diff options
| -rw-r--r-- | src/dotty/tools/dotc/core/Denotations.scala | 285 | ||||
| -rw-r--r-- | src/dotty/tools/dotc/core/TypeComparer.scala | 87 |
2 files changed, 196 insertions, 176 deletions
diff --git a/src/dotty/tools/dotc/core/Denotations.scala b/src/dotty/tools/dotc/core/Denotations.scala index 0f95fc591..7866d6697 100644 --- a/src/dotty/tools/dotc/core/Denotations.scala +++ b/src/dotty/tools/dotc/core/Denotations.scala @@ -6,6 +6,7 @@ import SymDenotations.{ SymDenotation, ClassDenotation, NoDenotation, NotDefined import Contexts.{Context, ContextBase} import Names.{Name, PreName} import Names.TypeName +import StdNames._ import Symbols.NoSymbol import Symbols._ import Types._ @@ -247,6 +248,25 @@ object Denotations { else asSingleDenotation } + /** Handle merge conflict by throwing a `MergeError` exception */ + private def mergeConflict(tp1: Type, tp2: Type)(implicit ctx: Context): Type = { + def showType(tp: Type) = tp match { + case ClassInfo(_, cls, _, _, _) => cls.showLocated + case bounds: TypeBounds => i"type bounds $bounds" + case _ => tp.show + } + if (true) throw new MergeError(s"cannot merge ${showType(tp1)} with ${showType(tp2)}", tp1, tp2) + else throw new Error(s"cannot merge ${showType(tp1)} with ${showType(tp2)}") // flip condition for debugging + } + + /** Merge two lists of names. If names in corresponding positions match, keep them, + * otherwise generate new synthetic names. + */ + def mergeNames[N <: Name](names1: List[N], names2: List[N], syntheticName: Int => N): List[N] = { + for ((name1, name2, idx) <- (names1, names2, 0 until names1.length).zipped) + yield if (name1 == name2) name1 else syntheticName(idx) + }.toList + /** Form a denotation by conjoining with denotation `that`. * * NoDenotations are dropped. MultiDenotations are handled by merging @@ -277,6 +297,50 @@ object Denotations { */ def & (that: Denotation, pre: Type, safeIntersection: Boolean = false)(implicit ctx: Context): Denotation = { + /** Normally, `tp1 & tp2`. Special cases for matching methods and classes, with + * the possibility of raising a merge error. + */ + def infoMeet(tp1: Type, tp2: Type): Type = { + if (tp1 eq tp2) tp1 + else tp1 match { + case tp1: TypeBounds => + tp2 match { + case tp2: TypeBounds => if (safeIntersection) tp1 safe_& tp2 else tp1 & tp2 + case tp2: ClassInfo if tp1 contains tp2 => tp2 + case _ => mergeConflict(tp1, tp2) + } + case tp1: ClassInfo => + tp2 match { + case tp2: ClassInfo if tp1.cls eq tp2.cls => tp1.derivedClassInfo(tp1.prefix & tp2.prefix) + case tp2: TypeBounds if tp2 contains tp1 => tp1 + case _ => mergeConflict(tp1, tp2) + } + case tp1 @ MethodType(names1, formals1) if isTerm => + tp2 match { + case tp2 @ MethodType(names2, formals2) if ctx.typeComparer.matchingParams(formals1, formals2, tp1.isJava, tp2.isJava) && + tp1.isImplicit == tp2.isImplicit => + tp1.derivedMethodType( + mergeNames(names1, names2, nme.syntheticParamName), + formals1, + infoMeet(tp1.resultType, tp2.resultType.subst(tp2, tp1))) + case _ => + mergeConflict(tp1, tp2) + } + case tp1: PolyType if isTerm => + tp2 match { + case tp2: PolyType if ctx.typeComparer.matchingTypeParams(tp1, tp2) => + tp1.derivedPolyType( + mergeNames(tp1.paramNames, tp2.paramNames, tpnme.syntheticTypeParamName), + tp1.paramBounds, + infoMeet(tp1.resultType, tp2.resultType.subst(tp2, tp1))) + case _: MethodicType => + mergeConflict(tp1, tp2) + } + case _ => + tp1 & tp2 + } + } + /** Try to merge denot1 and denot2 without adding a new signature. */ def