GradleMethodInliner

A gradle plugin to mark methods for inlining.

Installation

To use this plugin, you need to add my maven server to your plugin repositories:

pluginManagement {
    repositories {
        maven {
            name = "lenni0451 releases"
            url = "https://maven.lenni0451.net/releases"
        }
    }
}

After adding the repository, you can add the plugin to your project:

plugins {
    id "net.lenni0451.method-inliner" version "x.x.x"
}

The plugin will automatically load the required compileOnly dependencies.

Usage

Inlining methods

To mark a method for inlining, you need to add the InlineMethod annotation to it:

@InlineMethod
private static void inlined() {

Limitations:

• The method must be private
• Recursive methods are not supported
• The inlined method gets removed. Make sure that it is not accessed using reflection or similar
• Only INVOKEVIRTUAL and INVOKESTATIC calls are inlined. INVOKESPECIAL and INVOKEINTERFACE calls are not supported

Inlining public methods/keeping the method

Inlining public methods is also possible but a bit more limited.
To inline a public method you need to set keep to true in the InlineMethod annotation:

@InlineMethod(keep = true)
public static void inlined() {

When using keep = true on a non-static method, a warning will be printed to the console.

Limitations:

• The method must be static
• Only INVOKEVIRTUAL and INVOKESTATIC calls are inlined. INVOKESPECIAL and INVOKEINTERFACE calls are not supported
• Accessing private fields/methods of the class will result in exceptions at runtime

Example

Let's say we have the following class:

public class Test {

    public static void main(String[] args) {
        inlined();
        notInlined();
    }

    @InlineMethod
    private static void inlined() {
        System.out.println("Inlined method");
    }

    private static void notInlined() {
        System.out.println("Not inlined method");
    }

}

In this case, the inlined method will be inlined, but the notInlined method will not be inlined.

The compiled bytecode of the class will look like this:

public class Test {

    public static void main(String[] args) {
        System.out.println("Inlined method");
        notInlined();
    }

    private static void notInlined() {
        System.out.println("Not inlined method");
    }

}