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|
package dotty.tools.dotc
package core
import Positions._, Types._, Contexts._, Constants._, Names._, Flags._
import SymDenotations._, Symbols._, StdNames._, Annotations._
object TypedTrees {
object tpd {
type Modifiers = Trees.Modifiers[Type]
type Tree = Trees.Tree[Type]
type TypTree = Trees.TypTree[Type]
type TermTree = Trees.TermTree[Type]
type PatternTree = Trees.PatternTree[Type]
type SymTree = Trees.SymTree[Type]
type ProxyTree = Trees.ProxyTree[Type]
type NameTree = Trees.NameTree[Type]
type RefTree = Trees.RefTree[Type]
type DefTree = Trees.DefTree[Type]
type TreeCopier = Trees.TreeCopier[Type]
type TreeAccumulator[T] = Trees.TreeAccumulator[T, Type]
type TreeTransformer[C] = Trees.TreeTransformer[Type, C]
type Ident = Trees.Ident[Type]
type Select = Trees.Select[Type]
type This = Trees.This[Type]
type Super = Trees.Super[Type]
type Apply = Trees.Apply[Type]
type TypeApply = Trees.TypeApply[Type]
type Literal = Trees.Literal[Type]
type New = Trees.New[Type]
type Pair = Trees.Pair[Type]
type Typed = Trees.Typed[Type]
type NamedArg = Trees.NamedArg[Type]
type Assign = Trees.Assign[Type]
type Block = Trees.Block[Type]
type If = Trees.If[Type]
type Match = Trees.Match[Type]
type CaseDef = Trees.CaseDef[Type]
type Return = Trees.Return[Type]
type Try = Trees.Try[Type]
type Throw = Trees.Throw[Type]
type SeqLiteral = Trees.SeqLiteral[Type]
type TypeTree = Trees.TypeTree[Type]
type SingletonTypeTree = Trees.SingletonTypeTree[Type]
type SelectFromTypeTree = Trees.SelectFromTypeTree[Type]
type AndTypeTree = Trees.AndTypeTree[Type]
type OrTypeTree = Trees.OrTypeTree[Type]
type RefineTypeTree = Trees.RefineTypeTree[Type]
type AppliedTypeTree = Trees.AppliedTypeTree[Type]
type TypeBoundsTree = Trees.TypeBoundsTree[Type]
type Bind = Trees.Bind[Type]
type Alternative = Trees.Alternative[Type]
type UnApply = Trees.UnApply[Type]
type ValDef = Trees.ValDef[Type]
type DefDef = Trees.DefDef[Type]
type TypeDef = Trees.TypeDef[Type]
type Template = Trees.Template[Type]
type ClassDef = Trees.ClassDef[Type]
type Import = Trees.Import[Type]
type PackageDef = Trees.PackageDef[Type]
type Annotated = Trees.Annotated[Type]
type EmptyTree = Trees.EmptyTree[Type]
type Shared = Trees.Shared[Type]
private implicit def pos(implicit ctx: Context): Position = ctx.position
def defPos(sym: Symbol)(implicit ctx: Context) = ctx.position union sym.coord.toPosition
def Modifiers(sym: Symbol)(implicit ctx: Context): Modifiers = Trees.Modifiers[Type](
sym.flags & ModifierFlags,
if (sym.privateWithin.exists) sym.privateWithin.asType.name else tpnme.EMPTY,
sym.annotations map (_.tree))
def Ident(tp: NamedType)(implicit ctx: Context): Ident =
Trees.Ident(tp.name).withType(tp).checked
def Select(pre: Tree, tp: NamedType)(implicit ctx: Context): Select =
Trees.Select(pre, tp.name).withType(tp).checked
def This(cls: ClassSymbol)(implicit ctx: Context): This =
Trees.This(cls.name).withType(cls.thisType).checked
def Super(qual: Tree, mixin: Symbol = NoSymbol)(implicit ctx: Context): Super = {
val cls = qual.tpe.typeSymbol
val (owntype, mix) =
if (mixin.exists) (mixin.typeConstructor, mixin.asType.name)
else (ctx.glb(cls.info.parents), tpnme.EMPTY)
