Eliminate a bunch of -Xlint warnings.

Mostly unused private code, unused imports, and points where
an extra pair of parentheses is necessary for scalac to have
confidence in our intentions.

8 files changed, 19 insertions, 22 deletions

diff --git a/src/compiler/scala/tools/nsc/typechecker/ContextErrors.scala b/src/compiler/scala/tools/nsc/typechecker/ContextErrors.scala
index 0af75a2aad..86ee7939c8 100644
--- a/src/compiler/scala/tools/nsc/typechecker/ContextErrors.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/ContextErrors.scala
@@ -20,7 +20,6 @@ trait ContextErrors {
 
   import global._
   import definitions._
-  import treeInfo._
 
   object ErrorKinds extends Enumeration {
     type ErrorKind = Value
diff --git a/src/compiler/scala/tools/nsc/typechecker/Contexts.scala b/src/compiler/scala/tools/nsc/typechecker/Contexts.scala
index 429bd7d682..836e0c3a38 100644
--- a/src/compiler/scala/tools/nsc/typechecker/Contexts.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/Contexts.scala
@@ -594,11 +594,11 @@ trait Contexts { self: Analyzer =>
       def restore(): Type = savedTypeBounds.foldLeft(tp) { case (current, (sym, savedInfo)) =>
         def bounds_s(tb: TypeBounds) = if (tb.isEmptyBounds) "<empty bounds>" else s"TypeBounds(lo=${tb.lo}, hi=${tb.hi})"
         //@M TODO: when higher-kinded types are inferred, probably need a case PolyType(_, TypeBounds(...)) if ... =>
-        val tb @ TypeBounds(lo, hi) = sym.info.bounds
-        val isUnique                = lo <:< hi && hi <:< lo
-        val isPresent               = current contains sym
-        def saved_s                 = bounds_s(savedInfo.bounds)
-        def current_s               = bounds_s(sym.info.bounds)
+        val TypeBounds(lo, hi) = sym.info.bounds
+        val isUnique           = lo <:< hi && hi <:< lo
+        val isPresent          = current contains sym
+        def saved_s            = bounds_s(savedInfo.bounds)
+        def current_s          = bounds_s(sym.info.bounds)
 
         if (isUnique && isPresent)
           devWarningResult(s"Preserving inference: ${sym.nameString}=$hi in $current (based on $current_s) before restoring $sym to saved $saved_s")(
@@ -962,15 +962,15 @@ trait Contexts { self: Analyzer =>
           // import check from being misled by symbol lookups which are not
           // actually used.
           val other = lookupImport(imp2, requireExplicit = !sameDepth)
-          def imp1wins = { imports = imp1 :: imports.tail.tail }
-          def imp2wins = { impSym = other ; imports = imports.tail }
+          def imp1wins() = { imports = imp1 :: imports.tail.tail }
+          def imp2wins() = { impSym = other ; imports = imports.tail }
 
           if (!other.exists) // imp1 wins; drop imp2 and continue.
-            imp1wins
+            imp1wins()
           else if (sameDepth && !imp1Explicit && imp2Explicit) // imp2 wins; drop imp1 and continue.
-            imp2wins
+            imp2wins()
           else resolveAmbiguousImport(name, imp1, imp2) match {
-            case Some(imp) => if (imp eq imp1) imp1wins else imp2wins
+            case Some(imp) => if (imp eq imp1) imp1wins() else imp2wins()
             case _         => lookupError = ambiguousImports(imp1, imp2)
           }
         }
diff --git a/src/compiler/scala/tools/nsc/typechecker/Duplicators.scala b/src/compiler/scala/tools/nsc/typechecker/Duplicators.scala
index ad45fc0354..b9e4b4f591 100644
--- a/src/compiler/scala/tools/nsc/typechecker/Duplicators.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/Duplicators.scala
@@ -80,7 +80,7 @@ abstract class Duplicators extends Analyzer {
             BodyDuplicator.super.silent(_.typedType(Ident(sym.name))) match {
               case SilentResultValue(t) =>
                 sym1 = t.symbol
-                debuglog("fixed by trying harder: "+(sym, sym1, context))
+                debuglog("fixed by trying harder: "+((sym, sym1, context)))
               case _ =>
             }
           }
diff --git a/src/compiler/scala/tools/nsc/typechecker/Implicits.scala b/src/compiler/scala/tools/nsc/typechecker/Implicits.scala
index 2331f82a58..4b84c21112 100644
--- a/src/compiler/scala/tools/nsc/typechecker/Implicits.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/Implicits.scala
@@ -311,7 +311,7 @@ trait Implicits {
       (info2 == NoImplicitInfo) ||
       (info1 != NoImplicitInfo) && {
         if (info1.sym.isStatic && info2.sym.isStatic) {
-          improvesCache get (info1, info2) match {
+          improvesCache get ((info1, info2)) match {
             case Some(b) => if (Statistics.canEnable) Statistics.incCounter(improvesCachedCount); b
             case None =>
               val result = isStrictlyMoreSpecific(info1.tpe, info2.tpe, info1.sym, info2.sym)
diff --git a/src/compiler/scala/tools/nsc/typechecker/Infer.scala b/src/compiler/scala/tools/nsc/typechecker/Infer.scala
index 9f16f65a6a..15ed784ae0 100644
--- a/src/compiler/scala/tools/nsc/typechecker/Infer.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/Infer.scala
@@ -1269,7 +1269,7 @@ trait Infer extends Checkable {
             // TODO: reinstate checkBounds, return params that fail to meet their bounds to undetparams
             Some(targs)
           } catch ifNoInstance { msg =>
-            debuglog("NO INST "+ (tvars, tvars map (_.constr)))
+            debuglog("NO INST "+ ((tvars, tvars map (_.constr))))
             NoConstructorInstanceError(tree, resTp, pt, msg)
             None
           }
diff --git a/src/compiler/scala/tools/nsc/typechecker/RefChecks.scala b/src/compiler/scala/tools/nsc/typechecker/RefChecks.scala
index b7221a78ec..a349881d6d 100644
--- a/src/compiler/scala/tools/nsc/typechecker/RefChecks.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/RefChecks.scala
@@ -1124,7 +1124,7 @@ abstract class RefChecks extends InfoTransform with scala.reflect.internal.trans
      *     accessor for that field. The instance is created lazily, on first access.
      */
     private def eliminateModuleDefs(moduleDef: Tree): List[Tree] = exitingRefchecks {
-      val ModuleDef(mods, name, impl) = moduleDef
+      val ModuleDef(_, _, impl) = moduleDef
       val module        = moduleDef.symbol
       val site          = module.owner
       val moduleName    = module.name.toTermName
@@ -1485,7 +1485,7 @@ abstract class RefChecks extends InfoTransform with scala.reflect.internal.trans
     private def transformIf(tree: If): Tree = {
       val If(cond, thenpart, elsepart) = tree
       def unitIfEmpty(t: Tree): Tree =
-        if (t == EmptyTree) Literal(Constant()).setPos(tree.pos).setType(UnitClass.tpe) else t
+        if (t == EmptyTree) Literal(Constant(())).setPos(tree.pos).setType(UnitClass.tpe) else t
 
