Java example source code file (Inject.java)
The Inject.java Java example source code/*
* Copyright (c) 2005, 2011, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code 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
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
package ilib;
import java.io.IOException;
import java.io.File;
import java.io.FileOutputStream;
import java.io.DataOutputStream;
import java.util.List;
import java.util.Iterator;
import java.util.ArrayList;
public class Inject implements RuntimeConstants {
public static byte[] instrumentation(Options opt,
ClassLoader loader,
String className,
byte[] classfileBuffer) {
ClassReaderWriter c = new ClassReaderWriter(classfileBuffer);
(new Inject(className, c, loader == null, opt)).doit();
return c.result();
}
static boolean verbose = false;
final String className;
final ClassReaderWriter c;
final boolean isSystem;
final Options options;
int constantPoolCount;
int methodsCount;
int methodsCountPos;
int profiler;
int wrappedTrackerIndex = 0;
int thisClassIndex = 0;
TrackerInjector callInjector;
TrackerInjector allocInjector;
TrackerInjector defaultInjector;
static interface TrackerInjector extends Injector {
void reinit(int tracker);
int stackSize(int currentSize);
}
static class SimpleInjector implements TrackerInjector {
byte[] injection;
public int stackSize(int currentSize) {
return currentSize;
}
public void reinit(int tracker) {
injection = new byte[3];
injection[0] = (byte)opc_invokestatic;
injection[1] = (byte)(tracker >> 8);
injection[2] = (byte)tracker;
}
public byte[] bytecodes(String className, String methodName, int location) {
return injection;
}
}
static class ObjectInjector implements TrackerInjector {
byte[] injection;
public int stackSize(int currentSize) {
return currentSize + 1;
}
public void reinit(int tracker) {
injection = new byte[4];
injection[0] = (byte)opc_dup;
injection[1] = (byte)opc_invokestatic;
injection[2] = (byte)(tracker >> 8);
injection[3] = (byte)tracker;
}
public byte[] bytecodes(String className, String methodName, int location) {
return injection;
}
}
class IndexedInjector implements TrackerInjector {
int counter = 0;
int tracker;
List<Info> infoList = new ArrayList<>();
public int stackSize(int currentSize) {
return currentSize + 1;
}
public void reinit(int tracker) {
this.tracker = tracker;
}
void dump(File outDir, String filename) throws IOException {
try (FileOutputStream fileOut =
new FileOutputStream(new File(outDir, filename));
DataOutputStream dataOut = new DataOutputStream(fileOut))
{
String currentClassName = null;
dataOut.writeInt(infoList.size());
for (Iterator<Info> it = infoList.iterator(); it.hasNext(); ) {
Info info = it.next();
if (!info.className.equals(currentClassName)) {
dataOut.writeInt(123456); // class name marker
currentClassName = info.className;
dataOut.writeUTF(currentClassName);
}
dataOut.writeInt(info.location);
dataOut.writeUTF(info.methodName);
}
}
}
public byte[] bytecodes(String className, String methodName, int location) {
byte[] injection = new byte[6];
int injectedIndex = options.fixedIndex != 0? options.fixedIndex : ++counter;
infoList.add(new Info(counter, className, methodName, location));
injection[0] = (byte)opc_sipush;
injection[1] = (byte)(injectedIndex >> 8);
injection[2] = (byte)injectedIndex;
injection[3] = (byte)opc_invokestatic;
injection[4] = (byte)(tracker >> 8);
injection[5] = (byte)tracker;
return injection;
}
}
Inject(String className, ClassReaderWriter c, boolean isSystem, Options options) {
this.className = className;
this.c = c;
this.isSystem = isSystem;
this.options = options;
