diff options
author | Paul Phillips <paulp@improving.org> | 2013-09-12 13:28:06 -0700 |
---|---|---|
committer | Paul Phillips <paulp@improving.org> | 2013-09-13 02:42:37 -0700 |
commit | 671e6e03c7e096eda0c27262ae8605fa7af76f59 (patch) | |
tree | b415fb7915ec80503605387b6ccd2ab29d9887a2 /src | |
parent | 33a819f61b8b9c19708e8ae22bf25adf6cc7ac24 (diff) | |
download | scala-671e6e03c7e096eda0c27262ae8605fa7af76f59.tar.gz scala-671e6e03c7e096eda0c27262ae8605fa7af76f59.tar.bz2 scala-671e6e03c7e096eda0c27262ae8605fa7af76f59.zip |
Corrects behavior of finalResultType.
The implementation had come to depend on finalResultType
accidentally doing things beyond its charter - in particular,
widening types. After hunting down and fixing the call sites
depending on the bugs, I was able to rewrite the method to do
only what it's supposed to do.
I threw in a different way of writing it entirely to suggest how
some correctness might be obtained in the future. It's a lot
harder for a method written like this to break.
Diffstat (limited to 'src')
11 files changed, 28 insertions, 21 deletions
diff --git a/src/compiler/scala/tools/nsc/ast/TreeDSL.scala b/src/compiler/scala/tools/nsc/ast/TreeDSL.scala index d7a32c3be0..53304bee30 100644 --- a/src/compiler/scala/tools/nsc/ast/TreeDSL.scala +++ b/src/compiler/scala/tools/nsc/ast/TreeDSL.scala @@ -192,7 +192,7 @@ trait TreeDSL { } class DefSymStart(val sym: Symbol) extends SymVODDStart with DefCreator { - def symType = sym.tpe.finalResultType + def symType = sym.tpe_*.finalResultType def tparams = sym.typeParams map TypeDef def vparamss = mapParamss(sym)(ValDef) } diff --git a/src/compiler/scala/tools/nsc/transform/Erasure.scala b/src/compiler/scala/tools/nsc/transform/Erasure.scala index c74fc620ca..48eb570654 100644 --- a/src/compiler/scala/tools/nsc/transform/Erasure.scala +++ b/src/compiler/scala/tools/nsc/transform/Erasure.scala @@ -268,7 +268,7 @@ abstract class Erasure extends AddInterfaces else abbrvTag(sym).toString } else if (sym.isDerivedValueClass) { - val unboxed = sym.derivedValueClassUnbox.info.finalResultType + val unboxed = sym.derivedValueClassUnbox.tpe_*.finalResultType val unboxedSeen = (tp memberType sym.derivedValueClassUnbox).finalResultType def unboxedMsg = if (unboxed == unboxedSeen) "" else s", seen within ${sym.simpleName} as $unboxedSeen" logResult(s"Erasure of value class $sym (underlying type $unboxed$unboxedMsg) is") { diff --git a/src/compiler/scala/tools/nsc/transform/ExtensionMethods.scala b/src/compiler/scala/tools/nsc/transform/ExtensionMethods.scala index 1c32721444..ca8065b519 100644 --- a/src/compiler/scala/tools/nsc/transform/ExtensionMethods.scala +++ b/src/compiler/scala/tools/nsc/transform/ExtensionMethods.scala @@ -234,7 +234,7 @@ abstract class ExtensionMethods extends Transform with TypingTransformers { if (extensionBody.tpe <:< extensionMono.finalResultType) extensionBody else - gen.mkCastPreservingAnnotations(extensionBody, extensionMono.finalResultType) // SI-7818 e.g. mismatched existential skolems + gen.mkCastPreservingAnnotations(extensionBody, extensionMono.finalResultType) // SI-7818 e.g. mismatched existential skolems // Record the extension method. Later, in `Extender#transformStats`, these will be added to the companion object. extensionDefs(companion) += atPos(tree.pos)(DefDef(extensionMeth, castBody)) diff --git a/src/compiler/scala/tools/nsc/transform/TailCalls.scala b/src/compiler/scala/tools/nsc/transform/TailCalls.scala index 6f422fcc90..b471d16ddd 100644 --- a/src/compiler/scala/tools/nsc/transform/TailCalls.scala +++ b/src/compiler/scala/tools/nsc/transform/TailCalls.scala @@ -156,7 +156,7 @@ abstract class TailCalls extends Transform { private def mkLabel() = { val label = method.newLabel(newTermName("_" + method.name), method.pos) val thisParam = method.newSyntheticValueParam(currentClass.typeOfThis) - label setInfo MethodType(thisParam :: method.tpe.params, method.tpe.finalResultType) + label setInfo MethodType(thisParam :: method.tpe.params, method.tpe_*.finalResultType) if (isEligible) label