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org.opalj.ai

FloatValuesFactory

trait FloatValuesFactory extends ValuesDomain

Defines factory methods to create concrete representations of constant float values.

Self Type
FloatValuesFactory
Source
FloatValuesFactory.scala
Linear Supertypes
ValuesDomain, AnyRef, Any
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  1. FloatValuesFactory
  2. ValuesDomain
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Type Members

  1. abstract type DomainIllegalValue <: IllegalValue with DomainValue

    Abstracts over the concrete type of IllegalValue.

    Abstracts over the concrete type of IllegalValue.

    This type needs to be refined whenever the class IllegalValue is refined or the type DomainValue is refined.

    Definition Classes
    ValuesDomain
  2. abstract type DomainReferenceValue >: Null <: ReferenceValue with DomainTypedValue[ReferenceType]
    Definition Classes
    ValuesDomain
  3. abstract type DomainReturnAddressValue <: ReturnAddressValue with DomainValue

    Abstracts over the concrete type of ReturnAddressValue.

    Abstracts over the concrete type of ReturnAddressValue. Needs to be fixed by some sub-trait/sub-class. In the simplest case (i.e., when neither the Value trait nor the ReturnAddressValue trait was refined) it is sufficient to write:

    type DomainReturnAddressValue = ReturnAddressValue
    Definition Classes
    ValuesDomain
  4. abstract type DomainReturnAddressValues <: ReturnAddressValues with DomainValue
    Definition Classes
    ValuesDomain
  5. abstract type DomainTypedValue[+T <: Type] >: Null <: DomainValue
    Definition Classes
    ValuesDomain
  6. abstract type DomainValue >: Null <: Value

    Abstracts over the concrete type of Value.

    Abstracts over the concrete type of Value. Needs to be refined by traits that inherit from Domain and which extend Domain's Value trait.

    Definition Classes
    ValuesDomain
  7. type ExceptionValue = DomainReferenceValue

    A simple type alias of the type DomainValue; used to facilitate comprehension.

    A simple type alias of the type DomainValue; used to facilitate comprehension.

    Definition Classes
    ValuesDomain
  8. type ExceptionValues = Iterable[ExceptionValue]

    A type alias for Iterables of ExceptionValues; used to facilitate comprehension.

    A type alias for Iterables of ExceptionValues; used to facilitate comprehension.

    Definition Classes
    ValuesDomain
  9. type Locals = collection.mutable.Locals[DomainValue]

    An instruction's current register values/locals are represented using an array.

    An instruction's current register values/locals are represented using an array.

    Definition Classes
    ValuesDomain
  10. type LocalsArray = Array[Locals]
    Definition Classes
    ValuesDomain
  11. type Operands = Chain[DomainValue]

    An instruction's operands are represented using a list where the first element of the list represents the top level operand stack value.

    An instruction's operands are represented using a list where the first element of the list represents the top level operand stack value.

    Definition Classes
    ValuesDomain
  12. type OperandsArray = Array[Operands]
    Definition Classes
    ValuesDomain
  13. class IllegalValue extends Value

    Represents a value that has no well defined state/type.

    Represents a value that has no well defined state/type. Such values are the result of a join of two incompatible values and are generally only found in registers (in the locals) and then identify a value that is dead.

    Attributes
    protected
    Definition Classes
    ValuesDomain
    See also

    org.opalj.ai.Domain.Value for further details.

  14. trait RETValue extends Value
    Definition Classes
    ValuesDomain
  15. trait ReferenceValue extends TypedValue[ReferenceType] with IsReferenceValue[DomainReferenceValue]
    Definition Classes
    ValuesDomain
  16. class ReturnAddressValue extends RETValue

    Stores a single return address (i.e., a program counter/index into the code array).

    Stores a single return address (i.e., a program counter/index into the code array).

    Definition Classes
    ValuesDomain
    Note

    Though the framework completely handles all aspects related to return address values, it is nevertheless necessary that this class inherits from Value as return addresses are stored on the stack/in the registers. However, if the Value trait should be refined, all additional methods may – from the point-of-view of OPAL-AI - just throw an OperationNotSupportedException as these additional methods will never be called by OPAL-AI.

  17. class ReturnAddressValues extends RETValue

    A collection of (not furhter stored) return address values.

    A collection of (not furhter stored) return address values. Primarily used when we join the executions of subroutines.

    Definition Classes
    ValuesDomain
  18. trait TypedValue[+T <: Type] extends Value with KnownType
    Definition Classes
    ValuesDomain
  19. trait Value extends AnyRef

    Abstracts over a concrete operand stack value or a value stored in one of the local variables/registers.

    Abstracts over a concrete operand stack value or a value stored in one of the local variables/registers.

    Use Of Value/Dependencies On Value

    In general, subclasses and users of a Domain should not have/declare a direct dependency on Value. Instead they should use DomainValue as otherwise extensibility of a Domain may be hampered or even be impossible. The only exceptions are, of course, classes that directly inherit from this class.

