/**
   * Returns the live methods of a program whose root methods are the <tt>main</tt> method of a set
   * of classes.
   *
   * @param classes Names of classes containing root methods
   * @param context Repository for accessing BLOAT stuff
   * @return The <tt>MemberRef</tt>s of the live methods
   */
  private static Collection liveMethods(final Collection classes, final BloatContext context) {

    // Determine the roots of the call graph
    final Set roots = new HashSet();
    Iterator iter = classes.iterator();
    while (iter.hasNext()) {
      final String className = (String) iter.next();
      try {
        final ClassEditor ce = context.editClass(className);
        final MethodInfo[] methods = ce.methods();

        for (int i = 0; i < methods.length; i++) {
          final MethodEditor me = context.editMethod(methods[i]);

          if (!me.name().equals("main")) {
            continue;
          }

          BloatBenchmark.tr("  Root " + ce.name() + "." + me.name() + me.type());
          roots.add(me.memberRef());
        }

      } catch (final ClassNotFoundException ex1) {
        BloatBenchmark.err.println("** Could not find class: " + ex1.getMessage());
        System.exit(1);
      }
    }

    if (roots.isEmpty()) {
      BloatBenchmark.err.print("** No main method found in classes: ");
      iter = classes.iterator();
      while (iter.hasNext()) {
        final String name = (String) iter.next();
        BloatBenchmark.err.print(name);
        if (iter.hasNext()) {
          BloatBenchmark.err.print(", ");
        }
      }
      BloatBenchmark.err.println("");
    }

    context.setRootMethods(roots);
    final CallGraph cg = context.getCallGraph();

    final Set liveMethods = new TreeSet(new MemberRefComparator());
    liveMethods.addAll(cg.liveMethods());

    return (liveMethods);
  }
Esempio n. 2
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  /**
   * Performs the actual editing of a class. Does a whole mess of stuff including reading in the
   * classfile, building data structures to represent the class file, converting the CFG for each
   * method in the class into SSA form, perform some anlayses and optimizations on the method, and
   * finally committing it back to the class file. Phew.
   */
  private static void editClass(final String className) {
    ClassFile classFile; // Holds info about a class (implements
    // ClassInfo)

    // Get information about the class className
    try {
      classFile = (ClassFile) Main.context.loadClass(className);
    } catch (final ClassNotFoundException ex) {
      System.err.println("** Couldn't find class: " + ex.getMessage());
      return;
    }

    if (!Main.FORCE) {
      // Check to see if the file is up-to-date (i.e. has been
      // recompiled since it was last optimized). If so, do nothing
      // because the FORCE flag is false.

      final File source = classFile.file();
      final File target = classFile.outputFile();

      if ((source != null)
          && (target != null)
          && source.exists()
          && target.exists()
          && (source.lastModified() < target.lastModified())) {

        if (Main.VERBOSE) {
          System.out.println(classFile.name() + " is up to date");
        }

        return;
      }
    }

    if (Main.DEBUG) {
      // Print the contents of the class file to System.out
      classFile.print(System.out);
    }

    final ClassEditor c = Main.context.editClass(classFile);

    boolean skip = false;

    final String name = c.type().className();
    final String qual = c.type().qualifier() + "/*";

    // Edit only classes explicitly mentioned.
    if (Main.ONLY.size() > 0) {
      skip = true;

      // Only edit classes we explicitly don't name.
      for (int i = 0; i < Main.ONLY.size(); i++) {
        final String pkg = (String) Main.ONLY.get(i);

        if (name.equals(pkg) || qual.equals(pkg)) {
          skip = false;
          break;
        }
      }
    }

    // Don't edit classes we explicitly skip.
    if (!skip) {
      for (int i = 0; i < Main.SKIP.size(); i++) {
        final String pkg = (String) Main.SKIP.get(i);

        if (name.equals(pkg) || qual.equals(pkg)) {
          skip = true;
          break;
        }
      }
    }

    if (skip) {
      if (Main.VERBOSE) {
        System.out.println("Skipping " + c.type().className());
      }

      // We're done with this class file, decrement its reference count
      Main.context.release(classFile);
      return;
    }

    // Touch the output file first. That is, create the file, but make
    // it empty, just to make sure we can create it.

    try {
      final File f = classFile.outputFile();

      if (f.exists()) {
        f.delete();
      }

      final File dir = new File(f.getParent());
      dir.mkdirs();

      if (!dir.exists()) {
        throw new RuntimeException("Couldn't create directory: " + dir);
      }

      final DataOutputStream out = new DataOutputStream(new FileOutputStream(f));
      new PrintStream(out).println();
      out.close();
    } catch (final IOException e) {
      e.printStackTrace();
      System.exit(1);
    }

    if (Main.VERBOSE) {
      System.out.println("Optimizing " + c.type().className());
    }

