From 96ba0ab422d7f9747e93461524991cf5ceeb48c4 Mon Sep 17 00:00:00 2001
From: jeff
Date: Thu, 19 Mar 2015 02:20:32 -0400
Subject: fix issue with naming method arguments and the local variable tables

---
 src/cuchaz/enigma/TranslatingTypeLoader.java       |  2 +-
 .../enigma/bytecode/LocalVariableRenamer.java      | 70 ++++++++++++++++++++--
 .../enigma/bytecode/MethodParameterWriter.java     | 14 +++++
 .../enigma/bytecode/MethodParametersAttribute.java |  3 +-
 4 files changed, 82 insertions(+), 7 deletions(-)

diff --git a/src/cuchaz/enigma/TranslatingTypeLoader.java b/src/cuchaz/enigma/TranslatingTypeLoader.java
index ecd7d642..dce4b859 100644
--- a/src/cuchaz/enigma/TranslatingTypeLoader.java
+++ b/src/cuchaz/enigma/TranslatingTypeLoader.java
@@ -233,7 +233,7 @@ public class TranslatingTypeLoader implements ITypeLoader {
 		// do all kinds of deobfuscating transformations on the class
 		new BridgeMarker(m_jarIndex).markBridges(c);
 		new MethodParameterWriter(m_deobfuscatingTranslator).writeMethodArguments(c);
-		new LocalVariableRenamer().rename(c);
+		new LocalVariableRenamer(m_deobfuscatingTranslator).rename(c);
 		new ClassTranslator(m_deobfuscatingTranslator).translate(c);
 		
 		return c;
diff --git a/src/cuchaz/enigma/bytecode/LocalVariableRenamer.java b/src/cuchaz/enigma/bytecode/LocalVariableRenamer.java
index c87c25be..1179560a 100644
--- a/src/cuchaz/enigma/bytecode/LocalVariableRenamer.java
+++ b/src/cuchaz/enigma/bytecode/LocalVariableRenamer.java
@@ -6,9 +6,20 @@ import javassist.bytecode.ByteArray;
 import javassist.bytecode.CodeAttribute;
 import javassist.bytecode.ConstPool;
 import javassist.bytecode.LocalVariableAttribute;
+import javassist.bytecode.LocalVariableTypeAttribute;
+import cuchaz.enigma.mapping.ArgumentEntry;
+import cuchaz.enigma.mapping.BehaviorEntry;
+import cuchaz.enigma.mapping.EntryFactory;
+import cuchaz.enigma.mapping.Translator;
 
 
 public class LocalVariableRenamer {
+	
+	private Translator m_translator;
+	
+	public LocalVariableRenamer(Translator translator) {
+		m_translator = translator;
+	}
 
 	public void rename(CtClass c) {
 		for (CtBehavior behavior : c.getDeclaredBehaviors()) {
@@ -18,18 +29,67 @@ public class LocalVariableRenamer {
 			if (codeAttribute == null) {
 				continue;
 			}
+			
+			BehaviorEntry behaviorEntry = EntryFactory.getBehaviorEntry(behavior);
+			ConstPool constants = c.getClassFile().getConstPool();
+			
 			LocalVariableAttribute table = (LocalVariableAttribute)codeAttribute.getAttribute(LocalVariableAttribute.tag);
-			if (table == null) {
-				continue;
+			if (table != null) {
+				renameTable(behaviorEntry, constants, table);
 			}
 			
-			ConstPool constants = c.getClassFile().getConstPool();
-			for (int i=0; i<table.tableLength(); i++) {
-				renameVariable(table, i, constants.addUtf8Info("v" + i));
+			LocalVariableTypeAttribute typeTable = (LocalVariableTypeAttribute)codeAttribute.getAttribute(LocalVariableAttribute.typeTag);
+			if (typeTable != null) {
+				renameTable(behaviorEntry, constants, typeTable);
 			}
 		}
 	}
 
