mockit.internal.faking.FakedClassModifier Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of jmockit Show documentation
Show all versions of jmockit Show documentation
JMockit is a Java toolkit for automated developer testing.
It contains APIs for the creation of the objects to be tested, for mocking dependencies, and for faking external
APIs; JUnit (4 & 5) and TestNG test runners are supported.
It also contains an advanced code coverage tool.
/*
* Copyright (c) 2006 Rogério Liesenfeld
* This file is subject to the terms of the MIT license (see LICENSE.txt).
*/
package mockit.internal.faking;
import javax.annotation.*;
import static java.lang.reflect.Modifier.*;
import mockit.*;
import mockit.external.asm.*;
import mockit.internal.*;
import mockit.internal.faking.FakeMethods.*;
import mockit.internal.state.*;
import mockit.internal.util.*;
import static mockit.external.asm.Opcodes.*;
/**
* Responsible for generating all necessary bytecode in the redefined (real) class.
* Such code will redirect calls made on "real" methods to equivalent calls on the corresponding "fake" methods.
* The original code won't be executed by the running JVM until the class redefinition is undone.
*
* Methods in the real class with no corresponding fake methods are unaffected.
*
* Any fields (static or not) in the real class remain untouched.
*/
final class FakedClassModifier extends BaseClassModifier
{
private static final int ABSTRACT_OR_SYNTHETIC = Access.ABSTRACT + Access.SYNTHETIC;
@Nonnull private final FakeMethods fakeMethods;
private final boolean useClassLoadingBridgeForUpdatingFakeState;
@Nonnull private final Class fakedClass;
private FakeMethod fakeMethod;
private boolean isConstructor;
/**
* Initializes the modifier for a given real/fake class pair.
*
* The fake instance provided will receive calls for any instance methods defined in the fake class.
* Therefore, it needs to be later recovered by the modified bytecode inside the real method.
* To enable this, the fake instance is added to a global data structure made available through the
* {@link TestRun#getFake(String)} method.
*
* @param cr the class file reader for the real class
* @param realClass the class to be faked, or a base type of an implementation class to be faked
* @param fake an instance of the fake class
* @param fakeMethods contains the set of fake methods collected from the fake class; each fake method is identified
* by a pair composed of "name" and "desc", where "name" is the method name, and "desc" is the JVM internal
* description of the parameters; once the real class modification is complete this set will be empty, unless no
* corresponding real method was found for any of its method identifiers
*/
FakedClassModifier(
@Nonnull ClassReader cr, @Nonnull Class realClass, @Nonnull MockUp fake, @Nonnull FakeMethods fakeMethods)
{
super(cr);
fakedClass = realClass;
this.fakeMethods = fakeMethods;
ClassLoader classLoaderOfRealClass = realClass.getClassLoader();
useClassLoadingBridgeForUpdatingFakeState = ClassLoad.isClassLoaderWithNoDirectAccess(classLoaderOfRealClass);
inferUseOfClassLoadingBridge(classLoaderOfRealClass, fake);
}
private void inferUseOfClassLoadingBridge(@Nullable ClassLoader classLoaderOfRealClass, @Nonnull Object fake)
{
setUseClassLoadingBridge(classLoaderOfRealClass);
if (!useClassLoadingBridge && !isPublic(fake.getClass().getModifiers())) {
useClassLoadingBridge = true;
}
}
/**
* If the specified method has a fake definition, then generates bytecode to redirect calls made to it to the fake
* method. If it has no fake, does nothing.
*
* @param access not relevant
* @param name together with desc, used to identity the method in given set of fake methods
* @param signature not relevant
* @param exceptions not relevant
*
* @return null if the method was redefined, otherwise a MethodWriter that writes out the visited
* method code without changes
*/
@Override
public MethodVisitor visitMethod(
int access, @Nonnull String name, @Nonnull String desc, @Nullable String signature, @Nullable String[] exceptions)
{
if ((access & ABSTRACT_OR_SYNTHETIC) != 0) {
if (isAbstract(access)) {
// Marks a matching fake method (if any) as having the corresponding faked method.
