A utility class for asm stuff; part of a larger project not on git yet

ASMUtil.java

package org.jmt.alan.util;

import java.util.HashMap;
import java.util.Map;

import org.objectweb.asm.Opcodes;
import org.objectweb.asm.Type;
import org.objectweb.asm.tree.AbstractInsnNode;
import org.objectweb.asm.tree.FieldInsnNode;
import org.objectweb.asm.tree.InsnList;
import org.objectweb.asm.tree.InvokeDynamicInsnNode;
import org.objectweb.asm.tree.LabelNode;
import org.objectweb.asm.tree.LdcInsnNode;
import org.objectweb.asm.tree.MethodInsnNode;

public class ASMUtil {

	public static InsnList cloneInsnList(InsnList il) {
		Map<LabelNode, LabelNode> labelMap = new HashMap<>();
		InsnList out = new InsnList();
		il.forEach(i -> {
			if (i instanceof LabelNode) {
				LabelNode ln = (LabelNode) i;
				LabelNode nln = new LabelNode();
				labelMap.put(ln, nln);
				out.add(nln);
			} else {
				out.add(i.clone(labelMap));
			}
		});
		return out;
	}
	
	public static Map<LabelNode, LabelNode> getLabelMap(InsnList il) {
		Map<LabelNode, LabelNode> labelMap = new HashMap<>();
		il.forEach(i -> {
			if (i instanceof LabelNode) {
				LabelNode ln = (LabelNode) i;
				LabelNode nln = new LabelNode();
				labelMap.put(ln, nln);
			}
		});
		return labelMap;
	}
	
	/**
	 * Returns true if the last result in the Instruction list returns a Type 2 value
	 * 
	 * This is needed because of how java handles values.
	 *  
	 * @param il
	 * @return
	 */
	public static boolean isType2(InsnList il) {
		AbstractInsnNode ain = il.getLast();
		switch (ain.getOpcode()) {
		// May be type 2 depending on context
		case Opcodes.LDC:
			LdcInsnNode lin = (LdcInsnNode) ain;
			if (lin.cst instanceof Double || lin.cst instanceof Long)
				return true;
			return false;
		case Opcodes.DUP2:
		case Opcodes.DUP2_X1:
		case Opcodes.DUP2_X2:
			// Annoyingly depends on previous insn so recurse
			InsnList tmp = cloneInsnList(il);
			tmp.remove(tmp.getLast());
			return isType2(tmp);
		case Opcodes.GETSTATIC:
		case Opcodes.GETFIELD:
			FieldInsnNode fin = (FieldInsnNode) ain;
			Type t = Type.getType(fin.desc);
			if (t.getSort() == Type.LONG || t.getSort() == Type.DOUBLE) {
				return true;
			} else {
				return false;
			}
		case Opcodes.INVOKEVIRTUAL:
		case Opcodes.INVOKESPECIAL:
		case Opcodes.INVOKESTATIC:
		case Opcodes.INVOKEINTERFACE:
			MethodInsnNode min = (MethodInsnNode) ain;
			Type rt = Type.getReturnType(min.desc);
			if (rt.getSort() == Type.LONG || rt.getSort() == Type.DOUBLE) {
				return true;
			} else {
				return false;
			}
		case Opcodes.INVOKEDYNAMIC:
			InvokeDynamicInsnNode idin = (InvokeDynamicInsnNode) ain;
			Type dt = Type.getReturnType(idin.desc);
			if (dt.getSort() == Type.LONG || dt.getSort() == Type.DOUBLE) {
				return true;
			} else {
				return false;
			}
		// Automatically Type 2
		case Opcodes.DCONST_0:
		case Opcodes.DCONST_1:
		case Opcodes.LCONST_0:
		case Opcodes.LCONST_1:
		case Opcodes.LLOAD:
		case Opcodes.DLOAD:
		case Opcodes.LALOAD:
		case Opcodes.DALOAD:
		case Opcodes.LADD:
		case Opcodes.DADD:
		case Opcodes.LSUB:
		case Opcodes.DSUB:
		case Opcodes.LMUL:
		case Opcodes.DMUL:
		case Opcodes.LDIV:
		case Opcodes.DDIV:
		case Opcodes.LREM:
		case Opcodes.DREM:
		case Opcodes.LNEG:
		case Opcodes.DNEG:
		case Opcodes.LSHL:
		case Opcodes.LSHR:
		case Opcodes.LUSHR:
		case Opcodes.LAND:
		case Opcodes.LOR:
		case Opcodes.LXOR:
		case Opcodes.I2L:
		case Opcodes.I2D:
		case Opcodes.L2D:
		case Opcodes.F2L:
		case Opcodes.F2D:
		case Opcodes.D2L:
			return true;
		default:
			return false;
		}
	}
}