Some much needed housecleaning regarding system...

Some much needed housecleaning regarding system properties. If you can
possibly resist the temptation, it'd be great if people could try to
go through the properties classes to get and set them, and also to set
property values somewhere fixed rather than using strings directly.
Review by community.

9 files changed, 47 insertions, 51 deletions

diff --git a/src/compiler/scala/tools/nsc/CompileSocket.scala b/src/compiler/scala/tools/nsc/CompileSocket.scala
index 305c4e211d..8d599c6c96 100644
--- a/src/compiler/scala/tools/nsc/CompileSocket.scala
+++ b/src/compiler/scala/tools/nsc/CompileSocket.scala
@@ -23,13 +23,12 @@ class CompileSocket {
   /** The prefix of the port identification file, which is followed
    *  by the port number.
    */
-  protected def dirName = "scalac-compile-server-port" //todo: lazy val
-
-  protected def cmdName = Properties.cmdName //todo: lazy val
+  protected lazy val dirName = "scalac-compile-server-port"
+  protected lazy val cmdName = Properties.scalaCmd
 
   /** The vm part of the command to start a new scala compile server */
   protected val vmCommand = Properties.scalaHome match {
-    case null     => cmdName
+    case ""       => cmdName
     case dirname  =>
       val trial = File(dirname) / "bin" / cmdName
       if (trial.canRead) trial.path
diff --git a/src/compiler/scala/tools/nsc/CompilerCommand.scala b/src/compiler/scala/tools/nsc/CompilerCommand.scala
index a805da1fcc..dd581e0878 100644
--- a/src/compiler/scala/tools/nsc/CompilerCommand.scala
+++ b/src/compiler/scala/tools/nsc/CompilerCommand.scala
@@ -26,7 +26,8 @@ class CompilerCommand(
   lazy val fileEndings = Properties.fileEndings
 
   /** The name of the command */
-  val cmdName = "scalac"
+  def cmdName = "scalac"
+  private def isFsc = cmdName == "fsc"
 
   private val helpSyntaxColumnWidth: Int =
     (settings.visibleSettings map (_.helpSyntax.length)) max
@@ -53,8 +54,7 @@ class CompilerCommand(
   // an informative message of some sort should be printed instead.
   // (note: do not add "files.isEmpty" do this list)
   val stopSettings = List[(() => Boolean, (Global) => String)](
-    ((() => (settings.help.value _)() && (cmdName == "fsc")),
-                                    fscUsageMsg + _.pluginOptionsHelp),
+    ((() => (settings.help.value _)() && isFsc), fscUsageMsg + _.pluginOptionsHelp),
     (settings.help.value _,         usageMsg + _.pluginOptionsHelp),
     (settings.Xhelp.value _,        _ => xusageMsg),
     (settings.Yhelp.value _,        _ => yusageMsg),
diff --git a/src/compiler/scala/tools/nsc/InterpreterLoop.scala b/src/compiler/scala/tools/nsc/InterpreterLoop.scala
index b8e25c4bd4..1ef249735f 100644
--- a/src/compiler/scala/tools/nsc/InterpreterLoop.scala
+++ b/src/compiler/scala/tools/nsc/InterpreterLoop.scala
@@ -555,10 +555,8 @@ class InterpreterLoop(in0: Option[BufferedReader], out: PrintWriter) {
     in = in0 match {
       case Some(in0)  => new SimpleReader(in0, out, true)
       case None       =>
-        val emacsShell = System.getProperty("env.emacs", "") != ""
-
         // the interpreter is passed as an argument to expose tab completion info
-        if (settings.Xnojline.value || emacsShell) new SimpleReader
+        if (settings.Xnojline.value || Properties.isEmacsShell) new SimpleReader
         else if (settings.noCompletion.value) InteractiveReader.createDefault()
         else InteractiveReader.createDefault(interpreter)
     }
diff --git a/src/compiler/scala/tools/nsc/Main.scala b/src/compiler/scala/tools/nsc/Main.scala
index 577439990d..4f945733fd 100644
--- a/src/compiler/scala/tools/nsc/Main.scala
+++ b/src/compiler/scala/tools/nsc/Main.scala
@@ -7,6 +7,7 @@
 package scala.tools.nsc
 
