scouter.org.objectweb.asm.commons.GeneratorAdapter Maven / Gradle / Ivy
// ASM: a very small and fast Java bytecode manipulation framework
// Copyright (c) 2000-2011 INRIA, France Telecom
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions
// are met:
// 1. Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// 2. Redistributions in binary form must reproduce the above copyright
// notice, this list of conditions and the following disclaimer in the
// documentation and/or other materials provided with the distribution.
// 3. Neither the name of the copyright holders nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
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package scouter.org.objectweb.asm.commons;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import scouter.org.objectweb.asm.ClassVisitor;
import scouter.org.objectweb.asm.ConstantDynamic;
import scouter.org.objectweb.asm.Handle;
import scouter.org.objectweb.asm.Label;
import scouter.org.objectweb.asm.MethodVisitor;
import scouter.org.objectweb.asm.Opcodes;
import scouter.org.objectweb.asm.Type;
/**
* A {@link MethodVisitor} with convenient methods to generate code. For example, using this
* adapter, the class below
*
*
* public class Example {
* public static void main(String[] args) {
* System.out.println("Hello world!");
* }
* }
*
*
* can be generated as follows:
*
*
* ClassWriter cw = new ClassWriter(0);
* cw.visit(V1_1, ACC_PUBLIC, "Example", null, "java/lang/Object", null);
*
* Method m = Method.getMethod("void <init> ()");
* GeneratorAdapter mg = new GeneratorAdapter(ACC_PUBLIC, m, null, null, cw);
* mg.loadThis();
* mg.invokeConstructor(Type.getType(Object.class), m);
* mg.returnValue();
* mg.endMethod();
*
* m = Method.getMethod("void main (String[])");
* mg = new GeneratorAdapter(ACC_PUBLIC + ACC_STATIC, m, null, null, cw);
* mg.getStatic(Type.getType(System.class), "out", Type.getType(PrintStream.class));
* mg.push("Hello world!");
* mg.invokeVirtual(Type.getType(PrintStream.class),
* Method.getMethod("void println (String)"));
* mg.returnValue();
* mg.endMethod();
*
* cw.visitEnd();
*
*
* @author Juozas Baliuka
* @author Chris Nokleberg
* @author Eric Bruneton
* @author Prashant Deva
*/
public class GeneratorAdapter extends LocalVariablesSorter {
private static final String CLASS_DESCRIPTOR = "Ljava/lang/Class;";
private static final Type BYTE_TYPE = Type.getObjectType("java/lang/Byte");
private static final Type BOOLEAN_TYPE = Type.getObjectType("java/lang/Boolean");
private static final Type SHORT_TYPE = Type.getObjectType("java/lang/Short");
private static final Type CHARACTER_TYPE = Type.getObjectType("java/lang/Character");
private static final Type INTEGER_TYPE = Type.getObjectType("java/lang/Integer");
private static final Type FLOAT_TYPE = Type.getObjectType("java/lang/Float");
private static final Type LONG_TYPE = Type.getObjectType("java/lang/Long");
private static final Type DOUBLE_TYPE = Type.getObjectType("java/lang/Double");
private static final Type NUMBER_TYPE = Type.getObjectType("java/lang/Number");
private static final Type OBJECT_TYPE = Type.getObjectType("java/lang/Object");
private static final Method BOOLEAN_VALUE = Method.getMethod("boolean booleanValue()");
private static final Method CHAR_VALUE = Method.getMethod("char charValue()");
private static final Method INT_VALUE = Method.getMethod("int intValue()");
private static final Method FLOAT_VALUE = Method.getMethod("float floatValue()");
private static final Method LONG_VALUE = Method.getMethod("long longValue()");
private static final Method DOUBLE_VALUE = Method.getMethod("double doubleValue()");
/** Constant for the {@link #math} method. */
public static final int ADD = Opcodes.IADD;
/** Constant for the {@link #math} method. */
public static final int SUB = Opcodes.ISUB;
/** Constant for the {@link #math} method. */
public static final int MUL = Opcodes.IMUL;
/** Constant for the {@link #math} method. */
public static final int DIV = Opcodes.IDIV;
/** Constant for the {@link #math} method. */
public static final int REM = Opcodes.IREM;
/** Constant for the {@link #math} method. */
public static final int NEG = Opcodes.INEG;
/** Constant for the {@link #math} method. */
public static final int SHL = Opcodes.ISHL;
/** Constant for the {@link #math} method. */
public static final int SHR = Opcodes.ISHR;
/** Constant for the {@link #math} method. */
public static final int USHR = Opcodes.IUSHR;
/** Constant for the {@link #math} method. */
public static final int AND = Opcodes.IAND;
/** Constant for the {@link #math} method. */
public static final int OR = Opcodes.IOR;
/** Constant for the {@link #math} method. */
public static final int XOR = Opcodes.IXOR;
/** Constant for the {@link #ifCmp} method. */
public static final int EQ = Opcodes.IFEQ;
/** Constant for the {@link #ifCmp} method. */
public static final int NE = Opcodes.IFNE;
/** Constant for the {@link #ifCmp} method. */
public static final int LT = Opcodes.IFLT;
/** Constant for the {@link #ifCmp} method. */
public static final int GE = Opcodes.IFGE;
/** Constant for the {@link #ifCmp} method. */
public static final int GT = Opcodes.IFGT;
/** Constant for the {@link #ifCmp} method. */
public static final int LE = Opcodes.IFLE;
/** The access flags of the visited method. */
private final int access;
/** The name of the visited method. */
private final String name;
/** The return type of the visited method. */
private final Type returnType;
/** The argument types of the visited method. */
private final Type[] argumentTypes;
/** The types of the local variables of the visited method. */
private final List localTypes = new ArrayList();
/**
* Constructs a new {@link GeneratorAdapter}. Subclasses must not use this constructor.