       cond.tpe match {
         case ConstantType(value) =>
diff --git a/src/compiler/scala/tools/nsc/typechecker/TreeCheckers.scala b/src/compiler/scala/tools/nsc/typechecker/TreeCheckers.scala
index 5c863469e4..5575d680ef 100644
--- a/src/compiler/scala/tools/nsc/typechecker/TreeCheckers.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/TreeCheckers.scala
@@ -283,7 +283,6 @@ abstract class TreeCheckers extends Analyzer {
 
       private def checkSymbolRefsRespectScope(tree: Tree) {
         def symbolOf(t: Tree): Symbol = Option(tree.symbol).getOrElse(NoSymbol)
-        def definedSymbolOf(t: Tree): Symbol = if (t.isDef) symbolOf(t) else NoSymbol
         val info = Option(symbolOf(tree).info).getOrElse(NoType)
         val referencedSymbols: List[Symbol] = {
           val directRef = tree match {
diff --git a/src/compiler/scala/tools/nsc/typechecker/Typers.scala b/src/compiler/scala/tools/nsc/typechecker/Typers.scala
index 33f1ed3386..c45328a5d3 100644
--- a/src/compiler/scala/tools/nsc/typechecker/Typers.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/Typers.scala
@@ -1134,7 +1134,7 @@ trait Typers extends Adaptations with Tags {
                         if (settings.warnValueDiscard.value)
                           context.unit.warning(tree.pos, "discarded non-Unit value")
                         return typedPos(tree.pos, mode, pt) {
-                          Block(List(tree), Literal(Constant()))
+                          Block(List(tree), Literal(Constant(())))
                         }
                       } else if (isNumericValueClass(sym) && isNumericSubType(tree.tpe, pt)) {
                         if (settings.warnNumericWiden.value)
@@ -1248,7 +1248,7 @@ trait Typers extends Adaptations with Tags {
       val savedUndetparams = context.undetparams
       silent(_.instantiate(tree, mode, UnitClass.tpe)) orElse { _ =>
           context.undetparams = savedUndetparams
-          val valueDiscard = atPos(tree.pos)(Block(List(instantiate(tree, mode, WildcardType)), Literal(Constant())))
+          val valueDiscard = atPos(tree.pos)(Block(List(instantiate(tree, mode, WildcardType)), Literal(Constant(()))))
           typed(valueDiscard, mode, UnitClass.tpe)
       }
     }
@@ -1507,7 +1507,7 @@ trait Typers extends Adaptations with Tags {
      */
     private def typedParentType(encodedtpt: Tree, templ: Template, inMixinPosition: Boolean): Tree = {
       val app = treeInfo.dissectApplied(encodedtpt)
-      val (treeInfo.Applied(core, targs, argss), decodedtpt) = (app, app.callee)
+      val (treeInfo.Applied(core, targs, argss), decodedtpt) = ((app, app.callee))
       val argssAreTrivial = argss == Nil || argss == ListOfNil
 
       // we cannot avoid cyclic references with `initialize` here, because when type macros arrive,
@@ -2988,9 +2988,8 @@ trait Typers extends Adaptations with Tags {
             else if (isByNameParamType(formals.head)) NOmode
             else BYVALmode
           )
-          var tree = typedArg(args.head, mode, typedMode, adapted.head)
           // formals may be empty, so don't call tail
-          tree :: loop(args.tail, formals drop 1, adapted.tail)
+          typedArg(args.head, mode, typedMode, adapted.head) :: loop(args.tail, formals drop 1, adapted.tail)
         }
       }
       loop(args0, formals0, adapted0)