Trees.Super(qual, mix).withType(SuperType(qual.tpe, owntype)).checked
}
def Apply(fn: Tree, args: List[Tree])(implicit ctx: Context): Apply = {
val fntpe @ MethodType(pnames, ptypes) = fn.tpe
assert(sameLength(ptypes, args))
Trees.Apply(fn, args).withType(fntpe.instantiate(args map (_.tpe))).checked
}
def TypeApply(fn: Tree, args: List[Tree])(implicit ctx: Context): TypeApply = {
val fntpe @ PolyType(pnames) = fn.tpe
assert(sameLength(pnames, args))
Trees.TypeApply(fn, args).withType(fntpe.instantiate(args map (_.tpe))).checked
}
def Literal(const: Constant)(implicit ctx: Context): Literal =
Trees.Literal(const).withType(const.tpe).checked
def New(tp: Type)(implicit ctx: Context): New =
Trees.New(TypeTree(tp)).withType(tp).checked
def Pair(left: Tree, right: Tree)(implicit ctx: Context): Pair =
Trees.Pair(left, right).withType(defn.PairType.appliedTo(left.tpe, right.tpe)).checked
def Typed(expr: Tree, tpt: Tree)(implicit ctx: Context): Typed =
Trees.Typed(expr, tpt).withType(tpt.tpe).checked
def NamedArg(name: TermName, arg: Tree)(implicit ctx: Context) =
Trees.NamedArg(name, arg).withType(arg.tpe).checked
def Assign(lhs: Tree, rhs: Tree)(implicit ctx: Context): Assign =
Trees.Assign(lhs, rhs).withType(defn.UnitType).checked
def Block(stats: List[Tree], expr: Tree)(implicit ctx: Context): Block = {
lazy val locals = localSyms(stats)
val blk = Trees.Block(stats, expr)
def widen(tp: Type): Type = tp match {
case tp: TermRef if locals contains tp.symbol =>
widen(tp.info)
case _ => tp
}
blk.withType(widen(expr.tpe))
}
def If(cond: Tree, thenp: Tree, elsep: Tree)(implicit ctx: Context): If =
Trees.If(cond, thenp, elsep).withType(thenp.tpe | elsep.tpe).checked
def Match(selector: Tree, cases: List[CaseDef])(implicit ctx: Context): Match =
Trees.Match(selector, cases).withType(ctx.lub(cases map (_.body.tpe))).checked
def CaseDef(pat: Tree, guard: Tree, body: Tree)(implicit ctx: Context): CaseDef =
Trees.CaseDef(pat, guard, body).withType(body.tpe).checked
def Return(expr: Tree, from: Ident)(implicit ctx: Context): Return =
Trees.Return(expr, from).withType(defn.NothingType).checked
def Throw(expr: Tree)(implicit ctx: Context): Throw =
Trees.Throw(expr).withType(defn.NothingType).checked
def SeqLiteral(elemtpt: Tree, elems: List[Tree])(implicit ctx: Context): SeqLiteral =
Trees.SeqLiteral(elemtpt, elems).withType(defn.RepeatedParamType.appliedTo(elemtpt.tpe)).checked
def TypeTree(tp: Type, original: Tree = EmptyTree)(implicit ctx: Context): TypeTree =
Trees.TypeTree(original).withType(tp).checked
def SingletonTypeTree(ref: Tree)(implicit ctx: Context): SingletonTypeTree =
Trees.SingletonTypeTree(ref).withType(ref.tpe).checked
def SelectFromTypeTree(qualifier: Tree, tp: TypeRef)(implicit ctx: Context): SelectFromTypeTree =
Trees.SelectFromTypeTree(qualifier, tp.name).withType(tp).checked
def AndTypeTree(left: Tree, right: Tree)(implicit ctx: Context): AndTypeTree =
Trees.AndTypeTree(left, right).withType(left.tpe & right.tpe).checked
def OrTypeTree(left: Tree, right: Tree)(implicit ctx: Context): OrTypeTree =
Trees.OrTypeTree(left, right).withType(left.tpe | right.tpe).checked
def RefineTypeTree(tpt: Tree, refinements: List[DefTree])(implicit ctx: Context): RefineTypeTree = {
