SI-10120 ReplReporter handles message indent

Instead of indenting source code to make messages
align on output, let the reporter add indentation,
only if the source is the console (and not a pastie
or a loaded file).

Previously, syntax errors were not indented.

```
$ skala
Welcome to Scala 2.12.2-20170108-010722-939abf1 (Java HotSpot(TM) 64-Bit Server VM, Java 1.8.0_111).
Type in expressions for evaluation. Or try :help.

scala> 'abc'
<console>:1: error: unclosed character literal (or use " for string literal "abc")
       'abc'
           ^

scala> :quit
$ scala
Welcome to Scala 2.12.1 (Java HotSpot(TM) 64-Bit Server VM, Java 1.8.0_111).
Type in expressions for evaluation. Or try :help.

scala> 'abc'
<console>:1: error: unclosed character literal
'abc'
    ^
```

Author: som-snytt

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

@@ -111,11 +111,8 @@ class IMain(initialSettings: Settings, protected val out: JPrintWriter) extends
     try body finally label = saved
   }
 
-  // the expanded prompt but without color escapes and without leading newline, for purposes of indenting
-  lazy val formatting = Formatting.forPrompt(replProps.promptText)
   lazy val reporter: ReplReporter = new ReplReporter(this)
 
-  import formatting.indentCode
   import reporter.{ printMessage, printUntruncatedMessage }
 
   // This exists mostly because using the reporter too early leads to deadlock.
@@ -867,8 +864,8 @@ class IMain(initialSettings: Settings, protected val out: JPrintWriter) extends
         |${preambleHeader format lineRep.readName}
         |${envLines mkString ("  ", ";\n  ", ";\n")}
         |$importsPreamble
-        |${indentCode(toCompute)}""".stripMargin
-      def preambleLength = preamble.length - toCompute.length - 1
+        |${toCompute}""".stripMargin
+      def preambleLength = preamble.length - toCompute.length
 
       val generate = (m: MemberHandler) => m extraCodeToEvaluate Request.this
 

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

@@ -9,7 +9,7 @@ package interpreter
 import reporters._
 import IMain._
 
-import scala.reflect.internal.util.Position
+import scala.reflect.internal.util.{OffsetPosition, Position}
 
 /** Like ReplGlobal, a layer for ensuring extra functionality.
  */
@@ -40,14 +40,25 @@ class ReplReporter(intp: IMain) extends ConsoleReporter(intp.settings, Console.i
     case INFO    => RESET
   }
 
+  private val promptLength = replProps.promptText.lines.toList.last.length
+  private val indentation  = " " * promptLength
+
+  // colorized console labels
+  override protected def clabel(severity: Severity): String = {
+    val label0 = super.clabel(severity)
+    if (replProps.colorOk) s"${severityColor(severity)}${label0}${RESET}" else label0
+  }
+
+  // shift indentation for source text entered at prompt
   override def print(pos: Position, msg: String, severity: Severity) {
-    val prefix = (
-      if (replProps.colorOk)
-        severityColor(severity) + clabel(severity) + RESET
-      else
-        clabel(severity)
-    )
-    printMessage(pos, prefix + msg)
+    val adjusted =
+      if (pos.source.file.name == "<console>")
+        new OffsetPosition(pos.source, pos.offset.getOrElse(0)) {
+          override def lineContent = s"${indentation}${super.lineContent}"
+          override def lineCaret   = s"${indentation}${super.lineCaret}"
+        }
+      else pos
+    super.print(adjusted, msg, severity)
   }
 
   override def printMessage(msg: String) {
@@ -63,12 +74,8 @@ class ReplReporter(intp: IMain) extends ConsoleReporter(intp.settings, Console.i
     else Console.println("[init] " + msg)
   }
 
-  override def displayPrompt() {
-    if (intp.totalSilence) ()
-    else super.displayPrompt()
-  }
+  override def displayPrompt() = if (!intp.totalSilence) super.displayPrompt()
 
   override def rerunWithDetails(setting: reflect.internal.settings.MutableSettings#Setting, name: String) =
     s"; for details, enable `:setting $name' or `:replay $name'"
-
 }

