1 files changed, 67 insertions, 0 deletions
diff --git a/src/StardewModdingAPI.AssemblyRewriters/Framework/BaseMethodFinder.cs b/src/StardewModdingAPI.AssemblyRewriters/Framework/BaseMethodFinder.cs
new file mode 100644
index 00000000..7526286a
--- /dev/null
+++ b/src/StardewModdingAPI.AssemblyRewriters/Framework/BaseMethodFinder.cs
@@ -0,0 +1,67 @@
+using System;
+using System.Linq;
+using System.Reflection;
+using Mono.Cecil;
+using Mono.Cecil.Cil;
+
+namespace StardewModdingAPI.AssemblyRewriters.Framework
+{
+    /// <summary>Base class for a method finder.</summary>
+    public abstract class BaseMethodFinder : IInstructionFinder
+    {
+        /*********
+        ** Public methods
+        *********/
+        /// <summary>Get whether a CIL instruction matches.</summary>
+        /// <param name="instruction">The IL instruction.</param>
+        /// <param name="platformChanged">Whether the mod was compiled on a different platform.</param>
+        public bool IsMatch(Instruction instruction, bool platformChanged)
+        {
+            if (instruction.OpCode != OpCodes.Call && instruction.OpCode != OpCodes.Callvirt)
+                return false; // not a method reference
+            return this.IsMatch(instruction, (MethodReference)instruction.Operand, platformChanged);
+        }
+
+
+        /*********
+        ** Protected methods
+        *********/
+        /// <summary>Get whether a method reference should be rewritten.</summary>
+        /// <param name="instruction">The IL instruction.</param>
+        /// <param name="methodRef">The method reference.</param>
+        /// <param name="platformChanged">Whether the mod was compiled on a different platform.</param>
+        protected abstract bool IsMatch(Instruction instruction, MethodReference methodRef, bool platformChanged);
+
+        /// <summary>Get whether a method definition matches the signature expected by a method reference.</summary>
+        /// <param name="definition">The method definition.</param>
+        /// <param name="reference">The method reference.</param>
+        protected bool HasMatchingSignature(MethodInfo definition, MethodReference reference)
+        {
+            // same name
+            if (definition.Name != reference.Name)
+                return false;
+
+            // same arguments
+            ParameterInfo[] definitionParameters = definition.GetParameters();
+            ParameterDefinition[] referenceParameters = reference.Parameters.ToArray();
+            if (referenceParameters.Length != definitionParameters.Length)
+                return false;
+            for (int i = 0; i < referenceParameters.Length; i++)
+            {
+                if (!RewriteHelper.IsMatchingType(definitionParameters[i].ParameterType, referenceParameters[i].ParameterType))
+                    return false;
+            }
+            return true;
+        }
+
+        /// <summary>Get whether a type has a method whose signature matches the one expected by a method reference.</summary>
+        /// <param name="type">The type to check.</param>
+        /// <param name="reference">The method reference.</param>
+        protected bool HasMatchingSignature(Type type, MethodReference reference)
+        {
+            return type
+                .GetMethods(BindingFlags.Instance | BindingFlags.DeclaredOnly | BindingFlags.Public)
+                .Any(method => this.HasMatchingSignature(method, reference));
+        }
+    }
+}