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/* NSC -- new Scala compiler
* Copyright 2005-2013 LAMP/EPFL
* @author Martin Odersky
*/
// Added: Sat Oct 7 16:08:21 2006
//todo: use inherited type info also for vars and values
// Added: Thu Apr 12 18:23:58 2007
//todo: disallow C#D in superclass
//todo: treat :::= correctly
package scala
package tools.nsc
package typechecker
import scala.collection.{mutable, immutable}
import scala.reflect.internal.util.{ BatchSourceFile, Statistics, shortClassOfInstance }
import mutable.ListBuffer
import symtab.Flags._
import Mode._
// Suggestion check whether we can do without priming scopes with symbols of outer scopes,
// like the IDE does.
/** This trait provides methods to assign types to trees.
*
* @author Martin Odersky
* @version 1.0
*/
trait Typers extends Adaptations with Tags with TypersTracking with PatternTypers {
self: Analyzer =>
import global._
import definitions._
import TypersStats._
final def forArgMode(fun: Tree, mode: Mode) =
if (treeInfo.isSelfOrSuperConstrCall(fun)) mode | SCCmode else mode
// namer calls typer.computeType(rhs) on DefDef / ValDef when tpt is empty. the result
// is cached here and re-used in typedDefDef / typedValDef
// Also used to cache imports type-checked by namer.
val transformed = new mutable.AnyRefMap[Tree, Tree]
final val shortenImports = false
// allows override of the behavior of the resetTyper method w.r.t comments
def resetDocComments() = {
clearDocComments()
}
def resetTyper() {
//println("resetTyper called")
resetContexts()
resetImplicits()
resetDocComments()
}
sealed abstract class SilentResult[+T] {
def isEmpty: Boolean
def nonEmpty = !isEmpty
@inline final def fold[U](none: => U)(f: T => U): U = this match {
case SilentResultValue(value) => f(value)
case _ => none
}
@inline final def map[U](f: T => U): SilentResult[U] = this match {
case SilentResultValue(value) => SilentResultValue(f(value))
case x: SilentTypeError => x
}
@inline final def filter(p: T => Boolean): SilentResult[T] = this match {
case SilentResultValue(value) if !p(value) => SilentTypeError(TypeErrorWrapper(new TypeError(NoPosition, "!p")))
case _ => this
}
@inline final def orElse[T1 >: T](f: Seq[AbsTypeError] => T1): T1 = this match {
case SilentResultValue(value) => value
case s : SilentTypeError => f(s.reportableErrors)
}
}
class SilentTypeError private(val errors: List[AbsTypeError]) extends SilentResult[Nothing] {
override def isEmpty = true
def err: AbsTypeError = errors.head
def reportableErrors = errors match {
case (e1: AmbiguousImplicitTypeError) +: _ =>
List(e1) // DRYer error reporting for neg/t6436b.scala
case all =>
all
}
}
object SilentTypeError {
def apply(errors: AbsTypeError*): SilentTypeError = new SilentTypeError(errors.toList)
def unapply(error: SilentTypeError): Option[AbsTypeError] = error.errors.headOption
}
case class SilentResultValue[+T](value: T) extends SilentResult[T] { override def isEmpty = false }
def newTyper(context: Context): Typer = new NormalTyper(context)
private class NormalTyper(context : Context) extends Typer(context)
// A transient flag to mark members of anonymous classes
// that are turned private by typedBlock
private final val SYNTHETIC_PRIVATE = TRANS_FLAG
private final val InterpolatorCodeRegex = """\$\{.*?\}""".r
private final val InterpolatorIdentRegex = """\$[$\w]+""".r // note that \w doesn't include $
abstract class Typer(context0: Context) extends TyperDiagnostics with Adaptation with Tag with PatternTyper with TyperContextErrors {
import context0.unit
import typeDebug.{ ptTree, ptBlock, ptLine, inGreen, inRed }
import TyperErrorGen._
val runDefinitions = currentRun.runDefinitions
import runDefinitions._
private val transformed: mutable.Map[Tree, Tree] = unit.transformed
val infer = new Inferencer {
def context = Typer.this.context
// See SI-3281 re undoLog
override def isCoercible(tp: Type, pt: Type) = undoLog undo viewExists(tp, pt)
}
/** Overridden to false in scaladoc and/or interactive. */
def canAdaptConstantTypeToLiteral = true
def canTranslateEmptyListToNil = true
def missingSelectErrorTree(tree: Tree, qual: Tree, name: Name): Tree = tree
def typedDocDef(docDef: DocDef, mode: Mode, pt: Type): Tree =
typed(docDef.definition, mode, pt)
/** Find implicit arguments and pass them to given tree.
*/
def applyImplicitArgs(fun: Tree): Tree = fun.tpe match {
case MethodType(params, _) =>
val argResultsBuff = new ListBuffer[SearchResult]()
val argBuff = new ListBuffer[Tree]()
// paramFailed cannot be initialized with params.exists(_.tpe.isError) because that would
// hide some valid errors for params preceding the erroneous one.
var paramFailed = false
var mkArg: (Name, Tree) => Tree = (_, tree) => tree
// DEPMETTODO: instantiate type vars that depend on earlier implicit args (see adapt (4.1))
//
// apply the substitutions (undet type param -> type) that were determined
// by implicit resolution of implicit arguments on the left of this argument
for(param <- params) {
var paramTp = param.tpe
for(ar <- argResultsBuff)
paramTp = paramTp.subst(ar.subst.from, ar.subst.to)
val res = if (paramFailed || (paramTp.isError && {paramFailed = true; true})) SearchFailure else inferImplicit(fun, paramTp, context.reportErrors, isView = false, context)
argResultsBuff += res
if (res.isSuccess) {
argBuff += mkArg(param.name, res.tree)
} else {
mkArg = gen.mkNamedArg // don't pass the default argument (if any) here, but start emitting named arguments for the following args
if (!param.hasDefault && !paramFailed) {
context.reportBuffer.errors.collectFirst {
case dte: DivergentImplicitTypeError => dte
} match {
case Some(divergent) =>
// DivergentImplicit error has higher priority than "no implicit found"
// no need to issue the problem again if we are still in silent mode
if (context.reportErrors) {
context.issue(divergent.withPt(paramTp))
context.reportBuffer.clearErrors {
case dte: DivergentImplicitTypeError => true
}
}
case _ =>
NoImplicitFoundError(fun, param)
}
paramFailed = true
}
/* else {
TODO: alternative (to expose implicit search failure more) -->
resolve argument, do type inference, keep emitting positional args, infer type params based on default value for arg
for (ar <- argResultsBuff) ar.subst traverse defaultVal
val targs = exprTypeArgs(context.undetparams, defaultVal.tpe, paramTp)
substExpr(tree, tparams, targs, pt)
}*/
}
}
val args = argBuff.toList
for (ar <- argResultsBuff) {
ar.subst traverse fun
for (arg <- args) ar.subst traverse arg
}
new ApplyToImplicitArgs(fun, args) setPos fun.pos
case ErrorType =>
fun
}
def viewExists(from: Type, to: Type): Boolean = (
!from.isError
&& !to.isError
&& context.implicitsEnabled
&& (inferView(EmptyTree, from, to, reportAmbiguous = false) != EmptyTree)
)
def inferView(tree: Tree, from: Type, to: Type, reportAmbiguous: Boolean): Tree =
inferView(tree, from, to, reportAmbiguous, saveErrors = true)
/** Infer an implicit conversion (`view`) between two types.
* @param tree The tree which needs to be converted.
* @param from The source type of the conversion
* @param to The target type of the conversion
* @param reportAmbiguous Should ambiguous implicit errors be reported?
* False iff we search for a view to find out
* whether one type is coercible to another.
* @param saveErrors Should ambiguous and divergent implicit errors that were buffered
* during the inference of a view be put into the original buffer.
* False iff we don't care about them.
