/***
* ASM: a very small and fast Java bytecode manipulation framework
* Copyright (c) 2000-2005 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
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
* THE POSSIBILITY OF SUCH DAMAGE.
*/
/*
* JBoss, Home of Professional Open Source
* Copyright 2009-10 Red Hat and individual contributors
* by the @authors tag. See the copyright.txt in the distribution for a
* full listing of individual contributors.
*
* This is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* This software 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this software; if not, write to the Free
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA, or see the FSF site: http://www.fsf.org.
*
* @authors Andrew Dinn
*/
package org.jboss.byteman.agent.adapter;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import org.jboss.byteman.agent.TransformContext;
import org.jboss.byteman.rule.Rule;
import org.jboss.byteman.rule.helper.Helper;
import org.objectweb.asm.*;
import org.objectweb.asm.commons.Method;
import org.objectweb.asm.commons.TableSwitchGenerator;
/**
* A modified version of the asm 3.0 GeneratorAdapter class which dispatches calls to methods of
* MethodVisitor to this rather than to the encapsulated MethodVisitor instance in field mv.
* Doing so gives the current instance a chance to observe all visit operations. Without it
* the current instance only sees visit operations invoked directly by previous visitors in
* the chain. This is necessary in order for the RuleTriggerAdapter to build a complete CFG
* for the method being visited.
*
* As a consequence of the above change this class cannot inherit the methods from LocalVariableSorter
* which allow introduction of new local variables. That's not actually much of a loss since the
* functionality provided by that class is of limited utility -- it only allows local variables to
* be introduced via a prior pipeline stage. Instead this class provides methods to track the number
* of locals employed so far and supports temporary introduction and removal of locals inside injected
* trigger or handler code. See methods {@link #newLocal(org.objectweb.asm.Type)}, {@link #popLocal(int)},
* {@link #loadLocal(int)} and {@link #storeLocal(int)}.
*
* Another reason to transplant code to this class is because it inherits functionality from
* RuleMethodAdapter which is used by RuleCheckAdapter and RuleTriggerAdapter to identify
* and classify local variables but provides functionality to modify bytecode which is only
* needed by RuleTriggerAdapter. So, the original class would have needed reparenting anyway.
*
* @author Andrew Dinn
* @author Juozas Baliuka
* @author Chris Nokleberg
* @author Eric Bruneton
*/
public class RuleGeneratorAdapter extends RuleMethodAdapter {
private static final String CLDESC = "Ljava/lang/Class;";
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 Method BOOLEAN_VALUE = Method.getMethod("boolean booleanValue()");
private final static Method CHAR_VALUE = Method.getMethod("char charValue()");
private final static Method INT_VALUE = Method.getMethod("int intValue()");
private final static Method FLOAT_VALUE = Method.getMethod("float floatValue()");
private final static Method LONG_VALUE = Method.getMethod("long longValue()");
private final static Method DOUBLE_VALUE = Method.getMethod("double doubleValue()");
/**
* Constant for the {@link #math math} method.
*/
public final static int ADD = Opcodes.IADD;
/**
* Constant for the {@link #math math} method.
*/
public final static int SUB = Opcodes.ISUB;
/**
* Constant for the {@link #math math} method.
*/
public final static int MUL = Opcodes.IMUL;
/**
* Constant for the {@link #math math} method.
*/
public final static int DIV = Opcodes.IDIV;
/**
* Constant for the {@link #math math} method.
*/
public final static int REM = Opcodes.IREM;
/**
* Constant for the {@link #math math} method.
*/
public final static int NEG = Opcodes.INEG;
/**
* Constant for the {@link #math math} method.
*/
public final static int SHL = Opcodes.ISHL;
/**
* Constant for the {@link #math math} method.
*/
public final static int SHR = Opcodes.ISHR;
/**
* Constant for the {@link #math math} method.
*/
public final static int USHR = Opcodes.IUSHR;
/**
* Constant for the {@link #math math} method.
*/
public final static int AND = Opcodes.IAND;
/**
* Constant for the {@link #math math} method.
*/
public final static int OR = Opcodes.IOR;
/**
* Constant for the {@link #math math} method.
*/
public final static int XOR = Opcodes.IXOR;
/**
* Constant for the {@link #ifCmp ifCmp} method.
*/
public final static int EQ = Opcodes.IFEQ;
/**
* Constant for the {@link #ifCmp ifCmp} method.
