| import java.lang.instrument.ClassFileTransformer; |
| import java.lang.instrument.Instrumentation; |
| import java.security.ProtectionDomain; |
| import java.util.HashSet; |
| import java.util.Set; |
| import jdk.internal.org.objectweb.asm.*; |
|
|
| |
| public final class PlayerSaveDiagnostics { |
| public static void premain(String args, Instrumentation instrumentation) { |
| instrumentation.addTransformer(new ClassFileTransformer() { |
| public byte[] transform(ClassLoader loader, String name, Class<?> type, |
| ProtectionDomain domain, byte[] bytes) { |
| if (!"net/minecraft/class_29".equals(name)) return null; |
| try { |
| ClassReader reader = new ClassReader(bytes); |
| ClassWriter writer = new ClassWriter(reader, ClassWriter.COMPUTE_MAXS); |
| int[] injected = {0}; |
| reader.accept(new ClassVisitor(Opcodes.ASM8, writer) { |
| public MethodVisitor visitMethod(int access, String method, String desc, |
| String signature, String[] exceptions) { |
| MethodVisitor delegate = super.visitMethod(access, method, desc, signature, exceptions); |
| if (!"method_262".equals(method)) return delegate; |
| return new MethodVisitor(Opcodes.ASM8, delegate) { |
| final Set<Label> handlers = new HashSet<>(); |
| boolean pending; |
| public void visitTryCatchBlock(Label start, Label end, Label handler, String caught) { |
| if ("java/lang/Exception".equals(caught)) handlers.add(handler); |
| super.visitTryCatchBlock(start, end, handler, caught); |
| } |
| public void visitLabel(Label label) { |
| super.visitLabel(label); |
| if (handlers.contains(label)) pending = true; |
| } |
| public void visitVarInsn(int opcode, int variable) { |
| if (pending && opcode == Opcodes.ASTORE) { |
| |
| super.visitInsn(Opcodes.DUP); |
| super.visitMethodInsn(Opcodes.INVOKEVIRTUAL, "java/lang/Throwable", |
| "printStackTrace", "()V", false); |
| pending = false; |
| injected[0]++; |
| } |
| super.visitVarInsn(opcode, variable); |
| } |
| }; |
| } |
| }, 0); |
| System.err.println("[player-save-diagnostics] exception logging hooks=" + injected[0]); |
| return injected[0] == 0 ? null : writer.toByteArray(); |
| } catch (Throwable failure) { |
| System.err.println("[player-save-diagnostics] skipped: " + failure); |
| return null; |
| } |
| } |
| }); |
| } |
| } |
|
|
