com.fitbur.bytebuddy.implementation.bytecode.Duplication Maven / Gradle / Ivy
package com.fitbur.bytebuddy.implementation.bytecode;
import com.fitbur.bytebuddy.description.type.TypeDescription;
import com.fitbur.bytebuddy.implementation.Implementation;
import com.fitbur.bytebuddy.jar.asm.MethodVisitor;
import com.fitbur.bytebuddy.jar.asm.Opcodes;
/**
* Duplicates a value that is lying on top of the stack.
*/
public enum Duplication implements StackManipulation {
/**
* A duplication of no values. This corresponds a no-op instruction.
*/
ZERO(StackSize.ZERO, Opcodes.NOP) {
@Override
public Size apply(MethodVisitor methodVisitor, Implementation.Context implementationContext) {
return new Size(0, 0);
}
},
/**
* A duplication of a single-sized stack values.
*/
SINGLE(StackSize.SINGLE, Opcodes.DUP),
/**
* A duplication of a double-sized stack value.
*/
DOUBLE(StackSize.DOUBLE, Opcodes.DUP2);
/**
* The size representing the impact of applying the duplication onto the operand stack.
*/
private final Size size;
/**
* The opcode that represents the manipulation.
*/
private final int opcode;
/**
* Creates a new duplication.
*
* @param stackSize The size representing the impact of applying the duplication onto the operand stack.
* @param opcode The opcode that represents the manipulation.
*/
Duplication(StackSize stackSize, int opcode) {
size = stackSize.toIncreasingSize();
this.opcode = opcode;
}
/**
* Duplicates a value given its type.
*
* @param typeDescription The type to be duplicated.
* @return A stack manipulation that duplicates the given type.
*/
public static StackManipulation duplicate(TypeDescription typeDescription) {
switch (typeDescription.getStackSize()) {
case SINGLE:
return SINGLE;
case DOUBLE:
return DOUBLE;
case ZERO:
return ZERO;
default:
throw new AssertionError();
}
}
@Override
public boolean isValid() {
return true;
}
@Override
public Size apply(MethodVisitor methodVisitor, Implementation.Context implementationContext) {
methodVisitor.visitInsn(opcode);
return size;
}
@Override
public String toString() {
return "Duplication." + name();
}
}