fakeMethods.findMethod(access, name, desc, signature);
}
return cw.visitMethod(access, name, desc, signature, exceptions);
}
isConstructor = "".equals(name);
if (isConstructor && isFakedSuperclass() || !hasFake(access, name, desc, signature)) {
return cw.visitMethod(access, name, desc, signature, exceptions);
}
startModifiedMethodVersion(access, name, desc, signature, exceptions);
if (isConstructor) {
generateCallToSuperConstructor();
}
else if (isNative(methodAccess)) {
generateCallToUpdateFakeState();
generateCallToFakeMethod();
generateMethodReturn();
mw.visitMaxStack(1); // dummy value, real one is calculated by ASM
return methodAnnotationsVisitor;
}
generateDynamicCallToFake();
return copyOriginalImplementationCode(isConstructor);
}
private boolean hasFake(int access, @Nonnull String name, @Nonnull String desc, @Nullable String signature)
{
String fakeName = getCorrespondingFakeName(name);
fakeMethod = fakeMethods.findMethod(access, fakeName, desc, signature);
return fakeMethod != null;
}
@Nonnull
private static String getCorrespondingFakeName(@Nonnull String name)
{
if ("".equals(name)) {
return "$init";
}
if ("".equals(name)) {
return "$clinit";
}
return name;
}
private boolean isFakedSuperclass() { return fakedClass != fakeMethods.getRealClass(); }
private void generateDynamicCallToFake()
{
Label startOfRealImplementation = null;
if (!isStatic(methodAccess) && !isConstructor && isFakedSuperclass()) {
Class targetClass = fakeMethods.getRealClass();
if (fakedClass.getClassLoader() == targetClass.getClassLoader()) {
startOfRealImplementation = new Label();
mw.visitVarInsn(ALOAD, 0);
mw.visitTypeInsn(INSTANCEOF, JavaType.getInternalName(targetClass));
mw.visitJumpInsn(IFEQ, startOfRealImplementation);
}
}
generateCallToUpdateFakeState();
if (isConstructor) {
generateConditionalCallForFakedConstructor();
}
else {
generateConditionalCallForFakedMethod(startOfRealImplementation);
}
}
private void generateCallToUpdateFakeState()
{
if (useClassLoadingBridgeForUpdatingFakeState) {
generateCallToControlMethodThroughClassLoadingBridge();
mw.visitTypeInsn(CHECKCAST, "java/lang/Boolean");
mw.visitMethodInsn(INVOKEVIRTUAL, "java/lang/Boolean", "booleanValue", "()Z", false);
}
else {
mw.visitLdcInsn(fakeMethods.getFakeClassInternalName());
mw.visitIntInsn(SIPUSH, fakeMethod.getIndexForFakeState());
mw.visitMethodInsn(
INVOKESTATIC, "mockit/internal/state/TestRun", "updateFakeState", "(Ljava/lang/String;I)Z", false);
}
}
private void generateCallToControlMethodThroughClassLoadingBridge()
{
generateCodeToObtainInstanceOfClassLoadingBridge(FakeBridge.MB);
// First and second "invoke" arguments:
generateCodeToPassThisOrNullIfStaticMethod();
mw.visitInsn(ACONST_NULL);
// Create array for call arguments (third "invoke" argument):
generateCodeToCreateArrayOfObject(mw, 2);
int i = 0;
generateCodeToFillArrayElement(i++, fakeMethods.getFakeClassInternalName());
generateCodeToFillArrayElement(i, fakeMethod.getIndexForFakeState());
generateCallToInvocationHandler();
}
private void generateConditionalCallForFakedMethod(@Nullable Label startOfRealImplementation)
{
if (startOfRealImplementation == null) {
//noinspection AssignmentToMethodParameter
startOfRealImplementation = new Label();
}
mw.visitJumpInsn(IFEQ, startOfRealImplementation);
generateCallToFakeMethod();
generateMethodReturn();
mw.visitLabel(startOfRealImplementation);
}
private void generateConditionalCallForFakedConstructor()
{
generateCallToFakeMethod();
int jumpInsnOpcode;
if (shouldUseClassLoadingBridge()) {
mw.visitLdcInsn(VOID_TYPE);
jumpInsnOpcode = IF_ACMPEQ;
}
else {
jumpInsnOpcode = fakeMethod.hasInvocationParameter ? IFNE : IFEQ;
}
Label startOfRealImplementation = new Label();
mw.visitJumpInsn(jumpInsnOpcode, startOfRealImplementation);
mw.visitInsn(RETURN);
mw.visitLabel(startOfRealImplementation);
}
private void generateCallToFakeMethod()
{
if (shouldUseClassLoadingBridge()) {
generateCallToFakeMethodThroughClassLoadingBridge();
}
else {
generateDirectCallToFakeMethod();
}
}
private boolean shouldUseClassLoadingBridge() { return useClassLoadingBridge || !fakeMethod.isPublic(); }
