public ReferenceValue generalize(TypedReferenceValue other) {
// If both types are identical, the generalization is the same too.
if (this.equals(other)) {
return this;
}
String thisType = this.type;
String otherType = other.type;
// If both types are nul, the generalization is null too.
if (thisType == null && otherType == null) {
return ValueFactory.REFERENCE_VALUE_NULL;
}
// If this type is null, the generalization is the other type, maybe null.
if (thisType == null) {
return other.generalizeMayBeNull(true);
}
// If the other type is null, the generalization is this type, maybe null.
if (otherType == null) {
return this.generalizeMayBeNull(true);
}
boolean mayBeNull = this.mayBeNull || other.mayBeNull;
// If the two types are equal, the generalization remains the same, maybe null.
if (thisType.equals(otherType)) {
return typedReferenceValue(this, mayBeNull);
}
// Start taking into account the type dimensions.
int thisDimensionCount = ClassUtil.internalArrayTypeDimensionCount(thisType);
int otherDimensionCount = ClassUtil.internalArrayTypeDimensionCount(otherType);
int commonDimensionCount = Math.min(thisDimensionCount, otherDimensionCount);
if (thisDimensionCount == otherDimensionCount) {
// See if we can take into account the referenced classes.
Clazz thisReferencedClass = this.referencedClass;
Clazz otherReferencedClass = other.referencedClass;
if (thisReferencedClass != null && otherReferencedClass != null) {
// Is one class simply an extension of the other one?
if (thisReferencedClass.extendsOrImplements(otherReferencedClass)) {
return typedReferenceValue(other, mayBeNull);
}
if (otherReferencedClass.extendsOrImplements(thisReferencedClass)) {
return typedReferenceValue(this, mayBeNull);
}
// Do the classes have a non-trivial common superclass?
Clazz commonClass = findCommonClass(thisReferencedClass, otherReferencedClass, false);
if (commonClass.getName().equals(ClassConstants.NAME_JAVA_LANG_OBJECT)) {
// Otherwise, do the classes have a common interface?
Clazz commonInterface = findCommonClass(thisReferencedClass, otherReferencedClass, true);
if (commonInterface != null) {
commonClass = commonInterface;
}
}
return new TypedReferenceValue(
commonDimensionCount == 0
? commonClass.getName()
: ClassUtil.internalArrayTypeFromClassName(
commonClass.getName(), commonDimensionCount),
commonClass,
mayBeNull);
}
} else if (thisDimensionCount > otherDimensionCount) {
// See if the other type is an interface type of arrays.
if (ClassUtil.isInternalArrayInterfaceName(
ClassUtil.internalClassNameFromClassType(otherType))) {
return typedReferenceValue(other, mayBeNull);
}
} else if (thisDimensionCount < otherDimensionCount) {
// See if this type is an interface type of arrays.
if (ClassUtil.isInternalArrayInterfaceName(
ClassUtil.internalClassNameFromClassType(thisType))) {
return typedReferenceValue(this, mayBeNull);
}
}
// Reduce the common dimension count if either type is an array of
// primitives type of this dimension.
if (commonDimensionCount > 0
&& (ClassUtil.isInternalPrimitiveType(otherType.charAt(commonDimensionCount)))
|| ClassUtil.isInternalPrimitiveType(thisType.charAt(commonDimensionCount))) {
commonDimensionCount--;
}
// Fall back on a basic Object or array of Objects type.
return commonDimensionCount != 0
? new TypedReferenceValue(
ClassUtil.internalArrayTypeFromClassName(
ClassConstants.NAME_JAVA_LANG_OBJECT, commonDimensionCount),
null,
mayBeNull)
: mayBeNull
? ValueFactory.REFERENCE_VALUE_JAVA_LANG_OBJECT_MAYBE_NULL
: ValueFactory.REFERENCE_VALUE_JAVA_LANG_OBJECT_NOT_NULL;
}
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;
}
/** Returns the generalization of this ReferenceValue and the given other ReferenceValue. */
public ReferenceValue generalize(ReferenceValue other) {
// If both types are identical, the generalization is the same too.
if (this.equals(other)) {
return this;
}
String thisType = this.type;
String otherType = other.type;
// If both types are nul, the generalization is null too.
if (thisType == null && otherType == null) {
return ValueFactory.REFERENCE_VALUE_NULL;
}
// If this type is null, the generalization is the other type, maybe null.
if (thisType == null) {
return other.generalizeMayBeNull(true);
}
// If the other type is null, the generalization is this type, maybe null.
if (otherType == null) {
return this.generalizeMayBeNull(true);
}
boolean mayBeNull = this.mayBeNull || other.mayBeNull;
// If the two types are equal, the generalization remains the same, maybe null.
if (thisType.equals(otherType)) {
return this.generalizeMayBeNull(mayBeNull);
}
// Start taking into account the type dimensions.
int thisDimensionCount = ClassUtil.internalArrayTypeDimensionCount(thisType);
int otherDimensionCount = ClassUtil.internalArrayTypeDimensionCount(otherType);
int commonDimensionCount = Math.min(thisDimensionCount, otherDimensionCount);
if (thisDimensionCount == otherDimensionCount) {
// See if we can take into account the referenced classes.
