static boolean isEclipseImplementation(ProcessingEnvironment environment) {
    Class<?> lookupClass = String.class;
    TypeElement element = environment.getElementUtils().getTypeElement(lookupClass.getCanonicalName());
    return element.getClass().getCanonicalName().startsWith("org.eclipse");
  }
Detect if current compiler is <a href="https://wiki.eclipse.org/JDT_Core_Programmer_Guide/ECJ">ECJ</a> (Eclipse Compiler).

@param environment runtime context of the compilation
@return true if current annotation processor is executed as part of ECJ, false otherwise.
value-processor/src/org/immutables/value/processor/meta/ProcessingEnvironments.java