 import java.io.File
+import File.pathSeparator
 
 import scala.concurrent.SyncVar
 
@@ -14,6 +15,7 @@ import scala.tools.nsc.interactive.{ RefinedBuildManager, SimpleBuildManager }
 import scala.tools.nsc.io.AbstractFile
 import scala.tools.nsc.reporters.{Reporter, ConsoleReporter}
 import scala.tools.nsc.util.{ BatchSourceFile, FakePos } //{Position}
+import Properties.{ versionString, copyrightString, residentPromptString, msilLibPath }
 
 /** The main class for NSC, a compiler for the programming
  *  language Scala.
@@ -21,10 +23,10 @@ import scala.tools.nsc.util.{ BatchSourceFile, FakePos } //{Position}
 object Main extends AnyRef with EvalLoop {
 
   val versionMsg = "Scala compiler " +
-    Properties.versionString + " -- " +
-    Properties.copyrightString
+    versionString + " -- " +
+    copyrightString
 
-  val prompt = Properties.residentPromptString
+  val prompt = residentPromptString
 
   var reporter: ConsoleReporter = _
 
@@ -82,12 +84,9 @@ object Main extends AnyRef with EvalLoop {
         buildManager.update(fileSet(command.files), Set.empty)
       }
     } else {
-      if (command.settings.target.value == "msil") {
-        val libpath = System.getProperty("msil.libpath")
-        if (libpath != null)
-          command.settings.assemrefs.value =
-            command.settings.assemrefs.value + File.pathSeparator + libpath
-      }
+      if (command.settings.target.value == "msil")
+        msilLibPath foreach (x => command.settings.assemrefs.value += (pathSeparator + x))
+
       try {
         val compiler = if (command.settings.Yrangepos.value) new interactive.Global(command.settings, reporter)
         else new Global(command.settings, reporter)
diff --git a/src/compiler/scala/tools/nsc/Properties.scala b/src/compiler/scala/tools/nsc/Properties.scala
index 8b30929092..346f5947cd 100644
--- a/src/compiler/scala/tools/nsc/Properties.scala
+++ b/src/compiler/scala/tools/nsc/Properties.scala
@@ -13,11 +13,14 @@ object Properties extends scala.util.PropertiesTrait {
   protected def pickJarBasedOn  = classOf[Global]
 
   // settings based on jar properties
-  def fileEndingString      = prop("file.ending", ".scala|.java")
-  def residentPromptString  = prop("resident.prompt", "\nnsc> ")
-  def shellPromptString     = prop("shell.prompt", "\nscala> ")
+  def fileEndingString      = scalaPropOrElse("file.ending", ".scala|.java")
+  def residentPromptString  = scalaPropOrElse("resident.prompt", "\nnsc> ")
+  def shellPromptString     = scalaPropOrElse("shell.prompt", "\nscala> ")
+
+  // settings based on system properties
+  def msilLibPath           = propOrNone("msil.libpath")
 
   // derived values
-  def cmdName               = if (isWin) "scala.bat" else "scala"
+  def isEmacsShell          = propIsSet("env.emacs")
   def fileEndings           = fileEndingString.split("""\|""").toList
 }
diff --git a/src/compiler/scala/tools/nsc/ScalaDoc.scala b/src/compiler/scala/tools/nsc/ScalaDoc.scala
index f3c7c686a0..4a9bbe8fd3 100644
--- a/src/compiler/scala/tools/nsc/ScalaDoc.scala
+++ b/src/compiler/scala/tools/nsc/ScalaDoc.scala
@@ -11,7 +11,8 @@ import java.io.File
 
 import scala.tools.nsc.reporters.{Reporter, ConsoleReporter}
 import scala.tools.nsc.util.FakePos //{Position}
-
+import Properties.msilLibPath
+import File.pathSeparator
 