*/
public final static int NE = Opcodes.IFNE;
/**
* Constant for the {@link #ifCmp ifCmp} method.
*/
public final static int LT = Opcodes.IFLT;
/**
* Constant for the {@link #ifCmp ifCmp} method.
*/
public final static int GE = Opcodes.IFGE;
/**
* Constant for the {@link #ifCmp ifCmp} method.
*/
public final static int GT = Opcodes.IFGT;
/**
* Constant for the {@link #ifCmp ifCmp} method.
*/
public final static int LE = Opcodes.IFLE;
/**
* Argument types of the method visited by this adapter.
*/
private final Type[] argumentTypes;
/**
* Return type of the method visited by this adapter.
*/
private final Type returnType;
/**
* Types of the local variables of the method visited by this adapter.
*/
private final List localTypes;
/**
* used to track active local variable slots
*/
private int nextLocal;
/**
* used to track maximum number of local variable slots
*/
private int localHighWater;
/**
* Creates a new {@link RuleGeneratorAdapter}.
*
* @param mv the method visitor to which this adapter delegates calls.
* @param access the method's access flags (see {@link org.objectweb.asm.Opcodes}).
* @param name the method's name.
* @param desc the method's descriptor (see {@link org.objectweb.asm.Type Type}).
* @param transformContext the current transform context
* @param rule the rule currently being injected
*/
public RuleGeneratorAdapter(
final MethodVisitor mv,
final TransformContext transformContext,
final int access,
final String name,
final String desc,
final Rule rule)
{
super(mv, transformContext, access, name, desc, rule);
this.argumentTypes = Type.getArgumentTypes(desc);
this.returnType = Type.getReturnType(desc);
localTypes = new ArrayList();
initLocalTypes();
}
/**
* initialise the local slot types array with the types of the method target and parameters.
* this is needed because we are only sent an initial frame identifying the local slots
* which belong to the method if a stackmap table has been included in the bytecode and this
* is nto always the case.
*/
private void initLocalTypes()
{
// owner of this method is an object
// localTypes.add(Type.getType(Object.class));
String name = getTriggerClassName().replace('.', '/');
if ((access & Opcodes.ACC_STATIC) == 0) {
// an instance method so slot 0 will contain the target object
localTypes.add(Type.getType("L" + name + ";"));
}
for (int i = 0; i < argumentTypes.length; i++) {
Type argumentType = argumentTypes[i];
int size = argumentType.getSize();
localTypes.add(argumentType);
if (size > 1) {
localTypes.add(null);
}
}
nextLocal = localHighWater = localTypes.size();
}
/**
* 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;
}
// ------------------------------------------------------------------------
// 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) {
visitInsn(Opcodes.ICONST_0 + value);
} else if (value >= Byte.MIN_VALUE && value <= Byte.MAX_VALUE) {
visitIntInsn(Opcodes.BIPUSH, value);
} else if (value >= Short.MIN_VALUE && value <= Short.MAX_VALUE) {
visitIntInsn(Opcodes.SIPUSH, value);
} else {
visitLdcInsn(Integer.valueOf(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) {
visitInsn(Opcodes.LCONST_0 + (int) value);
} else {
visitLdcInsn(Long.valueOf(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
visitInsn(Opcodes.FCONST_0 + (int) value);
} else {
visitLdcInsn(Float.valueOf(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
visitInsn(Opcodes.DCONST_0 + (int) value);
} else {
visitLdcInsn(Double.valueOf(value));
}
}
/**
* 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) {
visitInsn(Opcodes.ACONST_NULL);
} else {
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) {
visitInsn(Opcodes.ACONST_NULL);
} else {
switch (value.getSort()) {
case Type.BOOLEAN:
visitFieldInsn(Opcodes.GETSTATIC, "java/lang/Boolean",
"TYPE", CLDESC);
break;
case Type.CHAR:
visitFieldInsn(Opcodes.GETSTATIC, "java/lang/Character",
"TYPE", CLDESC);
break;
case Type.BYTE:
visitFieldInsn(Opcodes.GETSTATIC, "java/lang/Byte", "TYPE",
CLDESC);
break;
case Type.SHORT:
visitFieldInsn(Opcodes.GETSTATIC, "java/lang/Short", "TYPE",
CLDESC);
break;
case Type.INT:
visitFieldInsn(Opcodes.GETSTATIC, "java/lang/Integer",
"TYPE", CLDESC);
break;
case Type.FLOAT:
visitFieldInsn(Opcodes.GETSTATIC, "java/lang/Float", "TYPE",
CLDESC);
break;
case Type.LONG:
visitFieldInsn(Opcodes.GETSTATIC, "java/lang/Long", "TYPE",
CLDESC);
break;
case Type.DOUBLE:
visitFieldInsn(Opcodes.GETSTATIC, "java/lang/Double",
"TYPE", CLDESC);
break;
default:
visitLdcInsn(value);
}
}
}
/**
* 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) {
mv.visitLdcInsn(handle);
}
// ------------------------------------------------------------------------
// 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) {
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) {
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");
}
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 t = argumentTypes[arg + i];
loadInsn(t, index);
index += t.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));
}
/**
* 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) {
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) {
visitInsn(type.getOpcode(Opcodes.IASTORE));
}
// ------------------------------------------------------------------------
// Instructions to manage the stack
// ------------------------------------------------------------------------
/**
* Generates a POP instruction.
