From 039b1cb1a5b8738bb3731035838d2fcaeb317d07 Mon Sep 17 00:00:00 2001 From: Paul Phillips Date: Tue, 29 Jan 2013 13:16:23 -0800 Subject: Changes many calls to normalize to dealiasWiden. Calling normalize is very aggressive and is usually the wrong thing. It is one of the leading contributors to non-determinism in compiler outcomes (often of the form "I gave a debugging or logging compiler option and it started/stopped working") and should be used only in very specific circumstances. Almost without exception, dealiasWiden is what you want; not widen, not normalize. If possible I will remove normalize from Type entirely, making it private to those areas of the compiler which actually require it. --- src/compiler/scala/tools/nsc/typechecker/Typers.scala | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) (limited to 'src/compiler/scala/tools/nsc/typechecker/Typers.scala') diff --git a/src/compiler/scala/tools/nsc/typechecker/Typers.scala b/src/compiler/scala/tools/nsc/typechecker/Typers.scala index 8fbc143fbf..51a31f6fc7 100644 --- a/src/compiler/scala/tools/nsc/typechecker/Typers.scala +++ b/src/compiler/scala/tools/nsc/typechecker/Typers.scala @@ -2437,7 +2437,7 @@ trait Typers extends Adaptations with Tags { // but not in real life (i.e., now that's we've reset the method's type skolems' // infos back to their pre-GADT-constraint state) if (isFullyDefined(pt) && !(body1.tpe <:< pt)) - body1 = typedPos(body1.pos)(gen.mkCast(body1, pt.normalize)) + body1 = typedPos(body1.pos)(gen.mkCast(body1, pt.dealiasWiden)) } @@ -2507,7 +2507,7 @@ trait Typers extends Adaptations with Tags { */ def synthesizePartialFunction(paramName: TermName, paramPos: Position, tree: Tree, mode: Mode, pt: Type): Tree = { assert(pt.typeSymbol == PartialFunctionClass, s"PartialFunction synthesis for match in $tree requires PartialFunction expected type, but got $pt.") - val targs = pt.normalize.typeArgs + val targs = pt.dealiasWiden.typeArgs // if targs.head isn't fully defined, we can translate --> error targs match { @@ -2665,10 +2665,10 @@ trait Typers extends Adaptations with Tags { def decompose(pt: Type): (Symbol, List[Type], Type) = if ((isFunctionType(pt) || (pt.typeSymbol == PartialFunctionClass && numVparams == 1 && fun.body.isInstanceOf[Match])) && // see bug901 for a reason why next conditions are needed - ( pt.normalize.typeArgs.length - 1 == numVparams + ( pt.dealiasWiden.typeArgs.length - 1 == numVparams || fun.vparams.exists(_.tpt.isEmpty) )) - (pt.typeSymbol, pt.normalize.typeArgs.init, pt.normalize.typeArgs.last) + (pt.typeSymbol, pt.dealiasWiden.typeArgs.init, pt.dealiasWiden.typeArgs.last) else (FunctionClass(numVparams), fun.vparams map (x => NoType), WildcardType) @@ -3316,7 +3316,7 @@ trait Typers extends Adaptations with Tags { if (fun1.tpe.isErroneous) duplErrTree else { - val resTp = fun1.tpe.finalResultType.normalize + val resTp = fun1.tpe.finalResultType.dealiasWiden val nbSubPats = args.length val (formals, formalsExpanded) = extractorFormalTypes(fun0.pos, resTp, nbSubPats, fun1.symbol) @@ -3364,7 +3364,7 @@ trait Typers extends Adaptations with Tags { def extractorForUncheckedType(pos: Position, pt: Type): Option[Tree] = if (isPastTyper) None else { // only look at top-level type, can't (reliably) do anything about unchecked type args (in general) // but at least make a proper type before passing it elsewhere - val pt1 = pt.dealias match { + val pt1 = pt.dealiasWiden match { case tr @ TypeRef(pre, sym, args) if args.nonEmpty => copyTypeRef(tr, pre, sym, sym.typeParams map (_.tpeHK)) // replace actual type args with dummies case pt1 => pt1 } @@ -4209,7 +4209,7 @@ trait Typers extends Adaptations with Tags { if (newPatternMatching && (pt.typeSymbol == PartialFunctionClass)) synthesizePartialFunction(newTermName(context.unit.fresh.newName("x")), tree.pos, tree, mode, pt) else { - val arity = if (isFunctionType(pt)) pt.normalize.typeArgs.length - 1 else 1 + val arity = if (isFunctionType(pt)) pt.dealiasWiden.typeArgs.length - 1 else 1 val params = for (i <- List.range(0, arity)) yield atPos(tree.pos.focusStart) { ValDef(Modifiers(PARAM | SYNTHETIC), -- cgit v1.2.3