mergeDenot(denot1: Denotation, denot2: SingleDenotation): Denotation = denot1 match { case denot1 @ MultiDenotation(denot11, denot12) => @@ -289,96 +353,95 @@ object Denotations { } case denot1: SingleDenotation => if (denot1 eq denot2) denot1 - else if (denot1.matches(denot2)) { - val info1 = denot1.info - val info2 = denot2.info - val sym1 = denot1.symbol - val sym2 = denot2.symbol - - val sym2Accessible = sym2.isAccessibleFrom(pre) - - /** Does `sym1` come before `sym2` in the linearization of `pre`? */ - def precedes(sym1: Symbol, sym2: Symbol) = { - def precedesIn(bcs: List[ClassSymbol]): Boolean = bcs match { - case bc :: bcs1 => (sym1 eq bc) || !(sym2 eq bc) && precedesIn(bcs1) - case Nil => true - } - (sym1 ne sym2) && - (sym1.derivesFrom(sym2) || - !sym2.derivesFrom(sym1) && precedesIn(pre.baseClasses)) - } + else if (denot1.matches(denot2)) mergeSingleDenot(denot1, denot2) + else NoDenotation + } - /** Similar to SymDenotation#accessBoundary, but without the special cases. */ - def accessBoundary(sym: Symbol) = - if (sym.is(Private)) sym.owner - else sym.privateWithin.orElse( - if (sym.is(Protected)) sym.owner.enclosingPackageClass - else defn.RootClass - ) - - /** Establish a partial order "preference" order between symbols. - * Give preference to `sym1` over `sym2` if one of the following - * conditions holds, in decreasing order of weight: - * 1. sym1 is concrete and sym2 is abstract - * 2. The owner of sym1 comes before the owner of sym2 in the linearization - * of the type of the prefix `pre`. - * 3. The access boundary of sym2 is properly contained in the access - * boundary of sym1. For protected access, we count the enclosing - * package as access boundary. - * 4. sym1 a method but sym2 is not. - * The aim of these criteria is to give some disambiguation on access which - * - does not depend on textual order or other arbitrary choices - * - minimizes raising of doubleDef errors - */ - def preferSym(sym1: Symbol, sym2: Symbol) = - sym1.eq(sym2) || - sym1.isAsConcrete(sym2) && - (!sym2.isAsConcrete(sym1) || - precedes(sym1.owner, sym2.owner) || - accessBoundary(sym2).isProperlyContainedIn(accessBoundary(sym1)) || - sym1.is(Method) && !sym2.is(Method)) || - sym1.info.isErroneous - - /** Sym preference provided types also override */ - def prefer(sym1: Symbol, sym2: Symbol, info1: Type, info2: Type) = - preferSym(sym1, sym2) && info1.overrides(info2) - - def handleDoubleDef = - if (preferSym(sym1, sym2)) denot1 - else if (preferSym(sym2, sym1)) denot2 - else doubleDefError(denot1, denot2, pre) - - if (sym2Accessible && prefer(sym2, sym1, info2, info1)) denot2 - else { - val sym1Accessible = sym1.isAccessibleFrom(pre) - if (sym1Accessible && prefer(sym1, sym2, info1, info2)) denot1 - else if (sym1Accessible && sym2.exists && !sym2Accessible) denot1 - else if (sym2Accessible && sym1.exists && !sym1Accessible) denot2 - else if (isDoubleDef(sym1, sym2)) handleDoubleDef - else { - val sym = - if (!sym1.exists) sym2 - else if (!sym2.exists) sym1 - else if (preferSym(sym2, sym1)) sym2 - else sym1 - val jointInfo = - try - if (safeIntersection) - info1 safe_& info2 - else - info1 & info2 - catch { - case ex: MergeError => - if (pre.widen.classSymbol.is(Scala2x) || ctx.scala2Mode) - info1 // follow Scala2 linearization - - // compare with way merge is performed in SymDenotation#computeMembersNamed - else - throw new MergeError(s"${ex.getMessage} as members of type ${pre.show}", ex.tp1, ex.tp2) - } - new JointRefDenotation(sym, jointInfo, denot1.validFor & denot2.validFor) + /** Try to merge single-denotations. */ + def mergeSingleDenot(denot1: SingleDenotation, denot2: SingleDenotation): SingleDenotation = { + val info1 = denot1.info + val info2 = denot2.info + val sym1 = denot1.symbol + val sym2 = denot2.symbol + + val sym2Accessible = sym2.isAccessibleFrom(pre) + + /** Does `sym1` come before `sym2` in the linearization of `pre`? */ + def precedes(sym1: Symbol, sym2: Symbol) = { + def precedesIn(bcs: List[ClassSymbol]): Boolean = bcs match { + case bc :: bcs1 => (sym1 eq bc) || !(sym2 eq bc) && precedesIn(bcs1) + case Nil => true + } + (sym1 ne sym2) && + (sym1.derivesFrom(sym2) || + !sym2.derivesFrom(sym1) && precedesIn(pre.baseClasses)) + } + + /** Similar to SymDenotation#accessBoundary, but without the special cases. */ + def accessBoundary(sym: Symbol) = + if (sym.is(Private)) sym.owner + else sym.privateWithin.orElse( + if (sym.is(Protected)) sym.owner.enclosingPackageClass + else defn.RootClass) + + /** Establish a partial order "preference" order between symbols. + * Give preference to `sym1` over `sym2` if one of the following + * conditions holds, in decreasing order of weight: + * 1. sym1 is concrete and sym2 is abstract + * 2. The owner of sym1 comes before the owner of sym2 in the linearization + * of the type of the prefix `pre`. + * 3. The access boundary of sym2 is properly contained in the access + * boundary of sym1. For protected access, we count the enclosing + * package as access boundary. + * 4. sym1 a method but sym2 is not. + * The aim of these criteria is to give some disambiguation on access which + * - does not depend on textual order or other arbitrary choices + * - minimizes raising of doubleDef errors + */ + def preferSym(sym1: Symbol, sym2: Symbol) = + sym1.eq(sym2) || + sym1.isAsConcrete(sym2) && + (!sym2.isAsConcrete(sym1) || + precedes(sym1.owner, sym2.owner) || + accessBoundary(sym2).isProperlyContainedIn(accessBoundary(sym1)) || + sym1.is(Method) && !sym2.is(Method)) || + sym1.info.isErroneous + + /** Sym preference provided types also override */ + def prefer(sym1: Symbol, sym2: Symbol, info1: Type, info2: Type) = + preferSym(sym1, sym2) && info1.overrides(info2) + + def handleDoubleDef = + if (preferSym(sym1, sym2)) denot1 + else if (preferSym(sym2, sym1)) denot2 + else doubleDefError(denot1, denot2, pre) + + if (sym2Accessible && prefer(sym2, sym1, info2, info1)) denot2 + else { + val sym1Accessible = sym1.isAccessibleFrom(pre) + if (sym1Accessible && prefer(sym1, sym2, info1, info2)) denot1 + else if (sym1Accessible && sym2.exists && !sym2Accessible) denot1 + else if (sym2Accessible && sym1.exists && !sym1Accessible) denot2 + else if (isDoubleDef(sym1, sym2)) handleDoubleDef + else { + val sym = + if (!sym1.exists) sym2 + else if (!sym2.exists) sym1 + else if (preferSym(sym2, sym1)) sym2 + else sym1 + val jointInfo = + try infoMeet(info1, info2) + catch { + case ex: MergeError => + if (pre.widen.classSymbol.is(Scala2x) || ctx.scala2Mode) + info1 // follow Scala2 linearization - + // compare with way merge is performed in SymDenotation#computeMembersNamed + else + throw new MergeError(s"${ex.getMessage} as members of type ${pre.show}", ex.tp1, ex.tp2) } - } - } else NoDenotation + new JointRefDenotation(sym, jointInfo, denot1.validFor & denot2.validFor) + } + } } if (this eq that) this @@ -399,6 +462,46 @@ object Denotations { */ def | (that: Denotation, pre: Type)(implicit ctx: Context): Denotation = { + /** Normally, `tp1 | tp2`. Special cases