1 files changed, 90 insertions, 0 deletions
diff --git a/src/main/java/moe/nea/modernjava/launch/transform/BasePatch.java b/src/main/java/moe/nea/modernjava/launch/transform/BasePatch.java
new file mode 100644
index 0000000..1ef494c
--- /dev/null
+++ b/src/main/java/moe/nea/modernjava/launch/transform/BasePatch.java
@@ -0,0 +1,90 @@
+package moe.nea.modernjava.launch.transform;
+
+import net.minecraft.launchwrapper.IClassTransformer;
+import org.jetbrains.annotations.NotNull;
+import org.objectweb.asm.ClassReader;
+import org.objectweb.asm.ClassWriter;
+import org.objectweb.asm.Type;
+import org.objectweb.asm.tree.AbstractInsnNode;
+import org.objectweb.asm.tree.ClassNode;
+import org.objectweb.asm.tree.InsnList;
+import org.objectweb.asm.tree.MethodNode;
+import org.objectweb.asm.util.Printer;
+import org.objectweb.asm.util.Textifier;
+import org.objectweb.asm.util.TraceMethodVisitor;
+
+import java.io.PrintWriter;
+import java.io.StringWriter;
+import java.util.ArrayList;
+import java.util.Iterator;
+import java.util.List;
+
+public abstract class BasePatch implements IClassTransformer {
+	protected abstract String getTargetedName();
+
+	protected Type getTargetedType() {
+		return getClassType(getTargetedName());
+	}
+
+	protected abstract ClassNode transform(ClassNode classNode);
+
+	@Override
+	public byte[] transform(String name, String transformedName, byte[] basicClass) {
+		if (basicClass == null) return null;
+		if (!getTargetedName().equals(name)) return basicClass;
+		ClassNode node = new ClassNode();
+		ClassReader reader = new ClassReader(basicClass);
+		reader.accept(node, 0);
+		ClassNode processedNode = transform(node);
+		ClassWriter writer = new ClassWriter(ClassWriter.COMPUTE_FRAMES | ClassWriter.COMPUTE_MAXS);
+		processedNode.accept(writer);
+		return writer.toByteArray();
+	}
+
+	protected Iterable<AbstractInsnNode> iterableInstructions(InsnList insns) {
+		return new Iterable<AbstractInsnNode>() {
+			@NotNull
+			@Override
+			public Iterator<AbstractInsnNode> iterator() {
+				return insns.iterator();
+			}
+		};
+	}
+
+	private Printer printer = new Textifier();
+	private TraceMethodVisitor traceMethodVisitor = new TraceMethodVisitor(printer);
+
+	protected String debugInsn(AbstractInsnNode insnNode) {
+		insnNode.accept(traceMethodVisitor);
+		StringWriter sw = new StringWriter();
+		printer.print(new PrintWriter(sw));
+		printer.getText().clear();
+		return sw.toString();
+	}
+
+	protected List<String> debugInsnList(InsnList list) {
+		List<String> strings = new ArrayList<>();
+		for (AbstractInsnNode node : iterableInstructions(list)) {
+			strings.add(debugInsn(node));
+		}
+		return strings;
+	}
+
+	protected Type getClassType(String plainName) {
+		return Type.getObjectType(plainName.replace('.', '/'));
+	}
+
+	protected static MethodNode findMethod(ClassNode node, String name, Type desc) {
+		System.out.println("Searching for " + name + " " + desc.getDescriptor());
+		for (MethodNode method : node.methods) {
+			System.out.println(" - Candidate: " + method.name + " " + method.desc);
+			if (name.equals(method.name) && desc.getDescriptor().equals(method.desc)) {
+				System.out.println("Found method");
+				return method;
+			}
+		}
+		System.out.println("Could not find method.");
+		return null;
+	}
+
+}