substInfo (method.tpe.typeParams, tparams) diff --git a/src/compiler/scala/tools/nsc/transform/UnCurry.scala b/src/compiler/scala/tools/nsc/transform/UnCurry.scala index 16c803e2e8..93a36f8f01 100644 --- a/src/compiler/scala/tools/nsc/transform/UnCurry.scala +++ b/src/compiler/scala/tools/nsc/transform/UnCurry.scala @@ -158,11 +158,12 @@ abstract class UnCurry extends InfoTransform */ private def nonLocalReturnTry(body: Tree, key: Symbol, meth: Symbol) = { localTyper typed { - val extpe = nonLocalReturnExceptionType(meth.tpe.finalResultType) + val restpe = meth.tpe_*.finalResultType + val extpe = nonLocalReturnExceptionType(restpe) val ex = meth.newValue(nme.ex, body.pos) setInfo extpe - val argType = meth.tpe.finalResultType withAnnotation (AnnotationInfo marker UncheckedClass.tpe) + val argType = restpe withAnnotation (AnnotationInfo marker UncheckedClass.tpe) val pat = gen.mkBindForCase(ex, NonLocalReturnControlClass, List(argType)) - val rhs = ( + val rhs = ( IF ((ex DOT nme.key)() OBJ_EQ Ident(key)) THEN ((ex DOT nme.value)()) ELSE (Throw(Ident(ex))) @@ -739,7 +740,7 @@ abstract class UnCurry extends InfoTransform case p if rpsymbols(p.symbol) => toArrayType(p.symbol.tpe) case p => p.symbol.tpe } - val forwresult = dd.symbol.tpe.finalResultType + val forwresult = dd.symbol.tpe_*.finalResultType val forwformsyms = map2(forwformals, flatparams)((tp, oldparam) => currentClass.newValueParameter(oldparam.name, oldparam.symbol.pos).setInfo(tp) ) diff --git a/src/compiler/scala/tools/nsc/typechecker/MethodSynthesis.scala b/src/compiler/scala/tools/nsc/typechecker/MethodSynthesis.scala index 263b5ad784..787c7ebf63 100644 --- a/src/compiler/scala/tools/nsc/typechecker/MethodSynthesis.scala +++ b/src/compiler/scala/tools/nsc/typechecker/MethodSynthesis.scala @@ -413,7 +413,7 @@ 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 = atPos(derivedSym.pos.focus)(derivedSym.tpe.finalResultType match { + val tpt = atPos(derivedSym.pos.focus)(derivedSym.tpe_*.finalResultType.widen match { case ExistentialType(_, _) => TypeTree() case _ if mods.isDeferred => TypeTree() case tp => TypeTree(tp) diff --git a/src/compiler/scala/tools/nsc/typechecker/Typers.scala b/src/compiler/scala/tools/nsc/typechecker/Typers.scala index 629513ada3..1f5ad3534e 100644 --- a/src/compiler/scala/tools/nsc/typechecker/Typers.scala +++ b/src/compiler/scala/tools/nsc/typechecker/Typers.scala @@ -363,7 +363,7 @@ trait Typers extends Adaptations with Tags with TypersTracking with PatternTyper check(owner, scope, pt, tree setType tp1.typeSymbol.classBound) else if (owner == NoSymbol) tree setType packSymbols(hiddenSymbols.reverse, tp1) - else if (!phase.erasedTypes) { // privates + else if (!isPastTyper) { // privates val badSymbol = hiddenSymbols.head SymbolEscapesScopeError(tree, badSymbol) } else tree @@ -2103,7 +2103,7 @@ trait Typers extends Adaptations with Tags with TypersTracking with PatternTyper case PolyType(_, restpe) => paramssTypes(restpe) case _ => Nil } - def resultType = meth.tpe.finalResultType + def resultType = meth.tpe_*.finalResultType def nthParamPos(n1: Int, n2: Int) = try ddef.vparamss(n1)(n2).pos catch { case _: IndexOutOfBoundsException => meth.pos } diff --git a/src/reflect/scala/reflect/internal/Definitions.scala b/src/reflect/scala/reflect/internal/Definitions.scala index 90a1ab39d5..c56637874c 100644 --- a/src/reflect/scala/reflect/internal/Definitions.scala +++ b/src/reflect/scala/reflect/internal/Definitions.scala @@ -695,6 +695,19 @@ trait Definitions extends api.StandardDefinitions { case NullaryMethodType(restpe) => restpe case _ => tp } + + /** An implementation of finalResultType which does only what + * finalResultType is documented to do. Defining it externally to + * Type helps ensure people can't come to depend on accidental + * aspects of its behavior. This is all of it! + */ + def finalResultType(tp: Type): Type = tp match { + case PolyType(_, restpe) => finalResultType(restpe) + case MethodType(_, restpe) => finalResultType(restpe) + case NullaryMethodType(restpe) => finalResultType(restpe) + case _ => tp + } + def abstractFunctionForFunctionType(tp: Type) = { assert(isFunctionType(tp), tp) abstractFunctionType(tp.typeArgs.init, tp.typeArgs.last) diff --git a/src/reflect/scala/reflect/internal/Trees.scala b/src/reflect/scala/reflect/internal/Trees.scala index 84818a6f42..63d66b18dc 100644 --- a/src/reflect/scala/reflect/internal/Trees.scala +++ b/src/reflect/scala/reflect/internal/Trees.scala @@ -1048,7 +1048,7 @@ trait Trees extends api.Trees { self: SymbolTable => sym.name.toTermName, sym.typeParams map TypeDef, vparamss, - TypeTree(sym.tpe.finalResultType) setPos sym.pos.focus, + TypeTree(sym.tpe_*.finalResultType.widen) setPos sym.pos.focus, rhs) setSymbol sym } diff --git a/src/reflect/scala/reflect/internal/Types.scala b/src/reflect/scala/reflect/internal/Types.scala index ad9001ca4e..3adbbf13fc 100644 --- a/src/reflect/scala/reflect/internal/Types.scala +++ b/src/reflect/scala/reflect/internal/Types.scala @@ -144,7 +144,6 @@ trait Types override def isErroneous = underlying.isErroneous override def isStable: Boolean = underlying.isStable override def isVolatile = underlying.isVolatile - override def finalResultType = underlying.finalResultType override def paramSectionCount = underlying.paramSectionCount override def paramss = underlying.paramss override def params = underlying.params @@ -189,7 +188,6 @@ trait Types override def deconst = maybeRewrap(underlying.deconst) override def resultType = maybeRewrap(underlying.resultType) override def resultType(actuals: List[Type]) = maybeRewrap(underlying.resultType(actuals)) - override def finalResultType = maybeRewrap(underlying.finalResultType) override def paramSectionCount = 0 override def paramss: List[List[Symbol]] = List() override def params: List[Symbol] = List() @@ -440,7 +438,7 @@ trait Types /** For a curried/nullary method or poly type its non-method result type, * the type itself for all other types */ - def finalResultType: Type = this + final def finalResultType: Type = definitions finalResultType this /** For a method type, the number of its value parameter sections, * 0 for all other types */ @@ -1240,7 +1238,6 @@ trait Types if (pre.isOmittablePrefix) pre.fullName + ".type" else prefixString + "type" } - /* override def typeOfThis: Type = typeSymbol.typeOfThis override def bounds: TypeBounds = TypeBounds(this, this) @@ -2564,8 +2561,6 @@ trait Types //TODO this may be generalised so that the only constraint is dependencies are acyclic def approximate: MethodType = MethodType(params, resultApprox) - override def finalResultType: Type = resultType.finalResultType - override def safeToString = paramString(this) + resultType override def cloneInfo(owner: Symbol) = { @@ -2592,7 +2587,6 @@ trait Types override def isTrivial = resultType.isTrivial && (resultType eq resultType.withoutAnnotations) override def prefix: Type = resultType.prefix override def narrow: Type = resultType.narrow - override def finalResultType: Type = resultType.finalResultType override def termSymbol: Symbol = resultType.termSymbol override def typeSymbol: Symbol = resultType.typeSymbol override def parents: List[Type] = resultType.parents @@ -2642,7 +2636,6 @@ trait Types override def baseType(clazz: Symbol): Type = resultType.baseType(clazz) override def narrow: Type = resultType.narrow override def isVolatile = resultType.isVolatile - override def finalResultType: Type = resultType.finalResultType /** @M: typeDefSig wraps a TypeBounds in a PolyType * to represent a higher-kinded type parameter diff --git a/src/repl/scala/tools/nsc/interpreter/ExprTyper.scala b/src/repl/scala/tools/nsc/interpreter/ExprTyper.scala index 6406dacc24..bb5fe07fc9 100644 --- a/src/repl/scala/tools/nsc/interpreter/ExprTyper.scala +++ b/src/repl/scala/tools/nsc/interpreter/ExprTyper.scala @@ -28,7 +28,7 @@ trait ExprTyper { case IR.Success => val sym0 = symbolOfTerm(name) // drop NullaryMethodType - sym0.cloneSymbol setInfo exitingTyper(sym0.info.finalResultType) + sym0.cloneSymbol setInfo exitingTyper(sym0.tpe_*.finalResultType) case _ => NoSymbol } } |