Merge pull request #3385 from xeno-by/ticket/8158

fixes some typos and types

6 files changed, 43 insertions, 18 deletions

diff --git a/src/compiler/scala/tools/reflect/quasiquotes/Quasiquotes.scala b/src/compiler/scala/tools/reflect/quasiquotes/Quasiquotes.scala
index 7d777ef7d5..3e703924e8 100644
--- a/src/compiler/scala/tools/reflect/quasiquotes/Quasiquotes.scala
+++ b/src/compiler/scala/tools/reflect/quasiquotes/Quasiquotes.scala
@@ -11,7 +11,7 @@ abstract class Quasiquotes extends Parsers
   val global: c.universe.type = c.universe
   import c.universe._
 
-  def debug(msg: String): Unit =
+  def debug(msg: => String): Unit =
     if (settings.Yquasiquotedebug.value) println(msg)
 
   lazy val (universe: Tree, args, parts, parse, reify, method) = c.macroApplication match {
@@ -48,7 +48,7 @@ abstract class Quasiquotes extends Parsers
     val tree = parse(code)
     debug(s"parsed:\n${showRaw(tree)}\n$tree\n")
     val reified = reify(tree)
-    val sreified =
+    def sreified =
       reified
         .toString
         .replace("scala.reflect.runtime.`package`.universe.build.", "")
diff --git a/src/reflect/scala/reflect/internal/Symbols.scala b/src/reflect/scala/reflect/internal/Symbols.scala
index c2689fe7e9..f49ddaf6ca 100644
--- a/src/reflect/scala/reflect/internal/Symbols.scala
+++ b/src/reflect/scala/reflect/internal/Symbols.scala
@@ -2519,6 +2519,10 @@ trait Symbols extends api.Symbols { self: SymbolTable =>
         if (settings.debug.value) parentsString(tp.parents)
         else briefParentsString(tp.parents)
       )
+      def isStructuralThisType = (
+        // prevents disasters like SI-8158
+        owner.isInitialized && owner.isStructuralRefinement && tp == owner.tpe
+      )
       if (isType) typeParamsString(tp) + (
         if (isClass) " extends " + parents
         else if (isAliasType) " = " + tp.resultType
@@ -2529,10 +2533,11 @@ trait Symbols extends api.Symbols { self: SymbolTable =>
       )
       else if (isModule) "" //  avoid "object X of type X.type"
       else tp match {
-        case PolyType(tparams, res)  => typeParamsString(tp) + infoString(res)
-        case NullaryMethodType(res)  => infoString(res)
-        case MethodType(params, res) => valueParamsString(tp) + infoString(res)
-        case _                       => ": " + tp
+        case PolyType(tparams, res)    => typeParamsString(tp) + infoString(res)
+        case NullaryMethodType(res)    => infoString(res)
+        case MethodType(params, res)   => valueParamsString(tp) + infoString(res)
+        case _ if isStructuralThisType => ": " + owner.name
+        case _                         => ": " + tp
       }
     }
 
diff --git a/src/reflect/scala/reflect/internal/Types.scala b/src/reflect/scala/reflect/internal/Types.scala
index d0c322ca6b..92beffb761 100644
--- a/src/reflect/scala/reflect/internal/Types.scala
+++ b/src/reflect/scala/reflect/internal/Types.scala
@@ -1456,7 +1456,7 @@ trait Types
 
     override def safeToString = scalaNotation(_.toString)
 
-    /** Bounds notation used in Scala sytanx.
+    /** Bounds notation used in Scala syntax.
       * For example +This <: scala.collection.generic.Sorted[K,This].
       */
     private[internal] def scalaNotation(typeString: Type => String): String = {
diff --git a/src/reflect/scala/reflect/internal/tpe/TypeToStrings.scala b/src/reflect/scala/reflect/internal/tpe/TypeToStrings.scala
index ebc4394d25..a062fc8209 100644
--- a/src/reflect/scala/reflect/internal/tpe/TypeToStrings.scala
+++ b/src/reflect/scala/reflect/internal/tpe/TypeToStrings.scala
@@ -3,19 +3,29 @@ package reflect
 package internal
 package tpe
 