    Refining Value

    If you directly extend/refine this trait (i.e., in a subclass of the Domain trait you write something like trait Value extends super.Value), make sure that you also extend all classes/traits that inherit from this type (this may require a deep mixin composition and that you refine the type DomainType accordingly). However, OPAL was designed such that extending this class should – in general – not be necessary. It may also be easier to encode the desired semantics – as far as possible – as part of the domain.

    Implementing Value

    Standard inheritance from this trait is always supported and is the primary mechanism to model an abstract domain's lattice w.r.t. some special type of value. In general, the implementation should try to avoid creating new instances of values unless strictly required to model the domain's semantics. This will greatly improve the overall performance as this framework heavily uses reference-based equality checks to speed up the evaluation.

    Definition Classes
    ValuesDomain
    Note

    OPAL does not rely on any special equality semantics w.r.t. values and never directly or indirectly calls a Value's equals or eq method. Hence, a domain can encode equality such that it best fits its need. However, some of the provided domains rely on the following semantics for equals: Two domain values have to be equal (==) iff they represent the same information. This includes additional information, such as, the value of the origin. E.g., a value (AnIntegerValue) that represents an arbitrary Integer value has to return true if the domain value with which it is compared also represents an arbitrary Integer value (AnIntegerValue). However, it may still be necessary to use multiple objects to represent an arbitrary integer value if, e.g., constraints should be attached to specific values. For example, after a comparison of an integer value with a predefined value (e.g., AnIntegerValue < 4) it is possible to constrain the respective value on the subsequent paths (< 4 on one path and >= 4 on the other path). To make that possible, it is however necessary to distinguish the AnIntegervalue from some other AnIntegerValue to avoid constraining unrelated values.

    public void foo(int a,int b) {
        if(a < 4) {
            z = a - 2 // here a is constrained (< 4), b and z are unconstrained
        }
        else {
            z = a + 2 // here a is constrained (>= 4), b and z are unconstrained
        }
    }

    In general, equals is only defined for values belonging to the same domain. If values need to be compared across domains, they need to be adapted to a target domain first.

Abstract Value Members

  1. abstract val DomainReferenceValue: ClassTag[DomainReferenceValue]

    The class tag can be used to create type safe arrays or to extract the concrete type of the domain value.

    The class tag can be used to create type safe arrays or to extract the concrete type of the domain value.

    val DomainReferenceValue(v) = value // of type "DomainValue"
    // v is now of the type DomainReferenceValue
    Definition Classes
    ValuesDomain
  2. implicit abstract val DomainValue: ClassTag[DomainValue]

    The class tag for the type DomainValue.

    The class tag for the type DomainValue.

    Required to generate instances of arrays in which values of type DomainValue can be stored in a type-safe manner.

    Initialization

    In the sub-trait or class that fixes the type of DomainValue it is necessary to implement this abstract val using:

    val DomainValueTag : ClassTag[DomainValue] = implicitly

    (As of Scala 2.10 it is necessary that you do not use implicit in the subclass - it will compile, but fail at runtime.)

    Definition Classes
    ValuesDomain
  3. abstract def FloatValue(origin: ValueOrigin, value: Float): DomainTypedValue[FloatType]

    Factory method to create a DomainValue with the specified origin.

    Factory method to create a DomainValue with the specified origin. The origin is typically the program counter of the instruction that created this value/where the value was observed for the first time.

    The domain may ignore the information about the origin (origin).

  4. abstract def FloatValue(origin: ValueOrigin): DomainTypedValue[FloatType]

    Factory method to create a DomainValue with the specified origin.

    Factory method to create a DomainValue with the specified origin. The origin is typically the program counter of the instruction that created this value/where the value was observed for the first time.

    The domain may ignore the information about the origin (origin).

  5. abstract def MetaInformationUpdateIllegalValue: MetaInformationUpdate[DomainIllegalValue]

    The result of the merge of two incompatible values has to be reported as a MetaInformationUpdate[DomainIllegalValue].

    The result of the merge of two incompatible values has to be reported as a MetaInformationUpdate[DomainIllegalValue].

    Definition Classes
    ValuesDomain
  6. abstract def ReturnAddressValue(address: PC): DomainReturnAddressValue

    Factory method to create an instance of a ReturnAddressValue.

    Factory method to create an instance of a ReturnAddressValue.

    Definition Classes
    ValuesDomain
  7. abstract val TheIllegalValue: DomainIllegalValue

    The singleton instance of the IllegalValue.

    The singleton instance of the IllegalValue.

    Definition Classes
    ValuesDomain
  8. abstract val TheReturnAddressValues: DomainReturnAddressValues

    The singleton instance of ReturnAddressValues

    The singleton instance of ReturnAddressValues

    Definition Classes
    ValuesDomain

Concrete Value Members

  1. final def !=(arg0: Any): Boolean
    Definition Classes
    AnyRef → Any
  2. final def ##(): Int
    Definition Classes
    AnyRef → Any
  3. final def ==(arg0: Any): Boolean
    Definition Classes
    AnyRef → Any
  4. final def StructuralUpdateIllegalValue: StructuralUpdate[Nothing]

    The result of merging two values should never be reported as a StructuralUpdate if the computed value is an IllegalValue.

