Merge pull request #2907 from paulp/pr/typetree-original-rangepos

Eliminate TypeTrees with null original.

2 files changed, 15 insertions, 24 deletions

diff --git a/src/compiler/scala/tools/nsc/transform/ExplicitOuter.scala b/src/compiler/scala/tools/nsc/transform/ExplicitOuter.scala
index 48263a496e..d6a6e027cb 100644
--- a/src/compiler/scala/tools/nsc/transform/ExplicitOuter.scala
+++ b/src/compiler/scala/tools/nsc/transform/ExplicitOuter.scala
@@ -373,16 +373,10 @@ abstract class ExplicitOuter extends InfoTransform
 
     /** The definition tree of the outer accessor of current class
      */
-    def outerAccessorDef: Tree = {
-      val outerAcc = outerAccessor(currentClass)
-      val rhs: Tree =
-        if (outerAcc.isDeferred) EmptyTree
-        else This(currentClass) DOT outerField(currentClass)
-
-      /*  If we don't re-type the tree, we see self-type related crashes like #266.
-       */
-      localTyper typed {
-        (DEF(outerAcc) withPos currentClass.pos withType null) === rhs
+    def outerAccessorDef: Tree = localTyper typed {
+      outerAccessor(currentClass) match {
+        case acc if acc.isDeferred => DefDef(acc, EmptyTree)
+        case acc                   => DefDef(acc, Select(This(currentClass), outerField(currentClass)))
       }
     }
 
@@ -404,12 +398,8 @@ abstract class ExplicitOuter extends InfoTransform
         else if (mixinPrefix.typeArgs.nonEmpty) gen.mkAttributedThis(mixinPrefix.typeSymbol)
         else gen.mkAttributedQualifier(mixinPrefix)
       )
-      localTyper typed {
-        (DEF(outerAcc) withPos currentClass.pos) === {
-          // Need to cast for nested outer refs in presence of self-types. See ticket #3274.
-          gen.mkCast(transformer.transform(path), outerAcc.info.resultType)
-        }
-      }
+      // Need to cast for nested outer refs in presence of self-types. See ticket #3274.
+      localTyper typed DefDef(outerAcc, gen.mkCast(transformer.transform(path), outerAcc.info.resultType))
     }
 
     /** The main transformation method */
diff --git a/src/compiler/scala/tools/nsc/typechecker/MethodSynthesis.scala b/src/compiler/scala/tools/nsc/typechecker/MethodSynthesis.scala
index 3a5845c8ca..263b5ad784 100644
--- a/src/compiler/scala/tools/nsc/typechecker/MethodSynthesis.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/MethodSynthesis.scala
@@ -397,6 +397,12 @@ trait MethodSynthesis {
         if (mods.isDeferred) basisSym
         else basisSym.getter(enclClass)
       )
+      // Range position errors ensue if we don't duplicate this in some
+      // circumstances (at least: concrete vals with existential types.)
+      private def tptOriginal = (
+        if (mods.isDeferred) tree.tpt                       // keep type tree of original abstract field
+        else tree.tpt.duplicate setPos tree.tpt.pos.focus   // focused position of original tpt
+      )
 
       override def derivedTree: DefDef = {
         // For existentials, don't specify a type for the getter, even one derived
@@ -407,16 +413,11 @@ trait MethodSynthesis {
         // starts compiling (instead of failing like it's supposed to) because the typer
         // expects to be able to identify escaping locals in typedDefDef, and fails to
         // spot that brand of them. In other words it's an artifact of the implementation.
-        val tpt = derivedSym.tpe.finalResultType match {
+        val tpt = atPos(derivedSym.pos.focus)(derivedSym.tpe.finalResultType match {
           case ExistentialType(_, _)  => TypeTree()
           case _ if mods.isDeferred   => TypeTree()
           case tp                     => TypeTree(tp)
-        }
-        tpt setPos derivedSym.pos.focus
-        // keep type tree of original abstract field
-        if (mods.isDeferred)
-          tpt setOriginal tree.tpt
-
+        })
         // TODO - reconcile this with the DefDef creator in Trees (which
         //   at this writing presented no way to pass a tree in for tpt.)
         atPos(derivedSym.pos) {
@@ -425,7 +426,7 @@ trait MethodSynthesis {
             derivedSym.name.toTermName,
             Nil,
             Nil,
-            tpt,
+            tpt setOriginal tptOriginal,
             if (mods.isDeferred) EmptyTree else fieldSelection
           ) setSymbol derivedSym
         }