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

@@ -278,13 +278,13 @@ scala> // both of the following should abort immediately:
 
 scala> def x => y => z
 <console>:1: error: '=' expected but '=>' found.
-def x => y => z
-      ^
+       def x => y => z
+             ^
 
 scala> [1,2,3]
 <console>:1: error: illegal start of definition
-[1,2,3]
-^
+       [1,2,3]
+       ^
 
 scala> 
 

test/files/jvm/interpreter.check

@@ -15,7 +15,7 @@ scala> {
   }
   println(code.eval)
 }
-<console>:19: free term: Ident(TermName("x")) defined by res0  in <console>:18:14
+<console>:19: free term: Ident(TermName("x")) defined by res0  in <console>:18:7
          val code = reify {
                           ^
 2

test/files/run/reify_newimpl_22.check

@@ -14,7 +14,7 @@ scala> def foo[T]{
   }
   println(code.eval)
 }
-<console>:17: free type: Ident(TypeName("T")) defined by foo in <console>:16:16
+<console>:17: free type: Ident(TypeName("T")) defined by foo in <console>:16:9
          val code = reify {
                           ^
 foo: [T]=> Unit

test/files/run/reify_newimpl_23.check

@@ -5,7 +5,7 @@ scala> {
   val tt = implicitly[TypeTag[x.type]]
   println(tt)
 }
-<console>:15: free term: Ident(TermName("x")) defined by res0  in <console>:14:14
+<console>:15: free term: Ident(TermName("x")) defined by res0  in <console>:14:7
          val tt = implicitly[TypeTag[x.type]]
                             ^
 TypeTag[x.type]

test/files/run/reify_newimpl_25.check

@@ -4,7 +4,7 @@ scala> def foo[T]{
   val tt = implicitly[WeakTypeTag[List[T]]]
   println(tt)
 }
-<console>:13: free type: Ident(TypeName("T")) defined by foo in <console>:11:16
+<console>:13: free type: Ident(TypeName("T")) defined by foo in <console>:11:9
          val tt = implicitly[WeakTypeTag[List[T]]]
                             ^
 foo: [T]=> Unit

test/files/run/reify_newimpl_26.check

@@ -1,8 +1,8 @@
 
 scala> :type List[1, 2, 3]
 <console>:1: error: identifier expected but integer literal found.
-List[1, 2, 3]
-     ^
+       List[1, 2, 3]
+            ^
 
 scala> :type List(1, 2, 3)
 List[Int]
@@ -38,8 +38,8 @@ scala> :type protected lazy val f = 5
  Access to protected lazy value f not permitted because
  enclosing object $eval in package $line13 is not a subclass of
  object $iw where target is defined
-  lazy val $result = f
-                                           ^
+         lazy val $result = f
+                                                  ^
 
 scala> :type def f = 5
 => Int

test/files/run/repl-colon-type.check

@@ -5,3 +5,17 @@ Expected 41 lines, got 39
 -Type in expressions to have them evaluated.
 -Type :help for more information.
 
+@@ -14,4 +12,4 @@
+ <console>:1: error: illegal start of simple expression
+-- if (true) 1 else 2
+-  ^
++       - if (true) 1 else 2
++         ^
+ 
+@@ -19,4 +17,4 @@
+ <console>:1: error: ';' expected but integer literal found.
+-- - 1
+-    ^
++       - - 1
++           ^
+ 

test/files/run/t8918-unary-ids.check

@@ -48,8 +48,8 @@ object Y {
 def f[A](a: => A): Int at line 12 and
 def f[A](a: => Either[Exception,A]): Int at line 13
 have same type after erasure: (a: Function0)Int
-         def f[A](a: => Either[Exception, A]) = 2
-             ^
+  def f[A](a: => Either[Exception, A]) = 2
+      ^
 
 scala> :quit"""
 }

test/files/run/t9170.scala

@@ -96,7 +96,7 @@ class ScriptedTest {
   }
   @Test def `on compile error`(): Unit = {
     val engine = scripted
-    val err = "not found: value foo in def f = foo at line number 11 at column number 16"
+    val err = "not found: value foo in def f = foo at line number 11 at column number 9"
     assertThrows[ScriptException](engine.compile("def f = foo"), _ == err)
   }
 }