}
void doit() {
int i;
c.copy(4 + 2 + 2); // magic min/maj version
int constantPoolCountPos = c.generatedPosition();
constantPoolCount = c.copyU2();
// copy old constant pool
c.copyConstantPool(constantPoolCount);
if (verbose) {
System.out.println("ConstantPool expanded from: " +
constantPoolCount);
}
profiler = addClassToConstantPool(options.trackerClassName);
if (options.shouldInstrumentNew || options.shouldInstrumentObjectInit) {
if (options.shouldInstrumentIndexed) {
if (allocInjector == null) {
// first time - create it
allocInjector = new IndexedInjector();
}
int allocTracker = addMethodToConstantPool(profiler,
options.allocTrackerMethodName,
"(I)V");
allocInjector.reinit(allocTracker);
} else if (options.shouldInstrumentObject) {
if (allocInjector == null) {
// first time - create it
allocInjector = new ObjectInjector();
}
int allocTracker = addMethodToConstantPool(profiler,
options.allocTrackerMethodName,
"(Ljava/lang/Object;)V");
allocInjector.reinit(allocTracker);
} else {
if (allocInjector == null) {
// first time - create it
allocInjector = new SimpleInjector();
}
int allocTracker = addMethodToConstantPool(profiler,
options.allocTrackerMethodName,
"()V");
allocInjector.reinit(allocTracker);
}
defaultInjector = allocInjector;
}
if (options.shouldInstrumentCall) {
if (options.shouldInstrumentIndexed) {
if (callInjector == null) {
// first time - create it
callInjector = new IndexedInjector();
}
int callTracker = addMethodToConstantPool(profiler,
options.callTrackerMethodName,
"(I)V");
callInjector.reinit(callTracker);
} else {
if (callInjector == null) {
// first time - create it
callInjector = new SimpleInjector();
}
int callTracker = addMethodToConstantPool(profiler,
options.callTrackerMethodName,
"()V");
callInjector.reinit(callTracker);
}
defaultInjector = callInjector;
}
if (verbose) {
System.out.println("To: " + constantPoolCount);
}
c.setSection(1);
c.copy(2 + 2 + 2); // access, this, super
int interfaceCount = c.copyU2();
if (verbose) {
System.out.println("interfaceCount: " + interfaceCount);
}
c.copy(interfaceCount * 2);
copyFields(); // fields
copyMethods(); // methods
int attrCountPos = c.generatedPosition();
int attrCount = c.copyU2();
if (verbose) {
System.out.println("class attrCount: " + attrCount);
}
// copy the class attributes
copyAttrs(attrCount);
c.randomAccessWriteU2(constantPoolCountPos, constantPoolCount);
}
void copyFields() {
int count = c.copyU2();
if (verbose) {
System.out.println("fields count: " + count);
}
for (int i = 0; i < count; ++i) {
c.copy(6); // access, name, descriptor
int attrCount = c.copyU2();
if (verbose) {
System.out.println("field attr count: " + attrCount);
}
copyAttrs(attrCount);
}
}
void copyMethods() {
methodsCountPos = c.generatedPosition();
methodsCount = c.copyU2();
int initialMethodsCount = methodsCount;
if (verbose) {
System.out.println("methods count: " + methodsCount);
}
for (int i = 0; i < initialMethodsCount; ++i) {
copyMethod();
}
}
void copyMethod() {
int accessFlags = c.copyU2();// access flags
if (options.shouldInstrumentNativeMethods && (accessFlags & ACC_NATIVE) != 0) {
wrapNativeMethod(accessFlags);
return;
}
int nameIndex = c.copyU2(); // name
String methodName = c.constantPoolString(nameIndex);
c.copyU2(); // descriptor
int attrCount = c.copyU2(); // attribute count
if (verbose) {
System.out.println("methods attr count: " + attrCount);
}
for (int i = 0; i < attrCount; ++i) {
copyAttrForMethod(methodName, accessFlags);
}
}
void wrapNativeMethod(int accessFlags) {
// first, copy the native method with the name changed
// accessFlags have already been copied
