public void visitLibraryClass(LibraryClass libraryClass) {
if (shouldBeMarkedAsUsed(libraryClass)) {
markAsUsed(libraryClass);
// We're not going to analyze all library code. We're assuming that
// if this class is being used, all of its methods will be used as
// well. We'll mark them as such (here and in all subclasses).
// Mark the superclass.
Clazz superClass = libraryClass.superClass;
if (superClass != null) {
superClass.accept(this);
}
// Mark the interfaces.
Clazz[] interfaceClasses = libraryClass.interfaceClasses;
if (interfaceClasses != null) {
for (int index = 0; index < interfaceClasses.length; index++) {
if (interfaceClasses[index] != null) {
interfaceClasses[index].accept(this);
}
}
}
// Mark all methods.
libraryClass.methodsAccept(this);
}
}
/**
* Writes the given word to the given writer, after having adapted it, based on the renamed class
* names.
*/
private void writeUpdatedWord(Writer writer, String word) throws IOException {
if (word.length() > 0) {
String newWord = word;
boolean containsDots = word.indexOf('.') >= 0;
// Replace dots by forward slashes.
String className =
containsDots ? word.replace('.', ClassConstants.INTERNAL_PACKAGE_SEPARATOR) : word;
// Find the class corrsponding to the word.
Clazz clazz = classPool.getClass(className);
if (clazz != null) {
// Update the word if necessary.
String newClassName = clazz.getName();
if (!className.equals(newClassName)) {
// Replace forward slashes by dots.
newWord =
containsDots
? newClassName.replace(ClassConstants.INTERNAL_PACKAGE_SEPARATOR, '.')
: newClassName;
}
}
writer.write(newWord);
}
}
public int stackPopCount(Clazz clazz) {
int stackPopCount = super.stackPopCount(clazz);
// Some special cases.
switch (opcode) {
case InstructionConstants.OP_MULTIANEWARRAY:
// For each dimension, an integer size is popped from the stack.
stackPopCount += constant;
break;
case InstructionConstants.OP_PUTSTATIC:
case InstructionConstants.OP_PUTFIELD:
// The field value is be popped from the stack.
clazz.constantPoolEntryAccept(constantIndex, this);
stackPopCount += typeStackDelta;
break;
case InstructionConstants.OP_INVOKEVIRTUAL:
case InstructionConstants.OP_INVOKESPECIAL:
case InstructionConstants.OP_INVOKESTATIC:
case InstructionConstants.OP_INVOKEINTERFACE:
// The some parameters may be popped from the stack.
clazz.constantPoolEntryAccept(constantIndex, this);
stackPopCount += parameterStackDelta;
break;
}
return stackPopCount;
}
public void visitConstantInstruction(
Clazz clazz,
Method method,
CodeAttribute codeAttribute,
int offset,
ConstantInstruction constantInstruction) {
byte opcode = constantInstruction.opcode;
// Check for instructions that involve fields.
switch (opcode) {
case InstructionConstants.OP_LDC:
case InstructionConstants.OP_LDC_W:
// Mark the field, if any, as being read from and written to.
reading = true;
writing = true;
clazz.constantPoolEntryAccept(constantInstruction.constantIndex, this);
break;
case InstructionConstants.OP_GETSTATIC:
case InstructionConstants.OP_GETFIELD:
// Mark the field as being read from.
reading = true;
writing = false;
clazz.constantPoolEntryAccept(constantInstruction.constantIndex, this);
break;
case InstructionConstants.OP_PUTSTATIC:
case InstructionConstants.OP_PUTFIELD:
// Mark the field as being written to.
reading = false;
writing = true;
clazz.constantPoolEntryAccept(constantInstruction.constantIndex, this);
break;
}
}
/** Applies the given visitor to all referenced classes. */
public void referencedClassesAccept(ClassVisitor classVisitor) {
if (referencedClasses != null) {
for (int index = 0; index < referencedClasses.length; index++) {
Clazz referencedClass = referencedClasses[index];
if (referencedClass != null) {
referencedClass.accept(classVisitor);
}
}
}
}
public void visitInnerClassesInfo(Clazz clazz, InnerClassesInfo innerClassesInfo) {
// At this point, we only mark outer classes of this class.
