ProtocolLib/ProtocolLib/src/main/java/com/comphenix/protocol/reflect/compiler/BoxingHelper.java

293 lines
8.2 KiB
Java

/*
* ProtocolLib - Bukkit server library that allows access to the Minecraft protocol.
* Copyright (C) 2012 Kristian S. Stangeland
*
* This program is free software; you can redistribute it and/or modify it under the terms of the
* GNU General Public License as published by the Free Software Foundation; either version 2 of
* the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
* without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
* See the GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along with this program;
* if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
* 02111-1307 USA
*/
package com.comphenix.protocol.reflect.compiler;
import net.sf.cglib.asm.*;
/**
* Used by the compiler to automatically box and unbox values.
*/
class BoxingHelper {
private final static Type BYTE_TYPE = Type.getObjectType("java/lang/Byte");
private final static Type BOOLEAN_TYPE = Type.getObjectType("java/lang/Boolean");
private final static Type SHORT_TYPE = Type.getObjectType("java/lang/Short");
private final static Type CHARACTER_TYPE = Type.getObjectType("java/lang/Character");
private final static Type INTEGER_TYPE = Type.getObjectType("java/lang/Integer");
private final static Type FLOAT_TYPE = Type.getObjectType("java/lang/Float");
private final static Type LONG_TYPE = Type.getObjectType("java/lang/Long");
private final static Type DOUBLE_TYPE = Type.getObjectType("java/lang/Double");
private final static Type NUMBER_TYPE = Type.getObjectType("java/lang/Number");
private final static Type OBJECT_TYPE = Type.getObjectType("java/lang/Object");
private final static MethodDescriptor BOOLEAN_VALUE = MethodDescriptor.getMethod("boolean booleanValue()");
private final static MethodDescriptor CHAR_VALUE = MethodDescriptor.getMethod("char charValue()");
private final static MethodDescriptor INT_VALUE = MethodDescriptor.getMethod("int intValue()");
private final static MethodDescriptor FLOAT_VALUE = MethodDescriptor.getMethod("float floatValue()");
private final static MethodDescriptor LONG_VALUE = MethodDescriptor.getMethod("long longValue()");
private final static MethodDescriptor DOUBLE_VALUE = MethodDescriptor.getMethod("double doubleValue()");
private MethodVisitor mv;
public BoxingHelper(MethodVisitor mv) {
this.mv = mv;
}
/**
* Generates the instructions to box the top stack value. This value is
* replaced by its boxed equivalent on top of the stack.
*
* @param type the type of the top stack value.
*/
public void box(final Type type){
if(type.getSort() == Type.OBJECT || type.getSort() == Type.ARRAY) {
return;
}
if(type == Type.VOID_TYPE) {
push((String) null);
} else {
Type boxed = type;
switch(type.getSort()) {
case Type.BYTE:
boxed = BYTE_TYPE;
break;
case Type.BOOLEAN:
boxed = BOOLEAN_TYPE;
break;
case Type.SHORT:
boxed = SHORT_TYPE;
break;
case Type.CHAR:
boxed = CHARACTER_TYPE;
break;
case Type.INT:
boxed = INTEGER_TYPE;
break;
case Type.FLOAT:
boxed = FLOAT_TYPE;
break;
case Type.LONG:
boxed = LONG_TYPE;
break;
case Type.DOUBLE:
boxed = DOUBLE_TYPE;
break;
}
newInstance(boxed);
if(type.getSize() == 2) {
// Pp -> Ppo -> oPpo -> ooPpo -> ooPp -> o
dupX2();
dupX2();
pop();
} else {
// p -> po -> opo -> oop -> o
dupX1();
swap();
}
invokeConstructor(boxed, new MethodDescriptor("<init>", Type.VOID_TYPE, new Type[] {type}));
}
}
/**
* Generates the instruction to invoke a constructor.
*
* @param type the class in which the constructor is defined.
* @param method the constructor to be invoked.
*/
public void invokeConstructor(final Type type, final MethodDescriptor method){
invokeInsn(Opcodes.INVOKESPECIAL, type, method);
}
/**
* Generates a DUP_X1 instruction.
