public void visitCodeAttribute(Clazz clazz, Method method, CodeAttribute codeAttribute) {
// DEBUG =
// clazz.getName().equals("abc/Def") &&
// method.getName(clazz).equals("abc");
// The minimum variable size is determined by the arguments.
codeAttribute.u2maxLocals =
ClassUtil.internalMethodParameterSize(method.getDescriptor(clazz), method.getAccessFlags());
if (DEBUG) {
System.out.println(
"VariableSizeUpdater: "
+ clazz.getName()
+ "."
+ method.getName(clazz)
+ method.getDescriptor(clazz));
System.out.println(" Max locals: " + codeAttribute.u2maxLocals + " <- parameters");
}
// Go over all instructions.
codeAttribute.instructionsAccept(clazz, method, this);
// Remove the unused variables of the attributes.
codeAttribute.attributesAccept(clazz, method, variableCleaner);
}
/** Returns a shrunk descriptor or signature of the given method. */
private String shrinkDescriptor(Method method, String descriptor) {
// All parameters of non-static methods are shifted by one in the local
// variable frame.
int parameterIndex =
(method.getAccessFlags() & ClassConstants.INTERNAL_ACC_STATIC) != 0 ? 0 : 1;
// Go over the parameters.
InternalTypeEnumeration internalTypeEnumeration = new InternalTypeEnumeration(descriptor);
StringBuffer newDescriptorBuffer = new StringBuffer();
newDescriptorBuffer.append(internalTypeEnumeration.formalTypeParameters());
newDescriptorBuffer.append(ClassConstants.INTERNAL_METHOD_ARGUMENTS_OPEN);
while (internalTypeEnumeration.hasMoreTypes()) {
String type = internalTypeEnumeration.nextType();
if (ParameterUsageMarker.isParameterUsed(method, parameterIndex)) {
newDescriptorBuffer.append(type);
} else if (DEBUG) {
System.out.println(" Deleting parameter #" + parameterIndex + " [" + type + "]");
}
parameterIndex += ClassUtil.isInternalCategory2Type(type) ? 2 : 1;
}
newDescriptorBuffer.append(ClassConstants.INTERNAL_METHOD_ARGUMENTS_CLOSE);
newDescriptorBuffer.append(internalTypeEnumeration.returnType());
return newDescriptorBuffer.toString();
}
/**
* Marks the hierarchy of implementing or overriding methods corresponding to the given method, if
* any.
*/
protected void markMethodHierarchy(Clazz clazz, Method method) {
int accessFlags = method.getAccessFlags();
if ((accessFlags & (ClassConstants.ACC_PRIVATE | ClassConstants.ACC_STATIC)) == 0
&& !ClassUtil.isInitializer(method.getName(clazz))) {
// We can skip private and static methods in the hierarchy, and
// also abstract methods, unless they might widen a current
// non-public access.
int requiredUnsetAccessFlags =
ClassConstants.ACC_PRIVATE
| ClassConstants.ACC_STATIC
| ((accessFlags & ClassConstants.ACC_PUBLIC) == 0 ? 0 : ClassConstants.ACC_ABSTRACT);
clazz.accept(
new ConcreteClassDownTraveler(
new ClassHierarchyTraveler(
true,
true,
false,
true,
new NamedMethodVisitor(
method.getName(clazz),
method.getDescriptor(clazz),
new MemberAccessFilter(0, requiredUnsetAccessFlags, this)))));
}
}
public void visitSignatureAttribute(Clazz clazz, SignatureAttribute signatureAttribute) {
// Process the generic definitions, superclass, and implemented
// interfaces.
String signature = clazz.getString(signatureAttribute.u2signatureIndex);
// Count the signature types.
InternalTypeEnumeration internalTypeEnumeration = new InternalTypeEnumeration(signature);
int count = 0;
int interfacesCount = -1;
while (internalTypeEnumeration.hasMoreTypes()) {
String internalType = internalTypeEnumeration.nextType();
count++;
if (ClassUtil.isInternalClassType(internalType)) {
interfacesCount++;
}
}
// Put the signature types in an array.
internalTypeEnumeration = new InternalTypeEnumeration(signature);
String[] internalTypes = new String[count];
for (int index = 0; index < count; index++) {
String internalType = internalTypeEnumeration.nextType();
internalTypes[index] = internalType;
}
// Sort the interface types in the array.
