This IntelliJ plugin provides a modern and powerful tool window to analyze byte code. Its supports Java, Kotlin, Groovy, and other JVM language class files.
It's available on the official IntelliJ plugin marketplace.
The tool window is available via View | Tool Windows | Byte Code and will be shown by default in the lower right corner of IntelliJ.
Class files can be opened directly from the tool window or the "Analyze Byte Code" action. This action is available in the project view and the editor for JVM class or source files:
If the editor is the origin of the action execution, the analyzer will pick the class relative to the current cursor position. With this, it is easy to analyze inner, locale, or anonymous classes.
The plugin currently uses ASM 9.7 under the hood, supporting JVM class files up to version 23.
The heart of the tool window is the structure view of a class file. It gives a depth and human-readable insights into the individual elements of a given class file:
In addition to listing the method instructions, we can view the state of the method frames (locals and current stack) after the execution of each instruction:
The plain view provides a textified representation of the byte code:
The ASM view provides Java source code that contains all instructions to generate the class via the ASM library:
A view that provides the result of the de-compilation of the class file using IntelliJ's built-in decompilers.
This view provides insights into the constant pool entries of the class file:
The menu in the upper right corner of the tool window provides some generic byte code analyzing actions. These are providing a general way better to understand certain aspects of the byte code specification.
The byte code stores access values in a single compressed number. With the help of the access converter tool, we can break this number into single readable values or calculate a compressed one:
With the help of the signature parser, we can split a signature string into its components:
A built-in overview of all byte code instructions, with name, opcode, operands, stack modifications and a description:
Additionally, there is an action to verify the byte code of a class file:
In general, all packages starting with an underscore _ are internal. Therefore, the code in those packages is not intended to be used by other plugins and does not necessarily adhere to the semantics version rules.
If you want to contribute something, please follow the code style in the .editorconfig and sign your commits.
To update the bundled ASM library:
- Set the new version in the main
build.gradle.kts. (The new bundled ASM library should automatically be created or execute the Gradle taskshadowAsmJar.) - Update the globally defined ASM API version in
dev.turingcomplete.intellijbytecodeplugin._ui.DefaultClassFileContext.ASM_APIto the highest available version. - Set the new ASM version and latest supported Java version in the description block of the
plugin.xmland in theREADME.md. - New supported Java versions must be added to the field:
dev.turingcomplete.intellijbytecodeplugin.bytecode.ClassVersionUtils.CLASS_VERSIONS.
Open class files actions (e.g., the "open from disk" action) offer a way to read class files and open are new tab in the tool window.
- Extension name:
dev.turingcomplete.intellijbytecodeplugin.openClassFilesAction - Interface:
dev.turingcomplete.intellijbytecodeplugin.openclassfiles.OpenClassFilesToolWindowAction
To open a class file in the byte code analyzer tool window one of the methods in the service project.getService(ByteCodeToolService::class.java) can be called.
The byte code tools do not directly refer to an opened class file (use a byte code action for that).
- Extension name:
dev.turingcomplete.intellijbytecodeplugin.byteCodeTool - Interface:
dev.turingcomplete.intellijbytecodeplugin.tool.ByteCodeTool
Byte code views (e.g., the structure view) display a representation of the byte code.
- Extension name:
dev.turingcomplete.intellijbytecodeplugin.byteCodeViewCreator - Interface:
dev.turingcomplete.intellijbytecodeplugin.view.ByteCodeView$Creator
Byte code actions (e.g., the decompile action) will be added to each byte code view toolbar. They are working with the currently opened class file.
- Extension name:
dev.turingcomplete.intellijbytecodeplugin.byteCodeAction - Interface:
dev.turingcomplete.intellijbytecodeplugin.view.ByteCodeAction
Some tests are testing the parsing of the structure tree and the constant pool and the opening of files with all class files from the java base module and the groovy-all and kotlin-stdlib libraries. Since this involves tens of thousands of files, these tests take a lot of time. Therefore, execution in dev.turingcomplete.intellijbytecodeplugin.ClassFileConsumerTestCase.LIMIT_CLASSES is limited to 800 classes per library. This value should be increased significantly for at least one test run before a new version gets released.
Copyright (c) 2024 Marcel Kliemannel
Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License.
You may obtain a copy of the License at https://www.apache.org/licenses/LICENSE-2.0.
Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the LICENSE for the specific language governing permissions and limitations under the License.