org.checkerframework.dataflow.analysis

Interface Store<S extends Store<S>>

Type Parameters:

S - the type of the store returned by copy and that is used in leastUpperBound. Usually it is the implementing class itself, e.g. in T extends Store<T>.

All Known Implementing Classes:

CFAbstractStore, CFStore, ConstantPropagationStore, InitializationStore, KeyForStore, LiveVarStore, LockStore, NullnessStore

public interface Store<S extends Store<S>>

A store is used to keep track of the information that the org.checkerframework.dataflow analysis has accumulated at any given point in time.

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static class	Store.FlowRule A flow rule describes how stores flow along one edge between basic blocks.
static class	Store.Kind

Method Summary

Modifier and Type	Method and Description
boolean	canAlias(FlowExpressions.Receiver a, FlowExpressions.Receiver b) Can the objects a and b be aliases? Returns a conservative answer (i.e., returns true if not enough information is available to determine aliasing).
S	copy() Returns an exact copy of this store.
S	leastUpperBound(S other) Compute the least upper bound of two stores.
String	visualize(CFGVisualizer<?,S,?> viz) Delegate visualization responsibility to a visualizer.
S	widenedUpperBound(S previous) Compute an upper bound of two stores that is wider than the least upper bound of the two stores.

Method Detail

copy

S copy()

Returns an exact copy of this store.

Returns:

an exact copy of this store

leastUpperBound

S leastUpperBound(S other)

Compute the least upper bound of two stores.

Important: This method must fulfill the following contract:

• Does not change this.
• Does not change other.
• Returns a fresh object which is not aliased yet.
• Returns an object of the same (dynamic) type as this, even if the signature is more permissive.
• Is commutative.

widenedUpperBound

S widenedUpperBound(S previous)

Compute an upper bound of two stores that is wider than the least upper bound of the two stores. Used to jump to a higher abstraction to allow faster termination of the fixed point computations in Analysis. previous must be the previous store.

A particular analysis might not require widening and should implement this method by calling leastUpperBound.

Important: This method must fulfill the following contract:

• Does not change this.
• Does not change previous.
• Returns a fresh object which is not aliased yet.
• Returns an object of the same (dynamic) type as this, even if the signature is more permissive.
• Is commutative.

Parameters:

previous - must be the previous store

canAlias

boolean canAlias(FlowExpressions.Receiver a,
                 FlowExpressions.Receiver b)

Can the objects a and b be aliases? Returns a conservative answer (i.e., returns true if not enough information is available to determine aliasing).

visualize

String visualize(CFGVisualizer<?,S,?> viz)

Delegate visualization responsibility to a visualizer.

Parameters:

viz - the visualizer to visualize this store

Returns:

the String representation of this store