*/
def inferView(tree: Tree, from: Type, to: Type, reportAmbiguous: Boolean, saveErrors: Boolean): Tree = {
debuglog("infer view from "+from+" to "+to)//debug
if (isPastTyper) EmptyTree
else from match {
case MethodType(_, _) => EmptyTree
case OverloadedType(_, _) => EmptyTree
case PolyType(_, _) => EmptyTree
case _ =>
def wrapImplicit(from: Type): Tree = {
val result = inferImplicit(tree, functionType(from.withoutAnnotations :: Nil, to), reportAmbiguous, isView = true, context, saveAmbiguousDivergent = saveErrors)
if (result.subst != EmptyTreeTypeSubstituter) {
result.subst traverse tree
notifyUndetparamsInferred(result.subst.from, result.subst.to)
}
result.tree
}
wrapImplicit(from) orElse wrapImplicit(byNameType(from))
}
}
import infer._
private var namerCache: Namer = null
def namer = {
if ((namerCache eq null) || namerCache.context != context)
namerCache = newNamer(context)
namerCache
}
var context = context0
def context1 = context
def dropExistential(tp: Type): Type = tp match {
case ExistentialType(tparams, tpe) =>
new SubstWildcardMap(tparams).apply(tp)
case TypeRef(_, sym, _) if sym.isAliasType =>
val tp0 = tp.dealias
if (tp eq tp0) {
debugwarn(s"dropExistential did not progress dealiasing $tp, see SI-7126")
tp
} else {
val tp1 = dropExistential(tp0)
if (tp1 eq tp0) tp else tp1
}
case _ => tp
}
private def errorNotClass(tpt: Tree, found: Type) = { ClassTypeRequiredError(tpt, found); false }
private def errorNotStable(tpt: Tree, found: Type) = { TypeNotAStablePrefixError(tpt, found); false }
/** Check that `tpt` refers to a non-refinement class type */
def checkClassType(tpt: Tree): Boolean = {
val tpe = unwrapToClass(tpt.tpe)
isNonRefinementClassType(tpe) || errorNotClass(tpt, tpe)
}
/** Check that `tpt` refers to a class type with a stable prefix. */
def checkStablePrefixClassType(tpt: Tree): Boolean = {
val tpe = unwrapToStableClass(tpt.tpe)
def prefixIsStable = {
def checkPre = tpe match {
case TypeRef(pre, _, _) => pre.isStable || errorNotStable(tpt, pre)
case _ => false
}
// A type projection like X#Y can get by the stable check if the
// prefix is singleton-bounded, so peek at the tree too.
def checkTree = tpt match {
case SelectFromTypeTree(qual, _) => isSingleType(qual.tpe) || errorNotClass(tpt, tpe)
case _ => true
}
checkPre && checkTree
}
( (isNonRefinementClassType(tpe) || errorNotClass(tpt, tpe))
&& (isPastTyper || prefixIsStable)
)
}
/** Check that type `tp` is not a subtype of itself.
*/
def checkNonCyclic(pos: Position, tp: Type): Boolean = {
def checkNotLocked(sym: Symbol) = {
sym.initialize.lockOK || { CyclicAliasingOrSubtypingError(pos, sym); false }
}
tp match {
case TypeRef(pre, sym, args) =>
checkNotLocked(sym) &&
((!sym.isNonClassType) || checkNonCyclic(pos, appliedType(pre.memberInfo(sym), args), sym))
// @M! info for a type ref to a type parameter now returns a polytype
// @M was: checkNonCyclic(pos, pre.memberInfo(sym).subst(sym.typeParams, args), sym)
case SingleType(pre, sym) =>
checkNotLocked(sym)
case st: SubType =>
checkNonCyclic(pos, st.supertype)
case ct: CompoundType =>
ct.parents forall (x => checkNonCyclic(pos, x))
case _ =>
true
}
}
def checkNonCyclic(pos: Position, tp: Type, lockedSym: Symbol): Boolean = try {
if (!lockedSym.lock(CyclicReferenceError(pos, tp, lockedSym))) false
else checkNonCyclic(pos, tp)
} finally {
lockedSym.unlock()
}
def checkNonCyclic(sym: Symbol) {
if (!checkNonCyclic(sym.pos, sym.tpe_*)) sym.setInfo(ErrorType)
}
def checkNonCyclic(defn: Tree, tpt: Tree) {
if (!checkNonCyclic(defn.pos, tpt.tpe, defn.symbol)) {
tpt setType ErrorType
defn.symbol.setInfo(ErrorType)
}
}
def checkParamsConvertible(tree: Tree, tpe0: Type) {
def checkParamsConvertible0(tpe: Type) =
tpe match {
case MethodType(formals, restpe) =>
/*
if (formals.exists(_.typeSymbol == ByNameParamClass) && formals.length != 1)
error(pos, "methods with `=>`-parameter can be converted to function values only if they take no other parameters")
if (formals exists (isRepeatedParamType(_)))
error(pos, "methods with `*`-parameters cannot be converted to function values");
*/
if (tpe.isDependentMethodType)
DependentMethodTpeConversionToFunctionError(tree, tpe)
checkParamsConvertible(tree, restpe)
case _ =>
}
checkParamsConvertible0(tpe0)
}
/** Check that type of given tree does not contain local or private
* components.
*/
object checkNoEscaping extends TypeMap {
private var owner: Symbol = _
private var scope: Scope = _
private var hiddenSymbols: List[Symbol] = _
/** Check that type `tree` does not refer to private
* components unless itself is wrapped in something private
* (`owner` tells where the type occurs).
*/
def privates[T <: Tree](owner: Symbol, tree: T): T =
check(owner, EmptyScope, WildcardType, tree)
private def check[T <: Tree](owner: Symbol, scope: Scope, pt: Type, tree: T): T = {
this.owner = owner
this.scope = scope
hiddenSymbols = List()
val tp1 = apply(tree.tpe)
if (hiddenSymbols.isEmpty) tree setType tp1
else if (hiddenSymbols exists (_.isErroneous)) HiddenSymbolWithError(tree)
else if (isFullyDefined(pt)) tree setType pt
else if (tp1.typeSymbol.isAnonymousClass)
check(owner, scope, pt, tree setType tp1.typeSymbol.classBound)
else if (owner == NoSymbol)
tree setType packSymbols(hiddenSymbols.reverse, tp1)
else if (!isPastTyper) { // privates
val badSymbol = hiddenSymbols.head
SymbolEscapesScopeError(tree, badSymbol)
} else tree
}
def addHidden(sym: Symbol) =
if (!(hiddenSymbols contains sym)) hiddenSymbols = sym :: hiddenSymbols
override def apply(t: Type): Type = {
def checkNoEscape(sym: Symbol) {
if (sym.isPrivate && !sym.hasFlag(SYNTHETIC_PRIVATE)) {
var o = owner
while (o != NoSymbol && o != sym.owner && o != sym.owner.linkedClassOfClass &&
!o.isLocalToBlock && !o.isPrivate &&
!o.privateWithin.hasTransOwner(sym.owner))
o = o.owner
if (o == sym.owner || o == sym.owner.linkedClassOfClass)
addHidden(sym)
} else if (sym.owner.isTerm && !sym.isTypeParameterOrSkolem) {
var e = scope.lookupEntry(sym.name)
var found = false
while (!found && (e ne null) && e.owner == scope) {
if (e.sym == sym) {
found = true
addHidden(sym)
} else {
e = scope.lookupNextEntry(e)
}
}
}
}
mapOver(
t match {
case TypeRef(_, sym, args) =>
checkNoEscape(sym)
if (!hiddenSymbols.isEmpty && hiddenSymbols.head == sym &&
sym.isAliasType && sameLength(sym.typeParams, args)) {
hiddenSymbols = hiddenSymbols.tail
t.dealias
} else t
case SingleType(_, sym) =>
checkNoEscape(sym)
t
case _ =>
t
})
}
}
def reenterValueParams(vparamss: List[List[ValDef]]) {
for (vparams <- vparamss)
for (vparam <- vparams)
context.scope enter vparam.symbol
}
def reenterTypeParams(tparams: List[TypeDef]): List[Symbol] =
for (tparam <- tparams) yield {
context.scope enter tparam.symbol
tparam.symbol.deSkolemize
}
/** The qualifying class
* of a this or super with prefix `qual`.
* packageOk is equal false when qualifying class symbol
*/
def qualifyingClass(tree: Tree, qual: Name, packageOK: Boolean) =
context.enclClass.owner.ownerChain.find(o => qual.isEmpty || o.isClass && o.name == qual) match {
case Some(c) if packageOK || !c.isPackageClass => c
case _ => QualifyingClassError(tree, qual) ; NoSymbol
}
/** The typer for an expression, depending on where we are. If we are before a superclass
* call, this is a typer over a constructor context; otherwise it is the current typer.
*/
final def constrTyperIf(inConstr: Boolean): Typer =
if (inConstr) {
assert(context.undetparams.isEmpty, context.undetparams)
newTyper(context.makeConstructorContext)
} else this
@inline
final def withCondConstrTyper[T](inConstr: Boolean)(f: Typer => T): T =
if (inConstr) {
assert(context.undetparams.isEmpty, context.undetparams)
val c = context.makeConstructorContext
typerWithLocalContext(c)(f)
} else {
f(this)
}
@inline
final def typerWithCondLocalContext[T](c: => Context)(cond: Boolean)(f: Typer => T): T =
if (cond) typerWithLocalContext(c)(f) else f(this)
@inline
final def typerWithLocalContext[T](c: Context)(f: Typer => T): T = {
val res = f(newTyper(c))
if (c.hasErrors)
context.updateBuffer(c.flushAndReturnBuffer())
res
}
@inline
final def withSavedContext[T](c: Context)(f: => T) = {
val savedErrors = c.flushAndReturnBuffer()
val res = f
c.updateBuffer(savedErrors)
res
}
/** The typer for a label definition. If this is part of a template we
* first have to enter the label definition.