def refineType(tp: Type, refinement: Symbol): Type =
RefinedType(tp, refinement.name, refinement.info)
Trees.RefineTypeTree(tpt, refinements)
.withType((tpt.tpe /: (refinements map (_.symbol)))(refineType)).checked
}
def refineType(tp: Type, refinement: Symbol)(implicit ctx: Context): Type =
RefinedType(tp, refinement.name, refinement.info)
def AppliedTypeTree(tpt: Tree, args: List[Tree])(implicit ctx: Context): AppliedTypeTree =
Trees.AppliedTypeTree(tpt, args).withType(tpt.tpe.appliedTo(args map (_.tpe))).checked
def TypeBoundsTree(lo: Tree, hi: Tree)(implicit ctx: Context): TypeBoundsTree =
Trees.TypeBoundsTree(lo, hi).withType(TypeBounds(lo.tpe, hi.tpe)).checked
def Bind(sym: TermSymbol, body: Tree)(implicit ctx: Context): Bind =
Trees.Bind(sym.name, body)(defPos(sym)).withType(refType(sym)).checked
def Alternative(trees: List[Tree])(implicit ctx: Context): Alternative =
Trees.Alternative(trees).withType(ctx.lub(trees map (_.tpe))).checked
def UnApply(fun: Tree, args: List[Tree])(implicit ctx: Context): UnApply =
Trees.UnApply(fun, args).withType(fun.tpe.widen match {
case MethodType(_, paramType :: Nil) => paramType
}).checked
def refType(sym: Symbol)(implicit ctx: Context) = NamedType(sym.owner.thisType, sym)
def ValDef(sym: TermSymbol, rhs: Tree = EmptyTree)(implicit ctx: Context): ValDef =
Trees.ValDef(Modifiers(sym), sym.name, TypeTree(sym.info), rhs)(defPos(sym))
.withType(refType(sym)).checked
def DefDef(sym: TermSymbol, rhs: Tree = EmptyTree)(implicit ctx: Context): DefDef = {
val (tparams, mtp) = sym.info match {
case tp: PolyType =>
val tparams = ctx.newTypeParams(sym, tp.paramNames, EmptyFlags, tp.instantiateBounds)
(tparams, tp.instantiate(tparams map (_.typeConstructor)))
case tp => (Nil, tp)
}
def valueParamss(tp: Type): (List[List[TermSymbol]], Type) = tp match {
case tp @ MethodType(paramNames, paramTypes) =>
def valueParam(name: TermName, info: Type): TermSymbol =
ctx.newSymbol(sym, name, TermParam, info)
val params = (paramNames, paramTypes).zipped.map(valueParam)
val (paramss, rtp) = valueParamss(tp.instantiate(params map (_.typeConstructor)))
(params :: paramss, rtp)
case tp => (Nil, tp)
}
val (vparamss, rtp) = valueParamss(mtp)
Trees.DefDef(
Modifiers(sym), sym.name, tparams map TypeDef,
vparamss map (_ map (ValDef(_))), TypeTree(rtp), rhs)(defPos(sym))
.withType(refType(sym)).checked
}
def TypeDef(sym: TypeSymbol)(implicit ctx: Context): TypeDef =
Trees.TypeDef(Modifiers(sym), sym.name, TypeTree(sym.info))(defPos(sym))
.withType(refType(sym)).checked
def ClassDef(cls: ClassSymbol, typeParams: List[TypeSymbol], body: List[Tree])(implicit ctx: Context): ClassDef = {
val parents = cls.info.parents map (TypeTree(_))
val selfType =
if (cls.selfType eq cls.typeConstructor) EmptyValDef
else ValDef(ctx.newSelfSym(cls))
def isOwnTypeParamAccessor(stat: Tree) =
stat.symbol.owner == cls && (stat.symbol is TypeParam)
val (tparamAccessors, rest) = body partition isOwnTypeParamAccessor
val tparams =
(typeParams map TypeDef) ++
(tparamAccessors collect {
case td: TypeDef if !(typeParams contains td.symbol) => td
})
val findLocalDummy = new FindLocalDummyAccumulator(cls)
val localDummy = ((NoSymbol: Symbol) /: body)(findLocalDummy)
