Rewrite ClassInheritanceProvider

src/main/java/catserver/server/remapper/ClassInheritanceProvider.java

@@ -1,7 +1,12 @@
 package catserver.server.remapper;
 
 import net.md_5.specialsource.provider.InheritanceProvider;
+import net.minecraft.launchwrapper.Launch;
+import org.objectweb.asm.ClassReader;
+import org.objectweb.asm.ClassVisitor;
+import org.objectweb.asm.Opcodes;
 
+import java.io.InputStream;
 import java.util.Collection;
 import java.util.HashSet;
 
@@ -11,26 +16,59 @@ public class ClassInheritanceProvider implements InheritanceProvider {
     @Override
     public Collection<String> getParents(String className) {
         className = ReflectionTransformer.remapper.map(className);
+        try (InputStream is = Launch.classLoader.getResourceAsStream((className + ".class"))) {
+            if (is == null) {
+                return null;
+            }
+
+            ClassReader reader = new ClassReader(is);
+            ParentVisitor visitor = new ParentVisitor();
+
+            reader.accept(visitor, ClassReader.SKIP_CODE | ClassReader.SKIP_DEBUG | ClassReader.SKIP_FRAMES);
+
+            Collection<String> parents = new HashSet<>();
 
-        try {
-            Collection<String> parents = new HashSet<String>();
-            Class<?> reference = Class.forName(className.replace('/', '.'), false, this.getClass().getClassLoader()/*RemappedMethods.loader*/);
-            Class<?> extend = reference.getSuperclass();
-            if (extend != null) {
-                parents.add(reverseMap(extend));
+            if (visitor.getSuperName() != null && !visitor.getSuperName().equals("java/lang/Object")) {
+                parents.add(reverseMap(visitor.getSuperName()));
             }
 
-            for (Class<?> inter : reference.getInterfaces()) {
+            for (String inter : visitor.getInterfaces()) {
                 if (inter != null) {
                     parents.add(reverseMap(inter));
                 }
             }
 
             return parents;
+
         } catch (Exception e) {
-            // Empty catch block
+            System.err.println("Failed to read class for parents: " + className);
         }
+
         return null;
     }
 
+    private static class ParentVisitor extends ClassVisitor {
+        private String superName;
+        private String[] interfaces;
+
+        public ParentVisitor() {
+            super(Opcodes.ASM9);
+        }
+
+        @Override
+        public void visit(int version, int access, String name, String signature, String superName, String[] interfaces) {
+            this.superName = superName;
+            this.interfaces = interfaces;
+            super.visit(version, access, name, signature, superName, interfaces);
+        }
+
+        public String getSuperName() {
+            return superName;
+        }
+
+        public String[] getInterfaces() {
+            return interfaces == null ? new String[0] : interfaces;
+        }
+    }
+
 }