* Instead, they must use the {@link #GeneratorAdapter(int, MethodVisitor, int, String, String)}
* version.
*
* @param methodVisitor the method visitor to which this adapter delegates calls.
* @param access the method's access flags (see {@link Opcodes}).
* @param name the method's name.
* @param descriptor the method's descriptor (see {@link Type}).
* @throws IllegalStateException if a subclass calls this constructor.
*/
public GeneratorAdapter(
final MethodVisitor methodVisitor,
final int access,
final String name,
final String descriptor) {
this(Opcodes.ASM7, methodVisitor, access, name, descriptor);
if (getClass() != GeneratorAdapter.class) {
throw new IllegalStateException();
}
}
/**
* Constructs a new {@link GeneratorAdapter}.
*
* @param api the ASM API version implemented by this visitor. Must be one of {@link
* Opcodes#ASM4}, {@link Opcodes#ASM5}, {@link Opcodes#ASM6} or {@link Opcodes#ASM7}.
* @param methodVisitor the method visitor to which this adapter delegates calls.
* @param access the method's access flags (see {@link Opcodes}).
* @param name the method's name.
* @param descriptor the method's descriptor (see {@link Type}).
*/
protected GeneratorAdapter(
final int api,
final MethodVisitor methodVisitor,
final int access,
final String name,
final String descriptor) {
super(api, access, descriptor, methodVisitor);
this.access = access;
this.name = name;
this.returnType = Type.getReturnType(descriptor);
this.argumentTypes = Type.getArgumentTypes(descriptor);
}
/**
* Constructs a new {@link GeneratorAdapter}. Subclasses must not use this constructor.
* Instead, they must use the {@link #GeneratorAdapter(int, MethodVisitor, int, String, String)}
* version.
*
* @param access access flags of the adapted method.
* @param method the adapted method.
* @param methodVisitor the method visitor to which this adapter delegates calls.
*/
public GeneratorAdapter(
final int access, final Method method, final MethodVisitor methodVisitor) {
this(methodVisitor, access, method.getName(), method.getDescriptor());
}
/**
* Constructs a new {@link GeneratorAdapter}. Subclasses must not use this constructor.
* Instead, they must use the {@link #GeneratorAdapter(int, MethodVisitor, int, String, String)}
* version.
*
* @param access access flags of the adapted method.
* @param method the adapted method.
* @param signature the signature of the adapted method (may be {@literal null}).
* @param exceptions the exceptions thrown by the adapted method (may be {@literal null}).
* @param classVisitor the class visitor to which this adapter delegates calls.
*/
public GeneratorAdapter(
final int access,
final Method method,
final String signature,
final Type[] exceptions,
final ClassVisitor classVisitor) {
this(
access,
method,
classVisitor.visitMethod(
access,
method.getName(),
method.getDescriptor(),
signature,
getInternalNames(exceptions)));
}
/**
* Returns the internal names of the given types.
*
* @param types a set of types.
* @return the internal names of the given types.
*/
private static String[] getInternalNames(final Type[] types) {
if (types == null) {
return null;
}
String[] names = new String[types.length];
for (int i = 0; i < names.length; ++i) {
names[i] = types[i].getInternalName();
}
return names;
}
public int getAccess() {
return access;
}
public String getName() {
return name;
}
public Type getReturnType() {
return returnType;
}
public Type[] getArgumentTypes() {
return argumentTypes.clone();
}
// -----------------------------------------------------------------------------------------------
// Instructions to push constants on the stack
// -----------------------------------------------------------------------------------------------
/**
* 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(value);
}
}
/**
* 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 long value) {
if (value == 0L || value == 1L) {
mv.visitInsn(Opcodes.LCONST_0 + (int) value);
} else {
mv.visitLdcInsn(value);
}
}
/**
* 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 float value) {
int bits = Float.floatToIntBits(value);
if (bits == 0L || bits == 0x3F800000 || bits == 0x40000000) { // 0..2
mv.visitInsn(Opcodes.FCONST_0 + (int) value);
} else {
mv.visitLdcInsn(value);
}
}
/**
* 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 double value) {
long bits = Double.doubleToLongBits(value);
if (bits == 0L || bits == 0x3FF0000000000000L) { // +0.0d and 1.0d
mv.visitInsn(Opcodes.DCONST_0 + (int) value);
} else {
mv.visitLdcInsn(value);
}
}
/**
* Generates the instruction to push the given value on the stack.
