Package org.checkerframework.checker.nullness

Class KeyForValue

java.lang.Object

org.checkerframework.framework.flow.CFAbstractValue<KeyForValue>

org.checkerframework.checker.nullness.KeyForValue

All Implemented Interfaces:

AbstractValue<KeyForValue>

public class KeyForValue
extends CFAbstractValue<KeyForValue>

KeyForValue holds additional information about which maps this value is a key for. This extra information is required when adding the @KeyFor qualifier to the type is not a refinement of the type. For example,

     @NonNull Object o = map.get(param);
 

 Map<T, Object> map = ...;
 <T> T method(T param) {
   if (map.contains(param)) {
     @NonNull Object o = map.get(param);
     return param;
   }
 }
 

Inside the if statement, param is a key for "map". This would normally be represented as @KeyFor("map") T, but this is not a subtype of T, so the type cannot be refined. Instead, the value for param includes "map" in the list of keyForMaps. This information is used in KeyForAnnotatedTypeFactory.isKeyForMap(String, ExpressionTree).

Nested Class Summary

Nested classes/interfaces inherited from class org.checkerframework.framework.flow.CFAbstractValue

CFAbstractValue.AnnotationSetCombiner, CFAbstractValue.ValueGlb, CFAbstractValue.ValueLub

Field Summary

Fields inherited from class org.checkerframework.framework.flow.CFAbstractValue

analysis, annotations, atypeFactory, qualHierarchy, underlyingType

Constructor Summary

Constructors

Constructor	Description
KeyForValue(CFAbstractAnalysis<KeyForValue,?,?> analysis, AnnotationMirrorSet annotations, TypeMirror underlyingType)	Create a KeyForValue.

Method Summary

Modifier and Type	Method	Description
boolean	equals(@Nullable Object obj)
@Nullable Set<String>	getKeyForMaps()	Returns the maps for which this value is a key.
int	hashCode()
@Nullable KeyForValue	mostSpecific(@Nullable KeyForValue other, @Nullable KeyForValue backup)	Returns the more specific of two values this and other.
protected KeyForValue	upperBound(@Nullable KeyForValue other, TypeMirror upperBoundTypeMirror, boolean shouldWiden)	Returns an upper bound of this and other.

Methods inherited from class org.checkerframework.framework.flow.CFAbstractValue

canBeMissingAnnotations, getAnnotations, getUnderlyingType, greatestLowerBound, hasAnnotationFromEveryHierarchy, leastUpperBound, leastUpperBound, missingAnnotations, toString, toStringFullyQualified, toStringSimple, unionIfLarger, widenUpperBound

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Details

KeyForValue

public KeyForValue(CFAbstractAnalysis<KeyForValue,?,?> analysis,
 AnnotationMirrorSet annotations,
 TypeMirror underlyingType)

Create a KeyForValue.

Parameters:

analysis - the analysis

annotations - the annotations

underlyingType - the underlying type

Method Details

getKeyForMaps

public @Nullable Set<String> getKeyForMaps()

Returns the maps for which this value is a key.

Returns:

if the underlying type is a type variable or a wildcard, then the possibly-empty set of maps for which this value is a key; otherwise, null

equals

public boolean equals(@Nullable Object obj)

Description copied from class: CFAbstractValue

A subclass that adds state must override this method and CFAbstractValue.hashCode() to account for that state. The dataflow analysis uses equals to determine whether it has reached a fixed point, so ignoring some state could stop the analysis before that state has stabilized.

Overrides:

equals in class CFAbstractValue<KeyForValue>

hashCode

public int hashCode()

Overrides:

hashCode in class CFAbstractValue<KeyForValue>

upperBound

protected KeyForValue upperBound(@Nullable KeyForValue other,
 TypeMirror upperBoundTypeMirror,
 boolean shouldWiden)

Description copied from class: CFAbstractValue

Returns an upper bound of this and other. The underlying type of the value returned is upperBoundTypeMirror. If shouldWiden is false, this method returns the least upper bound of this and other.

This is the implementation of CFAbstractValue.leastUpperBound(CFAbstractValue, TypeMirror), CFAbstractValue.leastUpperBound(CFAbstractValue), CFAbstractValue.widenUpperBound(CFAbstractValue), and CFAbstractValue.upperBound(CFAbstractValue, boolean). Subclasses may override it.

Overrides:

upperBound in class CFAbstractValue<KeyForValue>

Parameters:

other - an abstract value

upperBoundTypeMirror - the underlying type of the returned value

shouldWiden - true if the method should perform widening

Returns:

an upper bound of this and other

mostSpecific

public @Nullable KeyForValue mostSpecific(@Nullable KeyForValue other,
 @Nullable KeyForValue backup)

Description copied from class: CFAbstractValue

Returns the more specific of two values this and other. If they do not contain information for all hierarchies, then it is possible that information from both this and other are taken.

If neither of the two is more specific for one of the hierarchies (i.e., if the two are incomparable as determined by QualifierHierarchy.isSubtypeShallow(AnnotationMirror, TypeMirror, AnnotationMirror, TypeMirror), then the respective value from backup is used.

Overrides:

mostSpecific in class CFAbstractValue<KeyForValue>

Parameters:

other - the other value to obtain information from

backup - the value to use if this and other are incomparable

Returns:

the more specific of two values this and other