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Definition Classes: root

Definition Classes: root

OPAL is a Scala-based framework for the static analysis, manipulation and creation of Java bytecode.

OPAL is a Scala-based framework for the static analysis, manipulation and creation of Java bytecode. OPAL is designed with performance, scalability and adaptability in mind.

Its main components are:

a library (Common) which provides generally useful data-structures and algorithms for static analyses.
a framework for implementing lattice based static analyses (Static Analysis Infrastructure)
a framework for parsing Java bytecode (Bytecode Infrastructure) that can be used to create arbitrary representations.
a library to create a one-to-one in-memory representation of Java bytecode (Bytecode Disassembler).
a library to create a representation of Java bytecode that facilitates writing simple static analyses (Bytecode Representation - org.opalj.br).
a scalable, easily customizable framework for the abstract interpretation of Java bytecode (Abstract Interpretation Framework - org.opalj.ai).
a library to extract dependencies between code elements and to facilitate checking architecture definitions.
a library for the lightweight manipulation and creation of Java bytecode (Bytecode Assembler).

General Design Decisions

Thread Safety

Unless explicitly noted, OPAL is thread safe. I.e., the classes defined by OPAL can be considered to be thread safe unless otherwise stated. (For example, it is possible to read and process class files concurrently without explicit synchronization on the client side.)

No `null` Values

Unless explicitly noted, OPAL does not null values I.e., fields that are accessible will never contain null values and methods will never return null. If a method accepts null as a value for a parameter or returns a null value it is always explicitly documented. In general, the behavior of methods that are passed null values is undefined unless explicitly documented.

No Typecasts for Collections

For efficiency reasons, OPAL sometimes uses mutable data-structures internally. After construction time, these data-structures are generally represented using their generic interfaces (e.g., scala.collection.{Set,Map}). However, a downcast (e.g., to add/remove elements) is always forbidden as it would effectively prevent thread-safety.

Assertions

OPAL makes heavy use of Scala's Assertion Facility to facilitate writing correct code. Hence, for production builds (after thorough testing(!)) it is highly recommend to build OPAL again using -Xdisable-assertions.

Definition Classes: org

package ai

Implementation of an abstract interpretation (ai) framework – also referred to as OPAL.

Please note that OPAL/the abstract interpreter just refers to the classes and traits defined in this package (ai). The classes and traits defined in the sub-packages (in particular in domain) are not considered to be part of the core of OPAL/the abstract interpreter.

Definition Classes: opalj
Note: This framework assumes that the analyzed bytecode is valid; i.e., the JVM's bytecode verifier would be able to verify the code. Furthermore, load-time errors (e.g., LinkageErrors) are – by default – completely ignored to facilitate the analysis of parts of a project. In general, if the presented bytecode is not valid, the result is undefined (i.e., OPAL may report meaningless results, crash or run indefinitely).
See also: org.opalj.ai.AI - Implements the abstract interpreter that processes a methods code and uses an analysis-specific domain to perform the abstract computations.
org.opalj.ai.Domain - The core interface between the abstract interpretation framework and the abstract domain that is responsible for performing the abstract computations.

package common

Definition Classes: ai

package domain

This package contains definitions of common domains that can be used for the implementation of analyses.

Types of Domains

In general, we distinguish two types of domains. First, domains that define a general interface (on top of the one defined by Domain), but do not directly provide an implementation. Hence, whenever you develop a new Domain you should consider implementing/using these domains to maximize reusability. Second, Domains that implement a specific interface (trait). In this case, we further distinguish between domains that provide a default implementation (per interface only one of these Domains can be used to create a final Domain) and those that can be stacked and basically refine the overall functionality.

Examples

Domains That Define a General Interface
- Origin defines two types which domains that provide information abou the origin of a value should consider to implement.
- TheProject defines a standard mechanism how a domain can access the current project.
- ...
Domains That Provide a Default Implementation
- Origin defines the functionality to return a value's origin if the value supports that.
- org.opalj.ai.domain.TheProject default implementation of the class hierarchy related methods using the project's class hierarchy.
- org.opalj.ai.domain.DefaultHandlingOfMethodResults basically implements a Domain's methods related to return instructions an uncaught exceptions.
- ...
Domains That Implement Stackable Functionality
- org.opalj.ai.domain.RecordThrownExceptions records information about all uncaught exceptions by intercepting a Domain's respective methods. However, it does provide a default implementation. Hence, a typical pattern is:

class MyDomain extends Domain with ...
    with DefaultHandlingOfMethodResults with RecordThrownExceptions

Thread Safety

Unless explicitly documented, a domain is never thread-safe. The general programming model is to use one Domain object per code block/method and therefore, thread-safety is not required for Domains that are used for the evaluation of methods. However domains that are used to adapt/transfer values should be thread safe (see org.opalj.ai.domain.ValuesCoordinatingDomain for further details).

Definition Classes: ai

package fpcf

Definition Classes: ai

package project

Definition Classes: ai

package util

Common utility functionality.

Definition Classes: ai

BoundedInterruptableAI

ComputationWithException

ComputationWithResult

ComputationWithResultAndException

ComputationWithSideEffectOnly

ComputationWithSideEffectOrException

ComputedValue

ComputedValueOrException

Configuration

CoreDomainFunctionality

CorrelationalDomain

CorrelationalDomainSupport

ExceptionsRaisedByCalledMethods

FieldAccessesDomain

FloatValuesDomain

FloatValuesFactory

GlobalLogContextProvider

IdentityBasedCorrelationChangeDetection

InstructionCountBoundedAI

IntegerRangeValuesFactory

IntegerValuesDomain

IntegerValuesFactory

InterpretationFailedException

MetaInformationUpdate

MetaInformationUpdateType

MethodCallsDomain

MonitorInstructionsDomain

MultiTracer

NoUpdate

NoUpdateType

PrimitiveValuesConversionsDomain

ReferenceValuesDomain

ReferenceValuesFactory

ReturnInstructionsDomain

Computation

sealed abstract class Computation[+V, +E] extends AnyRef

Encapsulates the result of a computation in a domain. In general, the result is either some value V or some exception(s) E. In some cases, however, when the domain cannot precisely determine the result, it may be both: some exceptional value(s) and a value.