*
* @param value the value to be pushed on the stack. May be {@literal null}.
*/
public void push(final String value) {
if (value == null) {
mv.visitInsn(Opcodes.ACONST_NULL);
} else {
mv.visitLdcInsn(value);
}
}
/**
* 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 Type value) {
if (value == null) {
mv.visitInsn(Opcodes.ACONST_NULL);
} else {
switch (value.getSort()) {
case Type.BOOLEAN:
mv.visitFieldInsn(Opcodes.GETSTATIC, "java/lang/Boolean", "TYPE", CLASS_DESCRIPTOR);
break;
case Type.CHAR:
mv.visitFieldInsn(Opcodes.GETSTATIC, "java/lang/Character", "TYPE", CLASS_DESCRIPTOR);
break;
case Type.BYTE:
mv.visitFieldInsn(Opcodes.GETSTATIC, "java/lang/Byte", "TYPE", CLASS_DESCRIPTOR);
break;
case Type.SHORT:
mv.visitFieldInsn(Opcodes.GETSTATIC, "java/lang/Short", "TYPE", CLASS_DESCRIPTOR);
break;
case Type.INT:
mv.visitFieldInsn(Opcodes.GETSTATIC, "java/lang/Integer", "TYPE", CLASS_DESCRIPTOR);
break;
case Type.FLOAT:
mv.visitFieldInsn(Opcodes.GETSTATIC, "java/lang/Float", "TYPE", CLASS_DESCRIPTOR);
break;
case Type.LONG:
mv.visitFieldInsn(Opcodes.GETSTATIC, "java/lang/Long", "TYPE", CLASS_DESCRIPTOR);
break;
case Type.DOUBLE:
mv.visitFieldInsn(Opcodes.GETSTATIC, "java/lang/Double", "TYPE", CLASS_DESCRIPTOR);
break;
default:
mv.visitLdcInsn(value);
break;
}
}
}
/**
* Generates the instruction to push a handle on the stack.
*
* @param handle the handle to be pushed on the stack.
*/
public void push(final Handle handle) {
if (handle == null) {
mv.visitInsn(Opcodes.ACONST_NULL);
} else {
mv.visitLdcInsn(handle);
}
}
/**
* Generates the instruction to push a constant dynamic on the stack.
*
* @param constantDynamic the constant dynamic to be pushed on the stack.
*/
public void push(final ConstantDynamic constantDynamic) {
if (constantDynamic == null) {
mv.visitInsn(Opcodes.ACONST_NULL);
} else {
mv.visitLdcInsn(constantDynamic);
}
}
// -----------------------------------------------------------------------------------------------
// Instructions to load and store method arguments
// -----------------------------------------------------------------------------------------------
/**
* Returns the index of the given method argument in the frame's local variables array.
*
* @param arg the index of a method argument.
* @return the index of the given method argument in the frame's local variables array.
*/
private int getArgIndex(final int arg) {
int index = (access & Opcodes.ACC_STATIC) == 0 ? 1 : 0;
for (int i = 0; i < arg; i++) {
index += argumentTypes[i].getSize();
}
return index;
}
/**
* Generates the instruction to push a local variable on the stack.
*
* @param type the type of the local variable to be loaded.
* @param index an index in the frame's local variables array.
*/
private void loadInsn(final Type type, final int index) {
mv.visitVarInsn(type.getOpcode(Opcodes.ILOAD), index);
}
/**
* Generates the instruction to store the top stack value in a local variable.
*
* @param type the type of the local variable to be stored.
* @param index an index in the frame's local variables array.
*/
private void storeInsn(final Type type, final int index) {
mv.visitVarInsn(type.getOpcode(Opcodes.ISTORE), index);
}
/** Generates the instruction to load 'this' on the stack. */
public void loadThis() {
if ((access & Opcodes.ACC_STATIC) != 0) {
throw new IllegalStateException("no 'this' pointer within static method");
}
mv.visitVarInsn(Opcodes.ALOAD, 0);
}
/**
* Generates the instruction to load the given method argument on the stack.
*
* @param arg the index of a method argument.
*/
public void loadArg(final int arg) {
loadInsn(argumentTypes[arg], getArgIndex(arg));
}
/**
* Generates the instructions to load the given method arguments on the stack.
