Package it.unive.lisa.analysis.impl.heap.pointbased

Class AllocationSites

java.lang.Object

it.unive.lisa.analysis.BaseLattice<S>

it.unive.lisa.analysis.lattices.SetLattice<AllocationSites,AllocationSite>

it.unive.lisa.analysis.impl.heap.pointbased.AllocationSites

All Implemented Interfaces:

HeapSemanticOperation, Lattice<AllocationSites>, NonRelationalHeapDomain<AllocationSites>, NonRelationalDomain<AllocationSites,SymbolicExpression,HeapEnvironment<AllocationSites>>, NonRelationalElement<AllocationSites,SymbolicExpression,HeapEnvironment<AllocationSites>>, SemanticEvaluator, java.lang.Iterable<AllocationSite>

public class AllocationSites
extends SetLattice<AllocationSites,AllocationSite>
implements NonRelationalHeapDomain<AllocationSites>

A heap domain tracking sets of AllocationSite.

Nested Class Summary

Nested classes/interfaces inherited from interface it.unive.lisa.analysis.heap.HeapSemanticOperation

HeapSemanticOperation.HeapReplacement

Field Summary

Fields inherited from class it.unive.lisa.analysis.lattices.SetLattice

elements

Fields inherited from interface it.unive.lisa.analysis.Lattice

BOTTOM_REPR, BOTTOM_STRING, TOP_REPR, TOP_STRING

Constructor Summary

Constructors

Constructor	Description
AllocationSites()	Builds an instance of HeapIdentiferSetLattice, corresponding to the top element.

Method Summary

Modifier and Type	Method	Description
HeapEnvironment<AllocationSites>	assume(HeapEnvironment<AllocationSites> environment, SymbolicExpression expression, ProgramPoint pp)	Yields the environment environment on which the expression expression is assumed to hold by this domain.
AllocationSites	bottom()	Yields the bottom element of this lattice.
boolean	canProcess(SymbolicExpression expression)	Yields true if the domain can process expression, false otherwise.
boolean	equals(java.lang.Object obj)
AllocationSites	eval(SymbolicExpression expression, HeapEnvironment<AllocationSites> environment, ProgramPoint pp)	Evaluates a SymbolicExpression, assuming that the values of program variables are the ones stored in environment.
java.util.List<HeapSemanticOperation.HeapReplacement>	getSubstitution()	Yields the substitution, in the form of a list of HeapSemanticOperation.HeapReplacements that must be processed in their order of appearance, that the creation of this heap domain caused.
int	hashCode()
boolean	isBottom()	Yields true if and only if this object represents the bottom of the lattice.
boolean	isTop()	Yields true if and only if this object represents the top of the lattice.
java.util.Iterator<AllocationSite>	iterator()
protected AllocationSites	lubAux(AllocationSites other)	Performs the least upper bound operation between this lattice element and the given one, assuming that base cases have already been handled.
protected AllocationSites	mk(java.util.Set<AllocationSite> set)	Utility for creating a concrete instance of SetLattice given a set.
DomainRepresentation	representation()	Yields a DomainRepresentation of the information contained in this domain's instance.
ExpressionSet<ValueExpression>	rewrite(SymbolicExpression expression, HeapEnvironment<AllocationSites> environment, ProgramPoint pp)	Rewrites a SymbolicExpression, getting rid of the parts that access heap structures, substituting them with synthetic HeapLocations representing the accessed locations.
SemanticDomain.Satisfiability	satisfies(SymbolicExpression expression, HeapEnvironment<AllocationSites> environment, ProgramPoint pp)	Checks whether expression is satisfied in environment, assuming that the values of program variables are the ones stored in environment and returning an instance of SemanticDomain.Satisfiability.
AllocationSites	top()	Yields the top element of this lattice.
boolean	tracksIdentifiers(Identifier id)	Yields true if the domain tracks information on the identifier id, false otherwise.