*/
public void dupX1(){
mv.visitInsn(Opcodes.DUP_X1);
}
/**
* Generates a DUP_X2 instruction.
*/
public void dupX2(){
mv.visitInsn(Opcodes.DUP_X2);
}
/**
* Generates a POP instruction.
*/
public void pop(){
mv.visitInsn(Opcodes.POP);
}
/**
* Generates a SWAP instruction.
*/
public void swap(){
mv.visitInsn(Opcodes.SWAP);
}
/**
* Generates the instruction to push the given value on the stack.
*
* @param value the value to be pushed on the stack.
*/
public void push(final boolean value){
push(value ? 1 : 0);
}
/**
* Generates the instruction to push the given value on the stack.
*
* @param value the value to be pushed on the stack.
*/
public void push(final int value) {
if (value >= -1 && value <= 5) {
mv.visitInsn(Opcodes.ICONST_0 + value);
} else if (value >= Byte.MIN_VALUE && value <= Byte.MAX_VALUE) {
mv.visitIntInsn(Opcodes.BIPUSH, value);
} else if (value >= Short.MIN_VALUE && value <= Short.MAX_VALUE) {
mv.visitIntInsn(Opcodes.SIPUSH, value);
} else {
mv.visitLdcInsn(new Integer(value));
}
}
/**
* Generates the instruction to create a new object.
*
* @param type the class of the object to be created.
*/
public void newInstance(final Type type){
typeInsn(Opcodes.NEW, type);
}
/**
* Generates the instruction to push the given value on the stack.
*
* @param value the value to be pushed on the stack. May be <tt>null</tt>.
*/
public void push(final String value) {
if (value == null) {
mv.visitInsn(Opcodes.ACONST_NULL);
} else {
mv.visitLdcInsn(value);
}
}
/**
* Generates the instructions to unbox the top stack value. This value is
* replaced by its unboxed equivalent on top of the stack.
*
* @param type
* the type of the top stack value.
*/
public void unbox(final Type type){
Type t = NUMBER_TYPE;
MethodDescriptor sig = null;
switch(type.getSort()) {
case Type.VOID:
return;
case Type.CHAR:
t = CHARACTER_TYPE;
sig = CHAR_VALUE;
break;
case Type.BOOLEAN:
t = BOOLEAN_TYPE;
sig = BOOLEAN_VALUE;
break;
case Type.DOUBLE:
sig = DOUBLE_VALUE;
break;
case Type.FLOAT:
sig = FLOAT_VALUE;
break;
case Type.LONG:
sig = LONG_VALUE;
break;
case Type.INT:
case Type.SHORT:
case Type.BYTE:
sig = INT_VALUE;
}
if(sig == null) {
checkCast(type);
} else {
checkCast(t);
invokeVirtual(t, sig);
}
}
/**
* Generates the instruction to check that the top stack value is of the
* given type.
*
* @param type a class or interface type.
*/
public void checkCast(final Type type){
if(!type.equals(OBJECT_TYPE)) {
typeInsn(Opcodes.CHECKCAST, type);
}
}
/**
* Generates the instruction to invoke a normal method.
*
* @param owner the class in which the method is defined.
* @param method the method to be invoked.
*/
public void invokeVirtual(final Type owner, final MethodDescriptor method){
invokeInsn(Opcodes.INVOKEVIRTUAL, owner, method);
}
/**
* Generates an invoke method instruction.
*
* @param opcode the instruction's opcode.
* @param type the class in which the method is defined.
* @param method the method to be invoked.
*/
private void invokeInsn(final int opcode, final Type type, final MethodDescriptor method){
String owner = type.getSort() == Type.ARRAY ? type.getDescriptor() : type.getInternalName();
mv.visitMethodInsn(opcode, owner, method.getName(), method.getDescriptor());
}
/**
* Generates a type dependent instruction.
*
* @param opcode the instruction's opcode.
* @param type the instruction's operand.
*/
private void typeInsn(final int opcode, final Type type){
String desc;
if(type.getSort() == Type.ARRAY) {
desc = type.getDescriptor();
} else {
desc = type.getInternalName();
}
mv.visitTypeInsn(opcode, desc);
}
}