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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

AIResult

sealed abstract class AIResult extends AnyRef

Encapsulates the result of the abstract interpretation of a method. If the abstract interpretation was cancelled, the result encapsulates the current state of the evaluation which can be used to continue the abstract interpretation later on if necessary/desired.

Source: AIResult.scala

Linear Supertypes

AnyRef, Any

Known Subclasses

AIAborted, AICompleted

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Abstract Value Members

abstract val cfJoins: IntTrieSet
The instructions where two or more control flow paths join.
The instructions where two or more control flow paths join.
Note
This information could be recomputed on-demand but is stored for performance reasons.
See also
org.opalj.br.Code.cfPCs, org.opalj.br.Code.cfJoins, org.opalj.br.Code.predecessorPCs
abstract val code: Code
The code for which the abstract interpretation was performed.
abstract val domain: Domain
The domain object that was used to perform the abstract interpretation.
abstract val evaluatedPCs: IntArrayStack
The list of evaluated instructions ordered by the evaluation time; subroutines are identified using the SUBROUTINE marker ids.
abstract val liveVariables: LiveVariables
The set of statically known live Variables.
abstract val localsArray: Domain.LocalsArray
The values stored in the registers.
The values stored in the registers.
For those instructions that were never executed (potentially dead code if the abstract interpretation succeeded) the locals array will be empty (the value will be null).
abstract val memoryLayoutBeforeSubroutineCall: List[(PC, Domain.OperandsArray, Domain.LocalsArray)]
Contains the memory layout before the call to a subroutine.
Contains the memory layout before the call to a subroutine. This list is empty if the abstract interpretation completed successfully.
abstract val operandsArray: Domain.OperandsArray
The array of the operand lists in effect before the execution of the instruction with the respective program counter.
The array of the operand lists in effect before the execution of the instruction with the respective program counter.
For those instructions that were never executed (potentially dead code if the abstract interpretation succeeded) the operands array will be empty (the value will be null).
abstract val subroutinesLocalsArray: Domain.LocalsArray
Contains the memory layout related to the method's subroutines (if any).
Contains the memory layout related to the method's subroutines (if any).
Note
This value is null if the method does not have subroutines (Java 6 and newer class files never contain subroutines) or if no subroutine was analyzed so far.
abstract val subroutinesOperandsArray: Domain.OperandsArray
Contains the memory layout related to the method's subroutines (if any).
Contains the memory layout related to the method's subroutines (if any).
Note
This value is null if the method does not have subroutines (Java 6 and newer class files never contain subroutines) or if no subroutine was analyzed so far.
abstract val subroutinesWereEvaluated: Boolean
True if and only if a subroutine (JSR) was actually evaluated.
abstract def wasAborted: Boolean
Returns true if the abstract interpretation was aborted.
abstract val worklist: List[PC]
The list of instructions that need to be interpreted next.
The list of instructions that need to be interpreted next. This list is empty if the abstract interpretation succeed.

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
Definition Classes
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def equals(arg0: AnyRef): Boolean
Definition Classes
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lazy val evaluatedInstructions: BitSet
Returns the information whether an instruction with a specific PC was evaluated at least once.
final def getClass(): Class[_ <: AnyRef]
Definition Classes
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Annotations
@native() @IntrinsicCandidate()
def hashCode(): Int
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Annotations
@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
Definition Classes
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@native() @IntrinsicCandidate()
def stateToString: String
Textual representation of the state encapsulated by this result.
lazy val subroutinePCs: IntArraySet
Returns all instructions that belong to a subroutine.
final def synchronized[T0](arg0: => T0): T0
Definition Classes
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def toString(): String
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final def wait(arg0: Long, arg1: Int): Unit
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Annotations
@throws(classOf[java.lang.InterruptedException])
final def wait(arg0: Long): Unit
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@throws(classOf[java.lang.InterruptedException])
final def wait(): Unit
Definition Classes
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Annotations
@throws(classOf[java.lang.InterruptedException])
final def wasEvaluated(pc: Int): Boolean
Returns true if the instruction with the given pc was evaluated at least once.
Returns true if the instruction with the given pc was evaluated at least once.
This operation is much more efficient than performing an exists check on the list of evaluated instructions!
Annotations
@inline()

Deprecated Value Members

def finalize(): Unit
Attributes
protected[lang]
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@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

AIResult

sealed abstract class AIResult extends AnyRef

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

AIResult

sealed abstract class AIResult extends AnyRef

Abstract Value Members

Concrete Value Members

Deprecated Value Members

Inherited from AnyRef

Inherited from Any

Ungrouped

No `null` Values

AIResult