Methods inherited from class it.unive.lisa.analysis.lattices.SetLattice

contains, elements, glb, isEmpty, lessOrEqualAux, size, toString, wideningAux

Methods inherited from class it.unive.lisa.analysis.BaseLattice

lessOrEqual, lub, widening

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Methods inherited from interface it.unive.lisa.analysis.Lattice

lessOrEqual, lub, widening

Methods inherited from interface it.unive.lisa.analysis.nonrelational.NonRelationalElement

glb, variable

Methods inherited from interface it.unive.lisa.analysis.nonrelational.heap.NonRelationalHeapDomain

rewriteAll

Constructor Detail

AllocationSites

public AllocationSites()

Builds an instance of HeapIdentiferSetLattice, corresponding to the top element.

Method Detail

isTop

public boolean isTop()

Description copied from interface: Lattice

Yields true if and only if this object represents the top of the lattice. The default implementation of this method uses reference equality between this and the value returned by Lattice.top(), thus assuming that the top element is a singleton. If this is not the case, override this method accordingly to provide a coherent test.

Specified by:

isTop in interface Lattice<AllocationSites>

Returns:

true if this is the top of the lattice

isBottom

public boolean isBottom()

Description copied from interface: Lattice

Yields true if and only if this object represents the bottom of the lattice. The default implementation of this method uses reference equality between this and the value returned by Lattice.bottom(), thus assuming that the bottom element is a singleton. If this is not the case, override this method accordingly to provide a coherent test.

Specified by:

isBottom in interface Lattice<AllocationSites>

Returns:

true if this is the bottom of the lattice

top

public AllocationSites top()

Description copied from interface: Lattice

Yields the top element of this lattice. The returned element should be unique across different calls to this method, since Lattice.isTop() uses reference equality by default. If the value returned by this method is not a singleton, override Lattice.isTop() accordingly to provide a coherent test.

Specified by:

top in interface Lattice<AllocationSites>

Returns:

the top element

bottom

public AllocationSites bottom()

Description copied from interface: Lattice

Yields the bottom element of this lattice. The returned element should be unique across different calls to this method, since Lattice.isBottom() uses reference equality by default. If the value returned by this method is not a singleton, override Lattice.isBottom() accordingly to provide a coherent test.

Specified by:

bottom in interface Lattice<AllocationSites>

Returns:

the bottom element

mk

protected AllocationSites mk(java.util.Set<AllocationSite> set)

Description copied from class: SetLattice

Utility for creating a concrete instance of SetLattice given a set. This decouples the instance of set used during computation of the elements to put in the lattice from the actual type of set underlying the lattice.

Specified by:

mk in class SetLattice<AllocationSites,AllocationSite>

Parameters:

set - the set containing the elements that must be included in the lattice instance

Returns:

a new concrete instance of SetLattice containing the elements of the given set

iterator

public java.util.Iterator<AllocationSite> iterator()

Specified by:

iterator in interface java.lang.Iterable<AllocationSite>

Overrides:

iterator in class SetLattice<AllocationSites,AllocationSite>

eval

public AllocationSites eval(SymbolicExpression expression,
                            HeapEnvironment<AllocationSites> environment,
                            ProgramPoint pp)

Description copied from interface: NonRelationalDomain

Evaluates a SymbolicExpression, assuming that the values of program variables are the ones stored in environment.

Specified by:

eval in interface NonRelationalDomain<AllocationSites,SymbolicExpression,HeapEnvironment<AllocationSites>>

Parameters:

expression - the expression to evaluate

environment - the environment containing the values of program variables for the evaluation

pp - the program point that where this operation is being evaluated

Returns:

an new instance of this domain, representing the abstract result of expression when evaluated on environment

satisfies

public SemanticDomain.Satisfiability satisfies(SymbolicExpression expression,
                                               HeapEnvironment<AllocationSites> environment,
                                               ProgramPoint pp)

Description copied from interface: NonRelationalElement

Checks whether expression is satisfied in environment, assuming that the values of program variables are the ones stored in environment and returning an instance of SemanticDomain.Satisfiability.