Clazz thisReferencedClass = this.referencedClass;
Clazz otherReferencedClass = other.referencedClass;
if (thisReferencedClass != null && otherReferencedClass != null) {
if (thisReferencedClass.extendsOrImplements(otherReferencedClass)) {
return other.generalizeMayBeNull(mayBeNull);
}
if (otherReferencedClass.extendsOrImplements(thisReferencedClass)) {
return this.generalizeMayBeNull(mayBeNull);
}
// Collect the superclasses and interfaces of this class.
Set thisSuperClasses = new HashSet();
thisReferencedClass.hierarchyAccept(
false, true, true, false, new ClassCollector(thisSuperClasses));
int thisSuperClassesCount = thisSuperClasses.size();
if (thisSuperClassesCount == 0 && thisReferencedClass.getSuperName() != null) {
throw new IllegalArgumentException(
"Can't find any super classes of ["
+ thisType
+ "] (not even immediate super class ["
+ thisReferencedClass.getSuperName()
+ "])");
}
// Collect the superclasses and interfaces of the other class.
Set otherSuperClasses = new HashSet();
otherReferencedClass.hierarchyAccept(
false, true, true, false, new ClassCollector(otherSuperClasses));
int otherSuperClassesCount = otherSuperClasses.size();
if (otherSuperClassesCount == 0 && otherReferencedClass.getSuperName() != null) {
throw new IllegalArgumentException(
"Can't find any super classes of ["
+ otherType
+ "] (not even immediate super class ["
+ otherReferencedClass.getSuperName()
+ "])");
}
if (DEBUG) {
System.out.println(
"ReferenceValue.generalize this ["
+ thisReferencedClass.getName()
+ "] with other ["
+ otherReferencedClass.getName()
+ "]");
System.out.println(" This super classes: " + thisSuperClasses);
System.out.println(" Other super classes: " + otherSuperClasses);
}
// Find the common superclasses.
thisSuperClasses.retainAll(otherSuperClasses);
if (DEBUG) {
System.out.println(" Common super classes: " + thisSuperClasses);
}
// 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 = thisSuperClasses.iterator();
while (commonSuperClasses.hasNext()) {
Clazz commonSuperClass = (Clazz) commonSuperClasses.next();
int superClassCount = superClassCount(commonSuperClass, thisSuperClasses);
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 ["
+ thisType
+ "] (with "
+ thisSuperClassesCount
+ " known super classes) and ["
+ otherType
+ "] (with "
+ otherSuperClassesCount
+ " known super classes)");
}
if (DEBUG) {
System.out.println(" Best common class: [" + commonClass.getName() + "]");
}
// TODO: Handle more difficult cases, with multiple global subclasses.
return new ReferenceValue(
commonDimensionCount == 0
? commonClass.getName()
: ClassUtil.internalArrayTypeFromClassName(
commonClass.getName(), commonDimensionCount),
commonClass,
mayBeNull);
}
} else if (thisDimensionCount > otherDimensionCount) {
// See if the other type is an interface type of arrays.
if (ClassUtil.isInternalArrayInterfaceName(
ClassUtil.internalClassNameFromClassType(otherType))) {
return other.generalizeMayBeNull(mayBeNull);
}
} else if (thisDimensionCount < otherDimensionCount) {
// See if this type is an interface type of arrays.
if (ClassUtil.isInternalArrayInterfaceName(
ClassUtil.internalClassNameFromClassType(thisType))) {
return this.generalizeMayBeNull(mayBeNull);
}
}
// Reduce the common dimension count if either type is an array of
// primitives type of this dimension.
if (commonDimensionCount > 0
&& (ClassUtil.isInternalPrimitiveType(otherType.charAt(commonDimensionCount)))
|| ClassUtil.isInternalPrimitiveType(thisType.charAt(commonDimensionCount))) {
commonDimensionCount--;
}
// Fall back on a basic Object or array of Objects type.
return commonDimensionCount == 0
? mayBeNull
? ValueFactory.REFERENCE_VALUE_JAVA_LANG_OBJECT_MAYBE_NULL
: ValueFactory.REFERENCE_VALUE_JAVA_LANG_OBJECT_NOT_NULL
: new ReferenceValue(
ClassUtil.internalArrayTypeFromClassName(
ClassConstants.INTERNAL_NAME_JAVA_LANG_OBJECT, commonDimensionCount),
null,
mayBeNull);
}