splice in typed, dup'ed, trees for TRUE and FALSE

sharing trees is bad
also, substing in untyped trees into typed outer trees is not good for your health

3 files changed, 10 insertions, 5 deletions

diff --git a/src/compiler/scala/tools/nsc/ast/TreeDSL.scala b/src/compiler/scala/tools/nsc/ast/TreeDSL.scala
index 0d19b781e2..8703de4e18 100644
--- a/src/compiler/scala/tools/nsc/ast/TreeDSL.scala
+++ b/src/compiler/scala/tools/nsc/ast/TreeDSL.scala
@@ -44,6 +44,11 @@ trait TreeDSL {
     def NULL          = LIT(null)
     def UNIT          = LIT(())
 
+    // for those preferring boring, predictable lives, without the thrills of tree-sharing
+    // (but with the perk of typed trees)
+    def TRUE_typed  = LIT(true) setType ConstantType(Constant(true))
+    def FALSE_typed = LIT(false) setType ConstantType(Constant(false))
+
     object WILD {
       def empty               = Ident(nme.WILDCARD)
       def apply(tpe: Type)    = Ident(nme.WILDCARD) setType tpe
diff --git a/src/compiler/scala/tools/nsc/typechecker/PatMatVirtualiser.scala b/src/compiler/scala/tools/nsc/typechecker/PatMatVirtualiser.scala
index 2091221916..4c5719b33c 100644
--- a/src/compiler/scala/tools/nsc/typechecker/PatMatVirtualiser.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/PatMatVirtualiser.scala
@@ -918,10 +918,10 @@ class Foo(x: Other) { x._1 } // no error in this order
           // one alternative may still generate multiple trees (e.g., an extractor call + equality test)
           // (for now,) alternatives may not bind variables (except wildcards), so we don't care about the final substitution built internally by makeTreeMakers
           val combinedAlts = altss map (altTreeMakers =>
-            ((casegen: Casegen) => combineExtractors(altTreeMakers :+ TrivialTreeMaker(casegen.one(TRUE)))(casegen))
+            ((casegen: Casegen) => combineExtractors(altTreeMakers :+ TrivialTreeMaker(casegen.one(TRUE_typed)))(casegen))
           )
 
-          val findAltMatcher = codegenAlt.matcher(EmptyTree, NoSymbol, BooleanClass.tpe)(combinedAlts, Some(x => FALSE))
+          val findAltMatcher = codegenAlt.matcher(EmptyTree, NoSymbol, BooleanClass.tpe)(combinedAlts, Some(x => FALSE_typed))
           codegenAlt.ifThenElseZero(findAltMatcher, substitution(next))
         }
       }
@@ -1713,7 +1713,7 @@ class Foo(x: Other) { x._1 } // no error in this order
 
         def flatMapCondStored(cond: Tree, condSym: Symbol, res: Tree, nextBinder: Symbol, next: Tree): Tree =
           ifThenElseZero(cond, BLOCK(
-            condSym    === TRUE,
+            condSym    === TRUE_typed,
             nextBinder === res,
             next
           ))
diff --git a/src/compiler/scala/tools/nsc/typechecker/Typers.scala b/src/compiler/scala/tools/nsc/typechecker/Typers.scala
index b061f4cbc3..47d5107f18 100644
--- a/src/compiler/scala/tools/nsc/typechecker/Typers.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/Typers.scala
@@ -2203,7 +2203,7 @@ trait Typers extends Modes with Adaptations with PatMatVirtualiser {
       import CODE._
 
       // need to duplicate the cases before typing them to generate the apply method, or the symbols will be all messed up
-      val casesTrue = if (isPartial) cases map (c => deriveCaseDef(c)(x => TRUE).duplicate) else Nil
+      val casesTrue = if (isPartial) cases map (c => deriveCaseDef(c)(x => TRUE_typed).duplicate) else Nil
 
       val applyMethod = {
         // rig the show so we can get started typing the method body -- later we'll correct the infos...
@@ -2241,7 +2241,7 @@ trait Typers extends Modes with Adaptations with PatMatVirtualiser {
         methodSym setInfoAndEnter MethodType(paramSyms, BooleanClass.tpe)
 
         val (selector1, selectorTp, casesAdapted, resTp, doTranslation) = methodBodyTyper.prepareTranslateMatch(selector, casesTrue, mode, BooleanClass.tpe)
-        val body = methodBodyTyper.translateMatch(selector1, selectorTp, casesAdapted, resTp, doTranslation, Some(scrutinee => FALSE))
+        val body = methodBodyTyper.translateMatch(selector1, selectorTp, casesAdapted, resTp, doTranslation, Some(scrutinee => FALSE_typed))
 
         DefDef(methodSym, body)
       }