Packages

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 av

Definition Classes: opalj

package ba

Implementation of an eDSL for creating Java bytecode.

Implementation of an eDSL for creating Java bytecode. The eDSL is designed to facilitate the creation of correct class files; i.e., whenever possible it tries to fill wholes. For example, when an interface is specified the library automatically ensures that the super class type is (initially) set to java.lang.Object as required by the JVM specification.

This package in particular provides functionality to convert org.opalj.br classes to org.opalj.da classes.

Definition Classes: opalj

package bc

Definition Classes: opalj

package bi

Implementation of a library for parsing Java bytecode and creating arbitrary representations.

OPAL's primary representation of Java byte code is the org.opalj.br representation which is defined in the respective package. A second representation that represents bytecode one-by-one is found in the org.opalj.da package.

This Package

Common constants and type definitions used across OPAL.

Definition Classes: opalj

package br

In this representation of Java bytecode references to a Java class file's constant pool and to attributes are replaced by direct references to the corresponding constant pool entries.

In this representation of Java bytecode references to a Java class file's constant pool and to attributes are replaced by direct references to the corresponding constant pool entries. This facilitates developing analyses and fosters comprehension.

Based on the fact that indirect references to constant pool entries are resolved and replaced by direct references this representation is called the resolved representation.

This representation of Java bytecode is considered as OPAL's standard representation for writing Scala based analyses. This representation is engineered such that it facilitates writing analyses that use pattern matching.

Definition Classes: opalj

package bytecode

Defines functionality commonly useful when processing Java bytecode.

Definition Classes: opalj

package collection

OPAL's collection library is primarily designed with high performance in mind.

Design Goals

OPAL's collection library is primarily designed with high performance in mind. I.e., all methods provided by the collection library are reasonably optimized. However, providing a very large number of methods is a non-goal. Overall, OPAL's collection library provides:

collection classes that are manually specialized for primitive data-types.
collection classes that are optimized for particularly small collections of values.
collection classes that target special use cases such as using a collection as a workset/worklist.
collection classes that offer special methods that minimize the number of steps when compared to general purpose methods.

Integration With Scala's Collection Library

Hence, OPAL's collection library complements Scala's default collection library and is not intended to replace it. Integration with Scala's collection library is primarily provided by means of iterators (OPAL's Iterators inherit from Scala's Iterators). Furthermore the companion object of each of OPAL's collection classes generally provides factory methods that facilitate the conversion from Scala collection classes to OPAL collection classes.

Status

The collection library is growing. Nevertheless, the existing classes are production ready.

Definition Classes: opalj

package concurrent

Common constants, factory methods and objects used throughout OPAL when performing concurrent computations.

Definition Classes: opalj

package constraints

Defines helper values and methods related to modeling constraints.

Definition Classes: opalj

package control

Defines common control abstractions.

Definition Classes: opalj

package da

Defines convenience methods related to representing certain class file elements.

Definition Classes: opalj

package de

Functionality to extract dependencies between class files.

Definition Classes: opalj

package fpcf

The fixpoint computations framework (fpcf) is a general framework to perform fixpoint computations of properties ordered by a lattice.

The fixpoint computations framework (fpcf) is a general framework to perform fixpoint computations of properties ordered by a lattice. The framework in particular supports the development of static analyses.

In this case, the fixpoint computations/static analyses are generally operating on the code and need to be executed until the computations have reached their (implicit) fixpoint. The fixpoint framework explicitly supports resolving cyclic dependencies/computations. A prime use case of the fixpoint framework are all those analyses that may interact with the results of other analyses.

For example, an analysis that analyzes all field write accesses to determine if we can refine a field's type (for the purpose of the analysis) can (reuse) the information about the return types of methods, which however may depend on the refined field types.

The framework is generic enough to facilitate the implementation of anytime algorithms.

Definition Classes: opalj
Note: This framework assumes that all data-structures (e.g., dependee lists and properties) that are passed to the framework are effectively immutable! (Effectively immutable means that a data structure is never updated after it was passed to the framework.)
,
The dependency relation is as follows: “A depends on B” === “A is the depender, B is the dependee”. === “B is depended on by A”
,
The very core of the framework is described in: Lattice Based Modularization of Static Analyses

package graphs

This package defines graph algorithms as well as factory methods to describe and compute graphs and trees.

This package supports the following types of graphs:

graphs based on explicitly connected nodes (org.opalj.graphs.Node),
graphs where the relationship between the nodes are encoded externally (org.opalj.graphs.Graph).

Definition Classes: opalj

package io

Various io-related helper methods and classes.

