1 files changed, 82 insertions, 0 deletions
diff --git a/src/SMAPI/Framework/ModLoading/Finders/FieldFinder.cs b/src/SMAPI/Framework/ModLoading/Finders/FieldFinder.cs
new file mode 100644
index 00000000..00805815
--- /dev/null
+++ b/src/SMAPI/Framework/ModLoading/Finders/FieldFinder.cs
@@ -0,0 +1,82 @@
+using Mono.Cecil;
+using Mono.Cecil.Cil;
+
+namespace StardewModdingAPI.Framework.ModLoading.Finders
+{
+    /// <summary>Finds incompatible CIL instructions that reference a given field.</summary>
+    internal class FieldFinder : IInstructionHandler
+    {
+        /*********
+        ** Properties
+        *********/
+        /// <summary>The full type name for which to find references.</summary>
+        private readonly string FullTypeName;
+
+        /// <summary>The field name for which to find references.</summary>
+        private readonly string FieldName;
+
+        /// <summary>The result to return for matching instructions.</summary>
+        private readonly InstructionHandleResult Result;
+
+
+        /*********
+        ** Accessors
+        *********/
+        /// <summary>A brief noun phrase indicating what the instruction finder matches.</summary>
+        public string NounPhrase { get; }
+
+
+        /*********
+        ** Public methods
+        *********/
+        /// <summary>Construct an instance.</summary>
+        /// <param name="fullTypeName">The full type name for which to find references.</param>
+        /// <param name="fieldName">The field name for which to find references.</param>
+        /// <param name="result">The result to return for matching instructions.</param>
+        public FieldFinder(string fullTypeName, string fieldName, InstructionHandleResult result)
+        {
+            this.FullTypeName = fullTypeName;
+            this.FieldName = fieldName;
+            this.Result = result;
+            this.NounPhrase = $"{fullTypeName}.{fieldName} field";
+        }
+
+        /// <summary>Perform the predefined logic for a method if applicable.</summary>
+        /// <param name="module">The assembly module containing the instruction.</param>
+        /// <param name="method">The method definition containing the instruction.</param>
+        /// <param name="assemblyMap">Metadata for mapping assemblies to the current platform.</param>
+        /// <param name="platformChanged">Whether the mod was compiled on a different platform.</param>
+        public virtual InstructionHandleResult Handle(ModuleDefinition module, MethodDefinition method, PlatformAssemblyMap assemblyMap, bool platformChanged)
+        {
+            return InstructionHandleResult.None;
+        }
+
+        /// <summary>Perform the predefined logic for an instruction if applicable.</summary>
+        /// <param name="module">The assembly module containing the instruction.</param>
+        /// <param name="cil">The CIL processor.</param>
+        /// <param name="instruction">The instruction to handle.</param>
+        /// <param name="assemblyMap">Metadata for mapping assemblies to the current platform.</param>
+        /// <param name="platformChanged">Whether the mod was compiled on a different platform.</param>
+        public virtual InstructionHandleResult Handle(ModuleDefinition module, ILProcessor cil, Instruction instruction, PlatformAssemblyMap assemblyMap, bool platformChanged)
+        {
+            return this.IsMatch(instruction)
+                ? this.Result
+                : InstructionHandleResult.None;
+        }
+
+
+        /*********
+        ** Protected methods
+        *********/
+        /// <summary>Get whether a CIL instruction matches.</summary>
+        /// <param name="instruction">The IL instruction.</param>
+        protected bool IsMatch(Instruction instruction)
+        {
+            FieldReference fieldRef = RewriteHelper.AsFieldReference(instruction);
+            return
+                fieldRef != null
+                && fieldRef.DeclaringType.FullName == this.FullTypeName
+                && fieldRef.Name == this.FieldName;
+        }
+    }
+}