In the latter case the abstract interpreter will generally follow all possible paths. A computation that declares to return a result (i.e., the type V is not Nothing) must not return a result and/or throw an exception if the computation did not finish.

Querying Computations

Before accessing a computation's result (result or exceptions) it first has to be checked whether the computation returned normally (returnsNormally) or threw an exception (throwsException). Only if returnsNormally returns true the methods result and hasResult are defined.

V: The result of the computation. Typically a DomainValue; if the computation is executed for its side effect (e.g., as in case of a monitorenter or monitorexit instruction) the type of V maybe Nothing.
E: The exception(s) that maybe thrown by the computation. Typically, a DomainValue which represents a reference value with type java.lang.Throwable or a subtype thereof. If multiple exceptions may be thrown it may also be a set or Iterable of DomainValues (e.g., ExceptionValues).

Source: Computation.scala
Note: The precise requirements on the result of a computation are determined by the Domain object's methods that perform computations.

Linear Supertypes

AnyRef, Any

Known Subclasses

ComputationFailed, ComputationWithSideEffectOnly, ComputationWithSideEffectOrException, ComputedValue, ComputedValueOrException, ThrowsException

Ordering

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Inherited

Computation
AnyRef
Any

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Abstract Value Members

abstract def exceptions: E
The exception or exceptions when the computation raised an exception; defined if and only if throwsException returns true.
The exception or exceptions when the computation raised an exception; defined if and only if throwsException returns true.
E.g., the invocation of a method may lead to several (checked/unchecked) exceptions.
Annotations
@throws(scala.this.throws.<init>$default$1[UnsupportedOperationException])
abstract def hasResult: Boolean
Returns true if this computation has a result value, false otherwise.
Returns true if this computation has a result value, false otherwise.
Note
A method with return type void may return normally (returnsNormally), but will never have a result. I.e., for such method, hasResult will always be false.
abstract def result: V
The return value of the computation (if any); defined if and only if hasResult returns true.
The return value of the computation (if any); defined if and only if hasResult returns true.
Annotations
@throws(scala.this.throws.<init>$default$1[UnsupportedOperationException])
abstract def returnsNormally: Boolean
Returns true if this computation may have returned normally without throwing an exception.
Returns true if this computation may have returned normally without throwing an exception. Given that some computations are performed for their side effect only, the computation may not have a result.
abstract def throwsException: Boolean
Returns true if this computation may have raised an exception.
abstract def updateExceptions[X](exceptions: X): Computation[V, X]
Updates the exception associated with the represented computation.
Updates the exception associated with the represented computation.
This method is only supported if the computation had an associated exception!
Annotations
@throws(scala.this.throws.<init>$default$1[UnsupportedOperationException])
abstract def updateResult[X](result: X): Computation[X, E]
Updates the result associated with the represented computation.
Updates the result associated with the represented computation.
This method is only supported if the computation had a result!
Annotations
@throws(scala.this.throws.<init>$default$1[UnsupportedOperationException])

Concrete Value Members

final def !=(arg0: Any): Boolean
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final def ##: Int
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final def ==(arg0: Any): Boolean
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final def asInstanceOf[T0]: T0
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def clone(): AnyRef
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protected[lang]
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@throws(classOf[java.lang.CloneNotSupportedException]) @native() @IntrinsicCandidate()
final def eq(arg0: AnyRef): Boolean
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def equals(arg0: AnyRef): Boolean
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final def getClass(): Class[_ <: AnyRef]
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@native() @IntrinsicCandidate()
def hashCode(): Int
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@native() @IntrinsicCandidate()
final def isInstanceOf[T0]: Boolean
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final def ne(arg0: AnyRef): Boolean
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final def notify(): Unit
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@native() @IntrinsicCandidate()
final def notifyAll(): Unit
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@native() @IntrinsicCandidate()
final def synchronized[T0](arg0: => T0): T0
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def toString(): String
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final def wait(arg0: Long, arg1: Int): Unit
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@throws(classOf[java.lang.InterruptedException])
final def wait(arg0: Long): Unit
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@throws(classOf[java.lang.InterruptedException])
final def wait(): Unit
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@throws(classOf[java.lang.InterruptedException])

Deprecated Value Members

def finalize(): Unit
Attributes
protected[lang]
Definition Classes
AnyRef
Annotations
@throws(classOf[java.lang.Throwable]) @Deprecated
Deprecated

Packages

General Design Decisions

Thread Safety

No `null` Values

No Typecasts for Collections

Assertions

Types of Domains

Thread Safety

Computation

sealed abstract class Computation[+V, +E] extends AnyRef

Querying Computations

Abstract Value Members

Concrete Value Members

Deprecated Value Members

Inherited from AnyRef

Inherited from Any

Ungrouped

Packages

General Design Decisions

Thread Safety

No null Values

No Typecasts for Collections

Assertions

Types of Domains

Thread Safety

Computation

sealed abstract class Computation[+V, +E] extends AnyRef

Querying Computations

Abstract Value Members

Concrete Value Members

Deprecated Value Members

Inherited from AnyRef

Inherited from Any

Ungrouped

No `null` Values

Computation