Remap argument names

Signed-off-by: Graham <gpe@openrs2.dev>

asm/src/main/java/dev/openrs2/asm/ClassNodeRemapper.kt

@@ -1,6 +1,7 @@
 package dev.openrs2.asm
 
 import dev.openrs2.asm.classpath.ExtendedRemapper
+import org.objectweb.asm.Type
 import org.objectweb.asm.commons.Remapper
 import org.objectweb.asm.tree.AbstractInsnNode
 import org.objectweb.asm.tree.ClassNode
@@ -13,6 +14,7 @@ import org.objectweb.asm.tree.LdcInsnNode
 import org.objectweb.asm.tree.MethodInsnNode
 import org.objectweb.asm.tree.MethodNode
 import org.objectweb.asm.tree.MultiANewArrayInsnNode
+import org.objectweb.asm.tree.ParameterNode
 import org.objectweb.asm.tree.TypeInsnNode
 
 fun ClassNode.remap(remapper: ExtendedRemapper) {
@@ -57,6 +59,14 @@ fun FieldNode.remap(remapper: ExtendedRemapper, owner: String) {
 }
 
 fun MethodNode.remap(remapper: ExtendedRemapper, owner: String) {
+    if (parameters == null) {
+        parameters = List(Type.getArgumentTypes(desc).size) { ParameterNode(null, 0) }
+    }
+
+    for ((index, parameter) in parameters.withIndex()) {
+        parameter.remap(remapper, owner, name, desc, index)
+    }
+
     name = remapper.mapMethodName(owner, name, desc)
     desc = remapper.mapMethodDesc(desc)
     signature = remapper.mapSignature(signature, false)
@@ -75,6 +85,10 @@ fun MethodNode.remap(remapper: ExtendedRemapper, owner: String) {
     }
 }
 
+fun ParameterNode.remap(remapper: ExtendedRemapper, owner: String, methodName: String, desc: String, index: Int) {
+    name = remapper.mapArgumentName(owner, methodName, desc, index, name)
+}
+
 fun AbstractInsnNode.remap(remapper: ExtendedRemapper) {
     when (this) {
         is FrameNode -> throw UnsupportedOperationException("SKIP_FRAMES and COMPUTE_FRAMES must be used")

asm/src/main/java/dev/openrs2/asm/classpath/ExtendedRemapper.kt

@@ -15,4 +15,14 @@ abstract class ExtendedRemapper : Remapper() {
     open fun mapMethodOwner(owner: String, name: String, descriptor: String): String {
         return mapType(owner)
     }
+
+    open fun mapArgumentName(
+        owner: String,
+        name: String,
+        descriptor: String,
+        index: Int,
+        argumentName: String?
+    ): String? {
+        return argumentName
+    }
 }

deob/src/main/java/dev/openrs2/deob/ArgRef.kt

@@ -0,0 +1,5 @@
+package dev.openrs2.deob
+
+import dev.openrs2.asm.MemberRef
+
+data class ArgRef(val method: MemberRef, val index: Int)

deob/src/main/java/dev/openrs2/deob/remap/ArgumentMappingGenerator.kt

@@ -0,0 +1,21 @@
+package dev.openrs2.deob.remap
+
+import dev.openrs2.deob.ArgRef
+import dev.openrs2.deob.util.map.NameMap
+
+class ArgumentMappingGenerator(
+    private val nameMap: NameMap
+) {
+    fun generate(): Map<ArgRef, String> {
+        val argumentNames = mutableMapOf<ArgRef, String>()
+
+        for ((methodRef, method) in nameMap.methods) {
+            for ((index, name) in method.arguments) {
+                val argument = ArgRef(methodRef, index)
+                argumentNames[argument] = name
+            }
+        }
+
+        return argumentNames
+    }
+}

deob/src/main/java/dev/openrs2/deob/remap/TypedRemapper.kt

@@ -5,6 +5,7 @@ import dev.openrs2.asm.MemberRef
 import dev.openrs2.asm.classpath.ClassPath
 import dev.openrs2.asm.classpath.ExtendedRemapper
 import dev.openrs2.asm.filter.UnionMemberFilter
+import dev.openrs2.deob.ArgRef
 import dev.openrs2.deob.Profile
 import dev.openrs2.deob.filter.BrowserControlFilter
 import dev.openrs2.deob.util.map.NameMap
@@ -17,6 +18,7 @@ class TypedRemapper private constructor(
     private val classes: Map<String, String>,
     private val fields: Map<DisjointSet.Partition<MemberRef>, String>,
     private val methods: Map<DisjointSet.Partition<MemberRef>, String>,
+    private val argumentNames: Map<ArgRef, String>,
     private val staticFields: Map<DisjointSet.Partition<MemberRef>, StaticField>,
     private val staticMethods: Map<DisjointSet.Partition<MemberRef>, String>
 ) : ExtendedRemapper() {
@@ -54,6 +56,17 @@ class TypedRemapper private constructor(
         return staticMethods.getOrDefault(partition, mapType(owner))
     }
 
+    override fun mapArgumentName(
+        owner: String,
+        name: String,
+        descriptor: String,
+        index: Int,
+        argumentName: String?
+    ): String? {
+        val argument = ArgRef(MemberRef(owner, name, descriptor), index)
+        return argumentNames[argument] ?: argumentName
+    }
+
     companion object {
         private val logger = InlineLogger()
 
@@ -79,6 +92,7 @@ class TypedRemapper private constructor(
                 nameMap,
                 inheritedMethodSets
             ).generate()
+            val argumentNames = ArgumentMappingGenerator(nameMap).generate()
 
             verifyMapping(classes, profile.maxObfuscatedNameLen)
             verifyMemberMapping(fields, profile.maxObfuscatedNameLen)
@@ -110,6 +124,7 @@ class TypedRemapper private constructor(
                 classes,
                 fields,
                 methods,
+                argumentNames,
                 staticFields,
                 staticMethods
             )