*/
public void pop() {
visitInsn(Opcodes.POP);
}
/**
* Generates a POP2 instruction.
*/
public void pop2() {
visitInsn(Opcodes.POP2);
}
/**
* Generates a DUP instruction.
*/
public void dup() {
visitInsn(Opcodes.DUP);
}
/**
* Generates a DUP2 instruction.
*/
public void dup2() {
visitInsn(Opcodes.DUP2);
}
/**
* Generates a DUP_X1 instruction.
*/
public void dupX1() {
visitInsn(Opcodes.DUP_X1);
}
/**
* Generates a DUP_X2 instruction.
*/
public void dupX2() {
visitInsn(Opcodes.DUP_X2);
}
/**
* Generates a DUP2_X1 instruction.
*/
public void dup2X1() {
visitInsn(Opcodes.DUP2_X1);
}
/**
* Generates a DUP2_X2 instruction.
*/
public void dup2X2() {
visitInsn(Opcodes.DUP2_X2);
}
/**
* Generates a SWAP instruction.
*/
public void swap() {
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) {
visitInsn(type.getOpcode(op));
}
/**
* Generates the instructions to compute the bitwise negation of the top
* stack value.
*/
public void not() {
visitInsn(Opcodes.ICONST_1);
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) {
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 == Type.DOUBLE_TYPE) {
if (to == Type.FLOAT_TYPE) {
visitInsn(Opcodes.D2F);
} else if (to == Type.LONG_TYPE) {
visitInsn(Opcodes.D2L);
} else {
visitInsn(Opcodes.D2I);
cast(Type.INT_TYPE, to);
}
} else if (from == Type.FLOAT_TYPE) {
if (to == Type.DOUBLE_TYPE) {
visitInsn(Opcodes.F2D);
} else if (to == Type.LONG_TYPE) {
visitInsn(Opcodes.F2L);
} else {
visitInsn(Opcodes.F2I);
cast(Type.INT_TYPE, to);
}
} else if (from == Type.LONG_TYPE) {
if (to == Type.DOUBLE_TYPE) {
visitInsn(Opcodes.L2D);
} else if (to == Type.FLOAT_TYPE) {
visitInsn(Opcodes.L2F);
} else {
visitInsn(Opcodes.L2I);
cast(Type.INT_TYPE, to);
}
} else {
if (to == Type.BYTE_TYPE) {
visitInsn(Opcodes.I2B);
} else if (to == Type.CHAR_TYPE) {
visitInsn(Opcodes.I2C);
} else if (to == Type.DOUBLE_TYPE) {
visitInsn(Opcodes.I2D);
} else if (to == Type.FLOAT_TYPE) {
visitInsn(Opcodes.I2F);
} else if (to == Type.LONG_TYPE) {
visitInsn(Opcodes.I2L);
} else if (to == Type.SHORT_TYPE) {
visitInsn(Opcodes.I2S);
}
}
}
}
// ------------------------------------------------------------------------
// Instructions to do boxing and unboxing operations
// ------------------------------------------------------------------------
/**
* 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 Method("<init>",
Type.VOID_TYPE,
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 t = NUMBER_TYPE;
Method 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);
}
}
// ------------------------------------------------------------------------
// Instructions to jump to other instructions
// ------------------------------------------------------------------------
/**
* Creates a new {@link org.objectweb.asm.Label}.
