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

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.)

Creates a domain value from the given value information that represents a properly domain value. A representation of a proper value is created even if the value information is provided for an uninitialized value.

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

Factory method to create an instance of a ReturnAddressValue.

The singleton instance of the IllegalValue.

The singleton instance of ReturnAddressValues

This project's class hierarchy.

Usually, just a redirect to the Project's class hierarchy or the default class hierarchy.

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.

Called by the abstract interpreter when the abstract interpretation of a method has ended. The abstract interpretation of a method ends if either the fixpoint is reached or the interpretation was aborted.

By default this method does nothing.

Domains that override this method are expected to also call super.abstractInterpretationEnded(aiResult).

Classes overriding this method generally have to call it!

This methods is called after the evaluation of the instruction with the given pc with respect to targetPC, but before the values are propagated (joined) and before it is checked whether the interpretation needs to be continued. I.e., if the operands (newOperands) or locals (newLocals) are further refined then the refined operands and locals are joined (if necessary).

This method is called immediately before a join operation with regard to the specified pc is performed.

Called by the framework after evaluating the instruction with the given pc. I.e., the state of all potential successor instructions was updated and the flow method was called – potentially multiple times – accordingly.

By default this method does nothing.

Called by the framework after performing a computation to inform the domain about the result. That is, after evaluating the effect of the instruction with currentPC on the current stack and register and (if necessary) joining the updated stack and registers with the stack and registers associated with the instruction successorPC. (Hence, this method is ONLY called for return instructions if the return instruction throws an IllegalMonitorStateException.) This function basically informs the domain about the instruction that may be evaluated next. The flow function is called for every possible successor of the instruction with currentPC. This includes all branch targets as well as those instructions that handle exceptions.

In some cases it will even be the case that flow is called multiple times with the same pair of program counters: (currentPC, successorPC). This may happen, e.g., in case of a switch instruction where multiple values have the same body/target instruction and we do not have precise information about the switch value. E.g., as in the following snippet:

switch (i) {  // pc: X => Y (for "1"), Y (for "2"), Y (for "3")
case 1:
case 2:
case 3: System.out.println("Great.");            // pc: Y
default: System.out.println("Not So Great.");    // pc: Z
}

The flow function is also called after instructions that are domain independent such as dup and load instructions which just manipulate the registers and stack in a generic way. This enables the domain to precisely follow the evaluation progress and in particular to perform control-flow dependent analyses.

Tests if subtype is known to be subtype of supertype. See org.opalj.br.ClassHierarchy's isSubtypeOf method for details.

Tests if subtype is known to be subtype of supertype. See org.opalj.br.ClassHierarchy's isSubtypeOf method for details.

Joins the given operand stacks and local variables.

In general there should be no need to refine this method. Overriding this method should only be done for analysis purposes.

Performance

This method heavily relies on reference comparisons to speed up the overall process of performing an abstract interpretation of a method. Hence, a computation should – whenever possible – return (one of) the original object(s) if that value has the same abstract state as the result. Furthermore, if all original values capture the same abstract state as the result of the computation, the "left" value/the value that was already used in the past should be returned.

Enables the customization of the behavior of the base join method.

This method in particular enables, in case of a MetaInformationUpdate, to raise the update type to force the continuation of the abstract interpretation process.

Methods should always override this method and should call the super method.

Classes overriding this method generally have to call it!

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.

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.

This function can be called when the instruction successorPC needs to be scheduled. The function will test if the instruction is already scheduled and – if so – returns the given worklist. Otherwise the instruction is scheduled in the correct (subroutine-)context.

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(...).

Replaces all occurrences of oldValue (using reference-quality) with newValue. If no occurrences are found, the original operands and locals data structures are returned.