// Inner class can be marked later, by InnerUsageMarker.
if (innerClassesInfo.u2innerClassIndex != 0
&& clazz.getName().equals(clazz.getClassName(innerClassesInfo.u2innerClassIndex))) {
markAsUsed(innerClassesInfo);
innerClassesInfo.innerClassConstantAccept(clazz, this);
innerClassesInfo.outerClassConstantAccept(clazz, this);
innerClassesInfo.innerNameConstantAccept(clazz, this);
}
}
public void visitAnyRefConstant(Clazz clazz, RefConstant refConstant) {
Clazz referencedClass = refConstant.referencedClass;
if (referencedClass != null
&& (referencedClass.getAccessFlags() & ClassConstants.INTERNAL_ACC_PUBLIC) == 0) {
setInvokesPackageVisibleMembers(clazz);
}
Member referencedMember = refConstant.referencedMember;
if (referencedMember != null
&& (referencedMember.getAccessFlags()
& (ClassConstants.INTERNAL_ACC_PUBLIC | ClassConstants.INTERNAL_ACC_PRIVATE))
== 0) {
setInvokesPackageVisibleMembers(clazz);
}
}
public void read(DataEntry dataEntry) throws IOException {
try {
// Get the input stream.
InputStream inputStream = dataEntry.getInputStream();
// Wrap it into a data input stream.
DataInputStream dataInputStream = new DataInputStream(inputStream);
// Create a Clazz representation.
Clazz clazz;
if (isLibrary) {
clazz = new LibraryClass();
clazz.accept(
new LibraryClassReader(
dataInputStream, skipNonPublicLibraryClasses, skipNonPublicLibraryClassMembers));
} else {
clazz = new ProgramClass();
clazz.accept(new ProgramClassReader(dataInputStream));
}
// Apply the visitor, if we have a real class.
String className = clazz.getName();
if (className != null) {
if (!dataEntry
.getName()
.replace(File.pathSeparatorChar, ClassConstants.PACKAGE_SEPARATOR)
.equals(className + ClassConstants.CLASS_FILE_EXTENSION)
&& warningPrinter != null) {
warningPrinter.print(
className,
"Warning: class ["
+ dataEntry.getName()
+ "] unexpectedly contains class ["
+ ClassUtil.externalClassName(className)
+ "]");
}
clazz.accept(classVisitor);
}
dataEntry.closeInputStream();
} catch (Exception ex) {
throw (IOException)
new IOException(
"Can't process class [" + dataEntry.getName() + "] (" + ex.getMessage() + ")")
.initCause(ex);
}
}
public void visitCodeAttribute(Clazz clazz, Method method, CodeAttribute codeAttribute) {
// DEBUG =
// clazz.getName().equals("abc/Def") &&
// method.getName(clazz).equals("abc");
// TODO: Remove this when the code has stabilized.
// Catch any unexpected exceptions from the actual visiting method.
try {
// Process the code.
visitCodeAttribute0(clazz, method, codeAttribute);
} catch (RuntimeException ex) {
System.err.println("Unexpected error while computing stack sizes:");
System.err.println(" Class = [" + clazz.getName() + "]");
System.err.println(
" Method = [" + method.getName(clazz) + method.getDescriptor(clazz) + "]");
System.err.println(
" Exception = [" + ex.getClass().getName() + "] (" + ex.getMessage() + ")");
if (DEBUG) {
method.accept(clazz, new ClassPrinter());
}
throw ex;
}
}
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);
}
/**
* 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 visitCodeAttribute0(Clazz clazz, Method method, CodeAttribute codeAttribute) {
if (DEBUG) {
System.out.println(
"StackSizeComputer: "
+ clazz.getName()
+ "."