*
* @param arg the index of the first method argument to be loaded.
* @param count the number of method arguments to be loaded.
*/
public void loadArgs(final int arg, final int count) {
int index = getArgIndex(arg);
for (int i = 0; i < count; ++i) {
Type argumentType = argumentTypes[arg + i];
loadInsn(argumentType, index);
index += argumentType.getSize();
}
}
/** Generates the instructions to load all the method arguments on the stack. */
public void loadArgs() {
loadArgs(0, argumentTypes.length);
}
/**
* Generates the instructions to load all the method arguments on the stack, as a single object
* array.
*/
public void loadArgArray() {
push(argumentTypes.length);
newArray(OBJECT_TYPE);
for (int i = 0; i < argumentTypes.length; i++) {
dup();
push(i);
loadArg(i);
box(argumentTypes[i]);
arrayStore(OBJECT_TYPE);
}
}
/**
* Generates the instruction to store the top stack value in the given method argument.
*
* @param arg the index of a method argument.
*/
public void storeArg(final int arg) {
storeInsn(argumentTypes[arg], getArgIndex(arg));
}
// -----------------------------------------------------------------------------------------------
// Instructions to load and store local variables
// -----------------------------------------------------------------------------------------------
/**
* Returns the type of the given local variable.
*
* @param local a local variable identifier, as returned by {@link
* LocalVariablesSorter#newLocal(Type)}.
* @return the type of the given local variable.
*/
public Type getLocalType(final int local) {
return localTypes.get(local - firstLocal);
}
@Override
protected void setLocalType(final int local, final Type type) {
int index = local - firstLocal;
while (localTypes.size() < index + 1) {
localTypes.add(null);
}
localTypes.set(index, type);
}
/**
* Generates the instruction to load the given local variable on the stack.
*
* @param local a local variable identifier, as returned by {@link
* LocalVariablesSorter#newLocal(Type)}.
*/
public void loadLocal(final int local) {
loadInsn(getLocalType(local), local);
}
/**
* Generates the instruction to load the given local variable on the stack.
*
* @param local a local variable identifier, as returned by {@link
* LocalVariablesSorter#newLocal(Type)}.
* @param type the type of this local variable.
*/
public void loadLocal(final int local, final Type type) {
setLocalType(local, type);
loadInsn(type, local);
}
/**
* Generates the instruction to store the top stack value in the given local variable.
*
* @param local a local variable identifier, as returned by {@link
* LocalVariablesSorter#newLocal(Type)}.
*/
public void storeLocal(final int local) {
storeInsn(getLocalType(local), local);
}
/**
* Generates the instruction to store the top stack value in the given local variable.
*
* @param local a local variable identifier, as returned by {@link
* LocalVariablesSorter#newLocal(Type)}.
* @param type the type of this local variable.
*/
public void storeLocal(final int local, final Type type) {
setLocalType(local, type);
storeInsn(type, local);
}
/**
* Generates the instruction to load an element from an array.
*
* @param type the type of the array element to be loaded.
*/
public void arrayLoad(final Type type) {
mv.visitInsn(type.getOpcode(Opcodes.IALOAD));
}
/**
* Generates the instruction to store an element in an array.
*
* @param type the type of the array element to be stored.
*/
public void arrayStore(final Type type) {
mv.visitInsn(type.getOpcode(Opcodes.IASTORE));
}
// -----------------------------------------------------------------------------------------------
// Instructions to manage the stack
// -----------------------------------------------------------------------------------------------
/** Generates a POP instruction. */
public void pop() {
mv.visitInsn(Opcodes.POP);
}
/** Generates a POP2 instruction. */
public void pop2() {
mv.visitInsn(Opcodes.POP2);
}
/** Generates a DUP instruction. */
public void dup() {
mv.visitInsn(Opcodes.DUP);
}
/** Generates a DUP2 instruction. */
public void dup2() {
mv.visitInsn(Opcodes.DUP2);
}
/** 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 DUP2_X1 instruction. */
public void dup2X1() {
mv.visitInsn(Opcodes.DUP2_X1);
}
/** Generates a DUP2_X2 instruction. */
public void dup2X2() {
mv.visitInsn(Opcodes.DUP2_X2);
}
/** Generates a SWAP instruction. */
public void swap() {
mv.visitInsn(Opcodes.SWAP);
}
/**
* Generates the instructions to swap the top two stack values.
*
* @param prev type of the top - 1 stack value.
* @param type type of the top stack value.
*/
public void swap(final Type prev, final Type type) {
if (type.getSize() == 1) {
if (prev.getSize() == 1) {
swap(); // Same as dupX1 pop.
} else {
dupX2();
pop();
}
} else {
if (prev.getSize() == 1) {
dup2X1();
pop2();
} else {
dup2X2();
pop2();
}
}
}
// -----------------------------------------------------------------------------------------------
// Instructions to do mathematical and logical operations
// -----------------------------------------------------------------------------------------------
/**
* Generates the instruction to do the specified mathematical or logical operation.
