag);
+            }
+
+            return false;
+        }
+
+
+        /*********
+        ** Private methods
+        *********/
+        /// <summary>Get the instruction handle flag for the given assembly reference, if any.</summary>
+        /// <param name="assemblyRef">The assembly reference.</param>
+        private InstructionHandleResult GetFlag(AssemblyNameReference assemblyRef)
+        {
+            return assemblyRef.Name switch
+            {
+                "System.Configuration.ConfigurationManager" => InstructionHandleResult.DetectedLegacyConfigurationDll,
+                "System.Runtime.Caching" => InstructionHandleResult.DetectedLegacyCachingDll,
+                "System.Security.Permission" => InstructionHandleResult.DetectedLegacyPermissionsDll,
+                _ => InstructionHandleResult.None
+            };
+        }
+    }
+}