Wrapper for PMD to run some warmup iterations and dump timing numbers to stdout. Drop this in the pmd-cli module.

BenchmarkPmd.java

/**
 * BSD-style license; for more info see http://pmd.sourceforge.net/license.html
 */

package net.sourceforge.pmd.cli;

import org.apache.commons.lang3.ArrayUtils;

public class BenchmarkPmd {
    public static void main(String[] args) {
        int runs = Integer.parseInt(args[0]);
        int warmup = Integer.parseInt(args[1]);
        String[] pmdArgs = ArrayUtils.subarray(args, 2, args.length);

        // warmup iterations are discarded
        for (int i = 0; i < warmup; i++) {
            PmdCli.mainWithoutExit(pmdArgs);
        }

        System.out.println("time_sec"); // one line as CSV header
        for (int i = 0; i < runs; i++) {
            long t0 = System.nanoTime();
            // Note that this relies on PMD not printing anything to stdout.
            // Use renderer empty (or dump report to a file) and no progress bar.
            PmdCli.mainWithoutExit(pmdArgs);
            long time = System.nanoTime() - t0;
            System.out.println(time / 1e9); 
        }
    }
}