Arrays.sort(internalTypes, count - interfacesCount, count);
// Recompose the signature types in a string.
StringBuffer newSignatureBuffer = new StringBuffer();
for (int index = 0; index < count; index++) {
// Is this not an interface type, or an interface type that isn't
// a duplicate of the previous interface type?
if (index < count - interfacesCount
|| !internalTypes[index].equals(internalTypes[index - 1])) {
newSignatureBuffer.append(internalTypes[index]);
}
}
String newSignature = newSignatureBuffer.toString();
// Did the signature change?
if (!newSignature.equals(signature)) {
// Update the signature.
((Utf8Constant) ((ProgramClass) clazz).constantPool[signatureAttribute.u2signatureIndex])
.setString(newSignatureBuffer.toString());
// Clear the referenced classes.
// TODO: Properly update the referenced classes.
signatureAttribute.referencedClasses = null;
}
}
/** Shrinks the array of referenced classes of the given method. */
private Clazz[] shrinkReferencedClasses(
Method method, String descriptor, Clazz[] referencedClasses) {
if (referencedClasses != null) {
// All parameters of non-static methods are shifted by one in the local
// variable frame.
int parameterIndex =
(method.getAccessFlags() & ClassConstants.INTERNAL_ACC_STATIC) != 0 ? 0 : 1;
int referencedClassIndex = 0;
int newReferencedClassIndex = 0;
// Go over the parameters.
InternalTypeEnumeration internalTypeEnumeration = new InternalTypeEnumeration(descriptor);
// Also look at the formal type parameters.
String type = internalTypeEnumeration.formalTypeParameters();
int count = new DescriptorClassEnumeration(type).classCount();
for (int counter = 0; counter < count; counter++) {
referencedClasses[newReferencedClassIndex++] = referencedClasses[referencedClassIndex++];
}
while (internalTypeEnumeration.hasMoreTypes()) {
// Consider the classes referenced by this parameter type.
type = internalTypeEnumeration.nextType();
count = new DescriptorClassEnumeration(type).classCount();
if (ParameterUsageMarker.isParameterUsed(method, parameterIndex)) {
// Copy the referenced classes.
for (int counter = 0; counter < count; counter++) {
referencedClasses[newReferencedClassIndex++] =
referencedClasses[referencedClassIndex++];
}
} else {
// Skip the referenced classes.
referencedClassIndex += count;
}
parameterIndex += ClassUtil.isInternalCategory2Type(type) ? 2 : 1;
}
// Also look at the return value.
type = internalTypeEnumeration.returnType();
count = new DescriptorClassEnumeration(type).classCount();
for (int counter = 0; counter < count; counter++) {
referencedClasses[newReferencedClassIndex++] = referencedClasses[referencedClassIndex++];
}
// Clear the unused entries.
while (newReferencedClassIndex < referencedClassIndex) {
referencedClasses[newReferencedClassIndex++] = null;
}
}
return referencedClasses;
}
/**
* Marks the hierarchy of implementing or overriding methods corresponding to the given method, if
* any.
*/
protected void markMethodHierarchy(Clazz clazz, Method method) {
int accessFlags = method.getAccessFlags();
if ((accessFlags & (ClassConstants.ACC_PRIVATE | ClassConstants.ACC_STATIC)) == 0
&& !ClassUtil.isInitializer(method.getName(clazz))) {
// We can skip private and static methods in the hierarchy, and
// also abstract methods, unless they might widen a current
// non-public access.
int requiredUnsetAccessFlags =
ClassConstants.ACC_PRIVATE
| ClassConstants.ACC_STATIC
| ((accessFlags & ClassConstants.ACC_PUBLIC) == 0 ? 0 : ClassConstants.ACC_ABSTRACT);
// Mark default implementations in interfaces down the hierarchy.