+ method.getName(clazz)
+ method.getDescriptor(clazz));
}
// Try to reuse the previous array.
int codeLength = codeAttribute.u4codeLength;
if (evaluated.length < codeLength) {
evaluated = new boolean[codeLength];
stackSizes = new int[codeLength];
} else {
Arrays.fill(evaluated, 0, codeLength, false);
}
// The initial stack is always empty.
stackSize = 0;
maxStackSize = 0;
// Evaluate the instruction block starting at the entry point of the method.
evaluateInstructionBlock(clazz, method, codeAttribute, 0);
// Evaluate the exception handlers.
codeAttribute.exceptionsAccept(clazz, method, this);
}
/**
* 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 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;
}
}
public String toString() {
return "certain="
+ certain
+ ", depth="
+ depth
+ ": "
+ reason
+ (clazz != null ? clazz.getName() : "(none)")
+ ": "
+ (member != null ? member.getName(clazz) : "(none)");
}
public void visitProgramMethod(ProgramClass programClass, ProgramMethod programMethod) {
targetClass.hierarchyAccept(
visitThisMember,
visitSuperMembers,
visitInterfaceMembers,
visitOverridingMembers,
new NamedMethodVisitor(
programMethod.getName(programClass),
programMethod.getDescriptor(programClass),
memberVisitor));
}
public void visitLibraryField(LibraryClass libraryClass, LibraryField libraryField) {
targetClass.hierarchyAccept(
visitThisMember,
visitSuperMembers,
visitInterfaceMembers,
visitOverridingMembers,
new NamedFieldVisitor(
libraryField.getName(libraryClass),
libraryField.getDescriptor(libraryClass),
memberVisitor));
}
public void visitInvokeDynamicConstant(Clazz clazz, InvokeDynamicConstant invokeDynamicConstant) {
if (shouldBeMarkedAsUsed(invokeDynamicConstant)) {
markAsUsed(invokeDynamicConstant);
markConstant(clazz, invokeDynamicConstant.u2nameAndTypeIndex);
// Mark the bootstrap methods attribute.
clazz.attributesAccept(
new MyBootStrapMethodUsageMarker(invokeDynamicConstant.u2bootstrapMethodAttributeIndex));
}
}
public void visitConstantInstruction(
Clazz clazz,
Method method,
CodeAttribute codeAttribute,
int offset,
ConstantInstruction constantInstruction) {
markConstant(clazz, constantInstruction.constantIndex);
// Also mark the parameterless constructor of the class, in case the
// string constant or class constant is being used in a Class.forName
// or a .class construct.
clazz.constantPoolEntryAccept(
constantInstruction.constantIndex, parameterlessConstructorMarker);
}
public void visitSignatureAttribute(
Clazz clazz, Method method, SignatureAttribute signatureAttribute) {
// Compute the new signature.
String signature = clazz.getString(signatureAttribute.u2signatureIndex);
String newSignature = shrinkDescriptor(method, signature);
// Update the signature.
signatureAttribute.u2signatureIndex =
new ConstantPoolEditor((ProgramClass) clazz).addUtf8Constant(newSignature);
// Update the referenced classes.
signatureAttribute.referencedClasses =
shrinkReferencedClasses(method, signature, signatureAttribute.referencedClasses);
}
/** Returns if the number of superclasses of the given class in the given set of classes. */
private int superClassCount(Clazz subClass, Set classes) {
int count = 0;
Iterator iterator = classes.iterator();
while (iterator.hasNext()) {
Clazz clazz = (Clazz) iterator.next();
if (subClass.extendsOrImplements(clazz)) {
count++;
}
}
return count;
}
public int stackPushCount(Clazz clazz) {
int stackPushCount = super.stackPushCount(clazz);
// Some special cases.
switch (opcode) {
case InstructionConstants.OP_GETSTATIC:
case InstructionConstants.OP_GETFIELD:
case InstructionConstants.OP_INVOKEVIRTUAL:
case InstructionConstants.OP_INVOKESPECIAL:
case InstructionConstants.OP_INVOKESTATIC:
case InstructionConstants.OP_INVOKEINTERFACE:
// The field value or a return value may be pushed onto the stack.
clazz.constantPoolEntryAccept(constantIndex, this);
stackPushCount += typeStackDelta;
break;
}
return stackPushCount;
}
/**
* Marks the hierarchy of implementing or overriding methods corresponding to the given method, if
* any.