 /** The main class for scaladoc, a front-end for the Scala compiler
  *  that generates documentation from source files.
@@ -56,11 +57,8 @@ object ScalaDoc {
         reporter.warning(null, "Phases are restricted when using Scaladoc")
       else try {
 
-        if (docSettings.target.value == "msil") {
-          val libpath = System.getProperty("msil.libpath")
-          if (libpath != null)
-            docSettings.assemrefs.value = docSettings.assemrefs.value + File.pathSeparator + libpath
-        }
+        if (docSettings.target.value == "msil")
+          msilLibPath foreach (x => docSettings.assemrefs.value += (pathSeparator + x))
 
         val docProcessor = new scala.tools.nsc.doc.DocFactory(reporter, docSettings)
         docProcessor.document(command.files)
diff --git a/src/compiler/scala/tools/nsc/interpreter/History.scala b/src/compiler/scala/tools/nsc/interpreter/History.scala
index 519d17f9d2..7bd4e89095 100644
--- a/src/compiler/scala/tools/nsc/interpreter/History.scala
+++ b/src/compiler/scala/tools/nsc/interpreter/History.scala
@@ -9,6 +9,7 @@ package interpreter
 import java.io.File
 import jline.{ ConsoleReader, History => JHistory }
 import scala.collection.JavaConversions.asBuffer
+import Properties.userHome
 
 /** Primarily, a wrapper for JLine's History.
  */
@@ -22,14 +23,13 @@ class History(val jhistory: JHistory) {
 
 object History {
   val ScalaHistoryFile = ".scala_history"
-  def homeDir = System.getProperty("user.home")
 
   def apply(reader: ConsoleReader): History =
     if (reader == null) apply()
     else new History(reader.getHistory)
 
   def apply(): History = new History(
-    try new JHistory(new File(homeDir, ScalaHistoryFile))
+    try new JHistory(new File(userHome, ScalaHistoryFile))
     // do not store history if error
     catch { case _: Exception => new JHistory() }
   )
diff --git a/src/compiler/scala/tools/nsc/io/Directory.scala b/src/compiler/scala/tools/nsc/io/Directory.scala
index 6a4e78560d..709ffdc1e0 100644
--- a/src/compiler/scala/tools/nsc/io/Directory.scala
+++ b/src/compiler/scala/tools/nsc/io/Directory.scala
@@ -14,11 +14,11 @@ import collection.Traversable
 
 object Directory
 {
-  import scala.util.Properties.{ tmpDir, homeDir, currentDir }
+  import scala.util.Properties.{ tmpDir, userHome, userDir }
 
   private def normalizePath(s: String) = Some(apply(Path(s).normalize))
-  def Current: Option[Directory]  = if (currentDir == "") None else normalizePath(currentDir)
-  def Home: Option[Directory]     = if (homeDir == "") None else normalizePath(homeDir)
+  def Current: Option[Directory]  = if (userDir == "") None else normalizePath(userDir)
+  def Home: Option[Directory]     = if (userHome == "") None else normalizePath(userHome)
   def TmpDir: Option[Directory]   = if (tmpDir == "") None else normalizePath(tmpDir)
 
   def apply(path: Path)       = path.toDirectory
diff --git a/src/compiler/scala/tools/util/PathResolver.scala b/src/compiler/scala/tools/util/PathResolver.scala
index 1a7c121d56..5c6bd2c884 100644
--- a/src/compiler/scala/tools/util/PathResolver.scala
+++ b/src/compiler/scala/tools/util/PathResolver.scala
@@ -7,6 +7,7 @@ package scala.tools
 package util
 
 import java.net.{ URL, MalformedURLException }
+import scala.util.Properties._
 import nsc.{ Settings, GenericRunnerSettings }
 import nsc.util.{ ClassPath, JavaClassPath, ScalaClassLoader }
 import nsc.io.{ File, Directory, Path }
@@ -17,8 +18,6 @@ import PartialFunction.condOpt
 // https://lampsvn.epfl.ch/trac/scala/wiki/Classpath
 
