org.checkerframework.dataflow.busyexpr

Class BusyExprStore

java.lang.Object

org.checkerframework.dataflow.busyexpr.BusyExprStore

All Implemented Interfaces:

Store<BusyExprStore>

public class BusyExprStore
extends Object
implements Store<BusyExprStore>

A busy expression store contains a set of busy expressions represented by nodes.

Nested Class Summary

Nested classes/interfaces inherited from interface org.checkerframework.dataflow.analysis.Store

Store.FlowRule, Store.Kind

Constructor Summary

Constructors

Constructor and Description
BusyExprStore() Create a new BusyExprStore.
BusyExprStore(Set<BusyExprValue> busyExprValueSet) Create a new BusyExprStore.

Method Summary

Modifier and Type	Method and Description
void	addUseInExpression(Node e) Add expressions to the store, add sub-expressions to the store recursively
boolean	canAlias(JavaExpression a, JavaExpression 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).
BusyExprStore	copy() Returns an exact copy of this store.
boolean	equals(@Nullable Object obj)
boolean	exprContainsVariable(Node expr, Node var) Return true if the expression contains variable var.
int	hashCode()
void	killBusyExpr(Node var) Kill expressions if they contain variable var.
BusyExprStore	leastUpperBound(BusyExprStore other) Compute the least upper bound of two stores.
void	putBusyExpr(BusyExprValue e) Add busy expression e to busy expression value set.
String	toString()
String	visualize(CFGVisualizer<?,BusyExprStore,?> viz) Delegate visualization responsibility to a visualizer.
BusyExprStore	widenedUpperBound(BusyExprStore previous) Compute an upper bound of two stores that is wider than the least upper bound of the two stores.

Methods inherited from class java.lang.Object

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

Constructor Detail

BusyExprStore

public BusyExprStore(Set<BusyExprValue> busyExprValueSet)

Create a new BusyExprStore.

Parameters:

busyExprValueSet - a set of busy expression abstract values. The parameter is captured and the caller should not retain an alias.

BusyExprStore

public BusyExprStore()

Create a new BusyExprStore.

Method Detail

killBusyExpr

public void killBusyExpr(Node var)

Kill expressions if they contain variable var.

Parameters:

var - a variable

exprContainsVariable

public boolean exprContainsVariable(Node expr,
                                    Node var)

Return true if the expression contains variable var. Note that .equals is used in the return statement to verify value equality, as the statement decides whether the two nodes have the same value, not represent the same CFG node.

Parameters:

expr - the expression checked

var - the variable

Returns:

true if the expression contains the variable

putBusyExpr

public void putBusyExpr(BusyExprValue e)

Add busy expression e to busy expression value set.

Parameters:

e - the busy expression to be added

addUseInExpression

public void addUseInExpression(Node e)

Add expressions to the store, add sub-expressions to the store recursively

Parameters:

e - the expression to be added

copy

public BusyExprStore copy()

Description copied from interface: Store

Returns an exact copy of this store.

Specified by:

copy in interface Store<BusyExprStore>

Returns:

an exact copy of this store

leastUpperBound

public BusyExprStore leastUpperBound(BusyExprStore other)

Description copied from interface: Store

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.

Specified by:

leastUpperBound in interface Store<BusyExprStore>

widenedUpperBound

public BusyExprStore widenedUpperBound(BusyExprStore previous)

Description copied from interface: Store

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.

Specified by:

widenedUpperBound in interface Store<BusyExprStore>

Parameters:

previous - must be the previous store

canAlias

public boolean canAlias(JavaExpression a,
                        JavaExpression b)

Description copied from interface: Store

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).

Specified by:

canAlias in interface Store<BusyExprStore>

visualize

public String visualize(CFGVisualizer<?,BusyExprStore,?> viz)

Description copied from interface: Store

Delegate visualization responsibility to a visualizer.

Specified by:

visualize in interface Store<BusyExprStore>

Parameters:

viz - the visualizer to visualize this store

Returns:

the String representation of this store

toString

public String toString()

Overrides:

toString in class Object

equals

public boolean equals(@Nullable Object obj)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object