/**
* Copyright (C) 2010-2017 Gordon Fraser, Andrea Arcuri and EvoSuite
* contributors
*
* This file is part of EvoSuite.
*
* EvoSuite 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 3.0 of the License, or
* (at your option) any later version.
*
* EvoSuite 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 Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with EvoSuite. If not, see <http://www.gnu.org/licenses/>.
*/
package org.evosuite.instrumentation;
import static org.objectweb.asm.Opcodes.INVOKESTATIC;
import java.util.LinkedList;
import java.util.List;
import org.evosuite.testcase.execution.ExecutionTracer;
import org.objectweb.asm.ClassVisitor;
import org.objectweb.asm.FieldVisitor;
import org.objectweb.asm.Label;
import org.objectweb.asm.MethodVisitor;
import org.objectweb.asm.Opcodes;
import org.objectweb.asm.Type;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* This visitor inserts a callback to at the exit of each <clinit>() method
* (i.e. after class initialization has ended). If the class has no static
* fields, no callback is inserted.
*
* @author galeotti
*
*/
public class EndOfClassInitializerVisitor extends ClassVisitor {
/**
* The method visitor for the containing class visitor. This method visitor
* implements the functionality of the containing class at the method level.
*
* @author galeotti
*/
private static class EndOfClassInitializerMethodVisitor extends MethodVisitor {
private final String className;
private final String methodName;
private Label startingTryLabel;
private Label endingTryLabel;
/**
* <p>
* Constructor for PutStaticMethodAdapter.
* </p>
*
* @param mv
* a {@link org.objectweb.asm.MethodVisitor} object.
* @param className
* a {@link java.lang.String} object.
* @param finalFields
* a {@link java.util.List} object.
*/
public EndOfClassInitializerMethodVisitor(String className, String methodName, MethodVisitor mv) {
super(Opcodes.ASM5, mv);
this.className = className;
this.methodName = methodName;
}
@Override
public void visitInsn(int opcode) {
if (opcode == Opcodes.RETURN && (methodName.equals("<clinit>"))) {
String executionTracerClassName = ExecutionTracer.class.getName().replace('.', '/');
String executionTracerDescriptor = Type.getMethodDescriptor(Type.VOID_TYPE, Type.getType(String.class));
String classNameWithDots = className.replace('/', '.');
super.visitLdcInsn(classNameWithDots);
super.visitMethodInsn(INVOKESTATIC, executionTracerClassName, EXIT_CLASS_INIT,
executionTracerDescriptor, false);
}
super.visitInsn(opcode);
}
@Override
public void visitCode() {
super.visitCode();
if (methodName.equals("<clinit>")) {
startingTryLabel = new Label();
endingTryLabel = new Label();
super.visitLabel(startingTryLabel);
}
}
@Override
public void visitEnd() {
if (methodName.equals("<clinit>")) {
super.visitLabel(endingTryLabel);
String executionTracerClassName = ExecutionTracer.class.getName().replace('.', '/');
String executionTracerDescriptor = Type.getMethodDescriptor(Type.VOID_TYPE, Type.getType(String.class));
String classNameWithDots = className.replace('/', '.');
super.visitLdcInsn(classNameWithDots);
super.visitMethodInsn(INVOKESTATIC, executionTracerClassName, EXIT_CLASS_INIT,
executionTracerDescriptor, false);
super.visitInsn(Opcodes.ATHROW);
// regenerate try-catch table
for (TryCatchBlock tryCatchBlock : tryCatchBlocks) {
super.visitTryCatchBlock(tryCatchBlock.start, tryCatchBlock.end, tryCatchBlock.handler,
tryCatchBlock.type);
}
// add new try-catch for exiting method
super.visitTryCatchBlock(startingTryLabel, endingTryLabel, endingTryLabel, null);
}
super.visitEnd();
}
private static class TryCatchBlock {
public TryCatchBlock(Label start, Label end, Label handler, String type) {
this.start = start;
this.end = end;
this.handler = handler;
this.type = type;
}
Label start;
Label end;
Label handler;
String type;
}
private final List<TryCatchBlock> tryCatchBlocks = new LinkedList<TryCatchBlock>();
@Override
public void visitTryCatchBlock(Label start, Label end, Label handler, String type) {
if (methodName.equals("<clinit>")) {
TryCatchBlock block = new TryCatchBlock(start, end, handler, type);
tryCatchBlocks.add(block);
}
super.visitTryCatchBlock(start, end, handler, type);
}
}
private static Logger logger = LoggerFactory.getLogger(EndOfClassInitializerVisitor.class);
private final String className;
public EndOfClassInitializerVisitor(ClassVisitor visitor, String className) {
super(Opcodes.ASM5, visitor);
this.className = className;
}
@Override
public MethodVisitor visitMethod(int methodAccess, String methodName, String descriptor, String signature,
String[] exceptions) {
MethodVisitor mv = super.visitMethod(methodAccess, methodName, descriptor, signature, exceptions);
if (methodName.equals("<clinit>")) {
clinitFound = true;
EndOfClassInitializerMethodVisitor staticResetMethodAdapter = new EndOfClassInitializerMethodVisitor(
className, methodName, mv);
return staticResetMethodAdapter;
} else {
return mv;
}
}
private boolean isInterface = false;
private boolean clinitFound = false;
private boolean hasStaticFields = false;
private static final String EXIT_CLASS_INIT = "exitClassInit";
@Override
public void visit(int version, int access, String name, String signature, String superName, String[] interfaces) {
super.visit(version, access, name, signature, superName, interfaces);
isInterface = ((access & Opcodes.ACC_INTERFACE) == Opcodes.ACC_INTERFACE);
}
@Override
public void visitEnd() {
if (!clinitFound && !isInterface && hasStaticFields) {
// create brand empty <clinit>()
createEmptyClassInit();
}
super.visitEnd();
}
private static boolean isStatic(int access) {
return (access & Opcodes.ACC_STATIC) == Opcodes.ACC_STATIC;
}
@Override
public FieldVisitor visitField(int access, String name, String desc, String signature, Object value) {
if (isStatic(access)) {
hasStaticFields = true;
}
return super.visitField(access, name, desc, signature, value);
}
private void createEmptyClassInit() {
logger.info("Creating <clinit> in class " + className);
MethodVisitor mv = cv.visitMethod(Opcodes.ACC_STATIC, "<clinit>", "()V", null, null);
mv.visitCode();
String executionTracerClassName = ExecutionTracer.class.getName().replace('.', '/');
String executionTracerDescriptor = Type.getMethodDescriptor(Type.VOID_TYPE, Type.getType(String.class));
String classNameWithDots = className.replace('/', '.');
mv.visitLdcInsn(classNameWithDots);
mv.visitMethodInsn(INVOKESTATIC, executionTracerClassName, EXIT_CLASS_INIT, executionTracerDescriptor, false);
mv.visitInsn(Opcodes.RETURN);
mv.visitMaxs(0, 0);
mv.visitEnd();
}
}