Definition Classes: opalj
Note: The implementations of the methods rely on Java NIO(2).

package issues

Defines implicit conversions to wrap some types of analyses such that they generate results of type org.opalj.br.analyses.ReportableAnalysisResult.

Definition Classes: opalj

package log

Definition Classes: opalj

package tac

Common definitions related to the definition and processing of three address code.

Definition Classes: opalj

package util

Utility methods.

Definition Classes: opalj

package value

Provides a general query interface for querying a value's properties.

Definition Classes: opalj

org.opalj

log

package log

Ordering

Alphabetic

Visibility

Public
Protected

Type Members

case class BasicLogMessage(level: Level = Info, message: String) extends LogMessage with Product with Serializable
Default implementation of a log message.
class ConsoleOPALLogger extends OPALLogger
The console logger is a very basic logger that ignores the context.
case class ExceptionLogMessage(level: Level = Info, category: Option[String] = None, baseMessage: String, t: Throwable) extends LogMessage with Product with Serializable
sealed abstract class Level extends AnyRef
Common super trait of all log levels.
trait LogContext extends AnyRef
A log context associates log messages with a specific context and logger.
A log context associates log messages with a specific context and logger. Using a log context facilitates the suppression of recurring message in a specific context and also makes it possible to direct messages to different targets. Before using a LogContext it has to be registered with the OPALLogger$.
OPAL uses two primary log contexts:
1. The GlobalLogContext$ which should be used for general log messages related to OPAL, such as the number of threads used for computations.
2. The log context associated with org.opalj.br.analyses.Projects to log project related information (e.g., such as project related results or configuration issues.)
Note
The registration of the LogContext with the OPALLogger does not prevent the garbage collection of the LogContext unless a logged message explicitly references its log context. This is – however – discouraged! If no message explicitly reference the log context it is then possible to unregister the log context in the finalize method that references the context.
trait LogMessage extends AnyRef
Description of a log message.
Description of a log message.
Implementation Guidelines
A LogMessage should never contain a direct reference to a LogContext object.
trait OPALLogger extends AnyRef
Facilitates the logging of messages that are relevant for the end user.
Facilitates the logging of messages that are relevant for the end user.
Usage
To use OPAL's logging facility use the companion object (OPALLogger$).
Note
The OPALLogger framework is not intended to be used by developers to help debug analysis; it is intended to be used to inform (end)-users about the analysis progress.
case class StandardLogContext extends LogContext with Product with Serializable
case class StandardLogMessage(level: Level = Info, category: Option[String] = None, message: String) extends LogMessage with Product with Serializable
Default implementation of a log message.

Value Members

object DevNullLogger extends OPALLogger
An instance of OPALLogger that does not perform _any logging_ .
An instance of OPALLogger that does not perform _any logging_ .
In general, it is HIGHLY recommended to use the ConsoleOPALLogger and to the set the minimium log level to Error.
case object Error extends Level with Product with Serializable
Factory for error level log messages.
Factory for error level log messages.
See also
OPALLogger$ for usage instructions.
case object Fatal extends Level with Product with Serializable
case object GlobalLogContext extends LogContext with Product with Serializable
The global log context which should be used to log global messages.
The global log context which should be used to log global messages.
This context is automatically registered with the OPALLogger framework and uses, by default, a ConsoleOPALLogger.
case object Info extends Level with Product with Serializable
Factory for info level log messages.
Factory for info level log messages.
See also
OPALLogger$ for usage instructions.
object LogMessage

object OPALLogger extends OPALLogger

OPAL's logging facility.

Usage

Basic

E.g., using the global context and the convenience methods.

implicit val logContext : LogContext = org.opalj.log.GlobalContext
OPALLogger.info("project", "the project is garbage collected")

OPALLogger.info("project", "the project is garbage collected")(org.opalj.log.GlobalContext)

Advanced

Logging a message only once.

implicit val logContext : LogContext = org.opalj.log.GlobalContext
OPALLogger.logOnce(Warn("project configuration", "the method cannot be resolved"))

Initialization

If the GlobalLogContext should not use the default ConsoleOPALLogger then the logger can be changed using updateLogger.

Thread Safety

Thread safe.

case object Warn extends Level with Product with Serializable
Factory for warn level log messages.
Factory for warn level log messages.
See also
OPALLogger$ for usage instructions.

Packages

General Design Decisions

Thread Safety

No null Values

No Typecasts for Collections

Assertions

This Package

Design Goals

Integration With Scala's Collection Library

Status

log

package log

Type Members

Implementation Guidelines

Usage

Value Members

Usage

Basic

Advanced

Initialization

Thread Safety

Ungrouped

No `null` Values

log