 object PathResolver {
-  def propOrElse(name: String, alt: String) = System.getProperty(name, alt)
-  def envOrElse(name: String, alt: String)  = Option(System getenv name) getOrElse alt
   def firstNonEmpty(xs: String*)            = xs find (_ != "") getOrElse ""
 
   private def fileOpt(f: Path): Option[String]      = f ifFile (_.path)
@@ -53,27 +52,26 @@ object PathResolver {
     def sourcePathEnv       =  envOrElse("SOURCEPATH", "")        // not used
     def scalaHomeEnv        =  envOrElse("SCALA_HOME", "")        // not used
     def javaBootClassPath   = propOrElse("sun.boot.class.path", searchForBootClasspath)
-    def javaUserClassPath   = propOrElse("java.class.path", "")
     def javaExtDirs         = propOrElse("java.ext.dirs", "")
-    def userHome            = propOrElse("user.home", "")
-    def scalaHome           = System.getProperty("scala.home")    // keep null so we know when it's unset
+    def javaUserClassPath   = propOrElse("java.class.path", classPathEnv)
     def scalaExtDirs        = propOrElse("scala.ext.dirs", "")
-    def scalaHomeGuessed    = searchForScalaHome
+
+    def scalaHome           = propOrElse("scala.home", null)
     def scalaHomeIsSet      = scalaHome != null
+    def scalaAutodetect     = propIsSet("scala.auto") && !propIsSet("scala.noauto")
 
     override def toString = """
       |object Environment {
+      |  scalaHome          = %s (autodetect = %s)
       |  javaBootClassPath  = <%d chars>
-      |  javaUserClassPath  = %s
       |  javaExtDirs        = %s
-      |  userHome           = %s
-      |  scalaHome          = %s
+      |  javaUserClassPath  = %s
       |  scalaExtDirs       = %s
       |}""".trim.stripMargin.format(
+        scalaHome, scalaAutodetect,
         javaBootClassPath.length,
-        ppcp(javaUserClassPath),
         ppcp(javaExtDirs),
-        userHome, scalaHome,
+        ppcp(javaUserClassPath),
         ppcp(scalaExtDirs)
       )
   }
@@ -116,15 +114,16 @@ object PathResolver {
 
     override def toString = """
       |object Defaults {
-      |  javaBootClassPath    = %s
       |  scalaHome            = %s
+      |  javaBootClassPath    = %s
       |  scalaLibDirFound     = %s
       |  scalaLibFound        = %s
       |  scalaBootClassPath   = %s
       |  scalaPluginPath      = %s
       |}""".trim.stripMargin.format(
+        scalaHome,
         ppcp(javaBootClassPath),
-        scalaHome, scalaLibDirFound, scalaLibFound,
+        scalaLibDirFound, scalaLibFound,
         ppcp(scalaBootClassPath), ppcp(scalaPluginPath)
       )
   }
@@ -207,17 +206,17 @@ class PathResolver(settings: Settings, context: JavaContext) {
       |object Calculated {
       |  scalaHome            = %s
       |  javaBootClassPath    = %s
+      |  javaExtDirs          = %s
       |  javaUserClassPath    = %s
       |  scalaBootClassPath   = %s
-      |  javaExtDirs          = %s
       |  scalaExtDirs         = %s
       |  userClassPath        = %s
       |  sourcePath           = %s
       |}""".trim.stripMargin.format(
         scalaHome,
-        ppcp(javaBootClassPath), ppcp(javaUserClassPath), ppcp(scalaBootClassPath),
-        ppcp(javaExtDirs), ppcp(scalaExtDirs),
-        ppcp(userClassPath), ppcp(sourcePath)
+        ppcp(javaBootClassPath), ppcp(javaExtDirs), ppcp(javaUserClassPath),
+        ppcp(scalaBootClassPath), ppcp(scalaExtDirs), ppcp(userClassPath),
+        ppcp(sourcePath)
       )
   }