*/
def labelTyper(ldef: LabelDef): Typer =
if (ldef.symbol == NoSymbol) { // labeldef is part of template
val typer1 = newTyper(context.makeNewScope(ldef, context.owner))
typer1.enterLabelDef(ldef)
typer1
} else this
/** Is symbol defined and not stale?
*/
def reallyExists(sym: Symbol) = {
if (isStale(sym)) sym.setInfo(NoType)
sym.exists
}
/** A symbol is stale if it is toplevel, to be loaded from a classfile, and
* the classfile is produced from a sourcefile which is compiled in the current run.
*/
def isStale(sym: Symbol): Boolean = {
sym.rawInfo.isInstanceOf[loaders.ClassfileLoader] && {
sym.rawInfo.load(sym)
(sym.sourceFile ne null) &&
(currentRun.compiledFiles contains sym.sourceFile.path)
}
}
/** Does the context of tree `tree` require a stable type?
*/
private def isStableContext(tree: Tree, mode: Mode, pt: Type) = {
def ptSym = pt.typeSymbol
def expectsStable = (
pt.isStable
|| mode.inQualMode && !tree.symbol.isConstant
|| !(tree.tpe <:< pt) && (ptSym.isAbstractType && pt.bounds.lo.isStable || ptSym.isRefinementClass)
)
( isNarrowable(tree.tpe)
&& mode.typingExprNotLhs
&& expectsStable
)
}
/** Make symbol accessible. This means:
* If symbol refers to package object, insert `.package` as second to last selector.
* (exception for some symbols in scala package which are dealiased immediately)
* Call checkAccessible, which sets tree's attributes.
* Also note that checkAccessible looks up sym on pre without checking that pre is well-formed
* (illegal type applications in pre will be skipped -- that's why typedSelect wraps the resulting tree in a TreeWithDeferredChecks)
* @return modified tree and new prefix type
*/
private def makeAccessible(tree: Tree, sym: Symbol, pre: Type, site: Tree): (Tree, Type) =
if (context.isInPackageObject(sym, pre.typeSymbol)) {
if (pre.typeSymbol == ScalaPackageClass && sym.isTerm) {
// short cut some aliases. It seems pattern matching needs this
// to notice exhaustiveness and to generate good code when
// List extractors are mixed with :: patterns. See Test5 in lists.scala.
//
// TODO SI-6609 Eliminate this special case once the old pattern matcher is removed.
def dealias(sym: Symbol) =
(atPos(tree.pos.makeTransparent) {gen.mkAttributedRef(sym)} setPos tree.pos, sym.owner.thisType)
sym.name match {
case nme.List => return dealias(ListModule)
case nme.Seq => return dealias(SeqModule)
case nme.Nil => return dealias(NilModule)
case _ =>
}
}
val qual = typedQualifier { atPos(tree.pos.makeTransparent) {
tree match {
case Ident(_) => Ident(rootMirror.getPackageObjectWithMember(pre, sym))
case Select(qual, _) => Select(qual, nme.PACKAGEkw)
case SelectFromTypeTree(qual, _) => Select(qual, nme.PACKAGEkw)
}
}}
val tree1 = atPos(tree.pos) {
tree match {
case Ident(name) => Select(qual, name)
case Select(_, name) => Select(qual, name)
case SelectFromTypeTree(_, name) => SelectFromTypeTree(qual, name)
}
}
(checkAccessible(tree1, sym, qual.tpe, qual), qual.tpe)
} else {
(checkAccessible(tree, sym, pre, site), pre)
}
/** Post-process an identifier or selection node, performing the following:
* 1. Check that non-function pattern expressions are stable (ignoring volatility concerns -- SI-6815)
* (and narrow the type of modules: a module reference in a pattern has type Foo.type, not "object Foo")
* 2. Check that packages and static modules are not used as values
* 3. Turn tree type into stable type if possible and required by context.
* 4. Give getClass calls a more precise type based on the type of the target of the call.
*/
protected def stabilize(tree: Tree, pre: Type, mode: Mode, pt: Type): Tree = {
// Side effect time! Don't be an idiot like me and think you
// can move "val sym = tree.symbol" before this line, because
// inferExprAlternative side-effects the tree's symbol.
if (tree.symbol.isOverloaded && !mode.inFunMode)
inferExprAlternative(tree, pt)
val sym = tree.symbol
val isStableIdPattern = mode.typingPatternNotConstructor && tree.isTerm
def isModuleTypedExpr = (
treeInfo.admitsTypeSelection(tree)
&& (isStableContext(tree, mode, pt) || sym.isModuleNotMethod)
)
def isStableValueRequired = (
isStableIdPattern
|| mode.in(all = EXPRmode, none = QUALmode) && !phase.erasedTypes
)
// To fully benefit from special casing the return type of
// getClass, we have to catch it immediately so expressions like
// x.getClass().newInstance() are typed with the type of x. TODO: If the
// type of the qualifier is inaccessible, we can cause private types to
// escape scope here, e.g. pos/t1107. I'm not sure how to properly handle
// this so for now it requires the type symbol be public.
def isGetClassCall = isGetClass(sym) && pre.typeSymbol.isPublic
def narrowIf(tree: Tree, condition: Boolean) =
if (condition) tree setType singleType(pre, sym) else tree
def checkStable(tree: Tree): Tree =
if (treeInfo.isStableIdentifierPattern(tree)) tree
else UnstableTreeError(tree)
if (tree.isErrorTyped)
tree
else if (!sym.isValue && isStableValueRequired) // (2)
NotAValueError(tree, sym)
else if (isStableIdPattern) // (1)
// A module reference in a pattern has type Foo.type, not "object Foo"
narrowIf(checkStable(tree), sym.isModuleNotMethod)
else if (isModuleTypedExpr) // (3)
narrowIf(tree, true)
else if (isGetClassCall) // (4)
tree setType MethodType(Nil, getClassReturnType(pre))
else
tree
}
private def isNarrowable(tpe: Type): Boolean = unwrapWrapperTypes(tpe) match {
case TypeRef(_, _, _) | RefinedType(_, _) => true
case _ => !phase.erasedTypes
}
def stabilizeFun(tree: Tree, mode: Mode, pt: Type): Tree = {
val sym = tree.symbol
val pre = tree match {
case Select(qual, _) => qual.tpe
case _ => NoPrefix
}
def stabilizable = (
pre.isStable
&& sym.tpe.params.isEmpty
&& (isStableContext(tree, mode, pt) || sym.isModule)
)
tree.tpe match {
case MethodType(_, _) if stabilizable => tree setType MethodType(Nil, singleType(pre, sym)) // TODO: should this be a NullaryMethodType?
case _ => tree
}
}
/** The member with given name of given qualifier tree */
def member(qual: Tree, name: Name) = {
def callSiteWithinClass(clazz: Symbol) = context.enclClass.owner hasTransOwner clazz
val includeLocals = qual.tpe match {
case ThisType(clazz) if callSiteWithinClass(clazz) => true
case SuperType(clazz, _) if callSiteWithinClass(clazz.typeSymbol) => true
case _ => phase.next.erasedTypes
}
if (includeLocals) qual.tpe member name
else qual.tpe nonLocalMember name
}
def silent[T](op: Typer => T,
reportAmbiguousErrors: Boolean = context.ambiguousErrors,
newtree: Tree = context.tree): SilentResult[T] = {
val rawTypeStart = if (Statistics.canEnable) Statistics.startCounter(rawTypeFailed) else null
val findMemberStart = if (Statistics.canEnable) Statistics.startCounter(findMemberFailed) else null
val subtypeStart = if (Statistics.canEnable) Statistics.startCounter(subtypeFailed) else null
val failedSilentStart = if (Statistics.canEnable) Statistics.startTimer(failedSilentNanos) else null
def stopStats() = {
if (Statistics.canEnable) Statistics.stopCounter(rawTypeFailed, rawTypeStart)
if (Statistics.canEnable) Statistics.stopCounter(findMemberFailed, findMemberStart)
if (Statistics.canEnable) Statistics.stopCounter(subtypeFailed, subtypeStart)
if (Statistics.canEnable) Statistics.stopTimer(failedSilentNanos, failedSilentStart)
}
try {
if (context.reportErrors ||
reportAmbiguousErrors != context.ambiguousErrors ||
newtree != context.tree) {
val context1 = context.makeSilent(reportAmbiguousErrors, newtree)
context1.undetparams = context.undetparams
context1.savedTypeBounds = context.savedTypeBounds
context1.namedApplyBlockInfo = context.namedApplyBlockInfo
val typer1 = newTyper(context1)
val result = op(typer1)
context.undetparams = context1.undetparams
context.savedTypeBounds = context1.savedTypeBounds
context.namedApplyBlockInfo = context1.namedApplyBlockInfo
if (context1.hasErrors) {
stopStats()
SilentTypeError(context1.errors: _*)
} else {
// If we have a successful result, emit any warnings it created.
context1.flushAndIssueWarnings()
SilentResultValue(result)
}
} else {
assert(context.bufferErrors || isPastTyper, "silent mode is not available past typer")
withSavedContext(context){
val res = op(this)
val errorsToReport = context.flushAndReturnBuffer()
if (errorsToReport.isEmpty) SilentResultValue(res) else SilentTypeError(errorsToReport.head)
}
}
} catch {
case ex: CyclicReference => throw ex
case ex: TypeError =>
// fallback in case TypeError is still thrown
// @H this happens for example in cps annotation checker
stopStats()
SilentTypeError(TypeErrorWrapper(ex))
}
}
/** Check whether feature given by `featureTrait` is enabled.
