Merge pull request scala#6045 from som-snytt/issue/banner

Opt-in REPL banner

project/VersionUtil.scala

@@ -1,6 +1,6 @@
 package scala.build
 
-import sbt._
+import sbt.{stringToProcess => _, _}
 import Keys._
 import java.util.{Date, Locale, Properties, TimeZone}
 import java.io.{File, FileInputStream}
@@ -11,6 +11,7 @@ import BuildSettings.autoImport._
 
 object VersionUtil {
   lazy val copyrightString = settingKey[String]("Copyright string.")
+  lazy val shellWelcomeString = settingKey[String]("Shell welcome banner string.")
   lazy val versionProperties = settingKey[Versions]("Version properties.")
   lazy val gitProperties = settingKey[GitProperties]("Current git information")
   lazy val buildCharacterPropertiesFile = settingKey[File]("The file which gets generated by generateBuildCharacterPropertiesFile")
@@ -27,6 +28,12 @@ object VersionUtil {
 
   lazy val generatePropertiesFileSettings = Seq[Setting[_]](
     copyrightString := "Copyright 2002-2017, LAMP/EPFL and Lightbend, Inc.",
+    shellWelcomeString := """
+      |     ________ ___   / /  ___  
+      |    / __/ __// _ | / /  / _ | 
+      |  __\ \/ /__/ __ |/ /__/ __ | 
+      | /____/\___/_/ |_/____/_/ | | 
+      |                          |/  %s""".stripMargin.lines.drop(1).map(s => s"${ "%n" }${ s }").mkString,
     resourceGenerators in Compile += generateVersionPropertiesFile.map(file => Seq(file)).taskValue,
     generateVersionPropertiesFile := generateVersionPropertiesFileImpl.value
   )
@@ -135,7 +142,10 @@ object VersionUtil {
   }
 
   private lazy val generateVersionPropertiesFileImpl: Def.Initialize[Task[File]] = Def.task {
-    writeProps(versionProperties.value.toMap + ("copyright.string" -> copyrightString.value),
+    writeProps(versionProperties.value.toMap ++ Seq(
+        "copyright.string" -> copyrightString.value,
+        "shell.welcome"    -> shellWelcomeString.value
+      ),
       (resourceManaged in Compile).value / s"${thisProject.value.id}.properties")
   }
 

src/compiler/scala/tools/nsc/GenericRunnerCommand.scala

@@ -63,38 +63,41 @@ s"""|Usage: $cmdName <options> [<script|class|object|jar> <arguments>]
 """.stripMargin
 
   override def usageMsg = f"""$shortUsageMsg
-The first given argument other than options to $cmdName designates
-what to run.  Runnable targets are:
+The first argument to $cmdName after the options designates what to run.
 
-  - a file containing scala source
-  - the name of a compiled class
-  - a runnable jar file with a valid Main-Class attribute
-  - or if no argument is given, the repl (interactive shell) is started
+If no argument is given, the Scala REPL, an interactive shell, is started.
 
-Options to $cmdName which reach the java runtime:
+Otherwise, the Scala runner will try to run the named target, either as
+a compiled class with a main method, a jar file with a Main-Class manifest
+header, or as a Scala source file to compile and run.
 
- -Dname=prop  passed directly to java to set system properties
- -J<arg>      -J is stripped and <arg> passed to java as-is
- -nobootcp    do not put the scala jars on the boot classpath (slower)
+The REPL accepts expressions to evaluate. Try `:help` to see more commands.
+
+The script runner will invoke the main method of a top-level object if
+it finds one; otherwise, the script code is run locally to a synthetic
+main method with arguments available in a variable `args`.
+
+Options to $cmdName which reach the Java runtime:
+
+ -Dname=prop  passed directly to Java to set system properties
+ -J<arg>      -J is stripped and <arg> passed to Java as-is
+ -nobootcp    do not put the Scala jars on the boot classpath (slower)
 
 Other startup options:
 