+	// DEBUG
+	@SuppressWarnings("unused")
+	private void dumpTable(LocalVariableAttribute table) {
+		for (int i=0; i<table.tableLength(); i++) {
+			System.out.println(String.format("\t%d (%d): %s %s",
+				i, table.index(i), table.variableName(i), table.descriptor(i)
+			));
+		}
+	}
+
+	private void renameTable(BehaviorEntry behaviorEntry, ConstPool constants, LocalVariableAttribute table) {
+		
+		// skip empty tables
+		if (table.tableLength() <= 0) {
+			return;
+		}
+		
+		// where do we start counting variables?
+		int starti = 0;
+		if (table.variableName(0).equals("this")) {
+			// skip the "this" variable
+			starti = 1;
+		}
+		
+		// rename method arguments first
+		int numArgs = 0;
+		if (behaviorEntry.getSignature() != null) {
+			numArgs = behaviorEntry.getSignature().getArgumentTypes().size();
+			for (int i=starti; i<starti + numArgs && i<table.tableLength(); i++) {
+				int argi = i - starti;
+				String argName = m_translator.translate(new ArgumentEntry(behaviorEntry, argi, ""));
+				if (argName == null) {
+					argName = "a" + (argi + 1);
+				}
+				renameVariable(table, i, constants.addUtf8Info(argName));
+			}
+		}
+		
+		// then rename the rest of the args, if any
+		for (int i=starti + numArgs; i<table.tableLength(); i++) {
+			int firstIndex = table.index(starti + numArgs);
+			renameVariable(table, i, constants.addUtf8Info("v" + (table.index(i) - firstIndex + 1)));
+		}
+	}
+	
 	private void renameVariable(LocalVariableAttribute table, int i, int stringId) {
 		// based off of LocalVariableAttribute.nameIndex()
 		ByteArray.write16bit(stringId, table.get(), i*10 + 6);
diff --git a/src/cuchaz/enigma/bytecode/MethodParameterWriter.java b/src/cuchaz/enigma/bytecode/MethodParameterWriter.java
index f64ca02a..87c9196d 100644
--- a/src/cuchaz/enigma/bytecode/MethodParameterWriter.java
+++ b/src/cuchaz/enigma/bytecode/MethodParameterWriter.java
@@ -15,6 +15,8 @@ import java.util.List;
 
 import javassist.CtBehavior;
 import javassist.CtClass;
+import javassist.bytecode.CodeAttribute;
+import javassist.bytecode.LocalVariableAttribute;
 import cuchaz.enigma.mapping.ArgumentEntry;
 import cuchaz.enigma.mapping.BehaviorEntry;
 import cuchaz.enigma.mapping.EntryFactory;
@@ -33,6 +35,15 @@ public class MethodParameterWriter {
 		
 		// Procyon will read method arguments from the "MethodParameters" attribute, so write those
 		for (CtBehavior behavior : c.getDeclaredBehaviors()) {
+			
+			// if there's a local variable table here, don't write a MethodParameters attribute
+			// let the local variable writer deal with it instead
+			// procyon starts doing really weird things if we give it both attributes
+			CodeAttribute codeAttribute = behavior.getMethodInfo().getCodeAttribute();
+			if (codeAttribute != null && codeAttribute.getAttribute(LocalVariableAttribute.tag) != null) {
+				continue;
+			}
+			
 			BehaviorEntry behaviorEntry = EntryFactory.getBehaviorEntry(behavior);
 
 			// get the number of arguments
@@ -53,6 +64,9 @@ public class MethodParameterWriter {
 			}
 			
 			// save the mappings to the class
+			for (String name : names) {
+				System.out.println("\t" + name);
+			}
 			MethodParametersAttribute.updateClass(behavior.getMethodInfo(), names);
 		}
 	}
diff --git a/src/cuchaz/enigma/bytecode/MethodParametersAttribute.java b/src/cuchaz/enigma/bytecode/MethodParametersAttribute.java
index bf959564..27f5b9b3 100644
--- a/src/cuchaz/enigma/bytecode/MethodParametersAttribute.java
+++ b/src/cuchaz/enigma/bytecode/MethodParametersAttribute.java
@@ -27,6 +27,7 @@ public class MethodParametersAttribute extends AttributeInfo {
 	}
 	
 	public static void updateClass(MethodInfo info, List<String> names) {
+		
 		// add the names to the class const pool
 		ConstPool constPool = info.getConstPool();
 		List<Integer> parameterNameIndices = new ArrayList<Integer>();
@@ -44,7 +45,7 @@ public class MethodParametersAttribute extends AttributeInfo {
 	
 	private static byte[] writeStruct(List<Integer> parameterNameIndices) {
 		// JVM 8 Spec says the struct looks like this:
-		// http://cr.openjdk.java.net/~mr/se/8/java-se-8-fr-spec-01/java-se-8-jvms-fr-diffs.pdf
+		// http://docs.oracle.com/javase/specs/jvms/se8/html/jvms-4.html#jvms-4.7.24
 		// uint8 num_params
 		// for each param:
 		// uint16 name_index -> points to UTF8 entry in constant pool, or 0 for no entry
-- 
cgit v1.2.3