for matching methods and classes, with + * the possibility of raising a merge error. + */ + def infoJoin(tp1: Type, tp2: Type): Type = tp1 match { + case tp1: TypeBounds => + tp2 match { + case tp2: TypeBounds => tp1 | tp2 + case tp2: ClassInfo if tp1 contains tp2 => tp1 + case _ => mergeConflict(tp1, tp2) + } + case tp1: ClassInfo => + tp2 match { + case tp2: ClassInfo if tp1.cls eq tp2.cls => tp1.derivedClassInfo(tp1.prefix | tp2.prefix) + case tp2: TypeBounds if tp2 contains tp1 => tp2 + case _ => mergeConflict(tp1, tp2) + } + case tp1 @ MethodType(names1, formals1) => + tp2 match { + case tp2 @ MethodType(names2, formals2) + if ctx.typeComparer.matchingParams(formals1, formals2, tp1.isJava, tp2.isJava) && + tp1.isImplicit == tp2.isImplicit => + tp1.derivedMethodType( + mergeNames(names1, names2, nme.syntheticParamName), + formals1, tp1.resultType | tp2.resultType.subst(tp2, tp1)) + case _ => + mergeConflict(tp1, tp2) + } + case tp1: PolyType => + tp2 match { + case tp2: PolyType if ctx.typeComparer.matchingTypeParams(tp1, tp2) => + tp1.derivedPolyType( + mergeNames(tp1.paramNames, tp2.paramNames, tpnme.syntheticTypeParamName), + tp1.paramBounds, tp1.resultType | tp2.resultType.subst(tp2, tp1)) + case _ => + mergeConflict(tp1, tp2) + } + case _ => + tp1 | tp2 + } + def unionDenot(denot1: SingleDenotation, denot2: SingleDenotation): Denotation = if (denot1.matches(denot2)) { val sym1 = denot1.symbol @@ -428,7 +531,8 @@ object Denotations { } lubSym(sym1.allOverriddenSymbols, NoSymbol) } - new JointRefDenotation(jointSym, info1 | info2, denot1.validFor & denot2.validFor) + new JointRefDenotation( + jointSym, infoJoin(info1, info2), denot1.validFor & denot2.validFor) } } else NoDenotation @@ -1134,5 +1238,4 @@ object Denotations { util.Stats.record("not defined here") override def getMessage() = msg } -} - +}
\ No newline at end of file diff --git a/src/dotty/tools/dotc/core/TypeComparer.scala b/src/dotty/tools/dotc/core/TypeComparer.scala index 91a3dd2b9..7f60f0231 100644 --- a/src/dotty/tools/dotc/core/TypeComparer.scala +++ b/src/dotty/tools/dotc/core/TypeComparer.scala @@ -1022,7 +1022,7 @@ class TypeComparer(initctx: Context) extends DotClass with ConstraintHandling { } /** Are `syms1` and `syms2` parameter lists with pairwise equivalent types? */ - private def matchingParams(formals1: List[Type], formals2: List[Type], isJava1: Boolean, isJava2: Boolean): Boolean = formals1 match { + def matchingParams(formals1: List[Type], formals2: List[Type], isJava1: Boolean, isJava2: Boolean): Boolean = formals1 match { case formal1 :: rest1 => formals2 match { case formal2 :: rest2 => @@ -1040,7 +1040,7 @@ class TypeComparer(initctx: Context) extends DotClass with ConstraintHandling { /** Do generic types `poly1` and `poly2` have type parameters that * have the same bounds (after renaming one set to the other)? */ - private def matchingTypeParams(poly1: GenericType, poly2: GenericType): Boolean = + def matchingTypeParams(poly1: PolyType, poly2: PolyType): Boolean = (poly1.paramBounds corresponds poly2.paramBounds)((b1, b2) => isSameType(b1, b2.subst(poly2, poly1))) @@ -1308,38 +1308,6 @@ class TypeComparer(initctx: Context) extends DotClass with ConstraintHandling { } case tp1: RecType => tp1.rebind(distributeAnd(tp1.parent, tp2)) - case tp1: TypeBounds => - tp2 match { - case tp2: TypeBounds => tp1 & tp2 - case tp2: ClassInfo if tp1 contains tp2 => tp2 - case _ => mergeConflict(tp1, tp2) - } - case tp1: ClassInfo => - tp2 match { - case tp2: ClassInfo