org.checkerframework.checker.index.upperbound

Class UpperBoundAnnotatedTypeFactory.UpperBoundQualifierHierarchy

java.lang.Object

org.checkerframework.framework.type.QualifierHierarchy

org.checkerframework.framework.util.MultiGraphQualifierHierarchy

org.checkerframework.checker.index.upperbound.UpperBoundAnnotatedTypeFactory.UpperBoundQualifierHierarchy

Enclosing class:

UpperBoundAnnotatedTypeFactory

protected final class UpperBoundAnnotatedTypeFactory.UpperBoundQualifierHierarchy
extends MultiGraphQualifierHierarchy

The qualifier hierarchy for the upperbound type system. The qh is responsible for determining the relationships within the qualifiers - especially subtyping relations.

Nested Class Summary

Nested classes/interfaces inherited from class org.checkerframework.framework.util.MultiGraphQualifierHierarchy

MultiGraphQualifierHierarchy.MultiGraphFactory

Field Summary

Fields inherited from class org.checkerframework.framework.util.MultiGraphQualifierHierarchy

bottoms, polymorphicQualifier, polyQualifiers, supertypesDirect, supertypesTransitive, tops

Constructor Summary

Constructors

Constructor and Description
UpperBoundQualifierHierarchy(MultiGraphQualifierHierarchy.MultiGraphFactory factory)

Method Summary

Modifier and Type	Method and Description
javax.lang.model.element.AnnotationMirror	greatestLowerBound(javax.lang.model.element.AnnotationMirror a1, javax.lang.model.element.AnnotationMirror a2) Returns the greatest lower bound for the qualifiers a1 and a2.
boolean	isSubtype(javax.lang.model.element.AnnotationMirror subAnno, javax.lang.model.element.AnnotationMirror superAnno) Computes subtyping as per the subtyping in the qualifier hierarchy structure unless both annotations are the same.
javax.lang.model.element.AnnotationMirror	leastUpperBound(javax.lang.model.element.AnnotationMirror a1, javax.lang.model.element.AnnotationMirror a2) Determines the least upper bound of a1 and a2.
int	numberOfIterationsBeforeWidening() Returns the number of iterations dataflow should perform before QualifierHierarchy.widenedUpperBound(AnnotationMirror, AnnotationMirror) is called or -1 if it should never be called.
javax.lang.model.element.AnnotationMirror	widenedUpperBound(javax.lang.model.element.AnnotationMirror newQualifier, javax.lang.model.element.AnnotationMirror previousQualifier) If the type hierarchy has an infinite ascending chain, then the dataflow analysis might never reach a fixed point.

Methods inherited from class org.checkerframework.framework.util.MultiGraphQualifierHierarchy

addPolyRelations, findBottoms, findLub, findTops, finish, getBottomAnnotation, getBottomAnnotations, getPolymorphicAnnotation, getTopAnnotation, getTopAnnotations, getTypeQualifiers, greatestLowerBoundTypeVariable, isSubtype, isSubtypeTypeVariable, isSubtypeTypeVariable, leastUpperBoundTypeVariable, toString, transitiveClosure

Methods inherited from class org.checkerframework.framework.type.QualifierHierarchy

canHaveEmptyAnnotationSet, findAnnotationInHierarchy, findAnnotationInSameHierarchy, getWidth, greatestLowerBound, greatestLowerBounds, greatestLowerBounds, greatestLowerBoundsTypeVariable, isSubtype, isSubtype, isValid, leastUpperBound, leastUpperBounds, leastUpperBounds, leastUpperBoundsTypeVariable, replacePolyAll, updateMappingToMutableSet

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

UpperBoundQualifierHierarchy

public UpperBoundQualifierHierarchy(MultiGraphQualifierHierarchy.MultiGraphFactory factory)

Parameters:

factory - MultiGraphFactory to use to construct this

Method Detail

greatestLowerBound

public javax.lang.model.element.AnnotationMirror greatestLowerBound(javax.lang.model.element.AnnotationMirror a1,
                                                                    javax.lang.model.element.AnnotationMirror a2)

Description copied from class: QualifierHierarchy

Returns the greatest lower bound for the qualifiers a1 and a2.

The two qualifiers have to be from the same qualifier hierarchy. Otherwise, null will be returned.

Overrides:

greatestLowerBound in class MultiGraphQualifierHierarchy

Parameters:

a1 - first annotation

a2 - second annotation

Returns:

greatest lower bound of the two annotations

leastUpperBound

public javax.lang.model.element.AnnotationMirror leastUpperBound(javax.lang.model.element.AnnotationMirror a1,
                                                                 javax.lang.model.element.AnnotationMirror a2)

Determines the least upper bound of a1 and a2. If a1 and a2 are both the same type of Value annotation, then the LUB is the result of taking the intersection of values from both a1 and a2.

Overrides:

leastUpperBound in class MultiGraphQualifierHierarchy

Returns:

the least upper bound of a1 and a2

widenedUpperBound

public javax.lang.model.element.AnnotationMirror widenedUpperBound(javax.lang.model.element.AnnotationMirror newQualifier,
                                                                   javax.lang.model.element.AnnotationMirror previousQualifier)

Description copied from class: QualifierHierarchy

If the type hierarchy has an infinite ascending chain, then the dataflow analysis might never reach a fixed point. To prevent this, implement this method such that it returns an upper bound for the two qualifiers that is a super type and not equal to the least upper bound. If this method is implemented, also override QualifierHierarchy.numberOfIterationsBeforeWidening() and change its return to a positive number.

newQualifier is newest qualifier dataflow computed for some expression and previousQualifier is the qualifier dataflow computed on the last iteration.

If the type hierarchy has no infinite ascending chain, returns the least upper bound of the two annotations.

Overrides:

widenedUpperBound in class QualifierHierarchy

Parameters:

newQualifier - new qualifier dataflow computed for some expression

previousQualifier - the previous qualifier dataflow computed on the last iteration

Returns:

an upper bound that is wider than the least upper bound of newQualifier and previousQualifier (or the lub if the type hierarchy does not require this)

numberOfIterationsBeforeWidening

public int numberOfIterationsBeforeWidening()

Description copied from class: QualifierHierarchy

Returns the number of iterations dataflow should perform before QualifierHierarchy.widenedUpperBound(AnnotationMirror, AnnotationMirror) is called or -1 if it should never be called.

Subclasses overriding this method should return some positive number or -1.

Overrides:

numberOfIterationsBeforeWidening in class QualifierHierarchy

Returns:

the number of iterations dataflow should perform before QualifierHierarchy.widenedUpperBound(AnnotationMirror, AnnotationMirror) is called or -1 if it should never be called.

isSubtype

public boolean isSubtype(javax.lang.model.element.AnnotationMirror subAnno,
                         javax.lang.model.element.AnnotationMirror superAnno)

Computes subtyping as per the subtyping in the qualifier hierarchy structure unless both annotations are the same. In this case, rhs is a subtype of lhs iff rhs contains at least every element of lhs.

Overrides:

isSubtype in class MultiGraphQualifierHierarchy

Parameters:

subAnno - the sub qualifier

superAnno - the super qualifier

Returns:

true if rhs is a subtype of lhs, false otherwise