Gradle ASMifier

What it is

Convenience tool that converts .java files to ASM instructions by wrapping the ASMifier tool around a Gradle incremental task that can convert multiple .java files at once.

This tool, as well as the one it's built upon, is meant to be used as a development tool for anyone who'd like to check how does Java code translate into bytecode instructions using ASM.

What it is not

This is not a tool to generate production code. Its .java target files are in a separate location from the production source files (similarly to the test sources, which are in a separate dir that isn't packaged into the production app).

How to use

Add the plugin to your project

You can find the latest version of the plugin here.

// build.gradle.kts
plugins {
    id("java") // or java-library
    id("com.likethesalad.asmifier") version "[latest]"
}

Add the ASMifier dependency

ASMifier is part of ASM's util library, which you can find here. This plugin needs to use that library to perform the conversion, so you must add it as part of your project's asmifier dependencies as shown below.

// build.gradle.kts
plugins { /* ... */ }

dependencies {
    asmifier("org.ow2.asm:asm-util:[latest]")
}

The asmifier dependency type is added by this plugin to ensure that its dependencies are separated from those of your app (similarly to configurations such as testImplementation are only used for a specific purpose and not to get packaged with your production code).

Add sources to transform

The .java sources that will be transformed by this plugin must be placed in a src dir named asmifier, as shown below.

app/
├─ build.gradle.kts
├─ src/
│  ├─ main/
│  │  ├─ java/
│  ├─ asmifier/
│  │  ├─ java/ <-- Here is where the asmifier .java target files must be placed

Run the Gradle task

To transform the .java target files you must run the gradle task named asmifier, like so:

./gradlew asmifier

Finding the ASMified sources

Once the asmifier task has finished, you can find its results in your app's build dir under build/generated/sources/asmifierDump, as shown below.

app/
├─ build/
│  ├─ generated/
│  │  ├─ sources/
│  │  │  ├─ asmifierDump/ <-- Here you will find the transformed files.

Try it out

You can clone this repo and try this plugin with this sample app. You can test it by running the gradlew command within the sample-app dir. You must make sure to cd into sample-app before running the gradlew command.