private void generateCallToFakeMethodThroughClassLoadingBridge()
{
generateCodeToObtainInstanceOfClassLoadingBridge(FakeMethodBridge.MB);
// First and second "invoke" arguments:
boolean isStatic = generateCodeToPassThisOrNullIfStaticMethod();
mw.visitInsn(ACONST_NULL);
// Create array for call arguments (third "invoke" argument):
JavaType[] argTypes = JavaType.getArgumentTypes(methodDesc);
generateCodeToCreateArrayOfObject(mw, 6 + argTypes.length);
int i = 0;
generateCodeToFillArrayElement(i++, fakeMethods.getFakeClassInternalName());
generateCodeToFillArrayElement(i++, classDesc);
generateCodeToFillArrayElement(i++, methodAccess);
if (fakeMethod.isAdvice) {
generateCodeToFillArrayElement(i++, methodName);
generateCodeToFillArrayElement(i++, methodDesc);
}
else {
generateCodeToFillArrayElement(i++, fakeMethod.name);
generateCodeToFillArrayElement(i++, fakeMethod.desc);
}
generateCodeToFillArrayElement(i++, fakeMethod.getIndexForFakeState());
generateCodeToFillArrayWithParameterValues(mw, argTypes, i, isStatic ? 0 : 1);
generateCallToInvocationHandler();
}
private void generateDirectCallToFakeMethod()
{
String fakeClassDesc = fakeMethods.getFakeClassInternalName();
int invokeOpcode;
if (fakeMethod.isStatic()) {
invokeOpcode = INVOKESTATIC;
}
else {
generateCodeToObtainFakeInstance(fakeClassDesc);
invokeOpcode = INVOKEVIRTUAL;
}
boolean canProceedIntoConstructor = generateArgumentsForFakeMethodInvocation();
mw.visitMethodInsn(invokeOpcode, fakeClassDesc, fakeMethod.name, fakeMethod.desc, false);
if (canProceedIntoConstructor) {
mw.visitMethodInsn(
INVOKEVIRTUAL, "mockit/internal/faking/FakeInvocation", "shouldProceedIntoConstructor", "()Z", false);
}
}
private void generateCodeToObtainFakeInstance(@Nonnull String fakeClassDesc)
{
mw.visitLdcInsn(fakeClassDesc);
mw.visitMethodInsn(
INVOKESTATIC, "mockit/internal/state/TestRun", "getFake", "(Ljava/lang/String;)Ljava/lang/Object;", false);
mw.visitTypeInsn(CHECKCAST, fakeClassDesc);
}
private boolean generateArgumentsForFakeMethodInvocation()
{
String fakedDesc = fakeMethod.isAdvice ? methodDesc : fakeMethod.fakeDescWithoutInvocationParameter;
JavaType[] argTypes = JavaType.getArgumentTypes(fakedDesc);
int varIndex = isStatic(methodAccess) ? 0 : 1;
boolean canProceedIntoConstructor = false;
if (fakeMethod.hasInvocationParameter) {
generateCallToCreateNewFakeInvocation(argTypes, varIndex);
// When invoking a constructor, the invocation object will need to be consulted for proceeding:
if (isConstructor) {
mw.visitInsn(fakeMethod.isStatic() ? DUP : DUP_X1);
canProceedIntoConstructor = true;
}
}
if (!fakeMethod.isAdvice) {
boolean forGenericMethod = fakeMethod.isForGenericMethod();
for (JavaType argType : argTypes) {
int opcode = argType.getOpcode(ILOAD);
mw.visitVarInsn(opcode, varIndex);
if (forGenericMethod && argType.getSort() >= JavaType.Sort.ARRAY) {
mw.visitTypeInsn(CHECKCAST, argType.getInternalName());
}
varIndex += argType.getSize();
}
}
return canProceedIntoConstructor;
}
private void generateCallToCreateNewFakeInvocation(@Nonnull JavaType[] argTypes, int initialParameterIndex)
{
generateCodeToPassThisOrNullIfStaticMethod();
int argCount = argTypes.length;
if (argCount == 0) {
mw.visitInsn(ACONST_NULL);
}
else {
generateCodeToCreateArrayOfObject(mw, argCount);
generateCodeToFillArrayWithParameterValues(mw, argTypes, 0, initialParameterIndex);
}
mw.visitLdcInsn(fakeMethods.getFakeClassInternalName());
mw.visitIntInsn(SIPUSH, fakeMethod.getIndexForFakeState());
mw.visitLdcInsn(classDesc);
mw.visitLdcInsn(methodName);
mw.visitLdcInsn(methodDesc);
mw.visitMethodInsn(
INVOKESTATIC, "mockit/internal/faking/FakeInvocation", "create",
"(Ljava/lang/Object;[Ljava/lang/Object;Ljava/lang/String;I" +
"Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;)Lmockit/internal/faking/FakeInvocation;", false);
}
private void generateMethodReturn()
{
if (shouldUseClassLoadingBridge() || fakeMethod.isAdvice) {
generateReturnWithObjectAtTopOfTheStack(methodDesc);
}
else {
JavaType returnType = JavaType.getReturnType(methodDesc);
mw.visitInsn(returnType.getOpcode(IRETURN));
}
}
}