.orElse(ctx.newLocalDummy(cls))
val impl = Trees.Template(parents, selfType, rest)
.withType(refType(localDummy)).checked
Trees.ClassDef(Modifiers(cls), cls.name, tparams, impl)(defPos(cls))
.withType(refType(cls)).checked
}
def Import(expr: Tree, selectors: List[Trees.UntypedTree])(implicit ctx: Context): Import =
Trees.Import(expr, selectors).withType(refType(ctx.newImportSymbol(Shared(expr)))).checked
def PackageDef(pid: RefTree, stats: List[Tree])(implicit ctx: Context): PackageDef =
Trees.PackageDef(pid, stats).withType(refType(pid.symbol)).checked
def Annotated(annot: Tree, arg: Tree)(implicit ctx: Context): Annotated =
Trees.Annotated(annot, arg).withType(AnnotatedType(List(Annotation(annot)), arg.tpe)).checked
val EmptyTree: Tree = Trees.EmptyTree[Type]
val EmptyValDef: ValDef = Trees.EmptyValDef[Type]
def Shared(tree: Tree): Shared =
Trees.Shared(tree).withType(tree.tpe)
// ------ Creating typed equivalents of trees that exist only in untyped form -------
def New(tp: Type, args: List[Tree])(implicit ctx: Context): Apply =
Apply(
Select(
New(tp),
TermRef(tp.normalizedPrefix, tp.typeSymbol.primaryConstructor.asTerm)),
args)
/** An object def
*
* object obs extends parents { decls }
*
* gets expanded to
*
* <module> lazy val obj = {
* class obj$ extends parents { this: obj.type => decls }
* new obj$
* }
*
* What's interesting here is that the block is well typed
* (because class obj$ is hoistable), but the type of the `obj` val is
* not expressible. What needs to happen in general when
* inferring the type of a val from its RHS, is: if the type contains
* a class that has the val itself as owner, then that class
* is remapped to have the val's owner as owner. Remapping could be
* done by cloning the class with the new owner and substituting
* everywhere in the tree. We know that remapping is safe
* because the only way a local class can appear in the RHS of a val is
* by being hoisted outside of a block, and the necessary checks are
* done at this point already.
*
* On the other hand, for method result type inference, if the type of
* the RHS of a method contains a class owned by the method, this would be
* an error.
*/
def ModuleDef(sym: TermSymbol, body: List[Tree])(implicit ctx: Context): ValDef = {
val modcls = sym.moduleClass.asClass
val clsdef = ClassDef(modcls, Nil, body)
val rhs = Block(List(clsdef), New(modcls.typeConstructor))
ValDef(sym, rhs)
}
/** A function def
*
* vparams => expr
*
* gets expanded to
*
* { def $anonfun(vparams) = expr; $anonfun: pt }
*
* where pt is the target type of the expression (FunctionN) unless
* otherwise specified.
*/
def Function(meth: TermSymbol, body: Tree, target: Type = NoType)(implicit ctx: Context): Block = {
val funtpe =
if (target.exists) target
else meth.info match {
case mt @ MethodType(_, formals) =>
assert(!mt.isDependent)
defn.FunctionType(formals, mt.resultType)
}
Block(
DefDef(meth, body) :: Nil,
Typed(Ident(TermRef(NoPrefix, meth)), TypeTree(funtpe)))
}
private class FindLocalDummyAccumulator(cls: ClassSymbol)(implicit ctx: Context) extends TreeAccumulator[Symbol] {
def apply(sym: Symbol, tree: Tree) =
if (sym.exists) sym
else if (tree.isDef) {
