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

DependencyCollectingDependencyProcessor

DependencyCountingDependencyProcessor

DependencyExtractor

DependencyProcessor

DependencyProcessorAdapter

DependencyProcessorDecorator

DependencyStore

DependencyStoreKey

DependencyStoreWithoutSelfDependenciesKey

DependencyTypes

FilterSelfDependencies

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

de

package de

Functionality to extract dependencies between class files.

Source: package.scala

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class DependencyCollectingDependencyProcessor extends DependencyProcessor
Collects all dependencies extracted by a DependencyExtractor.
Collects all dependencies extracted by a DependencyExtractor.
Thread Safety
This class is thread-safe. However, it does not make sense to call the method toStore unless the dependency extractor that uses this processor has completed.
class DependencyCountingDependencyProcessor extends DependencyProcessor
A dependency processor that just counts the number of dependencies.
A dependency processor that just counts the number of dependencies.
Typically, a DependencyProcessor is passed to a DependencyExtractor. The latter calls back the processDependency methods for each identified dependency.
class DependencyExtractor extends AnyRef
Traverses a org.opalj.br.SourceElement and identifies all dependencies between the element (org.opalj.br.ClassFile, org.opalj.br.Field or org.opalj.br.Method declaration) and any element it depends on.
Traverses a org.opalj.br.SourceElement and identifies all dependencies between the element (org.opalj.br.ClassFile, org.opalj.br.Field or org.opalj.br.Method declaration) and any element it depends on. The kind of the dependencies that are extracted are defined by the DependencyType enumeration.
Concurrency
The DependencyExtractor does not perform any kind of parallelization on its own. Users of a DependencyExtractor are expected to perform the parallelization (e.g., on the level of source elements) if desired.
Thread Safety
The DependencyExtractor does not define any relevant state and, hence, this class is thread-safe.
However, if multiple dependency extractors are executed concurrently and share the same DependencyProcessor or the same DepencencyExtractor is used by multiple threads concurrently, the DependencyProcessor has to be thread-safe.
Note
By default, self dependencies will be reported (e.g., a method that calls itself, a class that defines a field with the same type). If necessary or undesired, self dependencies can easily be filtered by a DependencyProcessor's processDependency method.
,
If the DependencyExtractor is extended, it is important to delegate all creations of VirtualSourceElements to the DependencyProcessor to make sure that the dependency processor can perform, e.g., some internalization.
trait DependencyProcessor extends AnyRef
A dependency processor processes dependencies between two source elements.
A dependency processor processes dependencies between two source elements.
Typically, a DependencyProcessor is passed to a DependencyExtractor. The latter calls back the processDependency methods for each identified dependency.
class DependencyProcessorAdapter extends DependencyProcessor
Basic implementation of the DependencyProcessor trait that does nothing when a dependency is reported.
class DependencyProcessorDecorator extends DependencyProcessor
Decorator for a given DependencyProcessor.
Decorator for a given DependencyProcessor.
Usage Scenario
If some special processing of some VirtualSourceElements needs to be done, but in other cases processing should just be delegated to another dependency processor.
Thread Safety
This class is thread-safe if the specified base dependency processor is also thread-safe.
class DependencyStore extends AnyRef
Stores extracted dependencies.
Stores extracted dependencies.
Thread Safety
This class is thread safe.
type DependencyType = de.DependencyTypes.Value
type DependencyTypesBitSet = Long
type DependencyTypesSet = Set[DependencyType]
trait FilterSelfDependencies extends DependencyProcessor
A DependencyProcessor that filters self-dependencies.
A DependencyProcessor that filters self-dependencies.
See also
DependencyStoreWithoutSelfDependenciesKey for a usage.

Value Members

object DependencyProcessorAdapter extends DependencyProcessorAdapter
object DependencyStore
object DependencyStoreKey extends ProjectInformationKey[DependencyStore, Nothing]
Key that can be used to get a DependencyStore that contains all dependencies.
Key that can be used to get a DependencyStore that contains all dependencies.
Usage
Just pass this object to a Project to get the DependencyStore.
object DependencyStoreWithoutSelfDependenciesKey extends ProjectInformationKey[DependencyStore, Nothing]
Key that can be used to get a DependencyStore that contains all dependencies except self dependencies.
Key that can be used to get a DependencyStore that contains all dependencies except self dependencies.
Usage
Just pass this object to a Project to get the DependencyStore.
object DependencyTypes extends Enumeration
Enumeration of all kinds of dependencies that are extracted by the DependencyExtractor.

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

de

package de

Type Members

Thread Safety

Concurrency

Thread Safety

Usage Scenario

Thread Safety

Thread Safety

Value Members

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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

de

package de

Type Members

Thread Safety

Concurrency

Thread Safety

Usage Scenario

Thread Safety

Thread Safety

Value Members

Usage

Usage

Inherited from AnyRef

Inherited from Any

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No `null` Values

de