AssembleMojo.java

/*
 * SPDX-FileCopyrightText: Copyright (c) 2016-2026 Objectionary.com
 * SPDX-License-Identifier: MIT
 */
package org.eolang.jeo;

import com.jcabi.log.Logger;
import java.io.File;
import java.nio.file.Path;
import org.apache.maven.artifact.DependencyResolutionRequiredException;
import org.apache.maven.plugin.AbstractMojo;
import org.apache.maven.plugin.MojoExecutionException;
import org.apache.maven.plugins.annotations.LifecyclePhase;
import org.apache.maven.plugins.annotations.Mojo;
import org.apache.maven.plugins.annotations.Parameter;
import org.apache.maven.project.MavenProject;

/**
 * Assembles XMIR representation of Java bytecode into executable class files.
 *
 * <p>This Maven plugin converts low-level EO representation (in XMIR format) into Java bytecode
 * that can be executed by the Java Virtual Machine. The plugin performs pure assembly without
 * applying any optimizations or improvements to the bytecode.</p>
 *
 * <p>The plugin supports optional bytecode verification to ensure generated classes are valid
 * and can be loaded by the JVM.</p>
 *
 * @since 0.1.0
 */
@Mojo(name = "assemble", defaultPhase = LifecyclePhase.PROCESS_CLASSES, requiresProject = false)
public final class AssembleMojo extends AbstractMojo {

    /**
     * Maven project instance.
     * <p>
     * Provides access to project configuration and dependencies required for bytecode verification.
     * </p>
     *
     * @since 0.2.0
     */
    @Parameter(defaultValue = "${project}", readonly = true)
    private MavenProject project;

    /**
     * Source directory containing XMIR files to be assembled.
     * <p>
     * This directory should contain EO files in XMIR format that represent Java bytecode
     * instructions. These files are typically generated by the disassemble goal.
     * </p>
     *
     * @since 0.2.0
     * @checkstyle MemberNameCheck (6 lines)
     */
    @Parameter(
        property = "jeo.assemble.sourcesDir",
        defaultValue = "${project.build.directory}/generated-sources/jeo-xmir"
    )
    private File sourcesDir;

    /**
     * Target directory for generated bytecode class files.
     * <p>
     * All assembled class files will be written to this directory, preserving the package
     * structure as defined in the source XMIR files.
     * </p>
     *
     * @since 0.2.0
     * @checkstyle MemberNameCheck (6 lines)
     */
    @Parameter(
        property = "jeo.assemble.outputDir",
        defaultValue = "${project.build.outputDirectory}"
    )
    private File outputDir;

    /**
     * Flag to skip bytecode verification after assembly.
     * <p>
     * By default, all generated bytecode is verified to ensure it conforms to JVM specifications
     * and can be loaded without errors. Set this parameter to {@code true} to skip verification,
     * which may speed up the build but could result in invalid class files.
     * </p>
     *
     * @since 0.2.0
     * @checkstyle MemberNameCheck (6 lines)
     */
    @Parameter(
        property = "jeo.assemble.skip.verification",
        defaultValue = "false"
    )
    private boolean skipVerification;

    /**
     * Flag to enable XMIR verification before assembling.
     * <p>
     * When enabled, verifies all XMIR files for structural integrity and correctness before
     * attempting to assemble them into bytecode. If any XMIR file is invalid or corrupted,
     * the build process will fail. This verification is disabled by default for performance.
     * </p>
     *
     * @since 0.8.0
     * @checkstyle MemberNameCheck (6 lines)
     */
    @Parameter(
        property = "jeo.assemble.xmir.verification",
        defaultValue = "false"
    )
    private boolean xmirVerification;

    /**
     * Flag to disable the plugin execution.
     * <p>
     * When set to {@code true}, the plugin will skip all processing and exit immediately.
     * This can be useful for conditional builds or troubleshooting.
     * </p>
     *
     * @since 0.2.0
     * @checkstyle MemberNameCheck (6 lines)
     */
    @Parameter(
        property = "jeo.assemble.disabled",
        defaultValue = "false"
    )
    private boolean disabled;

    /**
     * Enable debug logging for the assembling process.
     * @since 0.15.0
     * @checkstyle MemberNameCheck (6 lines)
     */
    @Parameter(property = "jeo.assemble.debug", defaultValue = "false")
    private boolean debug;

    @Override
    public void execute() throws MojoExecutionException {
        final Path src = new MavenPath(this.sourcesDir).resolve();
        final Path out = new MavenPath(this.outputDir).resolve();
        try {
            if (this.disabled) {
                Logger.info(this, "Assemble mojo is disabled, skipping");
            } else {
                if (this.xmirVerification) {
                    Logger.info(this, "Verifying all the XMIR files before assembling...");
                    new XmirFiles(src).verify();
                } else {
                    Logger.info(this, "XMIR verification before assembling is disabled, skipping");
                }
                new Assembler(
                    src,
                    out,
                    this.debug
                ).assemble();
                if (this.skipVerification) {
                    Logger.info(this, "Bytecode verification is disabled, skipping");
                } else {
                    Logger.info(this, "Verifying bytecode of all the generated classes...");
                    new PluginStartup(this.project, out).init();
                    new BytecodeClasses(out).verify();
                }
            }
        } catch (final DependencyResolutionRequiredException exception) {
            throw new MojoExecutionException(exception);
        }
    }
}