*/
protected void markMethodHierarchy(Clazz clazz, Method method) {
if ((method.getAccessFlags()
& (ClassConstants.INTERNAL_ACC_PRIVATE | ClassConstants.INTERNAL_ACC_STATIC))
== 0) {
clazz.accept(
new ConcreteClassDownTraveler(
new ClassHierarchyTraveler(
true,
true,
false,
true,
new NamedMethodVisitor(
method.getName(clazz),
method.getDescriptor(clazz),
new MemberAccessFilter(
0,
ClassConstants.INTERNAL_ACC_PRIVATE
| ClassConstants.INTERNAL_ACC_STATIC
| ClassConstants.INTERNAL_ACC_ABSTRACT,
this)))));
}
}
public void visitMethodHandleConstant(Clazz clazz, MethodHandleConstant methodHandleConstant) {
clazz.constantPoolEntryAccept(methodHandleConstant.u2referenceIndex, methodrefConstantVisitor);
}
/**
* Returns the most specific common superclass or interface of the given classes.
*
* @param class1 the first class.
* @param class2 the second class.
* @param interfaces specifies whether to look for a superclass or for an interface.
* @return the common class.
*/
private Clazz findCommonClass(Clazz class1, Clazz class2, boolean interfaces) {
// Collect the superclasses or the interfaces of this class.
Set superClasses1 = new HashSet();
class1.hierarchyAccept(
!interfaces, !interfaces, interfaces, false, new ClassCollector(superClasses1));
int superClasses1Count = superClasses1.size();
if (superClasses1Count == 0) {
if (interfaces) {
return null;
} else if (class1.getSuperName() != null) {
throw new IllegalArgumentException(
"Can't find any super classes of ["
+ class1.getName()
+ "] (not even immediate super class ["
+ class1.getSuperName()
+ "])");
}
}
// Collect the superclasses or the interfaces of the other class.
Set superClasses2 = new HashSet();
class2.hierarchyAccept(
!interfaces, !interfaces, interfaces, false, new ClassCollector(superClasses2));
int superClasses2Count = superClasses2.size();
if (superClasses2Count == 0) {
if (interfaces) {
return null;
} else if (class2.getSuperName() != null) {
throw new IllegalArgumentException(
"Can't find any super classes of ["
+ class2.getName()
+ "] (not even immediate super class ["
+ class2.getSuperName()
+ "])");
}
}
if (DEBUG) {
System.out.println(
"ReferenceValue.generalize this ["
+ class1.getName()
+ "] with other ["
+ class2.getName()
+ "] (interfaces = "
+ interfaces
+ ")");
System.out.println(" This super classes: " + superClasses1);
System.out.println(" Other super classes: " + superClasses2);
}
// Find the common superclasses.
superClasses1.retainAll(superClasses2);
if (DEBUG) {
System.out.println(" Common super classes: " + superClasses1);
}
if (interfaces && superClasses1.isEmpty()) {
return null;
}
// Find a class that is a subclass of all common superclasses,
// or that at least has the maximum number of common superclasses.
Clazz commonClass = null;
int maximumSuperClassCount = -1;
// Go over all common superclasses to find it. In case of
// multiple subclasses, keep the lowest one alphabetically,
// in order to ensure that the choice is deterministic.
Iterator commonSuperClasses = superClasses1.iterator();
while (commonSuperClasses.hasNext()) {
Clazz commonSuperClass = (Clazz) commonSuperClasses.next();
int superClassCount = superClassCount(commonSuperClass, superClasses1);
if (maximumSuperClassCount < superClassCount
|| (maximumSuperClassCount == superClassCount
&& commonClass != null
&& commonClass.getName().compareTo(commonSuperClass.getName()) > 0)) {
commonClass = commonSuperClass;
maximumSuperClassCount = superClassCount;
}
}
if (commonClass == null) {
throw new IllegalArgumentException(
"Can't find common super class of ["
+ class1.getName()
+ "] (with "
+ superClasses1Count
+ " known super classes) and ["
+ class2.getName()
+ "] (with "
+ superClasses2Count
+ " known super classes)");
}
if (DEBUG) {
System.out.println(" Best common class: [" + commonClass.getName() + "]");
}
return commonClass;
}
/**
* Applies the given class visitor to this mark's class, if any, and if this mark doesn't have a
* member.