val owner = tree.symbol.owner
if (owner.isLocalDummy && owner.owner == cls) owner
else if (owner == cls) foldOver(sym, tree)
else sym
} else foldOver(sym, tree)
}
implicit class addChecked[T <: Tree](val tree: T) extends AnyVal {
def checked(implicit ctx: Context): T = {
if (ctx.settings.YcheckTypedTrees.value) checkType(tree)
tree
}
}
}
import Trees._
def check(p: Boolean)(implicit ctx: Context): Unit = assert(p)
def checkType(tree: tpd.Tree)(implicit ctx: Context): Unit = tree match {
case Ident(name) =>
case Select(qualifier, name) =>
check(qualifier.isValue)
val denot = qualifier.tpe.member(name)
check(denot.hasAltWith(_.symbol == tree.symbol))
case This(cls) =>
case Super(qual, mixin) =>
check(qual.isValue)
val cls = qual.tpe.typeSymbol
check(cls.isClass)
check(mixin == NoSymbol || (cls.asClass.parents map (_.typeSymbol) contains mixin))
case Apply(fn, args) =>
def checkArg(arg: tpd.Tree, name: Name, formal: Type): Unit = {
arg match {
case NamedArg(argName, _) =>
check(argName == name)
case SeqLiteral(_, _) =>
check(defn.RepeatedParamClasses contains formal.typeSymbol)
case _ =>
check(arg.isValue)
}
check(arg.tpe <:< formal)
}
fn.tpe.widen match {
case MethodType(paramNames, paramTypes) =>
(args, paramNames, paramTypes).zipped foreach checkArg
case _ =>
check(false)
}
case TypeApply(fn, args) =>
def checkArg(arg: tpd.Tree, bounds: TypeBounds): Unit = {
check(arg.isType)
check(bounds contains arg.tpe)
}
fn.tpe.widen match {
case pt: PolyType =>
(args, pt.instantiateBounds(args map (_.tpe))).zipped foreach checkArg
case _ =>
check(false)
}
case Literal(const: Constant) =>
case New(tpt) =>
check(tpt.isType)
val cls = tpt.tpe.typeSymbol
check(cls.isClass)
check(!(cls is AbstractOrTrait))
case Pair(left, right) =>
check(left.isValue)
check(right.isValue)
case Typed(expr, tpt) =>
check(tpt.isType)
expr.tpe.widen match {
case tp: MethodType =>
val cls = tpt.tpe.typeSymbol
check(cls.isClass)
check((cls is Trait) ||
cls.primaryConstructor.info.paramTypess.flatten.isEmpty)
val absMembers = tpt.tpe.abstractTermMembers
check(absMembers.size == 1)
check(tp <:< absMembers.head.info)
case _ =>
check(expr.isValueOrPattern)
}
case NamedArg(name, arg) =>
case Assign(lhs, rhs) =>
check(lhs.isValue); check(rhs.isValue)
lhs.tpe match {
case ltpe: TermRef =>
check(ltpe.symbol is Mutable)
case _ =>
check(false)
}
check(rhs.tpe <:< lhs.tpe.widen)
case Block(stats, expr) =>
var hoisted: Set[Symbol] = Set()
lazy val locals = localSyms(stats)
check(expr.isValue)
def isNonLocal(sym: Symbol): Boolean =
!(locals contains sym) || isHoistableClass(sym)
def isHoistableClass(sym: Symbol) =
sym.isClass && {
(hoisted contains sym) || {
hoisted += sym
noLeaksInClass(sym.asClass)
}
}
def noLeaksIn(tp: Type): Boolean = tp forall {
case tp: NamedType => isNonLocal(tp.symbol)
case _ => true
}
def noLeaksInClass(sym: ClassSymbol): Boolean =
(sym.parents forall noLeaksIn) &&
(sym.decls.toList forall (t => noLeaksIn(t.info)))
check(noLeaksIn(tree.tpe))
case If(cond, thenp, elsep) =>
check(cond.isValue); check(thenp.isValue); check(elsep.isValue)
check(cond.tpe <:< defn.BooleanType)
case Match(selector, cases) =>
check(selector.isValue)
// are any checks that relate selector and patterns desirable?