*
* @return a new {@link org.objectweb.asm.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) {
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();
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 <tt>true</tt>.
*/
public void ifCmp(final Type type, final int mode, final Label label) {
int intOp = -1;
switch (type.getSort()) {
case Type.LONG:
visitInsn(Opcodes.LCMP);
break;
case Type.DOUBLE:
visitInsn(Opcodes.DCMPG);
break;
case Type.FLOAT:
visitInsn(Opcodes.FCMPG);
break;
case Type.ARRAY:
case Type.OBJECT:
switch (mode) {
case EQ:
visitJumpInsn(Opcodes.IF_ACMPEQ, label);
return;
case NE:
visitJumpInsn(Opcodes.IF_ACMPNE, label);
return;
}
throw new IllegalArgumentException("Bad comparison for type "
+ type);
default:
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;
}
visitJumpInsn(intOp, label);
return;
}
int jumpMode = mode;
switch (mode) {
case GE:
jumpMode = LT;
break;
case LE:
jumpMode = GT;
break;
}
visitJumpInsn(jumpMode, 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 <tt>true</tt>.
*/
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 <tt>true</tt>.
*/
public void ifZCmp(final int mode, final Label label) {
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 <tt>true</tt>.
*/
public void ifNull(final Label label) {
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 <tt>true</tt>.
*/
public void ifNonNull(final Label label) {
visitJumpInsn(Opcodes.IFNONNULL, label);
}
/**
* Generates the instruction to jump to the given label.
*
* @param label where to jump if the condition is <tt>true</tt>.
*/
public void goTo(final Label label) {
visitJumpInsn(Opcodes.GOTO, label);
}
/**
* Generates a RET instruction.
*
* @param local a local variable identifier, as returned by
* {@link org.objectweb.asm.commons.LocalVariablesSorter#newLocal(org.objectweb.asm.Type) newLocal()}.
*/
public void ret(final int local) {
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 <tt>true</tt> to use a TABLESWITCH instruction, or
* <tt>false</tt> 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 ascending");
}
}
Label def = newLabel();
Label end = newLabel();
if (keys.length > 0) {
int len = keys.length;
int min = keys[0];
int max = keys[len - 1];
int range = max - min + 1;
if (useTable) {
Label[] labels = new Label[range];
Arrays.fill(labels, def);
for (int i = 0; i < len; ++i) {
labels[keys[i] - min] = newLabel();
}
visitTableSwitchInsn(min, max, def, labels);
for (int i = 0; i < range; ++i) {
Label label = labels[i];
if (label != def) {
mark(label);
generator.generateCase(i + min, end);
}
}
} else {
Label[] labels = new Label[len];
for (int i = 0; i < len; ++i) {
labels[i] = newLabel();
}
visitLookupSwitchInsn(def, keys, labels);
for (int i = 0; i < len; ++i) {
mark(labels[i]);
generator.generateCase(keys[i], end);
}
}
}
mark(def);
generator.generateDefault();
mark(end);
}
/**
* Generates the instruction to return the top stack value to the caller.
*/
public void returnValue() {
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)
{
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.
*/
private void invokeInsn(
final int opcode,
final Type type,
final Method method,
final boolean itf)
{
String owner = type.getSort() == Type.ARRAY
? type.getDescriptor()
: type.getInternalName();
visitMethodInsn(opcode, owner, method.getName(),
method.getDescriptor(), itf);
}
/**
* 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 desc
* the method's descriptor (see {@link Type Type}).
* @param bsm
* the bootstrap method.
* @param bsmArgs
* 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(String name, String desc, Handle bsm,
Object... bsmArgs) {
visitInvokeDynamicInsn(name, desc, bsm, bsmArgs);
}
// ------------------------------------------------------------------------
// 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) {
String desc;
if (type.getSort() == Type.ARRAY) {
desc = type.getDescriptor();
} else {
desc = type.getInternalName();
}
visitTypeInsn(opcode, desc);
}
/**
* 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 typ;
switch (type.getSort()) {
case Type.BOOLEAN:
typ = Opcodes.T_BOOLEAN;
break;
case Type.CHAR:
typ = Opcodes.T_CHAR;
break;
case Type.BYTE:
typ = Opcodes.T_BYTE;
break;
case Type.SHORT:
typ = Opcodes.T_SHORT;
break;
case Type.INT:
typ = Opcodes.T_INT;
break;
case Type.FLOAT:
typ = Opcodes.T_FLOAT;
break;
case Type.LONG:
typ = Opcodes.T_LONG;
break;
case Type.DOUBLE:
typ = Opcodes.T_DOUBLE;
break;
default:
typeInsn(Opcodes.ANEWARRAY, type);
return;
}
visitIntInsn(Opcodes.NEWARRAY, typ);
}
// ------------------------------------------------------------------------
// Miscelaneous instructions
// ------------------------------------------------------------------------
/**
* Generates the instruction to compute the length of an array.