* If it is not, issue an error or a warning depending on whether the feature is required.
* @param construct A string expression that is substituted for "#" in the feature description string
* @param immediate When set, feature check is run immediately, otherwise it is run
* at the end of the typechecking run for the enclosing unit. This
* is done to avoid potential cyclic reference errors by implicits
* that are forced too early.
* @return if feature check is run immediately: true if feature is enabled, false otherwise
* if feature check is delayed or suppressed because we are past typer: true
*/
def checkFeature(pos: Position, featureTrait: Symbol, construct: => String = "", immediate: Boolean = false): Boolean =
if (isPastTyper) true
else {
val nestedOwners =
featureTrait.owner.ownerChain.takeWhile(_ != languageFeatureModule.moduleClass).reverse
val featureName = (nestedOwners map (_.name + ".")).mkString + featureTrait.name
def action(): Boolean = {
def hasImport = inferImplicit(EmptyTree: Tree, featureTrait.tpe, reportAmbiguous = true, isView = false, context).isSuccess
def hasOption = settings.language.value exists (s => s == featureName || s == "_")
val OK = hasImport || hasOption
if (!OK) {
val Some(AnnotationInfo(_, List(Literal(Constant(featureDesc: String)), Literal(Constant(required: Boolean))), _)) =
featureTrait getAnnotation LanguageFeatureAnnot
val req = if (required) "needs to" else "should"
val fqname = "scala.language." + featureName
val explain = (
if (currentRun.reportedFeature contains featureTrait) "" else
s"""|
|This can be achieved by adding the import clause 'import $fqname'
|or by setting the compiler option -language:$featureName.
|See the Scala docs for value $fqname for a discussion
|why the feature $req be explicitly enabled.""".stripMargin
)
currentRun.reportedFeature += featureTrait
val msg = s"$featureDesc $req be enabled\nby making the implicit value $fqname visible.$explain" replace ("#", construct)
if (required) unit.error(pos, msg)
else currentRun.featureWarnings.warn(pos, msg)
}
OK
}
if (immediate) {
action()
} else {
unit.toCheck += action
true
}
}
def checkExistentialsFeature(pos: Position, tpe: Type, prefix: String) = tpe match {
case extp: ExistentialType if !extp.isRepresentableWithWildcards =>
checkFeature(pos, ExistentialsFeature, prefix+" "+tpe)
case _ =>
}
/** Perform the following adaptations of expression, pattern or type `tree` wrt to
* given mode `mode` and given prototype `pt`:
* (-1) For expressions with annotated types, let AnnotationCheckers decide what to do
* (0) Convert expressions with constant types to literals (unless in interactive/scaladoc mode)
* (1) Resolve overloading, unless mode contains FUNmode
* (2) Apply parameterless functions
* (3) Apply polymorphic types to fresh instances of their type parameters and
* store these instances in context.undetparams,
* unless followed by explicit type application.
* (4) Do the following to unapplied methods used as values:
* (4.1) If the method has only implicit parameters pass implicit arguments
* (4.2) otherwise, if `pt` is a function type and method is not a constructor,
* convert to function by eta-expansion,
* (4.3) otherwise, if the method is nullary with a result type compatible to `pt`
* and it is not a constructor, apply it to ()
* otherwise issue an error
* (5) Convert constructors in a pattern as follows:
* (5.1) If constructor refers to a case class factory, set tree's type to the unique
* instance of its primary constructor that is a subtype of the expected type.
* (5.2) If constructor refers to an extractor, convert to application of
* unapply or unapplySeq method.
*
* (6) Convert all other types to TypeTree nodes.
* (7) When in TYPEmode but not FUNmode or HKmode, check that types are fully parameterized
* (7.1) In HKmode, higher-kinded types are allowed, but they must have the expected kind-arity
* (8) When in both EXPRmode and FUNmode, add apply method calls to values of object type.
* (9) If there are undetermined type variables and not POLYmode, infer expression instance
* Then, if tree's type is not a subtype of expected type, try the following adaptations:
* (10) If the expected type is Byte, Short or Char, and the expression
* is an integer fitting in the range of that type, convert it to that type.
* (11) Widen numeric literals to their expected type, if necessary
* (12) When in mode EXPRmode, convert E to { E; () } if expected type is scala.Unit.
* (13) When in mode EXPRmode, apply AnnotationChecker conversion if expected type is annotated.
* (14) When in mode EXPRmode, apply a view
* If all this fails, error
*/
protected def adapt(tree: Tree, mode: Mode, pt: Type, original: Tree = EmptyTree): Tree = {
def hasUndets = context.undetparams.nonEmpty
def hasUndetsInMonoMode = hasUndets && !mode.inPolyMode
def adaptToImplicitMethod(mt: MethodType): Tree = {
if (hasUndets) { // (9) -- should revisit dropped condition `hasUndetsInMonoMode`
// dropped so that type args of implicit method are inferred even if polymorphic expressions are allowed
// needed for implicits in 2.8 collection library -- maybe once #3346 is fixed, we can reinstate the condition?
context.undetparams = inferExprInstance(tree, context.extractUndetparams(), pt,
// approximate types that depend on arguments since dependency on implicit argument is like dependency on type parameter
mt.approximate,
keepNothings = false,
useWeaklyCompatible = true) // #3808
}
// avoid throwing spurious DivergentImplicit errors
if (context.hasErrors)
setError(tree)
else
withCondConstrTyper(treeInfo.isSelfOrSuperConstrCall(tree))(typer1 =>
if (original != EmptyTree && pt != WildcardType) (
typer1 silent { tpr =>
val withImplicitArgs = tpr.applyImplicitArgs(tree)
if (tpr.context.hasErrors) tree // silent will wrap it in SilentTypeError anyway
else tpr.typed(withImplicitArgs, mode, pt)
}
orElse { _ =>
val resetTree = resetAttrs(original)
debuglog(s"fallback on implicits: ${tree}/$resetTree")
val tree1 = typed(resetTree, mode)
// Q: `typed` already calls `pluginsTyped` and `adapt`. the only difference here is that
// we pass `EmptyTree` as the `original`. intended? added in 2009 (53d98e7d42) by martin.
tree1 setType pluginsTyped(tree1.tpe, this, tree1, mode, pt)
if (tree1.isEmpty) tree1 else adapt(tree1, mode, pt, EmptyTree)
}
)
else
typer1.typed(typer1.applyImplicitArgs(tree), mode, pt)
)
}
def instantiateToMethodType(mt: MethodType): Tree = {
val meth = tree match {
// a partial named application is a block (see comment in EtaExpansion)
case Block(_, tree1) => tree1.symbol
case _ => tree.symbol
}
if (!meth.isConstructor && isFunctionType(pt)) { // (4.2)
debuglog(s"eta-expanding $tree: ${tree.tpe} to $pt")
checkParamsConvertible(tree, tree.tpe)
val tree0 = etaExpand(context.unit, tree, this)
// #2624: need to infer type arguments for eta expansion of a polymorphic method
// context.undetparams contains clones of meth.typeParams (fresh ones were generated in etaExpand)
// need to run typer on tree0, since etaExpansion sets the tpe's of its subtrees to null
// can't type with the expected type, as we can't recreate the setup in (3) without calling typed
// (note that (3) does not call typed to do the polymorphic type instantiation --
// it is called after the tree has been typed with a polymorphic expected result type)
if (hasUndets)
instantiate(typed(tree0, mode), mode, pt)
else
typed(tree0, mode, pt)
}
else if (!meth.isConstructor && mt.params.isEmpty) // (4.3)
adapt(typed(Apply(tree, Nil) setPos tree.pos), mode, pt, original)
else if (context.implicitsEnabled)
MissingArgsForMethodTpeError(tree, meth)
else
setError(tree)
}
def adaptType(): Tree = {
// @M When not typing a type constructor (!context.inTypeConstructorAllowed)
// or raw type (tree.symbol.isJavaDefined && context.unit.isJava), types must be of kind *,
// and thus parameterized types must be applied to their type arguments
// @M TODO: why do kind-* tree's have symbols, while higher-kinded ones don't?
def properTypeRequired = (
tree.hasSymbolField
&& !context.inTypeConstructorAllowed
&& !(tree.symbol.isJavaDefined && context.unit.isJava)
)
// @M: don't check tree.tpe.symbol.typeParams. check tree.tpe.typeParams!!!
