File size: 3,483 Bytes
24010a2 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 | 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.*;
/** Log the exception vanilla 1.19 discards when player saving fails. */
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) {
// Preserve the original exception and catch behavior.
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;
}
}
});
}
}
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