*
* @param op a mathematical or logical operation. Must be one of ADD, SUB, MUL, DIV, REM, NEG,
* SHL, SHR, USHR, AND, OR, XOR.
* @param type the type of the operand(s) for this operation.
*/
public void math(final int op, final Type type) {
mv.visitInsn(type.getOpcode(op));
}
/** Generates the instructions to compute the bitwise negation of the top stack value. */
public void not() {
mv.visitInsn(Opcodes.ICONST_1);
mv.visitInsn(Opcodes.IXOR);
}
/**
* Generates the instruction to increment the given local variable.
*
* @param local the local variable to be incremented.
* @param amount the amount by which the local variable must be incremented.
*/
public void iinc(final int local, final int amount) {
mv.visitIincInsn(local, amount);
}
/**
* Generates the instructions to cast a numerical value from one type to another.
*
* @param from the type of the top stack value
* @param to the type into which this value must be cast.
*/
public void cast(final Type from, final Type to) {
if (from != to) {
if (from.getSort() < Type.BOOLEAN
|| from.getSort() > Type.DOUBLE
|| to.getSort() < Type.BOOLEAN
|| to.getSort() > Type.DOUBLE) {
throw new IllegalArgumentException("Cannot cast from " + from + " to " + to);
}
if (from == Type.DOUBLE_TYPE) {
if (to == Type.FLOAT_TYPE) {
mv.visitInsn(Opcodes.D2F);
} else if (to == Type.LONG_TYPE) {
mv.visitInsn(Opcodes.D2L);
} else {
mv.visitInsn(Opcodes.D2I);
cast(Type.INT_TYPE, to);
}
} else if (from == Type.FLOAT_TYPE) {
if (to == Type.DOUBLE_TYPE) {
mv.visitInsn(Opcodes.F2D);
} else if (to == Type.LONG_TYPE) {
mv.visitInsn(Opcodes.F2L);
} else {
mv.visitInsn(Opcodes.F2I);
cast(Type.INT_TYPE, to);
}
} else if (from == Type.LONG_TYPE) {
if (to == Type.DOUBLE_TYPE) {
mv.visitInsn(Opcodes.L2D);
} else if (to == Type.FLOAT_TYPE) {
mv.visitInsn(Opcodes.L2F);
} else {
mv.visitInsn(Opcodes.L2I);
cast(Type.INT_TYPE, to);
}
} else {
if (to == Type.BYTE_TYPE) {
mv.visitInsn(Opcodes.I2B);
} else if (to == Type.CHAR_TYPE) {
mv.visitInsn(Opcodes.I2C);
} else if (to == Type.DOUBLE_TYPE) {
mv.visitInsn(Opcodes.I2D);
} else if (to == Type.FLOAT_TYPE) {
mv.visitInsn(Opcodes.I2F);
} else if (to == Type.LONG_TYPE) {
mv.visitInsn(Opcodes.I2L);
} else if (to == Type.SHORT_TYPE) {
mv.visitInsn(Opcodes.I2S);
}
}
}
}
// -----------------------------------------------------------------------------------------------
// Instructions to do boxing and unboxing operations
// -----------------------------------------------------------------------------------------------
private static Type getBoxedType(final Type type) {
switch (type.getSort()) {
case Type.BYTE:
return BYTE_TYPE;
case Type.BOOLEAN:
return BOOLEAN_TYPE;
case Type.SHORT:
return SHORT_TYPE;
case Type.CHAR:
return CHARACTER_TYPE;
case Type.INT:
return INTEGER_TYPE;
case Type.FLOAT:
return FLOAT_TYPE;
case Type.LONG:
return LONG_TYPE;
case Type.DOUBLE:
return DOUBLE_TYPE;
default:
return type;
}
}
/**
* 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 boxedType = getBoxedType(type);
newInstance(boxedType);
if (type.getSize() == 2) {
// Pp -> Ppo -> oPpo -> ooPpo -> ooPp -> o
dupX2();
dupX2();
pop();
} else {
// p -> po -> opo -> oop -> o
dupX1();
swap();
}
invokeConstructor(boxedType, new Method("", Type.VOID_TYPE, new Type[] {type}));
}
}
/**
* Generates the instructions to box the top stack value using Java 5's valueOf() method. This
* value is replaced by its boxed equivalent on top of the stack.
*
* @param type the type of the top stack value.