// (e.g., m[Int] --> tree.tpe.symbol.typeParams.length == 1, tree.tpe.typeParams.length == 0!)
// @M: removed check for tree.hasSymbolField and replace tree.symbol by tree.tpe.symbol
// (TypeTree's must also be checked here, and they don't directly have a symbol)
def kindArityMismatch = (
context.inTypeConstructorAllowed
&& !sameLength(tree.tpe.typeParams, pt.typeParams)
)
// Note that we treat Any and Nothing as kind-polymorphic.
// We can't perform this check when typing type arguments to an overloaded method before the overload is resolved
// (or in the case of an error type) -- this is indicated by pt == WildcardType (see case TypeApply in typed1).
def kindArityMismatchOk = tree.tpe.typeSymbol match {
case NothingClass | AnyClass => true
case _ => pt == WildcardType
}
// todo. It would make sense when mode.inFunMode to instead use
// tree setType tree.tpe.normalize
// when typechecking, say, TypeApply(Ident(`some abstract type symbol`), List(...))
// because otherwise Ident will have its tpe set to a TypeRef, not to a PolyType, and `typedTypeApply` will fail
// but this needs additional investigation, because it crashes t5228, gadts1 and maybe something else
if (mode.inFunMode)
tree
else if (properTypeRequired && tree.symbol.typeParams.nonEmpty) // (7)
MissingTypeParametersError(tree)
else if (kindArityMismatch && !kindArityMismatchOk) // (7.1) @M: check kind-arity
KindArityMismatchError(tree, pt)
else tree match { // (6)
case TypeTree() => tree
case _ => TypeTree(tree.tpe) setOriginal tree
}
}
def insertApply(): Tree = {
assert(!context.inTypeConstructorAllowed, mode) //@M
val adapted = adaptToName(tree, nme.apply)
def stabilize0(pre: Type): Tree = stabilize(adapted, pre, MonoQualifierModes, WildcardType)
// TODO reconcile the overlap between Typers#stablize and TreeGen.stabilize
val qual = adapted match {
case This(_) =>
gen.stabilize(adapted)
case Ident(_) =>
val owner = adapted.symbol.owner
val pre =
if (owner.isPackageClass) owner.thisType
else if (owner.isClass) context.enclosingSubClassContext(owner).prefix
else NoPrefix
stabilize0(pre)
case Select(qualqual, _) =>
stabilize0(qualqual.tpe)
case other =>
other
}
typedPos(tree.pos, mode, pt) {
Select(qual setPos tree.pos.makeTransparent, nme.apply)
}
}
def adaptConstant(value: Constant): Tree = {
val sym = tree.symbol
if (sym != null && sym.isDeprecated) {
val msg = sym.toString + sym.locationString + " is deprecated: " + sym.deprecationMessage.getOrElse("")
unit.deprecationWarning(tree.pos, msg)
}
treeCopy.Literal(tree, value)
}
// Ignore type errors raised in later phases that are due to mismatching types with existential skolems
// We have lift crashing in 2.9 with an adapt failure in the pattern matcher.
// Here's my hypothsis why this happens. The pattern matcher defines a variable of type
//
// val x: T = expr
//
// where T is the type of expr, but T contains existential skolems ts.
// In that case, this value definition does not typecheck.
// The value definition
//
// val x: T forSome { ts } = expr
//
// would typecheck. Or one can simply leave out the type of the `val`:
//
// val x = expr
//
// SI-6029 shows another case where we also fail (in uncurry), but this time the expected
// type is an existential type.
//
// The reason for both failures have to do with the way we (don't) transform
// skolem types along with the trees that contain them. We'd need a
// radically different approach to do it. But before investing a lot of time to
// to do this (I have already sunk 3 full days with in the end futile attempts
// to consistently transform skolems and fix 6029), I'd like to
// investigate ways to avoid skolems completely.
//
// upd. The same problem happens when we try to typecheck the result of macro expansion against its expected type
// (which is the return type of the macro definition instantiated in the context of expandee):
//
// Test.scala:2: error: type mismatch;
// found : $u.Expr[Class[_ <: Object]]
// required: reflect.runtime.universe.Expr[Class[?0(in value <local Test>)]] where type ?0(in value <local Test>) <: Object
// scala.reflect.runtime.universe.reify(new Object().getClass)
// ^
// Therefore following Martin's advice I use this logic to recover from skolem errors after macro expansions
// (by adding the ` || tree.attachments.get[MacroExpansionAttachment].isDefined` clause to the conditional above).
//
def adaptMismatchedSkolems() = {
def canIgnoreMismatch = (
!context.reportErrors && isPastTyper
|| tree.hasAttachment[MacroExpansionAttachment]
)
def bound = pt match {
case ExistentialType(qs, _) => qs
case _ => Nil
}
def msg = sm"""
|Recovering from existential or skolem type error in
| $tree
|with type: ${tree.tpe}
| pt: $pt
| context: ${context.tree}
| adapted
""".trim
val boundOrSkolems = if (canIgnoreMismatch) bound ++ pt.skolemsExceptMethodTypeParams else Nil
boundOrSkolems match {
case Nil => AdaptTypeError(tree, tree.tpe, pt) ; setError(tree)
case _ => logResult(msg)(adapt(tree, mode, deriveTypeWithWildcards(boundOrSkolems)(pt)))
}
}
def fallbackAfterVanillaAdapt(): Tree = {
def isPopulatedPattern = {
if ((tree.symbol ne null) && tree.symbol.isModule)
inferModulePattern(tree, pt)
isPopulated(tree.tpe, approximateAbstracts(pt))
}
if (mode.inPatternMode && isPopulatedPattern)
return tree
val tree1 = constfold(tree, pt) // (10) (11)
if (tree1.tpe <:< pt)
return adapt(tree1, mode, pt, original)
if (mode.typingExprNotFun) {
// The <: Any requirement inhibits attempts to adapt continuation types
// to non-continuation types.
if (tree.tpe <:< AnyTpe) pt.dealias match {
case TypeRef(_, UnitClass, _) => // (12)
if (settings.warnValueDiscard)
context.unit.warning(tree.pos, "discarded non-Unit value")
return typedPos(tree.pos, mode, pt)(Block(List(tree), Literal(Constant(()))))
case TypeRef(_, sym, _) if isNumericValueClass(sym) && isNumericSubType(tree.tpe, pt) =>
if (settings.warnNumericWiden)
context.unit.warning(tree.pos, "implicit numeric widening")
return typedPos(tree.pos, mode, pt)(Select(tree, "to" + sym.name))
case _ =>
}
if (pt.dealias.annotations.nonEmpty && canAdaptAnnotations(tree, this, mode, pt)) // (13)
return typed(adaptAnnotations(tree, this, mode, pt), mode, pt)
if (hasUndets)
return instantiate(tree, mode, pt)
if (context.implicitsEnabled && !pt.isError && !tree.isErrorTyped) {
// (14); the condition prevents chains of views
debuglog("inferring view from " + tree.tpe + " to " + pt)
inferView(tree, tree.tpe, pt, reportAmbiguous = true) match {
case EmptyTree =>
case coercion =>
def msg = "inferred view from " + tree.tpe + " to " + pt + " = " + coercion + ":" + coercion.tpe
if (settings.logImplicitConv)
unit.echo(tree.pos, msg)
debuglog(msg)
val silentContext = context.makeImplicit(context.ambiguousErrors)
val res = newTyper(silentContext).typed(
new ApplyImplicitView(coercion, List(tree)) setPos tree.pos, mode, pt)
silentContext.firstError match {
case Some(err) => context.issue(err)
case None => return res
}
}
}
}
debuglog("error tree = " + tree)
if (settings.debug && settings.explaintypes)
explainTypes(tree.tpe, pt)
if (tree.tpe.isErroneous || pt.isErroneous)
setError(tree)
else
adaptMismatchedSkolems()
}
def vanillaAdapt(tree: Tree) = {
def applyPossible = {
def applyMeth = member(adaptToName(tree, nme.apply), nme.apply)
def hasPolymorphicApply = applyMeth.alternatives exists (_.tpe.typeParams.nonEmpty)
def hasMonomorphicApply = applyMeth.alternatives exists (_.tpe.paramSectionCount > 0)
dyna.acceptsApplyDynamic(tree.tpe) || (
if (mode.inTappMode)
tree.tpe.typeParams.isEmpty && hasPolymorphicApply
else
hasMonomorphicApply
)
}
def shouldInsertApply(tree: Tree) = mode.typingExprFun && {
tree.tpe match {
case _: MethodType | _: OverloadedType | _: PolyType => false
case _ => applyPossible
}
}
if (tree.isType)
adaptType()
else if (mode.typingExprNotFun && treeInfo.isMacroApplication(tree) && !isMacroExpansionSuppressed(tree))
macroExpand(this, tree, mode, pt)
else if (mode.typingConstructorPattern)
typedConstructorPattern(tree, pt)
else if (shouldInsertApply(tree))
insertApply()
else if (hasUndetsInMonoMode) { // (9)
assert(!context.inTypeConstructorAllowed, context) //@M
instantiatePossiblyExpectingUnit(tree, mode, pt)
}
else if (tree.tpe <:< pt)
tree
else
fallbackAfterVanillaAdapt()
}
// begin adapt
if (isMacroImplRef(tree)) {
if (treeInfo.isMacroApplication(tree)) adapt(unmarkMacroImplRef(tree), mode, pt, original)
else tree
} else tree.tpe match {
case atp @ AnnotatedType(_, _) if canAdaptAnnotations(tree, this, mode, pt) => // (-1)
adaptAnnotations(tree, this, mode, pt)
case ct @ ConstantType(value) if mode.inNone(TYPEmode | FUNmode) && (ct <:< pt) && canAdaptConstantTypeToLiteral => // (0)
adaptConstant(value)
case OverloadedType(pre, alts) if !mode.inFunMode => // (1)
inferExprAlternative(tree, pt)
adapt(tree, mode, pt, original)
case NullaryMethodType(restpe) => // (2)
adapt(tree setType restpe, mode, pt, original)
case TypeRef(_, ByNameParamClass, arg :: Nil) if mode.inExprMode => // (2)
adapt(tree setType arg, mode, pt, original)
case tp if mode.typingExprNotLhs && isExistentialType(tp) =>
adapt(tree setType tp.dealias.skolemizeExistential(context.owner, tree), mode, pt, original)
case PolyType(tparams, restpe) if mode.inNone(TAPPmode | PATTERNmode) && !context.inTypeConstructorAllowed => // (3)
// assert((mode & HKmode) == 0) //@M a PolyType in HKmode represents an anonymous type function,
// we're in HKmode since a higher-kinded type is expected --> hence, don't implicitly apply it to type params!
