From d410f8724042e6d341a5fdbaa1c835d377528775 Mon Sep 17 00:00:00 2001
From: Graham <gpe@openrs2.dev>
Date: Sat, 6 Jun 2020 15:59:15 +0100
Subject: [PATCH] Consider static and instance fields separately in
 FieldWriteAnalyzer

This fixes a bug where fields could never become static if a class had a
mixture of static and non-static fields and constructors.

Signed-off-by: Graham <gpe@openrs2.dev>
---
 .../dev/openrs2/deob/analysis/FieldWriteAnalyzer.kt   | 11 +++++++++--
 .../openrs2/deob/transform/FinalFieldTransformer.kt   | 11 ++++++-----
 2 files changed, 15 insertions(+), 7 deletions(-)

diff --git a/deob/src/main/java/dev/openrs2/deob/analysis/FieldWriteAnalyzer.kt b/deob/src/main/java/dev/openrs2/deob/analysis/FieldWriteAnalyzer.kt
index 9d6d6310..6bf41fae 100644
--- a/deob/src/main/java/dev/openrs2/deob/analysis/FieldWriteAnalyzer.kt
+++ b/deob/src/main/java/dev/openrs2/deob/analysis/FieldWriteAnalyzer.kt
@@ -15,11 +15,16 @@ class FieldWriteAnalyzer(
     private val classPath: ClassPath,
     private val frames: Array<Frame<ThisValue>>
 ) : DataFlowAnalyzer<Map<MemberDesc, FieldWriteCount>>(clazz.name, method) {
+    private val methodStatic = (method.access and Opcodes.ACC_STATIC) != 0
+
     override fun createEntrySet(): Map<MemberDesc, FieldWriteCount> {
         val set = mutableMapOf<MemberDesc, FieldWriteCount>()
 
         for (field in clazz.fields) {
-            set[MemberDesc(field)] = FieldWriteCount.NEVER
+            val fieldStatic = (field.access and Opcodes.ACC_STATIC) != 0
+            if (methodStatic == fieldStatic) {
+                set[MemberDesc(field)] = FieldWriteCount.NEVER
+            }
         }
 
         return set
@@ -60,7 +65,9 @@ class FieldWriteAnalyzer(
     ): Map<MemberDesc, FieldWriteCount> {
         if (insn !is FieldInsnNode) {
             return set
-        } else if (insn.opcode != Opcodes.PUTFIELD && insn.opcode != Opcodes.PUTSTATIC) {
+        } else if (methodStatic && insn.opcode != Opcodes.PUTSTATIC) {
+            return set
+        } else if (!methodStatic && insn.opcode != Opcodes.PUTFIELD) {
             return set
         }
 
diff --git a/deob/src/main/java/dev/openrs2/deob/transform/FinalFieldTransformer.kt b/deob/src/main/java/dev/openrs2/deob/transform/FinalFieldTransformer.kt
index 4b6a5ebe..1e3df671 100644
--- a/deob/src/main/java/dev/openrs2/deob/transform/FinalFieldTransformer.kt
+++ b/deob/src/main/java/dev/openrs2/deob/transform/FinalFieldTransformer.kt
@@ -29,7 +29,8 @@ class FinalFieldTransformer : Transformer() {
 
     override fun transformCode(classPath: ClassPath, library: Library, clazz: ClassNode, method: MethodNode): Boolean {
         val constructor = method.name == "<init>" || method.name == "<clinit>"
-        val thisCall = if (constructor && method.name == "<init>") {
+        val constructorStatic = (method.access and Opcodes.ACC_STATIC) != 0
+        val thisCall = if (constructor && !constructorStatic) {
             method.instructions.filterIsInstance<MethodInsnNode>()
                 .any { it.opcode == Opcodes.INVOKESPECIAL && it.owner == clazz.name && it.name == "<init>" }
         } else {
@@ -61,7 +62,8 @@ class FinalFieldTransformer : Transformer() {
                 }
 
                 val declaredOwner = classPath[insn.owner]!!.resolveField(MemberDesc(insn))!!.name
-                if (isThis && declaredOwner == clazz.name) {
+                val fieldStatic = insn.opcode == Opcodes.PUTSTATIC
+                if (isThis && declaredOwner == clazz.name && fieldStatic == constructorStatic) {
                     /*
                      * Writes inside constructors without a this(...) call to
                      * fields owned by the same class are analyzed separately - if
@@ -84,10 +86,9 @@ class FinalFieldTransformer : Transformer() {
             for (insn in exits) {
                 val counts = analyzer.getOutSet(insn) ?: emptyMap()
 
-                for (field in clazz.fields) {
-                    val count = counts.getOrDefault(MemberDesc(field), FieldWriteCount.NEVER)
+                for ((field, count) in counts) {
                     if (count != FieldWriteCount.EXACTLY_ONCE) {
-                        val partition = inheritedFieldSets[MemberRef(clazz, field)]!!
+                        val partition = inheritedFieldSets[MemberRef(clazz.name, field)]!!
                         nonFinalFields += partition
                     }
                 }