int nameIndex = c.readU2(); // name
String methodName = c.constantPoolString(nameIndex);
String wrappedMethodName = options.wrappedPrefix + methodName;
int wrappedNameIndex = writeCPEntryUtf8(wrappedMethodName);
c.writeU2(wrappedNameIndex); // change to the wrapped name
int descriptorIndex = c.copyU2(); // descriptor index
int attrCount = c.copyU2(); // attribute count
// need to replicate these attributes (esp Exceptions) in wrapper
// so mark this location so we can rewind
c.markLocalPositionStart();
for (int i = 0; i < attrCount; ++i) {
copyAttrForMethod(methodName, accessFlags);
}
if (true) {
System.err.println(" wrapped: " + methodName);
}
// now write the wrapper method
c.writeU2(accessFlags & ~ACC_NATIVE);
c.writeU2(nameIndex); // original unwrapped name
c.writeU2(descriptorIndex); // descriptor is the same
c.writeU2(attrCount + 1); // wrapped plus a code attribute
// rewind to wrapped attributes
c.rewind();
for (int i = 0; i < attrCount; ++i) {
copyAttrForMethod(methodName, accessFlags);
}
// generate a Code attribute for the wrapper method
int wrappedIndex = addMethodToConstantPool(getThisClassIndex(),
wrappedNameIndex,
descriptorIndex);
String descriptor = c.constantPoolString(descriptorIndex);
createWrapperCodeAttr(nameIndex, accessFlags, descriptor, wrappedIndex);
// increment method count
c.randomAccessWriteU2(methodsCountPos, ++methodsCount);
}
void copyAttrs(int attrCount) {
for (int i = 0; i < attrCount; ++i) {
copyAttr();
}
}
void copyAttr() {
c.copy(2); // name
int len = c.copyU4(); // attr len
if (verbose) {
System.out.println("attr len: " + len);
}
c.copy(len); // attribute info
}
void copyAttrForMethod(String methodName, int accessFlags) {
int nameIndex = c.copyU2(); // name
// check for Code attr
if (nameIndex == c.codeAttributeIndex) {
try {
copyCodeAttr(methodName);
} catch (IOException exc) {
System.err.println("Code Exception - " + exc);
System.exit(1);
}
} else {
int len = c.copyU4(); // attr len
if (verbose) {
System.out.println("method attr len: " + len);
}
c.copy(len); // attribute info
}
}
void copyAttrForCode(InjectBytecodes ib) throws IOException {
int nameIndex = c.copyU2(); // name
// check for Code attr
if (nameIndex == c.lineNumberAttributeIndex) {
ib.copyLineNumberAttr();
} else if (nameIndex == c.localVarAttributeIndex) {
ib.copyLocalVarAttr();
} else {
int len = c.copyU4(); // attr len
if (verbose) {
System.out.println("code attr len: " + len);
}
c.copy(len); // attribute info
}
}
void copyCodeAttr(String methodName) throws IOException {
if (verbose) {
System.out.println("Code attr found");
}
int attrLengthPos = c.generatedPosition();
int attrLength = c.copyU4(); // attr len
int maxStack = c.readU2(); // max stack
c.writeU2(defaultInjector == null? maxStack :
defaultInjector.stackSize(maxStack)); // big enough for injected code
c.copyU2(); // max locals
int codeLengthPos = c.generatedPosition();
int codeLength = c.copyU4(); // code length
if (options.targetMethod != null && !options.targetMethod.equals(methodName)) {
c.copy(attrLength - 8); // copy remainder minus already copied
return;
}
if (isSystem) {
if (codeLength == 1 && methodName.equals("finalize")) {
if (verbose) {
System.out.println("empty system finalizer not instrumented");
}
c.copy(attrLength - 8); // copy remainder minus already copied
return;
}
if (codeLength == 1 && methodName.equals("<init>")) {
if (verbose) {
System.out.println("empty system constructor not instrumented");
}
if (!options.shouldInstrumentObjectInit) {
c.copy(attrLength - 8); // copy remainder minus already copied
return;
}
}
if (methodName.equals("<clinit>")) {
if (verbose) {