case CaseDef(pat, guard, body) =>
check(pat.isValueOrPattern); check(guard.isValue); check(body.isValue)
check(guard.tpe <:< defn.BooleanType)
case Return(expr, from) =>
check(expr.isValue); check(from.isTerm)
check(from.tpe.termSymbol.isSourceMethod)
case Throw(expr) =>
check(expr.isValue)
check(expr.tpe <:< defn.ThrowableType)
case SeqLiteral(elemtpt, elems) =>
check(elemtpt.isType);
for (elem <- elems) {
check(elem.isValue)
check(elem.tpe <:< elemtpt.tpe)
}
case TypeTree(original) =>
if (!original.isEmpty) check(original.tpe == tree.tpe)
case SingletonTypeTree(ref) =>
check(ref.isValue)
check(ref.symbol.isStable)
case SelectFromTypeTree(qualifier, name) =>
check(qualifier.isType)
val denot = qualifier.tpe.member(name)
check(denot.exists)
check(denot.symbol == tree.symbol)
case AndTypeTree(left, right) =>
check(left.isType); check(right.isType)
case OrTypeTree(left, right) =>
check(left.isType); check(right.isType)
case RefineTypeTree(tpt, refinements) =>
check(tpt.isType)
def checkRefinements(forbidden: Set[Symbol], rs: List[tpd.DefTree]): Unit = rs match {
case r :: rs1 =>
val rsym = r.symbol
check(rsym.isTerm || rsym.isAbstractType)
if (rsym.isAbstractType) check(tpt.tpe.member(rsym.name).exists)
check(rsym.info forall {
case nt: NamedType => !(forbidden contains nt.symbol)
case _ => true
})
checkRefinements(forbidden - rsym, rs1)
case nil =>
}
checkRefinements(localSyms(refinements).toSet, refinements)
case AppliedTypeTree(tpt, args) =>
check(tpt.isType)
for (arg <- args) check(arg.isType)
check(sameLength(tpt.tpe.typeParams, args))
case TypeBoundsTree(lo, hi) =>
check(lo.isType); check(hi.isType)
check(lo.tpe <:< hi.tpe)
case Bind(sym, body) =>
// missing because it cannot be done easily bottom-up:
// check that Bind (and Alternative, and UnApply) only occur in patterns
check(body.isValueOrPattern)
check(!(tree.symbol is Method))
body match {
case Ident(nme.WILDCARD) =>
case _ => check(body.tpe <:< tree.symbol.info)
}
case Alternative(alts) =>
for (alt <- alts) check(alt.isValueOrPattern)
case UnApply(fun, args) =>
check(fun.isTerm)
val funtpe = fun.tpe.widen match {
case mt: MethodType => mt
case _ => check(false); ErrorType
}
for (arg <- args) check(arg.isValueOrPattern)
fun.symbol.name match { // check arg arity
case nme.unapplySeq =>
// args need to be wrapped in (...: _*)
check(args.length == 1)
check(args.head.tpe.typeSymbol == defn.RepeatedParamClass)
case nme.unapply =>
val rtp = funtpe.resultType
if (rtp == defn.BooleanType)
check(args.isEmpty)
else {
val (tycon, resArgs) = rtp.splitArgs
check(tycon == defn.OptionType)
check(resArgs.length == 1)
val normArgs = {
val (tp1, args1) = resArgs.head.splitArgs
if (defn.TupleClasses contains tp1.typeSymbol) args1
else args.head :: Nil
}
check(sameLength(normArgs, args))
}
}
case ValDef(mods, name, tpt, rhs) =>
check(!(tree.symbol is Method))
if (!rhs.isEmpty) {
check(rhs.isValue)
check(rhs.tpe <:< tpt.tpe)
}
case DefDef(mods, name, tparams, vparamss, tpt, rhs) =>
check(tree.symbol is Method)
if (!rhs.isEmpty) {
check(rhs.isValue)
check(rhs.tpe <:< tpt.tpe)
}
case TypeDef(mods, name, tpt) =>
check(tpt.tpe.isInstanceOf[TypeBounds])
case Template(parents, selfType, body) =>
case ClassDef(mods, name, tparams, impl) =>
case Import(expr, selectors) =>
check(expr.isValue)
check(expr.tpe.termSymbol.isStable)
case PackageDef(pid, stats) =>
check(pid.isValue)
check(pid.symbol.isPackage)
case Annotated(annot, arg) =>
check(annot.symbol.isClassConstructor)
check(annot.symbol.owner.isSubClass(defn.AnnotationClass))
check(arg.isType || arg.isValue)
case tpd.EmptyTree =>
case Shared(shared) =>
check(shared.isType || shared.isTerm)
}
implicit class TreeInfo(val tree: tpd.Tree) extends AnyVal {
def isValue(implicit ctx: Context): Boolean =
tree.isTerm && tree.tpe.widen.isValueType
def isValueOrPattern(implicit ctx: Context) =
tree.isValue || tree.isPattern
}
// ensure that constructors are fully applied?
// ensure that normal methods are fully applied?
def localSyms(stats: List[tpd.Tree])(implicit ctx: Context) =
for (stat <- stats if (stat.isDef)) yield stat.symbol
}
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