From c2809a16f8fc5ebd62f10479c74a1acf0a43319c Mon Sep 17 00:00:00 2001
From: Graham <gpe@openrs2.dev>
Date: Thu, 9 Jan 2020 19:06:41 +0000
Subject: [PATCH] Add OverrideTransformer

---
 .../openrs2/asm/classpath/ClassMetadata.kt    | 25 +++++++++
 .../java/dev/openrs2/deob/Deobfuscator.kt     |  4 +-
 .../deob/transform/OverrideTransformer.kt     | 56 +++++++++++++++++++
 3 files changed, 84 insertions(+), 1 deletion(-)
 create mode 100644 deob/src/main/java/dev/openrs2/deob/transform/OverrideTransformer.kt

diff --git a/asm/src/main/java/dev/openrs2/asm/classpath/ClassMetadata.kt b/asm/src/main/java/dev/openrs2/asm/classpath/ClassMetadata.kt
index 2574d50d..2116deba 100644
--- a/asm/src/main/java/dev/openrs2/asm/classpath/ClassMetadata.kt
+++ b/asm/src/main/java/dev/openrs2/asm/classpath/ClassMetadata.kt
@@ -13,6 +13,31 @@ abstract class ClassMetadata {
 
     abstract fun isNative(method: MemberDesc): Boolean
 
+    fun isOverride(method: MemberDesc): Boolean {
+        val superClass = this.superClass
+        if (superClass != null) {
+            if (superClass.methods.contains(method)) {
+                return true
+            }
+
+            if (superClass.isOverride(method)) {
+                return true
+            }
+        }
+
+        for (superInterface in superInterfaces) {
+            if (superInterface.methods.contains(method)) {
+                return true
+            }
+
+            if (superInterface.isOverride(method)) {
+                return true
+            }
+        }
+
+        return false
+    }
+
     override fun equals(other: Any?): Boolean {
         if (this === other) return true
         if (other !is ClassMetadata) return false
diff --git a/deob/src/main/java/dev/openrs2/deob/Deobfuscator.kt b/deob/src/main/java/dev/openrs2/deob/Deobfuscator.kt
index 11349384..2ff5ba53 100644
--- a/deob/src/main/java/dev/openrs2/deob/Deobfuscator.kt
+++ b/deob/src/main/java/dev/openrs2/deob/Deobfuscator.kt
@@ -19,6 +19,7 @@ import dev.openrs2.deob.transform.ExceptionTracingTransformer
 import dev.openrs2.deob.transform.FieldOrderTransformer
 import dev.openrs2.deob.transform.OpaquePredicateTransformer
 import dev.openrs2.deob.transform.OriginalNameTransformer
+import dev.openrs2.deob.transform.OverrideTransformer
 import dev.openrs2.deob.transform.RemapTransformer
 import dev.openrs2.deob.transform.ResetTransformer
 import dev.openrs2.deob.transform.UnusedArgTransformer
@@ -157,7 +158,8 @@ class Deobfuscator(private val input: Path, private val output: Path) {
             DummyLocalTransformer(),
             UnusedArgTransformer(),
             ResetTransformer(),
-            AccessTransformer()
+            AccessTransformer(),
+            OverrideTransformer()
         )
     }
 }
diff --git a/deob/src/main/java/dev/openrs2/deob/transform/OverrideTransformer.kt b/deob/src/main/java/dev/openrs2/deob/transform/OverrideTransformer.kt
new file mode 100644
index 00000000..7bae704b
--- /dev/null
+++ b/deob/src/main/java/dev/openrs2/deob/transform/OverrideTransformer.kt
@@ -0,0 +1,56 @@
+package dev.openrs2.deob.transform
+
+import com.github.michaelbull.logging.InlineLogger
+import dev.openrs2.asm.MemberDesc
+import dev.openrs2.asm.classpath.ClassPath
+import dev.openrs2.asm.classpath.Library
+import dev.openrs2.asm.transform.Transformer
+import org.objectweb.asm.Opcodes
+import org.objectweb.asm.Type
+import org.objectweb.asm.tree.AnnotationNode
+import org.objectweb.asm.tree.ClassNode
+import org.objectweb.asm.tree.MethodNode
+
+class OverrideTransformer : Transformer() {
+    private var overrides = 0
+
+    override fun preTransform(classPath: ClassPath) {
+        overrides = 0
+    }
+
+    override fun transformCode(
+        classPath: ClassPath,
+        library: Library,
+        clazz: ClassNode,
+        method: MethodNode
+    ): Boolean {
+        if (method.name == "<init>" || method.name == "<clinit>" || method.access and Opcodes.ACC_STATIC != 0) {
+            return false
+        }
+
+        if (!classPath[clazz.name].isOverride(MemberDesc(method))) {
+            return false
+        }
+
+        if (method.visibleAnnotations != null && method.visibleAnnotations.any { it.desc == OVERRIDE_DESC }) {
+            return false
+        }
+
+        if (method.visibleAnnotations == null) {
+            method.visibleAnnotations = mutableListOf()
+        }
+        method.visibleAnnotations.add(AnnotationNode(OVERRIDE_DESC))
+        overrides++
+
+        return false
+    }
+
+    override fun postTransform(classPath: ClassPath) {
+        logger.info { "Added $overrides override annotations" }
+    }
+
+    companion object {
+        val logger = InlineLogger()
+        val OVERRIDE_DESC: String = Type.getDescriptor(Override::class.java)
+    }
+}