*/
public void valueOf(final Type type) {
if (type.getSort() == Type.OBJECT || type.getSort() == Type.ARRAY) {
return;
}
if (type == Type.VOID_TYPE) {
push((String) null);
} else {
Type boxedType = getBoxedType(type);
invokeStatic(boxedType, new Method("valueOf", boxedType, new Type[] {type}));
}
}
/**
* 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 boxedType = NUMBER_TYPE;
Method unboxMethod;
switch (type.getSort()) {
case Type.VOID:
return;
case Type.CHAR:
boxedType = CHARACTER_TYPE;
unboxMethod = CHAR_VALUE;
break;
case Type.BOOLEAN:
boxedType = BOOLEAN_TYPE;
unboxMethod = BOOLEAN_VALUE;
break;
case Type.DOUBLE:
unboxMethod = DOUBLE_VALUE;
break;
case Type.FLOAT:
unboxMethod = FLOAT_VALUE;
break;
case Type.LONG:
unboxMethod = LONG_VALUE;
break;
case Type.INT:
case Type.SHORT:
case Type.BYTE:
unboxMethod = INT_VALUE;
break;
default:
unboxMethod = null;
break;
}
if (unboxMethod == null) {
checkCast(type);
} else {
checkCast(boxedType);
invokeVirtual(boxedType, unboxMethod);
}
}
// -----------------------------------------------------------------------------------------------
// Instructions to jump to other instructions
// -----------------------------------------------------------------------------------------------
/**
* Constructs a new {@link Label}.
*
* @return a new {@link Label}.
*/
public Label newLabel() {
return new Label();
}
/**
* Marks the current code position with the given label.
*
* @param label a label.
*/
public void mark(final Label label) {
mv.visitLabel(label);
}
/**
* Marks the current code position with a new label.
*
* @return the label that was created to mark the current code position.
*/
public Label mark() {
Label label = new Label();
mv.visitLabel(label);
return label;
}
/**
* Generates the instructions to jump to a label based on the comparison of the top two stack
* values.
*
* @param type the type of the top two stack values.
* @param mode how these values must be compared. One of EQ, NE, LT, GE, GT, LE.
* @param label where to jump if the comparison result is {@literal true}.
*/
public void ifCmp(final Type type, final int mode, final Label label) {
switch (type.getSort()) {
case Type.LONG:
mv.visitInsn(Opcodes.LCMP);
break;
case Type.DOUBLE:
mv.visitInsn(mode == GE || mode == GT ? Opcodes.DCMPL : Opcodes.DCMPG);
break;
case Type.FLOAT:
mv.visitInsn(mode == GE || mode == GT ? Opcodes.FCMPL : Opcodes.FCMPG);
break;
case Type.ARRAY:
case Type.OBJECT:
if (mode == EQ) {
mv.visitJumpInsn(Opcodes.IF_ACMPEQ, label);
return;
} else if (mode == NE) {
mv.visitJumpInsn(Opcodes.IF_ACMPNE, label);
return;
} else {
throw new IllegalArgumentException("Bad comparison for type " + type);
}
default:
int intOp = -1;
switch (mode) {
case EQ:
intOp = Opcodes.IF_ICMPEQ;
break;
case NE:
intOp = Opcodes.IF_ICMPNE;
break;
case GE:
intOp = Opcodes.IF_ICMPGE;
break;
case LT:
intOp = Opcodes.IF_ICMPLT;
break;
case LE:
intOp = Opcodes.IF_ICMPLE;
break;
case GT:
intOp = Opcodes.IF_ICMPGT;
break;
default:
throw new IllegalArgumentException("Bad comparison mode " + mode);
}
mv.visitJumpInsn(intOp, label);
return;
}
mv.visitJumpInsn(mode, label);
}
/**
* Generates the instructions to jump to a label based on the comparison of the top two integer
* stack values.
*
* @param mode how these values must be compared. One of EQ, NE, LT, GE, GT, LE.
* @param label where to jump if the comparison result is {@literal true}.
*/
public void ifICmp(final int mode, final Label label) {
ifCmp(Type.INT_TYPE, mode, label);
}
/**
* Generates the instructions to jump to a label based on the comparison of the top integer stack
* value with zero.
*
* @param mode how these values must be compared. One of EQ, NE, LT, GE, GT, LE.
* @param label where to jump if the comparison result is {@literal true}.
*/
public void ifZCmp(final int mode, final Label label) {
mv.visitJumpInsn(mode, label);
}
/**
* Generates the instruction to jump to the given label if the top stack value is null.
*
* @param label where to jump if the condition is {@literal true}.
*/
public void ifNull(final Label label) {
mv.visitJumpInsn(Opcodes.IFNULL, label);
}
/**
* Generates the instruction to jump to the given label if the top stack value is not null.
*
* @param label where to jump if the condition is {@literal true}.
*/
public void ifNonNull(final Label label) {
mv.visitJumpInsn(Opcodes.IFNONNULL, label);
}
/**
* Generates the instruction to jump to the given label.
*
* @param label where to jump if the condition is {@literal true}.
*/
public void goTo(final Label label) {
mv.visitJumpInsn(Opcodes.GOTO, label);
}
/**
* Generates a RET instruction.