// ticket #2197 triggered turning the assert into a guard
// I guess this assert wasn't violated before because type aliases weren't expanded as eagerly
// (the only way to get a PolyType for an anonymous type function is by normalisation, which applies eta-expansion)
// -- are we sure we want to expand aliases this early?
// -- what caused this change in behaviour??
val tparams1 = cloneSymbols(tparams)
val tree1 = (
if (tree.isType) tree
else TypeApply(tree, tparams1 map (tparam => TypeTree(tparam.tpeHK) setPos tree.pos.focus)) setPos tree.pos
)
context.undetparams ++= tparams1
notifyUndetparamsAdded(tparams1)
adapt(tree1 setType restpe.substSym(tparams, tparams1), mode, pt, original)
case mt: MethodType if mode.typingExprNotFunNotLhs && mt.isImplicit => // (4.1)
adaptToImplicitMethod(mt)
case mt: MethodType if mode.typingExprNotFunNotLhs && !hasUndetsInMonoMode && !treeInfo.isMacroApplicationOrBlock(tree) =>
instantiateToMethodType(mt)
case _ =>
vanillaAdapt(tree)
}
}
def instantiate(tree: Tree, mode: Mode, pt: Type): Tree = {
inferExprInstance(tree, context.extractUndetparams(), pt)
adapt(tree, mode, pt)
}
/** If the expected type is Unit: try instantiating type arguments
* with expected type Unit, but if that fails, try again with pt = WildcardType
* and discard the expression.
*/
def instantiateExpectingUnit(tree: Tree, mode: Mode): Tree = {
val savedUndetparams = context.undetparams
silent(_.instantiate(tree, mode, UnitTpe)) orElse { _ =>
context.undetparams = savedUndetparams
val valueDiscard = atPos(tree.pos)(Block(List(instantiate(tree, mode, WildcardType)), Literal(Constant(()))))
typed(valueDiscard, mode, UnitTpe)
}
}
def instantiatePossiblyExpectingUnit(tree: Tree, mode: Mode, pt: Type): Tree = {
if (mode.typingExprNotFun && pt.typeSymbol == UnitClass)
instantiateExpectingUnit(tree, mode)
else
instantiate(tree, mode, pt)
}
private def isAdaptableWithView(qual: Tree) = {
val qtpe = qual.tpe.widen
( !isPastTyper
&& qual.isTerm
&& !qual.isInstanceOf[Super]
&& ((qual.symbol eq null) || !qual.symbol.isTerm || qual.symbol.isValue)
&& !qtpe.isError
&& !qtpe.typeSymbol.isBottomClass
&& qtpe != WildcardType
&& !qual.isInstanceOf[ApplyImplicitView] // don't chain views
&& (context.implicitsEnabled || context.enrichmentEnabled)
// Elaborating `context.implicitsEnabled`:
// don't try to adapt a top-level type that's the subject of an implicit search
// this happens because, if isView, typedImplicit tries to apply the "current" implicit value to
// a value that needs to be coerced, so we check whether the implicit value has an `apply` method.
// (If we allow this, we get divergence, e.g., starting at `conforms` during ant quick.bin)
// Note: implicit arguments are still inferred (this kind of "chaining" is allowed)
)
}
def adaptToMember(qual: Tree, searchTemplate: Type, reportAmbiguous: Boolean = true, saveErrors: Boolean = true): Tree = {
if (isAdaptableWithView(qual)) {
qual.tpe.dealiasWiden match {
case et: ExistentialType =>
qual setType et.skolemizeExistential(context.owner, qual) // open the existential
case _ =>
}
inferView(qual, qual.tpe, searchTemplate, reportAmbiguous, saveErrors) match {
case EmptyTree => qual
case coercion =>
if (settings.logImplicitConv)
unit.echo(qual.pos,
"applied implicit conversion from %s to %s = %s".format(
qual.tpe, searchTemplate, coercion.symbol.defString))
typedQualifier(atPos(qual.pos)(new ApplyImplicitView(coercion, List(qual))))
}
}
else qual
}
/** Try to apply an implicit conversion to `qual` to that it contains
* a method `name` which can be applied to arguments `args` with expected type `pt`.
* If `pt` is defined, there is a fallback to try again with pt = ?.
* This helps avoiding propagating result information too far and solves
* #1756.
* If no conversion is found, return `qual` unchanged.
*
*/
def adaptToArguments(qual: Tree, name: Name, args: List[Tree], pt: Type, reportAmbiguous: Boolean, saveErrors: Boolean): Tree = {
def doAdapt(restpe: Type) =
//util.trace("adaptToArgs "+qual+", name = "+name+", argtpes = "+(args map (_.tpe))+", pt = "+pt+" = ")
adaptToMember(qual, HasMethodMatching(name, args map (_.tpe), restpe), reportAmbiguous, saveErrors)
if (pt == WildcardType)
doAdapt(pt)
else silent(_ => doAdapt(pt)) filter (_ != qual) orElse (_ =>
logResult(s"fallback on implicits in adaptToArguments: $qual.$name")(doAdapt(WildcardType))
)
}
/** Try to apply an implicit conversion to `qual` so that it contains
* a method `name`. If that's ambiguous try taking arguments into
* account using `adaptToArguments`.
*/
def adaptToMemberWithArgs(tree: Tree, qual: Tree, name: Name, mode: Mode, reportAmbiguous: Boolean, saveErrors: Boolean): Tree = {
def onError(reportError: => Tree): Tree = context.tree match {
case Apply(tree1, args) if (tree1 eq tree) && args.nonEmpty =>
( silent (_.typedArgs(args.map(_.duplicate), mode))
filter (xs => !(xs exists (_.isErrorTyped)))
map (xs => adaptToArguments(qual, name, xs, WildcardType, reportAmbiguous, saveErrors))
orElse ( _ => reportError)
)
case _ =>
reportError
}
silent(_.adaptToMember(qual, HasMember(name), reportAmbiguous = false)) orElse (errs =>
onError {
if (reportAmbiguous) errs foreach (context issue _)
setError(tree)
}
)
}
/** Try to apply an implicit conversion to `qual` to that it contains a
* member `name` of arbitrary type.
* If no conversion is found, return `qual` unchanged.
