Fix[JNA]: use agent to replace class at runtime

Fixes duplicate module package on recent Forge versions.

Author: khanhduytran0

JavaApp/Makefile

@@ -1,13 +1,17 @@
 # Prerequisite variables
 SOURCEDIR := src
 OUTPUTDIR := build
+
 SOURCES := $(shell find $(SOURCEDIR) -type f -name '*.java')
 CLASSES := $(SOURCES:$(SOURCEDIR)/%.java=$(OUTPUTDIR)/%.class)
 
+TARGETS := $(shell find $(SOURCEDIR) -mindepth 1 -maxdepth 1 -type d)
+TARGETS := $(TARGETS:$(SOURCEDIR)/%=$(OUTPUTDIR)/%.jar)
+
 # Add all jars to classpath and allow compiling with private API
 JCFLAGS := -cp "$(subst $() $(),:,$(wildcard $(SOURCEDIR)/*/):$(wildcard libs/*/*.jar))" -XDignore.symbol.file
 
-all: $(OUTPUTDIR)/launcher.jar $(OUTPUTDIR)/lwjgl.jar
+all: $(TARGETS)
 
 # Rules for building java class
 $(CLASSES): $(OUTPUTDIR)/%.class: $(SOURCEDIR)/%.java
@@ -22,7 +26,7 @@ $(CLASSES): $(OUTPUTDIR)/%.class: $(SOURCEDIR)/%.java
 $(OUTPUTDIR)/launcher.jar: $(CLASSES)
 	@set -e
 	@echo "Creating $@"
-	$(BOOTJDK)/jar -cf $@ -C $(basename $@) .
+	@$(BOOTJDK)/jar -cf $@ -C $(basename $@) .
 
 $(OUTPUTDIR)/lwjgl.jar: $(CLASSES)
 	@set -e
@@ -32,6 +36,12 @@ $(OUTPUTDIR)/lwjgl.jar: $(CLASSES)
 	@cp -R $(OUTPUTDIR)/lwjgl/* $(OUTPUTDIR)/lwjgl_lib/
 	@$(BOOTJDK)/jar -cf $@ -C $(OUTPUTDIR)/lwjgl_lib .
 
+$(OUTPUTDIR)/patchjna_agent.jar: $(CLASSES)
+	@set -e
+	@mv $(basename $@)/com/sun/jna/Platform.class $(basename $@)/com/sun/jna/Platform.class.patch
+	@echo "Creating $@"
+	@$(BOOTJDK)/jar -cfm $@ $(SOURCEDIR)/patchjna_agent.txt -C $(basename $@) .
+
 clean:
 	rm -rf $(OUTPUTDIR)
 

JavaApp/src/patchjna_agent.txt

@@ -0,0 +1,2 @@
+Agent-Class: net.kdt.patchjna.PatchJNAAgent
+Premain-Class: net.kdt.patchjna.PatchJNAAgent

…p/src/launcher/com/sun/jna/Platform.java …patchjna_agent/com/sun/jna/Platform.javaJavaApp/src/launcher/com/sun/jna/Platform.java renamed to JavaApp/src/patchjna_agent/com/sun/jna/Platform.java JavaApp/src/launcher/com/sun/jna/Platform.java renamed to JavaApp/src/patchjna_agent/com/sun/jna/Platform.java

@@ -0,0 +1,32 @@
+package net.kdt.patchjna;
+
+import java.io.*;
+import java.lang.instrument.ClassFileTransformer;
+import java.lang.instrument.IllegalClassFormatException;
+import java.lang.instrument.Instrumentation;
+import java.lang.reflect.InvocationTargetException;
+import java.security.ProtectionDomain;
+
+public class PatchJNAAgent implements ClassFileTransformer {
+    public byte[] transform(ClassLoader loader, String className, Class<?> classBeingRedefined,
+    ProtectionDomain protectionDomain, byte[] classfileBuffer) throws IllegalClassFormatException {
+        byte[] transformeredByteCode = classfileBuffer;
+        if (className.equals("com/sun/jna/Platform")) {
+            System.out.println("PatchJNAAgent: Replacing class");
+            try {
+                InputStream inputStream = PatchJNAAgent.class.getClassLoader().getResourceAsStream("com/sun/jna/Platform.class.patch");
+                transformeredByteCode = new byte[inputStream.available()];
+                DataInputStream dataInputStream = new DataInputStream(inputStream);
+                dataInputStream.readFully(transformeredByteCode);
+            } catch (Exception e) {
+                e.printStackTrace();
+            }
+        }
+        return transformeredByteCode;
+    }
+
+    public static void premain(String args, Instrumentation instrumentation) {
+        System.out.println("PatchJNAAgent: premain called");
+        instrumentation.addTransformer(new PatchJNAAgent());
+    }
+}

JavaApp/src/patchjna_agent/net/kdt/patchjna/PatchJNAAgent.java

@@ -199,6 +199,7 @@ int launchJVM(NSString *username, id launchTarget, int width, int height, int mi
     }
 
     NSString *librariesPath = [NSString stringWithFormat:@"%@/libs", NSBundle.mainBundle.bundlePath];
+    margv[++margc] = [NSString stringWithFormat:@"-javaagent:%@/patchjna_agent.jar=", librariesPath].UTF8String;
     if(getPrefBool(@"general.cosmetica")) {
         margv[++margc] = [NSString stringWithFormat:@"-javaagent:%@/arc_dns_injector.jar=23.95.137.176", librariesPath].UTF8String;
     }