*
* @param local a local variable identifier, as returned by {@link
* LocalVariablesSorter#newLocal(Type)}.
*/
public void ret(final int local) {
mv.visitVarInsn(Opcodes.RET, local);
}
/**
* Generates the instructions for a switch statement.
*
* @param keys the switch case keys.
* @param generator a generator to generate the code for the switch cases.
*/
public void tableSwitch(final int[] keys, final TableSwitchGenerator generator) {
float density;
if (keys.length == 0) {
density = 0;
} else {
density = (float) keys.length / (keys[keys.length - 1] - keys[0] + 1);
}
tableSwitch(keys, generator, density >= 0.5f);
}
/**
* Generates the instructions for a switch statement.
*
* @param keys the switch case keys.
* @param generator a generator to generate the code for the switch cases.
* @param useTable {@literal true} to use a TABLESWITCH instruction, or {@literal false} to use a
* LOOKUPSWITCH instruction.
*/
public void tableSwitch(
final int[] keys, final TableSwitchGenerator generator, final boolean useTable) {
for (int i = 1; i < keys.length; ++i) {
if (keys[i] < keys[i - 1]) {
throw new IllegalArgumentException("keys must be sorted in ascending order");
}
}
Label defaultLabel = newLabel();
Label endLabel = newLabel();
if (keys.length > 0) {
int numKeys = keys.length;
if (useTable) {
int min = keys[0];
int max = keys[numKeys - 1];
int range = max - min + 1;
Label[] labels = new Label[range];
Arrays.fill(labels, defaultLabel);
for (int i = 0; i < numKeys; ++i) {
labels[keys[i] - min] = newLabel();
}
mv.visitTableSwitchInsn(min, max, defaultLabel, labels);
for (int i = 0; i < range; ++i) {
Label label = labels[i];
if (label != defaultLabel) {
mark(label);
generator.generateCase(i + min, endLabel);
}
}
} else {
Label[] labels = new Label[numKeys];
for (int i = 0; i < numKeys; ++i) {
labels[i] = newLabel();
}
mv.visitLookupSwitchInsn(defaultLabel, keys, labels);
for (int i = 0; i < numKeys; ++i) {
mark(labels[i]);
generator.generateCase(keys[i], endLabel);
}
}
}
mark(defaultLabel);
generator.generateDefault();
mark(endLabel);
}
/** Generates the instruction to return the top stack value to the caller. */
public void returnValue() {
mv.visitInsn(returnType.getOpcode(Opcodes.IRETURN));
}
// -----------------------------------------------------------------------------------------------
// Instructions to load and store fields
// -----------------------------------------------------------------------------------------------
/**
* Generates a get field or set field instruction.
*
* @param opcode the instruction's opcode.
* @param ownerType the class in which the field is defined.
* @param name the name of the field.
* @param fieldType the type of the field.
*/
private void fieldInsn(
final int opcode, final Type ownerType, final String name, final Type fieldType) {
mv.visitFieldInsn(opcode, ownerType.getInternalName(), name, fieldType.getDescriptor());
}
/**
* Generates the instruction to push the value of a static field on the stack.
*
* @param owner the class in which the field is defined.
* @param name the name of the field.
* @param type the type of the field.
*/
public void getStatic(final Type owner, final String name, final Type type) {
fieldInsn(Opcodes.GETSTATIC, owner, name, type);
}
/**
* Generates the instruction to store the top stack value in a static field.
*
* @param owner the class in which the field is defined.
* @param name the name of the field.
* @param type the type of the field.
*/
public void putStatic(final Type owner, final String name, final Type type) {
fieldInsn(Opcodes.PUTSTATIC, owner, name, type);
}
/**
* Generates the instruction to push the value of a non static field on the stack.
*
* @param owner the class in which the field is defined.
* @param name the name of the field.
* @param type the type of the field.
*/
public void getField(final Type owner, final String name, final Type type) {
fieldInsn(Opcodes.GETFIELD, owner, name, type);
}
/**
* Generates the instruction to store the top stack value in a non static field.
*
* @param owner the class in which the field is defined.
* @param name the name of the field.
* @param type the type of the field.
*/
public void putField(final Type owner, final String name, final Type type) {
fieldInsn(Opcodes.PUTFIELD, owner, name, type);
}
// -----------------------------------------------------------------------------------------------
// Instructions to invoke methods
// -----------------------------------------------------------------------------------------------
/**
* 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.
* @param isInterface whether the 'type' class is an interface or not.
*/
private void invokeInsn(
final int opcode, final Type type, final Method method, final boolean isInterface) {
String owner = type.getSort() == Type.ARRAY ? type.getDescriptor() : type.getInternalName();
mv.visitMethodInsn(opcode, owner, method.getName(), method.getDescriptor(), isInterface);
}
/**
* 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 Method method) {
invokeInsn(Opcodes.INVOKEVIRTUAL, owner, method, false);
}
/**
* 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 Method method) {
invokeInsn(Opcodes.INVOKESPECIAL, type, method, false);
}
/**
* Generates the instruction to invoke a static method.
