further generalise CIL rewriters for reuse (#231)

1 files changed, 41 insertions, 0 deletions

diff --git a/src/StardewModdingAPI.AssemblyRewriters/Framework/RewriteHelper.cs b/src/StardewModdingAPI.AssemblyRewriters/Framework/RewriteHelper.cs
new file mode 100644
index 00000000..0307053f
--- /dev/null
+++ b/src/StardewModdingAPI.AssemblyRewriters/Framework/RewriteHelper.cs
@@ -0,0 +1,41 @@
+using System;
+using Mono.Cecil;
+
+namespace StardewModdingAPI.AssemblyRewriters.Framework
+{
+    /// <summary>Provides helper methods for field rewriters.</summary>
+    internal static class RewriteHelper
+    {
+        /*********
+        ** Public methods
+        *********/
+        /// <summary>Get whether a type matches a type reference.</summary>
+        /// <param name="type">The defined type.</param>
+        /// <param name="reference">The type reference.</param>
+        public static bool IsMatchingType(Type type, TypeReference reference)
+        {
+            // same namespace & name
+            if (type.Namespace != reference.Namespace || type.Name != reference.Name)
+                return false;
+
+            // same generic parameters
+            if (type.IsGenericType)
+            {
+                if (!reference.IsGenericInstance)
+                    return false;
+
+                Type[] defGenerics = type.GetGenericArguments();
+                TypeReference[] refGenerics = ((GenericInstanceType)reference).GenericArguments.ToArray();
+                if (defGenerics.Length != refGenerics.Length)
+                    return false;
+                for (int i = 0; i < defGenerics.Length; i++)
+                {
+                    if (!RewriteHelper.IsMatchingType(defGenerics[i], refGenerics[i]))
+                        return false;
+                }
+            }
+
+            return true;
+        }
+    }
+}