Package it.unive.lisa.analysis.nonrelational

Class Environment<M extends Environment<M,E,T>,E extends SymbolicExpression,T extends NonRelationalDomain<T,E,M>>

java.lang.Object

it.unive.lisa.analysis.lattices.FunctionalLattice<M,Identifier,T>

it.unive.lisa.analysis.nonrelational.VariableLift<M,E,T>

it.unive.lisa.analysis.nonrelational.Environment<M,E,T>

Type Parameters:

M - the concrete type of environment

E - the type of expressions that this domain can evaluate

T - the concrete instance of the NonRelationalDomain whose instances are mapped in this environment

All Implemented Interfaces:

BaseLattice<M>, Lattice<M>, ScopedObject<M>, SemanticDomain<M,E,Identifier>, StructuredObject, java.lang.Iterable<java.util.Map.Entry<Identifier,T>>

Direct Known Subclasses:

HeapEnvironment, TypeEnvironment, ValueEnvironment

public abstract class Environment<M extends Environment<M,E,T>,E extends SymbolicExpression,T extends NonRelationalDomain<T,E,M>>
extends VariableLift<M,E,T>

An environment for a NonRelationalDomain, that maps Identifiers to instances of such domain. This is a FunctionalLattice, that is, it implements a function mapping keys (identifiers) to values (instances of the domain), and lattice operations are automatically lifted for individual elements of the environment if they are mapped to the same key.

Nested Class Summary

Nested classes/interfaces inherited from class it.unive.lisa.analysis.lattices.FunctionalLattice

FunctionalLattice.FunctionalLift<V extends Lattice<V>>, FunctionalLattice.KeyFunctionalLift<K>

Field Summary

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

function, lattice

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

BOTTOM_STRING, TOP_STRING

Constructor Summary

Constructors

Constructor	Description
Environment(T domain)	Builds an empty environment.
Environment(T domain, java.util.Map<Identifier,T> function)	Builds an environment containing the given mapping.

Method Summary

Modifier and Type	Method	Description
M	assign(Identifier id, E expression, ProgramPoint pp, SemanticOracle oracle)	Yields a copy of this domain, where id has been assigned to value.
M	assume(E expression, ProgramPoint src, ProgramPoint dest, SemanticOracle oracle)	Yields a copy of this domain, modified by assuming that the given expression holds.
T	eval(E expression, ProgramPoint pp, SemanticOracle oracle)	Evaluates the given expression to an abstract value.
M	smallStepSemantics(E expression, ProgramPoint pp, SemanticOracle oracle)	Yields a copy of this domain, that has been modified accordingly to the semantics of the given expression.

Methods inherited from class it.unive.lisa.analysis.nonrelational.VariableLift

forgetIdentifier, forgetIdentifiersIf, knowsIdentifier, lubKeys, popScope, pushScope, satisfies, stateOfUnknown

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

equals, functionalLift, getKeys, getMap, getOtDefault, getState, getValues, glbAux, glbKeys, hashCode, isBottom, isTop, iterator, lessOrEqualAux, lubAux, mk, mkNewFunction, narrowingAux, putState, representation, toString, wideningAux

Methods inherited from class java.lang.Object

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

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

glb, lessOrEqual, lub, narrowing, widening

Methods inherited from interface java.lang.Iterable

forEach, spliterator

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

bottom, top

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

forgetIdentifiers, getAllDomainInstances, getDomainInstance

Methods inherited from interface it.unive.lisa.util.representation.StructuredObject

representation

Constructor Detail

Environment

public Environment(T domain)

Builds an empty environment.

Parameters:

domain - a singleton instance to be used during semantic operations to retrieve top and bottom values

Environment

public Environment(T domain,
                   java.util.Map<Identifier,T> function)

Builds an environment containing the given mapping. If function is null, the new environment is the top environment if lattice.isTop() holds, and it is the bottom environment if lattice.isBottom() holds.

Parameters:

domain - a singleton instance to be used during semantic operations to retrieve top and bottom values

function - the function representing the mapping contained in the new environment; can be null

Method Detail

assign

public M assign(Identifier id,
                E expression,
                ProgramPoint pp,
                SemanticOracle oracle)
         throws SemanticException

Description copied from interface: SemanticDomain

Yields a copy of this domain, where id has been assigned to value.

Parameters:

id - the identifier to assign the value to

expression - the expression to assign

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

oracle - the oracle for inter-domain communication

Returns:

a copy of this domain, modified by the assignment

Throws:

SemanticException - if an error occurs during the computation

smallStepSemantics

public M smallStepSemantics(E expression,
                            ProgramPoint pp,
                            SemanticOracle oracle)
                     throws SemanticException

Description copied from interface: SemanticDomain

Yields a copy of this domain, that has been modified accordingly to the semantics of the given expression.

Parameters:

expression - the expression whose semantics need to be computed

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

oracle - the oracle for inter-domain communication

Returns:

a copy of this domain, modified accordingly to the semantics of expression

Throws:

SemanticException - if an error occurs during the computation

eval

public T eval(E expression,
              ProgramPoint pp,
              SemanticOracle oracle)
       throws SemanticException

Evaluates the given expression to an abstract value.

Parameters:

expression - the expression to evaluate

pp - the program point where the evaluation happens

oracle - the oracle for inter-domain communication

Returns:

the abstract result of the evaluation

Throws:

SemanticException - if an error happens during the evaluation

assume

public M assume(E expression,
                ProgramPoint src,
                ProgramPoint dest,
                SemanticOracle oracle)
         throws SemanticException

Description copied from interface: SemanticDomain

Yields a copy of this domain, modified by assuming that the given expression holds. It is required that the returned domain is in relation with this one. A safe (but imprecise) implementation of this method can always return this.

Parameters:

expression - the expression to assume to hold.

src - the program point that where this operation is being evaluated, corresponding to the one that generated the given expression

dest - the program point where the execution will move after the expression has been assumed

oracle - the oracle for inter-domain communication

Returns:

the (optionally) modified copy of this domain

Throws:

SemanticException - if an error occurs during the computation