*/
public void arrayLength() {
visitInsn(Opcodes.ARRAYLENGTH);
}
/**
* Generates the instruction to throw an exception.
*/
public void throwException() {
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 msg the detailed message of the exception.
*/
public void throwException(final Type type, final String msg) {
newInstance(type);
dup();
push(msg);
invokeConstructor(type, Method.getMethod("void <init> (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() {
visitInsn(Opcodes.MONITORENTER);
}
/**
* Generates the instruction to release the monitor of the top stack value.
*/
public void monitorExit() {
visitInsn(Opcodes.MONITOREXIT);
}
// ------------------------------------------------------------------------
// Non instructions
// ------------------------------------------------------------------------
/**
* Marks the end of the visited method.
*/
public void endMethod() {
if ((access & Opcodes.ACC_ABSTRACT) == 0) {
visitMaxs(0, 0);
}
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)
{
if (exception == null) {
visitTryCatchBlock(start, end, mark(), null);
} else {
visitTryCatchBlock(start, end, mark(),
exception.getInternalName());
}
}
// local variable handling
/**
* override this so we can see track which local var slots are in use and avoid overwriting them
* @param opcode the bytecode operation
* @param var local variable index
*/
public void visitVarInsn(final int opcode, final int var)
{
if (var >= nextLocal || localTypes.get(var) == null) {
int size = 1;
Type type = null;
switch(opcode) {
// n.b. this fails to distinguish boolean types
// we need to check for them specially when we try
// to use a local which is marked as int
case Opcodes.ISTORE:
type = Type.INT_TYPE;
break;
case Opcodes.LSTORE:
type = Type.LONG_TYPE;
size = 2;
break;
case Opcodes.FSTORE:
type = Type.FLOAT_TYPE;
break;
case Opcodes.DSTORE:
type = Type.DOUBLE_TYPE;
size = 2;
break;
case Opcodes.ASTORE:
// we don't know exactly what type this is but at least we know it is an object
// we need to correct for this when injecting trigger code to update the local
// luckily we can use the binding type derived during the check phase to idenitfy
// the actual local type
type = Type.getType(Object.class);
break;
}
if (var < nextLocal) {
// just fill in the missing type
localTypes.set(var, type);
} else {
// we may not have seen some of the locals so leave a blank spot for them in the types array
for (int i = nextLocal; i < var; i++) {
localTypes.add(null);
}
// now add entry for var
localTypes.add(type);
if (size > 1) {
localTypes.add(null);
}
nextLocal = var + size;
if (nextLocal > localHighWater) {
localHighWater = nextLocal;
}
}
}
super.visitVarInsn(opcode, var);
}
/**
* return a new local slot index for a local var not currently in use. this must be released
* using popLocal before a new frame can be notified which means that the slot should only be
* allocated inside a generated trigger section and should be released before the trigger
* end of the trigger section by calling popLocal.
* @param valueType the type of the value to be stored in the local slot
* @return the index for the new slot
*/
public int newLocal(Type valueType)
{
int localIndex = nextLocal++;
localTypes.add(valueType);
if (valueType.getSize() > 1) {
nextLocal++;
localTypes.add(null);
}
if (nextLocal > localHighWater) {
localHighWater = nextLocal;
}
return localIndex;
}
/**
* free a previously allocated local slot
* @param local the slot to be released
*/
public void popLocal(int local)
{
Type type = (Type)localTypes.get(local);
int size = type.getSize();
if (nextLocal != local + size) {
throw new IndexOutOfBoundsException("popLocal was expecting " + (nextLocal - size ) + " but got " + local + " instead!");
}
if (size > 1) {
nextLocal--;
localTypes.remove(nextLocal);
}
nextLocal--;
localTypes.remove(nextLocal);
}
/**
* load a value onto the stack from a local var slot which can obtained from a call to newLocal or
* from a lcoal variable table entry.