    The result of merging two values should never be reported as a StructuralUpdate if the computed value is an IllegalValue. The JVM semantics guarantee that the value will not be used and, hence, continuing the interpretation is meaningless.

    Definition Classes
    ValuesDomain
    Note

    This method is solely defined for documentation purposes and to catch implementation errors early on.

  5. final def asInstanceOf[T0]: T0
    Definition Classes
    Any
  6. def clone(): AnyRef
    Attributes
    protected[java.lang]
    Definition Classes
    AnyRef
    Annotations
    @native() @throws( ... )
  7. final def eq(arg0: AnyRef): Boolean
    Definition Classes
    AnyRef
  8. def equals(arg0: Any): Boolean
    Definition Classes
    AnyRef → Any
  9. def finalize(): Unit
    Attributes
    protected[java.lang]
    Definition Classes
    AnyRef
    Annotations
    @throws( classOf[java.lang.Throwable] )
  10. final def getClass(): Class[_]
    Definition Classes
    AnyRef → Any
    Annotations
    @native()
  11. def hashCode(): Int
    Definition Classes
    AnyRef → Any
    Annotations
    @native()
  12. final def isInstanceOf[T0]: Boolean
    Definition Classes
    Any
  13. def mergeDomainValues(pc: PC, v1: DomainValue, v2: DomainValue): DomainValue

    Merges the given domain value v1 with the domain value v2 and returns the merged value which is v1 if v1 is an abstraction of v2, v2 if v2 is an abstraction of v1 or some other value if a new value is computed that abstracts over both values.

    Merges the given domain value v1 with the domain value v2 and returns the merged value which is v1 if v1 is an abstraction of v2, v2 if v2 is an abstraction of v1 or some other value if a new value is computed that abstracts over both values.

    This operation is commutative.

    Definition Classes
    ValuesDomain
  14. final def ne(arg0: AnyRef): Boolean
    Definition Classes
    AnyRef
  15. final def notify(): Unit
    Definition Classes
    AnyRef
    Annotations
    @native()
  16. final def notifyAll(): Unit
    Definition Classes
    AnyRef
    Annotations
    @native()
  17. def properties(pc: PC, propertyToString: (AnyRef) ⇒ String = (v) ⇒ v.toString): Option[String]

    Returns a string representation of the properties associated with the instruction with the respective program counter.

    Returns a string representation of the properties associated with the instruction with the respective program counter.

    Associating properties with an instruction and maintaining those properties is, however, at the sole responsibility of the Domain.

    This method is predefined to facilitate the development of support tools and is not used by the abstract interpretation framework.

    Domains that define (additional) properties should (abstract) override this method and should return a textual representation of the property.

    Definition Classes
    ValuesDomain
  18. def summarize(pc: PC, values: Iterable[DomainValue]): DomainValue

    Creates a summary of the given domain values by summarizing and joining the given values.

    Creates a summary of the given domain values by summarizing and joining the given values. For the precise details regarding the calculation of a summary see Value.summarize(...).

    pc

    The program counter that will be used for the summary value if a new value is returned that abstracts over/summarizes the given values.

    values

    An Iterable over one or more values.

    Definition Classes
    ValuesDomain
    Note

    The current algorithm is generic and should satisfy most needs, but it is not very efficient. However, it should be easy to tailor it for a specific domain/domain values, if need be.

  19. final def synchronized[T0](arg0: ⇒ T0): T0
    Definition Classes
    AnyRef
  20. def toString(): String
    Definition Classes
    AnyRef → Any
  21. def typeOfValue(value: DomainValue): TypeInformation

    Returns the type(type bounds) of the given value.

    Returns the type(type bounds) of the given value.

    In general a single value can have multiple type bounds which depend on the control flow. However, all types that the value represents must belong to the same computational type category. I.e., it is possible that the value either has the type "NullPointerException or IllegalArgumentException", but it will never have – at the same time – the (Java) types int and long. Furthermore, it is possible that the returned type(s) is(are) only an upper bound of the real type unless the type is a primitive type.

    This default implementation always returns org.opalj.ai.UnknownType.

    Implementing typeOfValue

    This method is typically not implemented by a single Domain trait/object, but is instead implemented collaboratively by all domains that implement the semantics of certain values. To achieve that, other Domain traits that implement a concrete domain's semantics have to abstract override this method and only return the value's type if the domain knows anything about the type. If a method that overrides this method has no knowledge about the given value, it should delegate this call to its super method.

    Example

    trait FloatValues extends Domain[...] {
      ...
        abstract override def typeOfValue(value: DomainValue): TypesAnswer =
        value match {
          case r: FloatValue ⇒ IsFloatValue
          case _             ⇒ super.typeOfValue(value)
        }
    }
    Definition Classes
    ValuesDomain
  22. final def wait(): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
  23. final def wait(arg0: Long, arg1: Int): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
  24. final def wait(arg0: Long): Unit
    Definition Classes
    AnyRef
    Annotations
    @native() @throws( ... )

Inherited from ValuesDomain

Inherited from AnyRef

Inherited from Any

Ungrouped