*/
def adaptToName(qual: Tree, name: Name) =
if (member(qual, name) != NoSymbol) qual
else adaptToMember(qual, HasMember(name))
private def validateNoCaseAncestor(clazz: Symbol) = {
if (!phase.erasedTypes) {
for (ancestor <- clazz.ancestors find (_.isCase)) {
unit.error(clazz.pos, (
"case %s has case ancestor %s, but case-to-case inheritance is prohibited."+
" To overcome this limitation, use extractors to pattern match on non-leaf nodes."
).format(clazz, ancestor.fullName))
}
}
}
private def checkEphemeral(clazz: Symbol, body: List[Tree]) = {
// NOTE: Code appears to be messy in this method for good reason: it clearly
// communicates the fact that it implements rather ad-hoc, arbitrary and
// non-regular set of rules that identify features that interact badly with
// value classes. This code can be cleaned up a lot once implementation
// restrictions are addressed.
val isValueClass = !clazz.isTrait
def where = if (isValueClass) "value class" else "universal trait extending from class Any"
def implRestriction(tree: Tree, what: String) =
unit.error(tree.pos, s"implementation restriction: $what is not allowed in $where" +
"\nThis restriction is planned to be removed in subsequent releases.")
/**
* Deeply traverses the tree in search of constructs that are not allowed
* in value classes (at any nesting level).
*
* All restrictions this object imposes are probably not fundamental but require
* fair amount of work and testing. We are conservative for now when it comes
* to allowing language features to interact with value classes.
* */
object checkEphemeralDeep extends Traverser {
override def traverse(tree: Tree): Unit = if (isValueClass) {
tree match {
case _: ModuleDef =>
//see https://issues.scala-lang.org/browse/SI-6359
implRestriction(tree, "nested object")
//see https://issues.scala-lang.org/browse/SI-6444
//see https://issues.scala-lang.org/browse/SI-6463
case cd: ClassDef if !cd.symbol.isAnonymousClass => // Don't warn about partial functions, etc. SI-7571
implRestriction(tree, "nested class") // avoiding Type Tests that might check the $outer pointer.
case Select(sup @ Super(qual, mix), selector) if selector != nme.CONSTRUCTOR && qual.symbol == clazz && mix != tpnme.EMPTY =>
//see https://issues.scala-lang.org/browse/SI-6483
implRestriction(sup, "qualified super reference")
case _ =>
}
super.traverse(tree)
}
}
for (stat <- body) {
def notAllowed(what: String) = unit.error(stat.pos, s"$what is not allowed in $where")
stat match {
// see https://issues.scala-lang.org/browse/SI-6444
// see https://issues.scala-lang.org/browse/SI-6463
case ClassDef(mods, _, _, _) if isValueClass =>
implRestriction(stat, s"nested ${ if (mods.isTrait) "trait" else "class" }")
case _: Import | _: ClassDef | _: TypeDef | EmptyTree => // OK
case DefDef(_, name, _, _, _, rhs) =>
if (stat.symbol.isAuxiliaryConstructor)
notAllowed("secondary constructor")
else if (isValueClass && (name == nme.equals_ || name == nme.hashCode_) && !stat.symbol.isSynthetic)
notAllowed(s"redefinition of $name method. See SIP-15, criterion 4.")
else if (stat.symbol != null && stat.symbol.isParamAccessor)
notAllowed("additional parameter")
checkEphemeralDeep.traverse(rhs)
case _: ValDef =>
notAllowed("field definition")
case _: ModuleDef =>
//see https://issues.scala-lang.org/browse/SI-6359
implRestriction(stat, "nested object")
case _ =>
notAllowed("this statement")
}
}
}
private def validateDerivedValueClass(clazz: Symbol, body: List[Tree]) = {
if (clazz.isTrait)
unit.error(clazz.pos, "only classes (not traits) are allowed to extend AnyVal")
if (!clazz.isStatic)
unit.error(clazz.pos, "value class may not be a "+
(if (clazz.owner.isTerm) "local class" else "member of another class"))
if (!clazz.isPrimitiveValueClass) {
clazz.primaryConstructor.paramss match {
case List(List(param)) =>
val decls = clazz.info.decls
val paramAccessor = clazz.constrParamAccessors.head
if (paramAccessor.isMutable)
unit.error(paramAccessor.pos, "value class parameter must not be a var")
val accessor = decls.toList.find(x => x.isMethod && x.accessedOrSelf == paramAccessor)
accessor match {
case None =>
unit.error(paramAccessor.pos, "value class parameter must be a val and not be private[this]")
case Some(acc) if acc.isProtectedLocal =>
unit.error(paramAccessor.pos, "value class parameter must not be protected[this]")
case Some(acc) =>
if (acc.tpe.typeSymbol.isDerivedValueClass)
unit.error(acc.pos, "value class may not wrap another user-defined value class")
checkEphemeral(clazz, body filterNot (stat => stat.symbol != null && stat.symbol.accessedOrSelf == paramAccessor))
}
case _ =>
unit.error(clazz.pos, "value class needs to have exactly one val parameter")
}
}
for (tparam <- clazz.typeParams)
if (tparam hasAnnotation definitions.SpecializedClass)
unit.error(tparam.pos, "type parameter of value class may not be specialized")
}
/** Typechecks a parent type reference.
*
* This typecheck is harder than it might look, because it should honor early
* definitions and also perform type argument inference with the help of super call
* arguments provided in `encodedtpt`.
*
* The method is called in batches (batch = 1 time per each parent type referenced),
* two batches per definition: once from namer, when entering a ClassDef or a ModuleDef
* and once from typer, when typechecking the definition.
*
* ***Arguments***
*
* `encodedtpt` represents the parent type reference wrapped in an `Apply` node
* which indicates value arguments (i.e. type macro arguments or super constructor call arguments)
* If no value arguments are provided by the user, the `Apply` node is still
* there, but its `args` will be set to `Nil`.
* This argument is synthesized by `tools.nsc.ast.Parsers.templateParents`.
*
* `templ` is an enclosing template, which contains a primary constructor synthesized by the parser.
* Such a constructor is a DefDef which contains early initializers and maybe a super constructor call
* (I wrote "maybe" because trait constructors don't call super constructors).
* This argument is synthesized by `tools.nsc.ast.Trees.Template`.
*
* `inMixinPosition` indicates whether the reference is not the first in the
* list of parents (and therefore cannot be a class) or the opposite.
*
* ***Return value and side effects***
*
* Returns a `TypeTree` representing a resolved parent type.
* If the typechecked parent reference implies non-nullary and non-empty argument list,
* this argument list is attached to the returned value in SuperArgsAttachment.
* The attachment is necessary for the subsequent typecheck to fixup a super constructor call
* in the body of the primary constructor (see `typedTemplate` for details).
*
* This method might invoke `typedPrimaryConstrBody`, hence it might cause the side effects
* described in the docs of that method. It might also attribute the Super(_, _) reference
* (if present) inside the primary constructor of `templ`.
*
* ***Example***
*
* For the following definition:
*
* class D extends {
* val x = 2
* val y = 4
* } with B(x)(3) with C(y) with T
*
* this method will be called six times:
*
* (3 times from the namer)
* typedParentType(Apply(Apply(Ident(B), List(Ident(x))), List(3)), templ, inMixinPosition = false)
* typedParentType(Apply(Ident(C), List(Ident(y))), templ, inMixinPosition = true)
* typedParentType(Apply(Ident(T), List()), templ, inMixinPosition = true)
*
* (3 times from the typer)
* <the same three calls>
*/
private def typedParentType(encodedtpt: Tree, templ: Template, inMixinPosition: Boolean): Tree = {
val app = treeInfo.dissectApplied(encodedtpt)
val (treeInfo.Applied(core, _, argss), decodedtpt) = ((app, app.callee))
val argssAreTrivial = argss == Nil || argss == ListOfNil
// we cannot avoid cyclic references with `initialize` here, because when type macros arrive,
// we'll have to check the probe for isTypeMacro anyways.