*/
public void acceptClassVisitor(ClassVisitor classVisitor) {
if (clazz != null && member == null) {
clazz.accept(classVisitor);
}
}
/** Returns whether this is mark is caused by the given class. */
public boolean isCausedBy(Clazz clazz) {
return clazz.equals(this.clazz);
}
public int instanceOf(String otherType, Clazz otherReferencedClass) {
String thisType = this.type;
// If this type is null, it is never an instance of any class.
if (thisType == null) {
return NEVER;
}
// Start taking into account the type dimensions.
int thisDimensionCount = ClassUtil.internalArrayTypeDimensionCount(thisType);
int otherDimensionCount = ClassUtil.internalArrayTypeDimensionCount(otherType);
int commonDimensionCount = Math.min(thisDimensionCount, otherDimensionCount);
// Strip any common array prefixes.
thisType = thisType.substring(commonDimensionCount);
otherType = otherType.substring(commonDimensionCount);
// If either stripped type is a primitive type, we can tell right away.
if (commonDimensionCount > 0
&& (ClassUtil.isInternalPrimitiveType(thisType.charAt(0))
|| ClassUtil.isInternalPrimitiveType(otherType.charAt(0)))) {
return !thisType.equals(otherType) ? NEVER : mayBeNull ? MAYBE : ALWAYS;
}
// Strip the class type prefix and suffix of this type, if any.
if (thisDimensionCount == commonDimensionCount) {
thisType = ClassUtil.internalClassNameFromClassType(thisType);
}
// Strip the class type prefix and suffix of the other type, if any.
if (otherDimensionCount == commonDimensionCount) {
otherType = ClassUtil.internalClassNameFromClassType(otherType);
}
// If this type is an array type, and the other type is not
// java.lang.Object, java.lang.Cloneable, or java.io.Serializable,
// this type can never be an instance.
if (thisDimensionCount > otherDimensionCount
&& !ClassUtil.isInternalArrayInterfaceName(otherType)) {
return NEVER;
}
// If the other type is an array type, and this type is not
// java.lang.Object, java.lang.Cloneable, or java.io.Serializable,
// this type can never be an instance.
if (thisDimensionCount < otherDimensionCount
&& !ClassUtil.isInternalArrayInterfaceName(thisType)) {
return NEVER;
}
// If this type may be null, it might not be an instance of any class.
if (mayBeNull) {
return MAYBE;
}
// If this type is equal to the other type, or if the other type is
// java.lang.Object, this type is always an instance.
if (thisType.equals(otherType) || ClassConstants.NAME_JAVA_LANG_OBJECT.equals(otherType)) {
return ALWAYS;
}
// If this type is an array type, it's ok.
if (thisDimensionCount > otherDimensionCount) {
return ALWAYS;
}
// If the other type is an array type, it might be ok.
if (thisDimensionCount < otherDimensionCount) {
return MAYBE;
}
// If the value extends the type, we're sure.
return referencedClass != null
&& otherReferencedClass != null
&& referencedClass.extendsOrImplements(otherReferencedClass)
? ALWAYS
: MAYBE;
}
/**
* Evaluates a block of instructions that hasn't been handled before, starting at the given offset
* and ending at a branch instruction, a return instruction, or a throw instruction. Branch
* instructions are handled recursively.
