1 files changed, 16 insertions, 0 deletions

diff --git a/src/main/java/cuchaz/enigma/mapping/entry/MethodDefEntry.java b/src/main/java/cuchaz/enigma/mapping/entry/MethodDefEntry.java
index 960b08d..fa9e668 100644
--- a/src/main/java/cuchaz/enigma/mapping/entry/MethodDefEntry.java
+++ b/src/main/java/cuchaz/enigma/mapping/entry/MethodDefEntry.java
@@ -42,4 +42,20 @@ public class MethodDefEntry extends MethodEntry implements DefEntry {
         public MethodDefEntry updateOwnership(ClassEntry classEntry) {
                 return new MethodDefEntry(new ClassEntry(classEntry.getName()), name, descriptor, signature, access);
         }
+
+        public int getArgumentIndex(ClassDefEntry ownerEntry, int localVariableIndex) {
+                int argumentIndex = localVariableIndex;
+
+                // Enum constructors have an implicit "name" and "ordinal" parameter as well as "this"
+                if (ownerEntry.getAccess().isEnum() && getName().startsWith("<")) {
+                        argumentIndex -= 2;
+                }
+
+                // If we're not static, "this" is bound to index 0
+                if (!getAccess().isStatic()) {
+                        argumentIndex -= 1;
+                }
+
+                return argumentIndex;
+        }
 }