System.out.println("system class initializer not instrumented");
}
c.copy(attrLength - 8); // copy remainder minus already copied
return;
}
}
if (options.shouldInstrumentObjectInit
&& (!className.equals("java/lang/Object")
|| !methodName.equals("<init>"))) {
c.copy(attrLength - 8); // copy remainder minus already copied
return;
}
InjectBytecodes ib = new InjectBytecodes(c, codeLength, className, methodName);
if (options.shouldInstrumentNew) {
ib.injectAfter(opc_new, allocInjector);
ib.injectAfter(opc_newarray, allocInjector);
ib.injectAfter(opc_anewarray, allocInjector);
ib.injectAfter(opc_multianewarray, allocInjector);
}
if (options.shouldInstrumentCall) {
ib.inject(0, callInjector.bytecodes(className, methodName, 0));
}
if (options.shouldInstrumentObjectInit) {
ib.inject(0, allocInjector.bytecodes(className, methodName, 0));
}
ib.adjustOffsets();
// fix up code length
int newCodeLength = c.generatedPosition() - (codeLengthPos + 4);
c.randomAccessWriteU4(codeLengthPos, newCodeLength);
if (verbose) {
System.out.println("code length old: " + codeLength +
", new: " + newCodeLength);
}
ib.copyExceptionTable();
int attrCount = c.copyU2();
for (int i = 0; i < attrCount; ++i) {
copyAttrForCode(ib);
}
// fix up attr length
int newAttrLength = c.generatedPosition() - (attrLengthPos + 4);
c.randomAccessWriteU4(attrLengthPos, newAttrLength);
if (verbose) {
System.out.println("attr length old: " + attrLength +
", new: " + newAttrLength);
}
}
int nextDescriptorIndex(String descriptor, int index) {
switch (descriptor.charAt(index)) {
case 'B': // byte
case 'C': // char
case 'I': // int
case 'S': // short
case 'Z': // boolean
case 'F': // float
case 'D': // double
case 'J': // long
return index + 1;
case 'L': // object
int i = index + 1;
while (descriptor.charAt(i) != ';') {
++i;
}
return i + 1;
case '[': // array
return nextDescriptorIndex(descriptor, index + 1);
}
throw new InternalError("should not reach here");
}
int getWrappedTrackerIndex() {
if (wrappedTrackerIndex == 0) {
wrappedTrackerIndex = addMethodToConstantPool(profiler,
options.wrappedTrackerMethodName,
"(Ljava/lang/String;I)V");
}
return wrappedTrackerIndex;
}
int getThisClassIndex() {
if (thisClassIndex == 0) {
thisClassIndex = addClassToConstantPool(className);
}
return thisClassIndex;
}
int computeMaxLocals(String descriptor, int accessFlags) {
int index = 1;
int slot = 0;
if ((accessFlags & ACC_STATIC) == 0) {
++slot;
}
char type;
while ((type = descriptor.charAt(index)) != ')') {
switch (type) {
case 'B': // byte
case 'C': // char
case 'I': // int
case 'S': // short
case 'Z': // boolean
case 'F': // float
case 'L': // object
case '[': // array
++slot;
break;
case 'D': // double
case 'J': // long
slot += 2;
break;
}
index = nextDescriptorIndex(descriptor, index);
}
return slot;
}
void createWrapperCodeAttr(int methodNameIndex, int accessFlags,
String descriptor, int wrappedIndex) {
int maxLocals = computeMaxLocals(descriptor, accessFlags);
c.writeU2(c.codeAttributeIndex); //
int attrLengthPos = c.generatedPosition();
c.writeU4(0); // attr len -- fix up below
c.writeU2(maxLocals + 4); // max stack
c.writeU2(maxLocals); // max locals
int codeLengthPos = c.generatedPosition();
c.writeU4(0); // code length -- fix up below
int methodStringIndex = writeCPEntryString(methodNameIndex);
c.writeU1(opc_ldc_w);
c.writeU2(methodStringIndex); // send the method name
c.writeU1(opc_sipush);
c.writeU2(options.fixedIndex);
c.writeU1(opc_invokestatic);
c.writeU2(getWrappedTrackerIndex());
// set-up args
int index = 1;
int slot = 0;
if ((accessFlags & ACC_STATIC) == 0) {
c.writeU1(opc_aload_0); // this