*/
private void evaluateInstructionBlock(
Clazz clazz, Method method, CodeAttribute codeAttribute, int instructionOffset) {
if (DEBUG) {
if (evaluated[instructionOffset]) {
System.out.println("-- (instruction block at " + instructionOffset + " already evaluated)");
} else {
System.out.println("-- instruction block:");
}
}
// Remember the initial stack size.
int initialStackSize = stackSize;
// Remember the maximum stack size.
if (maxStackSize < stackSize) {
maxStackSize = stackSize;
}
// Evaluate any instructions that haven't been evaluated before.
while (!evaluated[instructionOffset]) {
// Mark the instruction as evaluated.
evaluated[instructionOffset] = true;
Instruction instruction = InstructionFactory.create(codeAttribute.code, instructionOffset);
if (DEBUG) {
int stackPushCount = instruction.stackPushCount(clazz);
int stackPopCount = instruction.stackPopCount(clazz);
System.out.println(
"["
+ instructionOffset
+ "]: "
+ stackSize
+ " - "
+ stackPopCount
+ " + "
+ stackPushCount
+ " = "
+ (stackSize + stackPushCount - stackPopCount)
+ ": "
+ instruction.toString(instructionOffset));
}
// Compute the instruction's effect on the stack size.
stackSize -= instruction.stackPopCount(clazz);
if (stackSize < 0) {
throw new IllegalArgumentException(
"Stack size becomes negative after instruction "
+ instruction.toString(instructionOffset)
+ " in ["
+ clazz.getName()
+ "."
+ method.getName(clazz)
+ method.getDescriptor(clazz)
+ "]");
}
stackSizes[instructionOffset] = stackSize += instruction.stackPushCount(clazz);
// Remember the maximum stack size.
if (maxStackSize < stackSize) {
maxStackSize = stackSize;
}
// Remember the next instruction offset.
int nextInstructionOffset = instructionOffset + instruction.length(instructionOffset);
// Visit the instruction, in order to handle branches.
instruction.accept(clazz, method, codeAttribute, instructionOffset, this);
// Stop evaluating after a branch.
if (exitInstructionBlock) {
break;
}
// Continue with the next instruction.
instructionOffset = nextInstructionOffset;
if (DEBUG) {
if (evaluated[instructionOffset]) {
System.out.println("-- (instruction at " + instructionOffset + " already evaluated)");
}
}
}
// Restore the stack size for possible subsequent instruction blocks.
this.stackSize = initialStackSize;
}
public void visitCodeAttribute(Clazz clazz, Method method, CodeAttribute codeAttribute) {
// DEBUG =
// clazz.getName().equals("abc/Def") &&
// method.getName(clazz).equals("abc");
if (DEBUG) {
method.accept(clazz, new ClassPrinter());
}
branchTargetFinder.visitCodeAttribute(clazz, method, codeAttribute);
// Don't bother if there aren't any subroutines anyway.
if (!containsSubroutines(codeAttribute)) {
return;
}
if (DEBUG) {
System.out.println(
"SubroutineInliner: processing ["
+ clazz.getName()
+ "."
+ method.getName(clazz)
+ method.getDescriptor(clazz)
+ "]");
}
// Append the body of the code.
codeAttributeComposer.reset();
codeAttributeComposer.beginCodeFragment(codeAttribute.u4codeLength);
// Copy the non-subroutine instructions.
int offset = 0;
while (offset < codeAttribute.u4codeLength) {
Instruction instruction = InstructionFactory.create(codeAttribute.code, offset);
int instructionLength = instruction.length(offset);
// Is this returning subroutine?
if (branchTargetFinder.isSubroutine(offset)
&& branchTargetFinder.isSubroutineReturning(offset)) {
// Skip the subroutine.
if (DEBUG) {
System.out.println(
" Skipping original subroutine instruction " + instruction.toString(offset));
}
// Append a label at this offset instead.
codeAttributeComposer.appendLabel(offset);
} else {
// Copy the instruction, inlining any subroutine call recursively.
instruction.accept(clazz, method, codeAttribute, offset, this);
}
offset += instructionLength;
}
// Copy the exceptions. Note that exceptions with empty try blocks
// are automatically removed.
codeAttribute.exceptionsAccept(clazz, method, subroutineExceptionInliner);
if (DEBUG) {
System.out.println(" Appending label after code at [" + offset + "]");
}
// Append a label just after the code.
codeAttributeComposer.appendLabel(codeAttribute.u4codeLength);
// End and update the code attribute.
codeAttributeComposer.endCodeFragment();
codeAttributeComposer.visitCodeAttribute(clazz, method, codeAttribute);
if (DEBUG) {
method.accept(clazz, new ClassPrinter());
}
}