+import scala.collection.mutable.HashSet
+
 private[internal] trait TypeToStrings {
   self: SymbolTable =>
 
   /** The maximum number of recursions allowed in toString
     */
-  final val maxTostringRecursions = 50
+  final val maxToStringRecursions = 50
+
+  private var _toStringRecursions = 0
+  def toStringRecursions = _toStringRecursions
+  def toStringRecursions_=(value: Int) = _toStringRecursions = value
 
-  private var _tostringRecursions = 0
-  def tostringRecursions = _tostringRecursions
-  def tostringRecursions_=(value: Int) = _tostringRecursions = value
+  private var _toStringSubjects = HashSet[Type]()
+  def toStringSubjects = _toStringSubjects
 
   protected def typeToString(tpe: Type): String =
-    if (tostringRecursions >= maxTostringRecursions) {
+    // if (toStringSubjects contains tpe) {
+    //   // handles self-referential anonymous classes and who knows what else
+    //   "..."
+    // }
+    // else
+    if (toStringRecursions >= maxToStringRecursions) {
       devWarning("Exceeded recursion depth attempting to print " + util.shortClassOfInstance(tpe))
       if (settings.debug)
         (new Throwable).printStackTrace
@@ -24,9 +34,15 @@ private[internal] trait TypeToStrings {
     }
     else
       try {
-        tostringRecursions += 1
+        toStringRecursions += 1
+        // TODO: study performance impact of this cache
+        // to quote Jason:
+        //   I'm a little uneasy with the performance impact of the fail-safe. We end up calling Type#toString
+        //   when we generate error messages, including, importantly, errors issued during silent mode that are never issued.
+        // toStringSubjects += tpe
         tpe.safeToString
       } finally {
-        tostringRecursions -= 1
+        // toStringSubjects -= tpe
+        toStringRecursions -= 1
       }
 }
diff --git a/src/reflect/scala/reflect/runtime/JavaUniverseForce.scala b/src/reflect/scala/reflect/runtime/JavaUniverseForce.scala
index 6b3985d434..9224749864 100644
--- a/src/reflect/scala/reflect/runtime/JavaUniverseForce.scala
+++ b/src/reflect/scala/reflect/runtime/JavaUniverseForce.scala
@@ -41,7 +41,8 @@ trait JavaUniverseForce { self: runtime.JavaUniverse  =>
     // inaccessible: this._lubResults
     // inaccessible: this._glbResults
     // inaccessible: this._indent
-    // inaccessible: this._tostringRecursions
+    // inaccessible: this._toStringRecursions
+    // inaccessible: this._toStringSubjects
     // inaccessible: this.atomicIds
     // inaccessible: this.atomicExistentialIds
     // inaccessible: this._recursionTable
diff --git a/src/reflect/scala/reflect/runtime/SynchronizedTypes.scala b/src/reflect/scala/reflect/runtime/SynchronizedTypes.scala
index de78e527a7..83d471f91e 100644
--- a/src/reflect/scala/reflect/runtime/SynchronizedTypes.scala
+++ b/src/reflect/scala/reflect/runtime/SynchronizedTypes.scala
@@ -81,9 +81,12 @@ private[reflect] trait SynchronizedTypes extends internal.Types { self: SymbolTa
   override def indent = _indent.get
   override def indent_=(value: String) = _indent.set(value)
 
-  private lazy val _tostringRecursions = mkThreadLocalStorage(0)
-  override def tostringRecursions = _tostringRecursions.get
-  override def tostringRecursions_=(value: Int) = _tostringRecursions.set(value)
+  private lazy val _toStringRecursions = mkThreadLocalStorage(0)
+  override def toStringRecursions = _toStringRecursions.get
+  override def toStringRecursions_=(value: Int) = _toStringRecursions.set(value)
+
+  private lazy val _toStringSubjects = mkThreadLocalStorage(new mutable.HashSet[Type])
+  override def toStringSubjects = _toStringSubjects.get
 
   /* The idea of caches is as follows.
    * When in reflexive mode, a cache is either null, or one sentinal