// TODO: This may be premature if there aren't any concrete implementing classes.
clazz.accept(
new ClassAccessFilter(
ClassConstants.ACC_ABSTRACT,
0,
new ClassHierarchyTraveler(
false,
false,
false,
true,
new ProgramClassFilter(
new ClassAccessFilter(
ClassConstants.ACC_ABSTRACT,
0,
new NamedMethodVisitor(
method.getName(clazz),
method.getDescriptor(clazz),
new MemberAccessFilter(
0, requiredUnsetAccessFlags, defaultMethodUsageMarker)))))));
// Mark other implementations.
clazz.accept(
new ConcreteClassDownTraveler(
new ClassHierarchyTraveler(
true,
true,
false,
true,
new NamedMethodVisitor(
method.getName(clazz),
method.getDescriptor(clazz),
new MemberAccessFilter(0, requiredUnsetAccessFlags, this)))));
}
}
public void visitAnyParameterAnnotationsAttribute(
Clazz clazz, Method method, ParameterAnnotationsAttribute parameterAnnotationsAttribute) {
int[] annotationsCounts = parameterAnnotationsAttribute.u2parameterAnnotationsCount;
Annotation[][] annotations = parameterAnnotationsAttribute.parameterAnnotations;
// All parameters of non-static methods are shifted by one in the local
// variable frame.
int parameterIndex =
(method.getAccessFlags() & ClassConstants.INTERNAL_ACC_STATIC) != 0 ? 0 : 1;
int annotationIndex = 0;
int newAnnotationIndex = 0;
// Go over the parameters.
String descriptor = method.getDescriptor(clazz);
InternalTypeEnumeration internalTypeEnumeration = new InternalTypeEnumeration(descriptor);
while (internalTypeEnumeration.hasMoreTypes()) {
String type = internalTypeEnumeration.nextType();
if (ParameterUsageMarker.isParameterUsed(method, parameterIndex)) {
annotationsCounts[newAnnotationIndex] = annotationsCounts[annotationIndex];
annotations[newAnnotationIndex++] = annotations[annotationIndex];
}
annotationIndex++;
parameterIndex += ClassUtil.isInternalCategory2Type(type) ? 2 : 1;
}
// Update the number of parameters.
parameterAnnotationsAttribute.u2parametersCount = newAnnotationIndex;
// Clear the unused entries.
while (newAnnotationIndex < annotationIndex) {
annotationsCounts[newAnnotationIndex] = 0;
annotations[newAnnotationIndex++] = null;
}
}
public void visitCodeAttribute(Clazz clazz, Method method, CodeAttribute codeAttribute) {
// Get the original parameter size that was saved.
int oldParameterSize = ParameterUsageMarker.getParameterSize(method);
// Compute the new parameter size from the shrunk descriptor.
int newParameterSize =
ClassUtil.internalMethodParameterSize(method.getDescriptor(clazz), method.getAccessFlags());
if (oldParameterSize > newParameterSize) {
// Get the total size of the local variable frame.
int maxLocals = codeAttribute.u2maxLocals;
if (DEBUG) {
System.out.println(
"ParameterShrinker: "
+ clazz.getName()
+ "."
+ method.getName(clazz)
+ method.getDescriptor(clazz));
System.out.println(" Old parameter size = " + oldParameterSize);
System.out.println(" New parameter size = " + newParameterSize);
System.out.println(" Max locals = " + maxLocals);
}
// Create a variable map.
int[] variableMap = new int[maxLocals];
// Move unused parameters right after the parameter block.
int usedParameterIndex = 0;
int unusedParameterIndex = newParameterSize;
for (int parameterIndex = 0; parameterIndex < oldParameterSize; parameterIndex++) {
// Is the variable required as a parameter?
if (ParameterUsageMarker.isParameterUsed(method, parameterIndex)) {
// Keep the variable as a parameter.
variableMap[parameterIndex] = usedParameterIndex++;
} else {
if (DEBUG) {
System.out.println(" Deleting parameter #" + parameterIndex);
}
// Shift the variable to the unused parameter block,
// in case it is still used as a variable.
variableMap[parameterIndex] = unusedParameterIndex++;
// Visit the method, if required.
if (extraVariableMemberVisitor != null) {
method.accept(clazz, extraVariableMemberVisitor);
}
}
}
// Fill out the remainder of the map.
for (int variableIndex = oldParameterSize; variableIndex < maxLocals; variableIndex++) {
variableMap[variableIndex] = variableIndex;
}
// Set the map.
variableRemapper.setVariableMap(variableMap);
// Remap the variables.
variableRemapper.visitCodeAttribute(clazz, method, codeAttribute);
}
}
