Scala example source code file (IcodeComparison.scala)

This example Scala source code file (IcodeComparison.scala) is included in my "Source Code Warehouse" project. The intent of this project is to help you more easily find Scala source code examples by using tags.

All credit for the original source code belongs to scala-lang.org; I'm just trying to make examples easier to find. (For my Scala work, see my Scala examples and tutorials.)

Scala tags/keywords

directtest, eol, icodecomparison, list, parallel, string, xprint-icode

The IcodeComparison.scala Scala example source code

/* NSC -- new Scala compiler
 * Copyright 2005-2013 LAMP/EPFL
 * @author Paul Phillips
 */

package scala.tools.partest

import scala.tools.partest.nest.FileManager.compareContents

/** A class for testing icode.  All you need is this in a
 *  partest source file --
 *  {{{
 *    object Test extends IcodeComparison
 *  }}}
 *  -- and the generated output will be the icode for everything
 *  in that file.  See scaladoc for possible customizations.
 *  TODO promote me to partest
 */
abstract class IcodeComparison extends DirectTest {
  /** The phase after which icode is printed.
   *  Override to check icode at a different point,
   *  but you can't print at a phase that is not enabled
   *  in this compiler run. Defaults to "icode".
   */
  def printIcodeAfterPhase = "icode"

  /** When comparing the output of two phases, this is
   *  the other phase of interest, normally the preceding
   *  phase.  Defaults to "icode" for tests of optimizer phases.
   */
  def printSuboptimalIcodeAfterPhase = "icode"

  /** The source code to compile defaults to the test file.
   *  I.e., the test file compiles itself. For a comparison,
   *  the test file will be compiled three times.
   */
  def code = testPath.slurp()

  /** By default, the test code is compiled with -usejavacp. */
  override def extraSettings: String = "-usejavacp"

  /** Compile the test code and return the contents of all
   *  (sorted) .icode files, which are immediately deleted.
   *  @param arg0 at least one arg is required
   *  @param args must include -Xprint-icode:phase
   */
  def collectIcode(arg0: String, args: String*): List[String] = {
    compile("-d" :: testOutput.path :: arg0 :: args.toList : _*)
    val icodeFiles = testOutput.files.toList filter (_ hasExtension "icode")

    try     icodeFiles sortBy (_.name) flatMap (f => f.lines.toList)
    finally icodeFiles foreach (f => f.delete())
  }

  /** Collect icode at the default phase, `printIcodeAfterPhase`. */
  def collectIcode(): List[String] = collectIcode(s"-Xprint-icode:$printIcodeAfterPhase")

  /** Default show is showComparison. May be overridden for showIcode or similar. */
  def show() = showComparison()

  /** Compile the test code with and without optimization, and
   *  then print the diff of the icode.
   */
  def showComparison() = {
    val lines1 = collectIcode(s"-Xprint-icode:$printSuboptimalIcodeAfterPhase")
    val lines2 = collectIcode("-optimise", s"-Xprint-icode:$printIcodeAfterPhase")

    println(compareContents(lines1, lines2))
  }

  /** Print icode at the default phase, `printIcodeAfterPhase`. */
  def showIcode() = println(collectIcode() mkString EOL)
}