/** Construct a new compiler from a shared context. */
  public AptJavaCompiler(Context context) {
    super(preRegister(context));

    context.put(compilerKey, this);
    apt = Apt.instance(context);

    ClassReader classReader = ClassReader.instance(context);
    classReader.preferSource = true;

    // TEMPORARY NOTE: bark==log, but while refactoring, we maintain their
    // original identities, to remember the original intent.
    log = Log.instance(context);
    bark = Bark.instance(context);

    Options options = Options.instance(context);
    classOutput = options.get("-retrofit") == null;
    nocompile = options.get("-nocompile") != null;
    print = options.get("-print") != null;
    classesAsDecls = options.get("-XclassesAsDecls") != null;

    genSourceFileNames = new java.util.LinkedHashSet<String>();
    genClassFileNames = new java.util.LinkedHashSet<String>();

    // this forces a copy of the line map to be kept in the tree,
    // for use by com.sun.mirror.util.SourcePosition.
    lineDebugInfo = true;
  }
  /**
   * Main method: compile a list of files, return all compiled classes
   *
   * @param filenames The names of all files to be compiled.
   */
  public List<ClassSymbol> compile(
      List<String> filenames,
      Map<String, String> origOptions,
      ClassLoader aptCL,
      AnnotationProcessorFactory providedFactory,
      java.util.Set<Class<? extends AnnotationProcessorFactory>> productiveFactories,
      java.util.Set<java.io.File> aggregateGenFiles)
      throws Throwable {
    // as a JavaCompiler can only be used once, throw an exception if
    // it has been used before.
    assert !hasBeenUsed : "attempt to reuse JavaCompiler";
    hasBeenUsed = true;

    this.aggregateGenFiles = aggregateGenFiles;

    long msec = System.currentTimeMillis();

    ListBuffer<ClassSymbol> classes = new ListBuffer<ClassSymbol>();
    try {
      JavacFileManager fm = (JavacFileManager) fileManager;
      // parse all files
      ListBuffer<JCCompilationUnit> trees = new ListBuffer<JCCompilationUnit>();
      for (List<String> l = filenames; l.nonEmpty(); l = l.tail) {
        if (classesAsDecls) {
          if (!l.head.endsWith(".java")) { // process as class file
            ClassSymbol cs = reader.enterClass(names.fromString(l.head));
            try {
              cs.complete();
            } catch (Symbol.CompletionFailure cf) {
              bark.aptError("CantFindClass", l);
              continue;
            }

            classes.append(cs); // add to list of classes
            continue;
          }
        }
        JavaFileObject fo = fm.getJavaFileObjectsFromStrings(List.of(l.head)).iterator().next();
        trees.append(parse(fo));
      }

      // enter symbols for all files
      List<JCCompilationUnit> roots = trees.toList();

      if (errorCount() == 0) {
        boolean prev = bark.setDiagnosticsIgnored(true);
        try {
          enter.main(roots);
        } finally {
          bark.setDiagnosticsIgnored(prev);
        }
      }

      if (errorCount() == 0) {
        apt.main(roots, classes, origOptions, aptCL, providedFactory, productiveFactories);
        genSourceFileNames.addAll(apt.getSourceFileNames());
        genClassFileNames.addAll(apt.getClassFileNames());
      }

    } catch (Abort ex) {
    }

    if (verbose) log.printVerbose("total", Long.toString(System.currentTimeMillis() - msec));

    chk.reportDeferredDiagnostics();

    printCount("error", errorCount());
    printCount("warn", warningCount());

    return classes.toList();
  }