public ReferenceValue generalize(ReferenceValue other) {
return other.generalize(this);
}
public int equal(ReferenceValue other) {
return other.equal(this);
}
/** 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);
}