Specified by:

satisfies in interface NonRelationalElement<AllocationSites,SymbolicExpression,HeapEnvironment<AllocationSites>>

Parameters:

expression - the expression whose satisfiability is to be evaluated

environment - the environment containing the values of program variables for the satisfiability

pp - the program point that where this operation is being evaluated

Returns:

SemanticDomain.Satisfiability.SATISFIED if the expression is satisfied by the environment, SemanticDomain.Satisfiability.NOT_SATISFIED if it is not satisfied, or SemanticDomain.Satisfiability.UNKNOWN if it is either impossible to determine if it satisfied, or if it is satisfied by some values and not by some others (this is equivalent to a TOP boolean value)

hashCode

public int hashCode()

Overrides:

hashCode in class SetLattice<AllocationSites,AllocationSite>

equals

public boolean equals(java.lang.Object obj)

Overrides:

equals in class SetLattice<AllocationSites,AllocationSite>

representation

public DomainRepresentation representation()

Description copied from interface: NonRelationalElement

Yields a DomainRepresentation of the information contained in this domain's instance.

Specified by:

representation in interface NonRelationalElement<AllocationSites,SymbolicExpression,HeapEnvironment<AllocationSites>>

Returns:

the representation

getSubstitution

public java.util.List<HeapSemanticOperation.HeapReplacement> getSubstitution()

Description copied from interface: HeapSemanticOperation

Yields the substitution, in the form of a list of HeapSemanticOperation.HeapReplacements that must be processed in their order of appearance, that the creation of this heap domain caused. This substitution maps Identifiers in the pre-state to Identifiers in the post state. If no substitution needs to be applied, this method should return an empty list.

Specified by:

getSubstitution in interface HeapSemanticOperation

Returns:

the list of replacements

lubAux

protected AllocationSites lubAux(AllocationSites other)
                          throws SemanticException

Description copied from class: BaseLattice

Performs the least upper bound operation between this lattice element and the given one, assuming that base cases have already been handled. In particular, it is guaranteed that:

• other is not null
• other is neither top nor bottom
• this is neither top nor bottom
• this and other are not the same object (according both to == and to Object.equals(Object))

Overrides:

lubAux in class SetLattice<AllocationSites,AllocationSite>

Parameters:

other - the other lattice element

Returns:

the least upper bound between this and other

Throws:

SemanticException - if an error occurs during the computation

tracksIdentifiers

public boolean tracksIdentifiers(Identifier id)

Description copied from interface: SemanticEvaluator

Yields true if the domain tracks information on the identifier id, false otherwise.

Specified by:

tracksIdentifiers in interface SemanticEvaluator

Parameters:

id - the identifier

Returns:

true if the domain tracks information on the identifier id, false otherwise

canProcess

public boolean canProcess(SymbolicExpression expression)

Description copied from interface: SemanticEvaluator

Yields true if the domain can process expression, false otherwise.

Specified by:

canProcess in interface SemanticEvaluator

Parameters:

expression - the expression

Returns:

true if the domain can process expression, false otherwise.

assume

public HeapEnvironment<AllocationSites> assume(HeapEnvironment<AllocationSites> environment,
                                               SymbolicExpression expression,
                                               ProgramPoint pp)
                                        throws SemanticException

Description copied from interface: NonRelationalElement

Yields the environment environment on which the expression expression is assumed to hold by this domain.

Specified by:

assume in interface NonRelationalElement<AllocationSites,SymbolicExpression,HeapEnvironment<AllocationSites>>

Parameters:

environment - the environment

expression - the expression to be assumed

pp - the program point where expression occurs.

Returns:

the environment environment where expression is assumed to hold

Throws:

SemanticException - if an error occurs during the computation

rewrite

public ExpressionSet<ValueExpression> rewrite(SymbolicExpression expression,
                                              HeapEnvironment<AllocationSites> environment,
                                              ProgramPoint pp)
                                       throws SemanticException

Description copied from interface: NonRelationalHeapDomain

Rewrites a SymbolicExpression, getting rid of the parts that access heap structures, substituting them with synthetic HeapLocations representing the accessed locations. The expression(s) returned by this method should not contain HeapExpressions.

Note that a single expression might be rewritten to more than one expression, depending on the individual reasoning of the domain.

If no rewriting is necessary, the input expression can be returned instead.

Specified by:

rewrite in interface NonRelationalHeapDomain<AllocationSites>

Parameters:

expression - the expression to rewrite

environment - the environment containing information about the program variables

pp - the program point that where this expression is being rewritten

Returns:

the rewritten expressions, or the original one

Throws:

SemanticException - if something goes wrong during the rewriting