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Scala example source code file (PathResolver.scala)
The Scala PathResolver.scala source code/* NSC -- new Scala compiler * Copyright 2006-2011 LAMP/EPFL * @author Paul Phillips */ package scala.tools package util import java.net.{ URL, MalformedURLException } import scala.tools.reflect.WrappedProperties.AccessControl import nsc.{ Settings, GenericRunnerSettings } import nsc.util.{ ClassPath, JavaClassPath, ScalaClassLoader } import nsc.io.{ File, Directory, Path, AbstractFile } import ClassPath.{ JavaContext, DefaultJavaContext, join, split } import PartialFunction.condOpt // Loosely based on the draft specification at: // https://lampsvn.epfl.ch/trac/scala/wiki/Classpath object PathResolver { // Imports property/environment functions which suppress // security exceptions. import AccessControl._ def firstNonEmpty(xs: String*) = xs find (_ != "") getOrElse "" /** Map all classpath elements to absolute paths and reconstruct the classpath. */ def makeAbsolute(cp: String) = ClassPath.map(cp, x => Path(x).toAbsolute.path) /** pretty print class path */ def ppcp(s: String) = split(s) match { case Nil => "" case Seq(x) => x case xs => xs map ("\n" + _) mkString } /** Values found solely by inspecting environment or property variables. */ object Environment { private def searchForBootClasspath = ( systemProperties find (_._1 endsWith ".boot.class.path") map (_._2) getOrElse "" ) /** Environment variables which java pays attention to so it * seems we do as well. */ def classPathEnv = envOrElse("CLASSPATH", "") def sourcePathEnv = envOrElse("SOURCEPATH", "") def javaBootClassPath = propOrElse("sun.boot.class.path", searchForBootClasspath) def javaExtDirs = propOrEmpty("java.ext.dirs") def scalaHome = propOrEmpty("scala.home") def scalaExtDirs = propOrEmpty("scala.ext.dirs") /** The java classpath and whether to use it. */ def javaUserClassPath = propOrElse("java.class.path", "") def useJavaClassPath = propOrFalse("scala.usejavacp") override def toString = """ |object Environment { | scalaHome = %s (useJavaClassPath = %s) | javaBootClassPath = <%d chars> | javaExtDirs = %s | javaUserClassPath = %s | scalaExtDirs = %s |}""".trim.stripMargin.format( scalaHome, useJavaClassPath, javaBootClassPath.length, ppcp(javaExtDirs), ppcp(javaUserClassPath), ppcp(scalaExtDirs) ) } /** Default values based on those in Environment as interpreted according * to the path resolution specification. */ object Defaults { /* Against my better judgment, giving in to martin here and allowing * CLASSPATH as the default if no -cp is given. Only if there is no * command line option or environment variable is "." used. */ def scalaUserClassPath = firstNonEmpty(Environment.classPathEnv, ".") def scalaSourcePath = Environment.sourcePathEnv def javaBootClassPath = Environment.javaBootClassPath def javaUserClassPath = Environment.javaUserClassPath def javaExtDirs = Environment.javaExtDirs def useJavaClassPath = Environment.useJavaClassPath def scalaHome = Environment.scalaHome def scalaHomeDir = Directory(scalaHome) def scalaHomeExists = scalaHomeDir.isDirectory def scalaLibDir = Directory(scalaHomeDir / "lib") def scalaClassesDir = Directory(scalaHomeDir / "classes") def scalaLibAsJar = File(scalaLibDir / "scala-library.jar") def scalaLibAsDir = Directory(scalaClassesDir / "library") def scalaLibDirFound: Option[Directory] = if (scalaLibAsJar.isFile) Some(scalaLibDir) else if (scalaLibAsDir.isDirectory) Some(scalaClassesDir) else None def scalaLibFound = if (scalaLibAsJar.isFile) scalaLibAsJar.path else if (scalaLibAsDir.isDirectory) scalaLibAsDir.path else "" // XXX It must be time for someone to figure out what all these things // are intended to do. This is disabled here because it was causing all // the scala jars to end up on the classpath twice: one on the boot // classpath as set up by the runner (or regular classpath under -nobootcp) // and then again here. def scalaBootClassPath = "" // scalaLibDirFound match { // case Some(dir) if scalaHomeExists => // val paths = ClassPath expandDir dir.path // join(paths: _*) // case _ => "" // } def scalaExtDirs = Environment.scalaExtDirs def scalaPluginPath = (scalaHomeDir / "misc" / "scala-devel" / "plugins").path override def toString = """ |object Defaults { | scalaHome = %s | javaBootClassPath = %s | scalaLibDirFound = %s | scalaLibFound = %s | scalaBootClassPath = %s | scalaPluginPath = %s |}""".trim.stripMargin.format( scalaHome, ppcp(javaBootClassPath), scalaLibDirFound, scalaLibFound, ppcp(scalaBootClassPath), ppcp(scalaPluginPath) ) } def fromPathString(path: String, context: JavaContext = DefaultJavaContext): JavaClassPath = { val s = new Settings() s.classpath.value = path new PathResolver(s, context) result } /** With no arguments, show the interesting values in Environment and Defaults. * If there are arguments, show those in Calculated as if those options had been * given to a scala runner. */ def main(args: Array[String]): Unit = { if (args.isEmpty) { println(Environment) println(Defaults) } else { val settings = new Settings() val rest = settings.processArguments(args.toList, false)._2 val pr = new PathResolver(settings) println(" COMMAND: 'scala %s'".format(args.mkString(" "))) println("RESIDUAL: 'scala %s'\n".format(rest.mkString(" "))) pr.result.show } } } import PathResolver.{ Defaults, Environment, firstNonEmpty, ppcp } class PathResolver(settings: Settings, context: JavaContext) { def this(settings: Settings) = this(settings, if (settings.inline.value) new JavaContext else DefaultJavaContext) private def cmdLineOrElse(name: String, alt: String) = { (commandLineFor(name) match { case Some("") => None case x => x }) getOrElse alt } private def commandLineFor(s: String): Option[String] = condOpt(s) { case "javabootclasspath" => settings.javabootclasspath.value case "javaextdirs" => settings.javaextdirs.value case "bootclasspath" => settings.bootclasspath.value case "extdirs" => settings.extdirs.value case "classpath" | "cp" => settings.classpath.value case "sourcepath" => settings.sourcepath.value } /** Calculated values based on any given command line options, falling back on * those in Defaults. */ object Calculated { def scalaHome = Defaults.scalaHome def useJavaClassPath = settings.usejavacp.value || Defaults.useJavaClassPath def javaBootClassPath = cmdLineOrElse("javabootclasspath", Defaults.javaBootClassPath) def javaExtDirs = cmdLineOrElse("javaextdirs", Defaults.javaExtDirs) def javaUserClassPath = if (useJavaClassPath) Defaults.javaUserClassPath else "" def scalaBootClassPath = cmdLineOrElse("bootclasspath", Defaults.scalaBootClassPath) def scalaExtDirs = cmdLineOrElse("extdirs", Defaults.scalaExtDirs) def userClassPath = cmdLineOrElse("classpath", Defaults.scalaUserClassPath) def sourcePath = cmdLineOrElse("sourcepath", Defaults.scalaSourcePath) import context._ // Assemble the elements! def basis = List[Traversable[ClassPath[AbstractFile]]]( classesInPath(javaBootClassPath), // 1. The Java bootstrap class path. contentsOfDirsInPath(javaExtDirs), // 2. The Java extension class path. classesInExpandedPath(javaUserClassPath), // 3. The Java application class path. classesInPath(scalaBootClassPath), // 4. The Scala boot class path. contentsOfDirsInPath(scalaExtDirs), // 5. The Scala extension class path. classesInExpandedPath(userClassPath), // 6. The Scala application class path. sourcesInPath(sourcePath) // 7. The Scala source path. ) lazy val containers = basis.flatten.distinct override def toString = """ |object Calculated { | scalaHome = %s | javaBootClassPath = %s | javaExtDirs = %s | javaUserClassPath = %s | useJavaClassPath = %s | scalaBootClassPath = %s | scalaExtDirs = %s | userClassPath = %s | sourcePath = %s |}""".trim.stripMargin.format( scalaHome, ppcp(javaBootClassPath), ppcp(javaExtDirs), ppcp(javaUserClassPath), useJavaClassPath, ppcp(scalaBootClassPath), ppcp(scalaExtDirs), ppcp(userClassPath), ppcp(sourcePath) ) } def containers = Calculated.containers lazy val result = { val cp = new JavaClassPath(containers.toIndexedSeq, context) if (settings.Ylogcp.value) { Console.println("Classpath built from " + settings.toConciseString) Console.println("Defaults: " + PathResolver.Defaults) Console.println("Calculated: " + Calculated) val xs = (Calculated.basis drop 2).flatten.distinct println("After java boot/extdirs classpath has %d entries:" format xs.size) xs foreach (x => println(" " + x)) } cp } def asURLs = result.asURLs } Other Scala examples (source code examples)Here is a short list of links related to this Scala PathResolver.scala source code file: |
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