*
* @param owner the class in which the method is defined.
* @param method the method to be invoked.
*/
public void invokeStatic(final Type owner, final Method method) {
invokeInsn(Opcodes.INVOKESTATIC, owner, method, false);
}
/**
* Generates the instruction to invoke an interface method.
*
* @param owner the class in which the method is defined.
* @param method the method to be invoked.
*/
public void invokeInterface(final Type owner, final Method method) {
invokeInsn(Opcodes.INVOKEINTERFACE, owner, method, true);
}
/**
* Generates an invokedynamic instruction.
*
* @param name the method's name.
* @param descriptor the method's descriptor (see {@link Type}).
* @param bootstrapMethodHandle the bootstrap method.
* @param bootstrapMethodArguments the bootstrap method constant arguments. Each argument must be
* an {@link Integer}, {@link Float}, {@link Long}, {@link Double}, {@link String}, {@link
* Type} or {@link Handle} value. This method is allowed to modify the content of the array so
* a caller should expect that this array may change.
*/
public void invokeDynamic(
final String name,
final String descriptor,
final Handle bootstrapMethodHandle,
final Object... bootstrapMethodArguments) {
mv.visitInvokeDynamicInsn(name, descriptor, bootstrapMethodHandle, bootstrapMethodArguments);
}
// -----------------------------------------------------------------------------------------------
// Instructions to create objects and arrays
// -----------------------------------------------------------------------------------------------
/**
* 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) {
mv.visitTypeInsn(opcode, type.getInternalName());
}
/**
* 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 create a new array.
*
* @param type the type of the array elements.
*/
public void newArray(final Type type) {
int arrayType;
switch (type.getSort()) {
case Type.BOOLEAN:
arrayType = Opcodes.T_BOOLEAN;
break;
case Type.CHAR:
arrayType = Opcodes.T_CHAR;
break;
case Type.BYTE:
arrayType = Opcodes.T_BYTE;
break;
case Type.SHORT:
arrayType = Opcodes.T_SHORT;
break;
case Type.INT:
arrayType = Opcodes.T_INT;
break;
case Type.FLOAT:
arrayType = Opcodes.T_FLOAT;
break;
case Type.LONG:
arrayType = Opcodes.T_LONG;
break;
case Type.DOUBLE:
arrayType = Opcodes.T_DOUBLE;
break;
default:
typeInsn(Opcodes.ANEWARRAY, type);
return;
}
mv.visitIntInsn(Opcodes.NEWARRAY, arrayType);
}
// -----------------------------------------------------------------------------------------------
// Miscellaneous instructions
// -----------------------------------------------------------------------------------------------
/** Generates the instruction to compute the length of an array. */
public void arrayLength() {
mv.visitInsn(Opcodes.ARRAYLENGTH);
}
/** Generates the instruction to throw an exception. */
public void throwException() {
mv.visitInsn(Opcodes.ATHROW);
}
/**
* Generates the instructions to create and throw an exception. The exception class must have a
* constructor with a single String argument.
*
* @param type the class of the exception to be thrown.
* @param message the detailed message of the exception.
*/
public void throwException(final Type type, final String message) {
newInstance(type);
dup();
push(message);
invokeConstructor(type, Method.getMethod("void (String)"));
throwException();
}
/**
* 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 test if the top stack value is of the given type.
*
* @param type a class or interface type.
*/
public void instanceOf(final Type type) {
typeInsn(Opcodes.INSTANCEOF, type);
}
/** Generates the instruction to get the monitor of the top stack value. */
public void monitorEnter() {
mv.visitInsn(Opcodes.MONITORENTER);
}
/** Generates the instruction to release the monitor of the top stack value. */
public void monitorExit() {
mv.visitInsn(Opcodes.MONITOREXIT);
}
// -----------------------------------------------------------------------------------------------
// Non instructions
// -----------------------------------------------------------------------------------------------
/** Marks the end of the visited method. */
public void endMethod() {
if ((access & Opcodes.ACC_ABSTRACT) == 0) {
mv.visitMaxs(0, 0);
}
mv.visitEnd();
}
/**
* Marks the start of an exception handler.
*
* @param start beginning of the exception handler's scope (inclusive).
* @param end end of the exception handler's scope (exclusive).
* @param exception internal name of the type of exceptions handled by the handler.
*/
public void catchException(final Label start, final Label end, final Type exception) {
Label catchLabel = new Label();
if (exception == null) {
mv.visitTryCatchBlock(start, end, catchLabel, null);
} else {
mv.visitTryCatchBlock(start, end, catchLabel, exception.getInternalName());
}
mark(catchLabel);
}
}