net.bytebuddy.implementation.bytecode.Removal Maven / Gradle / Ivy
/*
* Copyright 2014 - Present Rafael Winterhalter
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package net.bytebuddy.implementation.bytecode;
import net.bytebuddy.description.type.TypeDefinition;
import net.bytebuddy.implementation.Implementation;
import org.objectweb.asm.MethodVisitor;
import org.objectweb.asm.Opcodes;
/**
* Removes a value from the operand stack.
*/
public enum Removal implements StackManipulation {
/**
* A removal of no value. This corresponds a no-op instruction.
*/
ZERO(StackSize.ZERO, Opcodes.NOP) {
/** {@inheritDoc} */
public Size apply(MethodVisitor methodVisitor, Implementation.Context implementationContext) {
return Size.ZERO;
}
},
/**
* A removal of a single-sized value.
*/
SINGLE(StackSize.SINGLE, Opcodes.POP),
/**
* A removal of a double-sized value.
*/
DOUBLE(StackSize.DOUBLE, Opcodes.POP2);
/**
* The size impact of the removal onto the operand stack.
*/
private final Size size;
/**
* The opcode to execute for the removal.
*/
private final int opcode;
/**
* Creates a new removal stack manipulation.
*
* @param stackSize The size impact of the removal onto the operand stack.
* @param opcode The opcode to execute for the removal.
*/
Removal(StackSize stackSize, int opcode) {
size = stackSize.toDecreasingSize();
this.opcode = opcode;
}
/**
* Removes a value from the operand stack dependant of its size.
*
* @param typeDefinition The type to remove from the stack.
* @return A stack manipulation that represents the removal.
*/
public static StackManipulation of(TypeDefinition typeDefinition) {
switch (typeDefinition.getStackSize()) {
case SINGLE:
return SINGLE;
case DOUBLE:
return DOUBLE;
case ZERO:
return ZERO;
default:
throw new AssertionError();
}
}
/**
* {@inheritDoc}
*/
public boolean isValid() {
return true;
}
/**
* {@inheritDoc}
*/
public Size apply(MethodVisitor methodVisitor, Implementation.Context implementationContext) {
methodVisitor.visitInsn(opcode);
return size;
}
}