    // Finally, we can start playing with the methods...
    final MethodInfo[] methods = c.methods();

    final int numMethods = methods.length + 1;
    ;
    int whichMethod = 0;

    for (int j = 0; j < methods.length; j++) {
      final MethodEditor m;

      try {
        m = Main.context.editMethod(methods[j]);
      } catch (final ClassFormatException ex) {
        System.err.println(ex.getMessage());
        continue;
      }

      if (Main.TRACE) {
        whichMethod++;
        System.out.println(
            "Optimizing "
                + name
                + "."
                + m.name()
                + " (method "
                + whichMethod
                + " of "
                + numMethods
                + ")");
      }

      if (Main.METHOD != null) {
        // A method name has been specified on the command line using
        // -only-method.
        boolean pass = true;

        String t = m.name() + m.type();

        if (t.equals(Main.METHOD)) {
          pass = false;
        }

        t = m.name();

        if (t.equals(Main.METHOD)) {
          pass = false;
        }

        if (pass) {
          // This isn't the method we're looking for.
          // Decrement its reference count.
          Main.context.release(methods[j]);
          continue;
        }
      }

      if (Main.DEBUG) {
        m.print(System.out);
      }

      if (m.isNative() || m.isAbstract()) {
        // We can't edit native or abstract methods
        Main.context.release(methods[j]);
        continue;
      }

      Main.bloatMethod(m, Main.context);
    }

    if (Main.ANNO) {
      String s = "Optimized with: EDU.purdue.cs.bloat.optimize.Main";

      for (int i = 0; i < Main.ARGS.length; i++) {
        if ((Main.ARGS[i].indexOf(' ') >= 0)
            || (Main.ARGS[i].indexOf('\t') >= 0)
            || (Main.ARGS[i].indexOf('\r') >= 0)
            || (Main.ARGS[i].indexOf('\n') >= 0)) {
          s += " '" + Main.ARGS[i] + "'";
        } else {
          s += " " + Main.ARGS[i];
        }
      }

      System.out.println(s);
      // c.constants().addConstant(Constant.UTF8, s);
    }

    Main.context.commit(classFile);
    Main.context.release(classFile);

    if (Main.TRACE) {
      System.out.println(Main.context.toString());
    }
  }
  /**
   * Performs intraprocedural BLOAT on a program's live methods.
   *
   * @param liveMethods Should be alphabetized. This way we can commit a class once we've BLOATed
   *     all of its methods.
   */
  private static void intraBloat(final Collection liveMethods, final BloatContext context) {

    ClassEditor prevClass = null;
    final Iterator iter = liveMethods.iterator();
    for (int count = 0; iter.hasNext(); count++) {
      MethodEditor live = null;
      ClassEditor ce = null; // Hack to make sure commit happens
      try {
        live = context.editMethod((MemberRef) iter.next());
        ce = context.editClass(live.declaringClass().classInfo());

      } catch (final NoSuchMethodException ex3) {
        BloatBenchmark.err.println("** Could not find method " + ex3.getMessage());
        System.exit(1);
      }

      /* So we can skip classes or packages */
      final String name = ce.type().className();
      final String qual = ce.type().qualifier() + "/*";
      boolean skip = false;
      for (int i = 0; i < BloatBenchmark.SKIP.size(); i++) {
        final String pkg = (String) BloatBenchmark.SKIP.get(i);

        if (name.equals(pkg) || qual.equals(pkg)) {
          skip = true;
          break;
        }
      }

      if (context.ignoreMethod(live.memberRef()) || skip) {
        // Don't display ignored methods, it's misleading.
        context.release(live.methodInfo());
        continue;
      }

      final Runtime runtime = Runtime.getRuntime();
      runtime.gc();

      final Date start = new Date();
      BloatBenchmark.tr(
          "  " + count + ") " + live.declaringClass().name() + "." + live.name() + live.type());
      BloatBenchmark.tr("    Start: " + start);

      try {
        EDU.purdue.cs.bloat.optimize.Main.TRACE = BloatBenchmark.TRACE;
        if (!BloatBenchmark.VERIFY) {
          EDU.purdue.cs.bloat.optimize.Main.VERIFY = false;
        }
        EDU.purdue.cs.bloat.optimize.Main.bloatMethod(live, context);

      } catch (final Exception oops) {
        BloatBenchmark.err.println("******************************************");
        BloatBenchmark.err.println(
            "Exception while BLOATing "
                + live.declaringClass().name()
                + "."
                + live.name()
                + live.type());
        BloatBenchmark.err.println(oops.getMessage());
        oops.printStackTrace(System.err);
        BloatBenchmark.err.println("******************************************");
      }

      // Commit here in an attempt to conserve memory
      context.commit(live.methodInfo());
      context.release(live.methodInfo());

      if (prevClass == null) {
        prevClass = ce;

      } else if (!prevClass.equals(ce)) {
        // We've finished BLOATed the methods for prevClass, commit
        // prevClass and move on
        BloatBenchmark.tr(prevClass.type() + " != " + ce.type());
        context.commit(prevClass.classInfo());
        context.release(prevClass.classInfo());
        // context.commitDirty();
        // tr(context.toString());
        prevClass = ce;

      } else {
        context.release(ce.classInfo());
      }

      final Date end = new Date();
      BloatBenchmark.tr("    Ellapsed time: " + (end.getTime() - start.getTime()) + " ms");
    }

    context.commitDirty();
  }