Package it.unive.lisa.analysis.nonrelational

Interface NonRelationalElement<T extends NonRelationalElement<T,E,F>,E extends SymbolicExpression,F extends FunctionalLattice<F,Identifier,T>>

Type Parameters:

T - the concrete type of the domain

E - the type of expressions that this domain can evaluate

F - the type of functional lattice that is used in conjuntion with this domain

All Superinterfaces:

Lattice<T>, SemanticEvaluator, StructuredObject

All Known Subinterfaces:

BaseInferredValue<T>, BaseNonRelationalTypeDomain<T>, BaseNonRelationalValueDomain<T>, InferredValue<T>, NonRelationalDomain<T,E,F>, NonRelationalHeapDomain<T>, NonRelationalTypeDomain<T>, NonRelationalValueDomain<T>

public interface NonRelationalElement<T extends NonRelationalElement<T,E,F>,E extends SymbolicExpression,F extends FunctionalLattice<F,Identifier,T>>
extends Lattice<T>, SemanticEvaluator

A non-relational domain, that is able to compute the value of a SymbolicExpressions of type E by knowing the values of all program variables. Instances of this class can be wrapped inside an FunctionalLattice to represent abstract values of individual Identifiers.

Field Summary

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

BOTTOM_STRING, TOP_STRING

Method Summary

Modifier and Type	Method	Description
F	assume(F environment, E expression, ProgramPoint src, ProgramPoint dest, SemanticOracle oracle)	Yields the environment environment on which the expression expression is assumed to hold by this domain.
default T	fixedVariable(Identifier id, ProgramPoint pp, SemanticOracle oracle)	Yields a fixed abstraction of the given variable.
Satisfiability	satisfies(E expression, F environment, ProgramPoint pp, SemanticOracle oracle)	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 Satisfiability.
default T	unknownVariable(Identifier id)	Yields the default abstraction returned whenever a functional lattice using this element as values is queried for the state of a variable not currently part of its mapping.

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

bottom, glb, isBottom, isTop, lessOrEqual, lub, narrowing, top, widening

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

canProcess

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

representation

Method Detail

satisfies

Satisfiability satisfies(E expression,
                         F environment,
                         ProgramPoint pp,
                         SemanticOracle oracle)
                  throws SemanticException

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 Satisfiability.

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

oracle - the oracle for inter-domain communication

Returns:

Satisfiability.SATISFIED if the expression is satisfied by the environment, Satisfiability.NOT_SATISFIED if it is not satisfied, or 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)

Throws:

SemanticException - if something goes wrong during the computation

assume

F assume(F environment,
         E expression,
         ProgramPoint src,
         ProgramPoint dest,
         SemanticOracle oracle)
  throws SemanticException

Yields the environment environment on which the expression expression is assumed to hold by this domain. The returned environment must be an updated version of the given one, where the relevant abstractions have been (optionally) updated. Returning the given environment as-is is always a sound implementation.

Parameters:

environment - the environment

expression - the expression to be assumed

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 environment environment where expression is assumed to hold

Throws:

SemanticException - if an error occurs during the computation

fixedVariable

default T fixedVariable(Identifier id,
                        ProgramPoint pp,
                        SemanticOracle oracle)
                 throws SemanticException

Yields a fixed abstraction of the given variable. The abstraction does not depend on the abstract values that get assigned to the variable, but is instead fixed among all possible execution paths. If this method does not return the bottom element (as the default implementation does), then Environment.assign(Identifier, SymbolicExpression, ProgramPoint, SemanticOracle) will store that abstract element instead of the one computed starting from the expression.

Parameters:

id - The identifier representing the variable being assigned

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

oracle - the oracle for inter-domain communication

Returns:

the fixed abstraction of the variable

Throws:

SemanticException - if an error occurs during the computation

unknownVariable

default T unknownVariable(Identifier id)

Yields the default abstraction returned whenever a functional lattice using this element as values is queried for the state of a variable not currently part of its mapping. Abstraction for such a variable might have been lost, for instance, due to a call to Lattice.top() on the function itself. The default implementation of this method returns Lattice.top().

Parameters:

id - the variable that is missing from the mapping

Returns:

a default abstraction for the variable