if tp1.cls eq tp2.cls => tp1.derivedClassInfo(tp1.prefix & tp2.prefix) - case tp2: TypeBounds if tp2 contains tp1 => tp1 - case _ => mergeConflict(tp1, tp2) - } - case tp1 @ MethodType(names1, formals1) => - tp2 match { - case tp2 @ MethodType(names2, formals2) - if matchingParams(formals1, formals2, tp1.isJava, tp2.isJava) && - tp1.isImplicit == tp2.isImplicit => - tp1.derivedMethodType( - mergeNames(names1, names2, nme.syntheticParamName), - formals1, tp1.resultType & tp2.resultType.subst(tp2, tp1)) - case _ => - mergeConflict(tp1, tp2) - } - case tp1: PolyType => - tp2 match { - case tp2: PolyType if matchingTypeParams(tp1, tp2) => - tp1.derivedGenericType( - mergeNames(tp1.paramNames, tp2.paramNames, tpnme.syntheticTypeParamName), - tp1.paramBounds, tp1.resultType & tp2.resultType.subst(tp2, tp1)) - case _ => - mergeConflict(tp1, tp2) - } case ExprType(rt1) => tp2 match { case ExprType(rt2) => @@ -1364,38 +1332,6 @@ class TypeComparer(initctx: Context) extends DotClass with ConstraintHandling { * The rhs is a proper supertype of the lhs. */ private def distributeOr(tp1: Type, tp2: Type): Type = tp1 match { - case tp1: TypeBounds => - tp2 match { - case tp2: TypeBounds => tp1 | tp2 - case tp2: ClassInfo if tp1 contains tp2 => tp1 - case _ => mergeConflict(tp1, tp2) - } - case tp1: ClassInfo => - tp2 match { - case tp2: ClassInfo if tp1.cls eq tp2.cls => tp1.derivedClassInfo(tp1.prefix | tp2.prefix) - case tp2: TypeBounds if tp2 contains tp1 => tp2 - case _ => mergeConflict(tp1, tp2) - } - case tp1 @ MethodType(names1, formals1) => - tp2 match { - case tp2 @ MethodType(names2, formals2) - if matchingParams(formals1, formals2, tp1.isJava, tp2.isJava) && - tp1.isImplicit == tp2.isImplicit => - tp1.derivedMethodType( - mergeNames(names1, names2, nme.syntheticParamName), - formals1, tp1.resultType | tp2.resultType.subst(tp2, tp1)) - case _ => - mergeConflict(tp1, tp2) - } - case tp1: GenericType => - tp2 match { - case tp2: GenericType if matchingTypeParams(tp1, tp2) => - tp1.derivedGenericType( - mergeNames(tp1.paramNames, tp2.paramNames, tpnme.syntheticTypeParamName), - tp1.paramBounds, tp1.resultType | tp2.resultType.subst(tp2, tp1)) - case _ => - mergeConflict(tp1, tp2) - } case ExprType(rt1) => ExprType(rt1 | tp2.widenExpr) case tp1: TypeVar if tp1.isInstantiated => @@ -1406,25 +1342,6 @@ class TypeComparer(initctx: Context) extends DotClass with ConstraintHandling { NoType } - /** Handle merge conflict by throwing a `MergeError` exception */ - private def mergeConflict(tp1: Type, tp2: Type): Type = { - def showType(tp: Type) = tp match { - case ClassInfo(_, cls, _, _, _) => cls.showLocated - case bounds: TypeBounds => i"type bounds $bounds" - case _ => tp.show - } - if (true) throw new MergeError(s"cannot merge ${showType(tp1)} with ${showType(tp2)}", tp1, tp2) - else throw new Error(s"cannot merge ${showType(tp1)} with ${showType(tp2)}") // flip condition for debugging - } - - /** Merge two lists of names. If names in corresponding positions match, keep them, - * otherwise generate new synthetic names. - */ - private def mergeNames[N <: Name](names1: List[N], names2: List[N], syntheticName: Int => N): List[N] = { - for ((name1, name2, idx) <- (names1, names2, 0 until names1.length).zipped) - yield if (name1 == name2) name1 else syntheticName(idx) - }.toList - /** Show type, handling type types better than the default */ private def showType(tp: Type)(implicit ctx: Context) = tp match { case ClassInfo(_, cls, _, _, _) => cls.showLocated |