split IInstructionFinder from IInstructionRewriter (#247)

1 files changed, 32 insertions, 0 deletions

diff --git a/src/StardewModdingAPI.AssemblyRewriters/Framework/BaseFieldFinder.cs b/src/StardewModdingAPI.AssemblyRewriters/Framework/BaseFieldFinder.cs
new file mode 100644
index 00000000..96e8b1c0
--- /dev/null
+++ b/src/StardewModdingAPI.AssemblyRewriters/Framework/BaseFieldFinder.cs
@@ -0,0 +1,32 @@
+using Mono.Cecil;
+using Mono.Cecil.Cil;
+
+namespace StardewModdingAPI.AssemblyRewriters.Framework
+{
+    /// <summary>Base class for a field finder.</summary>
+    public abstract class BaseFieldFinder : 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.Ldfld && instruction.OpCode != OpCodes.Ldsfld && instruction.OpCode != OpCodes.Stfld && instruction.OpCode != OpCodes.Stsfld)
+                return false; // not a field reference
+            return this.IsMatch(instruction, (FieldReference)instruction.Operand, platformChanged);
+        }
+
+
+        /*********
+        ** Protected methods
+        *********/
+        /// <summary>Get whether a field reference should be rewritten.</summary>
+        /// <param name="instruction">The IL instruction.</param>
+        /// <param name="fieldRef">The field reference.</param>
+        /// <param name="platformChanged">Whether the mod was compiled on a different platform.</param>
+        protected abstract bool IsMatch(Instruction instruction, FieldReference fieldRef, bool platformChanged);
+    }
+}