++slot;
}
char type;
while ((type = descriptor.charAt(index)) != ')') {
switch (type) {
case 'B': // byte
case 'C': // char
case 'I': // int
case 'S': // short
case 'Z': // boolean
c.writeU1(opc_iload);
c.writeU1(slot);
++slot;
break;
case 'F': // float
c.writeU1(opc_fload);
c.writeU1(slot);
++slot;
break;
case 'D': // double
c.writeU1(opc_dload);
c.writeU1(slot);
slot += 2;
break;
case 'J': // long
c.writeU1(opc_lload);
c.writeU1(slot);
slot += 2;
break;
case 'L': // object
case '[': // array
c.writeU1(opc_aload);
c.writeU1(slot);
++slot;
break;
}
index = nextDescriptorIndex(descriptor, index);
}
// call the wrapped version
if ((accessFlags & ACC_STATIC) == 0) {
c.writeU1(opc_invokevirtual);
} else {
c.writeU1(opc_invokestatic);
}
c.writeU2(wrappedIndex);
// return correct type
switch (descriptor.charAt(index+1)) {
case 'B': // byte
case 'C': // char
case 'I': // int
case 'S': // short
case 'Z': // boolean
c.writeU1(opc_ireturn);
break;
case 'F': // float
c.writeU1(opc_freturn);
break;
case 'D': // double
c.writeU1(opc_dreturn);
break;
case 'J': // long
c.writeU1(opc_lreturn);
break;
case 'L': // object
case '[': // array
c.writeU1(opc_areturn);
break;
case 'V': // void
c.writeU1(opc_return);
break;
}
// end of code
// fix up code length
int newCodeLength = c.generatedPosition() - (codeLengthPos + 4);
c.randomAccessWriteU4(codeLengthPos, newCodeLength);
c.writeU2(0); // exception table length
c.writeU2(0); // attribute count
// fix up attr length
int newAttrLength = c.generatedPosition() - (attrLengthPos + 4);
c.randomAccessWriteU4(attrLengthPos, newAttrLength);
}
int addClassToConstantPool(String className) {
int prevSection = c.setSection(0);
int classNameIndex = writeCPEntryUtf8(className);
int classIndex = writeCPEntryClass(classNameIndex);
c.setSection(prevSection);
return classIndex;
}
int addMethodToConstantPool(int classIndex,
String methodName,
String descr) {
int prevSection = c.setSection(0);
int methodNameIndex = writeCPEntryUtf8(methodName);
int descrIndex = writeCPEntryUtf8(descr);
c.setSection(prevSection);
return addMethodToConstantPool(classIndex, methodNameIndex, descrIndex);
}
int addMethodToConstantPool(int classIndex,
int methodNameIndex,
int descrIndex) {
int prevSection = c.setSection(0);
int nameAndTypeIndex = writeCPEntryNameAndType(methodNameIndex,
descrIndex);
int methodIndex = writeCPEntryMethodRef(classIndex, nameAndTypeIndex);
c.setSection(prevSection);
return methodIndex;
}
int writeCPEntryUtf8(String str) {
int prevSection = c.setSection(0);
int len = str.length();
c.writeU1(CONSTANT_UTF8); // Utf8 tag
c.writeU2(len);
for (int i = 0; i < len; ++i) {
c.writeU1(str.charAt(i));
}
c.setSection(prevSection);
return constantPoolCount++;
}
int writeCPEntryString(int utf8Index) {
int prevSection = c.setSection(0);
c.writeU1(CONSTANT_STRING);
c.writeU2(utf8Index);
c.setSection(prevSection);
return constantPoolCount++;
}
int writeCPEntryClass(int classNameIndex) {
int prevSection = c.setSection(0);
c.writeU1(CONSTANT_CLASS);
c.writeU2(classNameIndex);
c.setSection(prevSection);
return constantPoolCount++;
}
int writeCPEntryNameAndType(int nameIndex, int descrIndex) {
int prevSection = c.setSection(0);
c.writeU1(CONSTANT_NAMEANDTYPE);
c.writeU2(nameIndex);
c.writeU2(descrIndex);
c.setSection(prevSection);
return constantPoolCount++;
}
int writeCPEntryMethodRef(int classIndex, int nameAndTypeIndex) {
int prevSection = c.setSection(0);
c.writeU1(CONSTANT_METHOD);
c.writeU2(classIndex);
c.writeU2(nameAndTypeIndex);
c.setSection(prevSection);
return constantPoolCount++;
}
}
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