- -howtorun    what to run <script|object|jar|guess> (default: guess)
- -i <file>    preload <file> before starting the repl
+ -i <file>    preload <file> before starting the REPL
  -I <file>    preload <file>, enforcing line-by-line interpretation
- -e <string>  execute <string> as if entered in the repl
+ -e <string>  execute <string> as if entered in the REPL
  -save        save the compiled script in a jar for future use
  -nc          no compilation daemon: do not use the fsc offline compiler
 
-A file argument will be run as a scala script unless it contains only
-self-contained compilation units (classes and objects) and exactly one
-runnable main method.  In that case the file will be compiled and the
-main method invoked.  This provides a bridge between scripts and standard
-scala source.
+If the runner does not correctly guess how to run the target:
+
+ -howtorun    what to run <script|object|jar|guess> (default: guess)
 
 When running a script or using -e, an already running compilation daemon
-(fsc) is used, or a new one started on demand.  The -nc option can be
-used to prevent this.%n"""
+(fsc) is used, or a new one started on demand.  Use the -nc option to
+create a fresh compiler instead.%n"""
 }
 
 object GenericRunnerCommand {

src/repl/scala/tools/nsc/interpreter/ILoop.scala

@@ -1061,6 +1061,8 @@ class ILoop(in0: Option[BufferedReader], protected val out: JPrintWriter) extend
           }
           line
         }
+      } catch {
+        case t: Throwable => t.printStackTrace() ; scala.sys.exit(1)
       } finally splash.stop()
     }
     this.settings = settings

src/repl/scala/tools/nsc/interpreter/IMain.scala

@@ -1285,7 +1285,7 @@ object IMain {
     def isStripping        = isettings.unwrapStrings
     def isTruncating       = reporter.truncationOK
 
-    def stripImpl(str: String): String = naming.unmangle(str)
+    def stripImpl(str: String): String = if (isInitializeComplete) naming.unmangle(str) else str
   }
   private[interpreter] def defaultSettings = new Settings()
   private[scala] def defaultOut = new NewLinePrintWriter(new ConsoleWriter, true)

src/repl/scala/tools/nsc/interpreter/InteractiveReader.scala

@@ -111,6 +111,7 @@ class SplashLoop(reader: InteractiveReader, prompt: String) extends Runnable {
   def start(): Unit = result.synchronized {
     require(thread == null, "Already started")
     thread = new Thread(this)
+    thread.setDaemon(true)
     running = true
     thread.start()
   }

src/repl/scala/tools/nsc/interpreter/ReplProps.scala

@@ -6,11 +6,11 @@
 package scala.tools.nsc
 package interpreter
 
-import Properties.{ javaVersion, javaVmName, shellPromptString, shellWelcomeString,
-                    versionString, versionNumberString }
+import Properties.{javaVersion, javaVmName, shellPromptString, shellWelcomeString,
+                    versionString, versionNumberString}
 import scala.sys._
 import Prop._
-import java.util.{ Formattable, FormattableFlags, Formatter }
+import java.util.{Formattable, FormattableFlags, Formatter}
 
 class ReplProps {
   private def bool(name: String) = BooleanProp.keyExists(name)
@@ -57,11 +57,15 @@ class ReplProps {
   }
   val continuePrompt = encolor(continueText)
 
-  // Next time.
-  //def welcome = enversion(Prop[String]("scala.repl.welcome") or shellWelcomeString)
+  // -Dscala.repl.welcome=banner uses shell.welcome property
   def welcome = enversion {
     val p = Prop[String]("scala.repl.welcome")
-    if (p.isSet) p.get else shellWelcomeString
+    if (p.isSet) p.get match {
+      case "banner" => shellWelcomeString
+      case text     => text
+    } else
+      """Welcome to Scala %1$#s (%3$s, Java %2$s).
+        |Type in expressions for evaluation. Or try :help.""".stripMargin
   }
 
   val pasteDelimiter = Prop[String]("scala.repl.here")