* @param local the slot to load from
*/
public void loadLocal(int local)
{
Type type = (Type)localTypes.get(local);
visitVarInsn(type.getOpcode(Opcodes.ILOAD), local);
}
/**
* save a value on the stack to a local var slot
* @param local the slot to save to
*/
public void storeLocal(int local)
{
Type type = (Type)localTypes.get(local);
visitVarInsn(type.getOpcode(Opcodes.ISTORE), local);
}
public Type getLocalType(int local)
{
return (Type)localTypes.get(local);
}
/**
* ensure we allow enough room for any extra locals on the stack
*
* @param maxStack the maximum stack depth
* @param maxLocals the maximum local count
*/
public void visitMaxs(final int maxStack, final int maxLocals) {
if (localHighWater < maxLocals) {
localHighWater = maxLocals;
}
mv.visitMaxs(maxStack, localHighWater);
}
private void dumpFrame(int nLocal, Object[] local, int nStack, Object[] stack)
{
StringBuffer buffer = new StringBuffer();
String sepr;
Label l = new Label();
visitLabel(l);
buffer.append("Frame ");
buffer.append(l.getOffset());
buffer.append("\n");
buffer.append(" locals ");
buffer.append(nLocal);
buffer.append("\n ");
sepr = "";
for (int i = 0; i < nLocal; i++) {
buffer.append(sepr);
dumpType(buffer, local[i]);
sepr=",\n ";
}
buffer.append("\n stack ");
buffer.append(nStack);
buffer.append("\n ");
sepr = "";
for (int i = 0; i < nStack; i++) {
buffer.append(sepr);
dumpType(buffer, stack[i]);
sepr=",\n ";
}
Helper.out(buffer.toString());
}
private void dumpType(StringBuffer buffer, Object t)
{
if (t == Opcodes.TOP) {
buffer.append("TOP");
} else if (t == null) {
buffer.append("null");
} else if (t == Opcodes.INTEGER) {
buffer.append("int");
} else if (t == Opcodes.FLOAT) {
buffer.append("float");
} else if (t == Opcodes.DOUBLE) {
buffer.append("double");
} else if (t == Opcodes.LONG) {
buffer.append("long");
} else if (t == Opcodes.NULL) {
buffer.append("null");
} else if (t == Opcodes.UNINITIALIZED_THIS) {
buffer.append("uninit_this");
} else if (t instanceof String) {
buffer.append((String)t);
} else {
buffer.append(((Label)t).getOffset());
}
}
public void visitFrame(
final int type,
final int nLocal,
final Object[] local,
final int nStack,
final Object[] stack)
{
if (type != Opcodes.F_NEW) { // uncompressed frame
throw new IllegalStateException("ClassReader.accept() should be called with EXPAND_FRAMES flag");
}
// dumpFrame(nLocal, local, nStack, stack);
// adjust the local types array
int toRemove = localTypes.size();
for (int i = toRemove; i > 0; i--) {
localTypes.remove(i - 1);
}
int nextLocal = 0;
for (int i = 0; i < nLocal; i++) {
Object t = local[i];
if (t == Opcodes.TOP) {
localTypes.add(null);
} else if (t == null) {
localTypes.add(null);
} else if (t == Opcodes.INTEGER) {
localTypes.add(Type.INT_TYPE);
} else if (t == Opcodes.FLOAT) {
localTypes.add(Type.FLOAT_TYPE);
} else if (t == Opcodes.DOUBLE) {
localTypes.add(Type.DOUBLE_TYPE);
nextLocal++;
localTypes.add(null);
} else if (t == Opcodes.LONG) {
localTypes.add(Type.LONG_TYPE);
nextLocal++;
localTypes.add(null);
} else if (t == Opcodes.NULL) {
localTypes.add(null);
} else if (t == Opcodes.UNINITIALIZED_THIS) {
localTypes.add(null);
} else if (t instanceof String) {
localTypes.add(Type.getObjectType((String)t));
} else {
localTypes.add(null);
}
nextLocal++;
}
this.nextLocal = nextLocal;
mv.visitFrame(type, nLocal, local, nStack, stack);
}
}