// therefore I think it's reasonable to trade a more specific "inherits itself" error
// for a generic, yet understandable "cyclic reference" error
var probe = typedTypeConstructor(core.duplicate).tpe.typeSymbol
if (probe == null) probe = NoSymbol
probe.initialize
if (probe.isTrait || inMixinPosition) {
if (!argssAreTrivial) {
if (probe.isTrait) ConstrArgsInParentWhichIsTraitError(encodedtpt, probe)
else () // a class in a mixin position - this warrants an error in `validateParentClasses`
// therefore here we do nothing, e.g. don't check that the # of ctor arguments
// matches the # of ctor parameters or stuff like that
}
typedType(decodedtpt)
} else {
val supertpt = typedTypeConstructor(decodedtpt)
val supertparams = if (supertpt.hasSymbolField) supertpt.symbol.typeParams else Nil
def inferParentTypeArgs: Tree = {
typedPrimaryConstrBody(templ) {
val supertpe = PolyType(supertparams, appliedType(supertpt.tpe, supertparams map (_.tpeHK)))
val supercall = New(supertpe, mmap(argss)(_.duplicate))
val treeInfo.Applied(Select(ctor, nme.CONSTRUCTOR), _, _) = supercall
ctor setType supertpe // this is an essential hack, otherwise it will occasionally fail to typecheck
atPos(supertpt.pos.focus)(supercall)
} match {
case EmptyTree => MissingTypeArgumentsParentTpeError(supertpt); supertpt
case tpt => TypeTree(tpt.tpe) setPos supertpt.pos // SI-7224: don't .focus positions of the TypeTree of a parent that exists in source
}
}
val supertptWithTargs = if (supertparams.isEmpty || context.unit.isJava) supertpt else inferParentTypeArgs
// this is the place where we tell the typer what argss should be used for the super call
// if argss are nullary or empty, then (see the docs for `typedPrimaryConstrBody`)
// the super call dummy is already good enough, so we don't need to do anything
if (argssAreTrivial) supertptWithTargs else supertptWithTargs updateAttachment SuperArgsAttachment(argss)
}
}
/** Typechecks the mishmash of trees that happen to be stuffed into the primary constructor of a given template.
* Before commencing the typecheck, replaces the `pendingSuperCall` dummy with the result of `actualSuperCall`.
* `actualSuperCall` can return `EmptyTree`, in which case the dummy is replaced with a literal unit.
*
* ***Return value and side effects***
*
* If a super call is present in the primary constructor and is not erased by the transform, returns it typechecked.
* Otherwise (e.g. if the primary constructor is missing or the super call isn't there) returns `EmptyTree`.
*
* As a side effect, this method attributes the underlying fields of early vals.
* Early vals aren't typechecked anywhere else, so it's essential to call `typedPrimaryConstrBody`
* at least once per definition. It'd be great to disentangle this logic at some point.
*
* ***Example***
*
* For the following definition:
*
* class D extends {
* val x = 2
* val y = 4
* } with B(x)(3) with C(y) with T
*
* the primary constructor of `templ` will be:
*
* Block(List(
* ValDef(NoMods, x, TypeTree(), 2)
* ValDef(NoMods, y, TypeTree(), 4)
* global.pendingSuperCall,
* Literal(Constant(())))
*
* Note the `pendingSuperCall` part. This is the representation of a fill-me-in-later supercall dummy,
* which encodes the fact that supercall argss are unknown during parsing and need to be transplanted
* from one of the parent types. Read more about why the argss are unknown in `tools.nsc.ast.Trees.Template`.
*/
private def typedPrimaryConstrBody(templ: Template)(actualSuperCall: => Tree): Tree =
treeInfo.firstConstructor(templ.body) match {
case ctor @ DefDef(_, _, _, vparamss, _, cbody @ Block(cstats, cunit)) =>
val (preSuperStats, superCall) = {
val (stats, rest) = cstats span (x => !treeInfo.isSuperConstrCall(x))
(stats map (_.duplicate), if (rest.isEmpty) EmptyTree else rest.head.duplicate)
}
val superCall1 = (superCall match {
case global.pendingSuperCall => actualSuperCall
case EmptyTree => EmptyTree
}) orElse cunit
val cbody1 = treeCopy.Block(cbody, preSuperStats, superCall1)
val clazz = context.owner
assert(clazz != NoSymbol, templ)
val cscope = context.outer.makeNewScope(ctor, context.outer.owner)
val cbody2 = { // called both during completion AND typing.
val typer1 = newTyper(cscope)
// XXX: see about using the class's symbol....
clazz.unsafeTypeParams foreach (sym => typer1.context.scope.enter(sym))
typer1.namer.enterValueParams(vparamss map (_.map(_.duplicate)))
typer1.typed(cbody1)
}
val preSuperVals = treeInfo.preSuperFields(templ.body)
if (preSuperVals.isEmpty && preSuperStats.nonEmpty)
devWarning("Wanted to zip empty presuper val list with " + preSuperStats)
else
map2(preSuperStats, preSuperVals)((ldef, gdef) => gdef.tpt setType ldef.symbol.tpe)
if (superCall1 == cunit) EmptyTree
else cbody2 match {
case Block(_, expr) => expr
case tree => tree
}
case _ =>
EmptyTree
}
/** Makes sure that the first type tree in the list of parent types is always a class.
* If the first parent is a trait, prepend its supertype to the list until it's a class.
*/
private def normalizeFirstParent(parents: List[Tree]): List[Tree] = {
@annotation.tailrec
def explode0(parents: List[Tree]): List[Tree] = {
val supertpt :: rest = parents // parents is always non-empty here - it only grows
if (supertpt.tpe.typeSymbol == AnyClass) {
supertpt setType AnyRefTpe
parents
} else if (treeInfo isTraitRef supertpt) {
val supertpt1 = typedType(supertpt)
def supersuper = TypeTree(supertpt1.tpe.firstParent) setPos supertpt.pos.focus
if (supertpt1.isErrorTyped) rest
else explode0(supersuper :: supertpt1 :: rest)
} else parents
}
def explode(parents: List[Tree]) =
if (treeInfo isTraitRef parents.head) explode0(parents)
else parents
if (parents.isEmpty) Nil else explode(parents)
}
/** Certain parents are added in the parser before it is known whether
* that class also declared them as parents. For instance, this is an
* error unless we take corrective action here:
*
* case class Foo() extends Serializable
*
* So we strip the duplicates before typer.
*/
private def fixDuplicateSyntheticParents(parents: List[Tree]): List[Tree] = parents match {
case Nil => Nil
case x :: xs =>
val sym = x.symbol
x :: fixDuplicateSyntheticParents(
if (isPossibleSyntheticParent(sym)) xs filterNot (_.symbol == sym)
else xs
)
}
def typedParentTypes(templ: Template): List[Tree] = templ.parents match {
case Nil => List(atPos(templ.pos)(TypeTree(AnyRefTpe)))
case first :: rest =>
try {
val supertpts = fixDuplicateSyntheticParents(normalizeFirstParent(
typedParentType(first, templ, inMixinPosition = false) +:
(rest map (typedParentType(_, templ, inMixinPosition = true)))))
// if that is required to infer the targs of a super call
// typedParentType calls typedPrimaryConstrBody to do the inferring typecheck
// as a side effect, that typecheck also assigns types to the fields underlying early vals
// however if inference is not required, the typecheck doesn't happen
// and therefore early fields have their type trees not assigned
// here we detect this situation and take preventive measures
if (treeInfo.hasUntypedPreSuperFields(templ.body))
typedPrimaryConstrBody(templ)(EmptyTree)
supertpts mapConserve (tpt => checkNoEscaping.privates(context.owner, tpt))
}
catch {
case ex: TypeError =>
// fallback in case of cyclic errors
// @H none of the tests enter here but I couldn't rule it out
// upd. @E when a definition inherits itself, we end up here
// because `typedParentType` triggers `initialize` for parent types symbols
log("Type error calculating parents in template " + templ)
log("Error: " + ex)
ParentTypesError(templ, ex)
List(TypeTree(AnyRefTpe))
}
}
/** <p>Check that</p>
* <ul>
* <li>all parents are class types,</li>
* <li>first parent class is not a mixin; following classes are mixins,</li>
* <li>final classes are not inherited,</li>
* <li>
* sealed classes are only inherited by classes which are
* nested within definition of base class, or that occur within same
* statement sequence,
* </li>
* <li>self-type of current class is a subtype of self-type of each parent class.</li>
* <li>no two parents define same symbol.</li>
* </ul>
*/
def validateParentClasses(parents: List[Tree], selfType: Type) {
val pending = ListBuffer[AbsTypeError]()
def validateDynamicParent(parent: Symbol, parentPos: Position) =
if (parent == DynamicClass) checkFeature(parentPos, DynamicsFeature)
def validateParentClass(parent: Tree, superclazz: Symbol) =
if (!parent.isErrorTyped) {
val psym = parent.tpe.typeSymbol.initialize
checkStablePrefixClassType(parent)
if (psym != superclazz) {
if (psym.isTrait) {
val ps = psym.info.parents
if (!ps.isEmpty && !superclazz.isSubClass(ps.head.typeSymbol))
pending += ParentSuperSubclassError(parent, superclazz, ps.head.typeSymbol, psym)
} else {
pending += ParentNotATraitMixinError(parent, psym)
}
}
if (psym.isFinal)
pending += ParentFinalInheritanceError(parent, psym)
val sameSourceFile = context.unit.source.file == psym.sourceFile
if (psym.hasDeprecatedInheritanceAnnotation && !sameSourceFile) {
val suffix = psym.deprecatedInheritanceMessage map (": " + _) getOrElse ""
val msg = s"inheritance from ${psym.fullLocationString} is deprecated$suffix"
unit.deprecationWarning(parent.pos, msg)
}
if (psym.isSealed && !phase.erasedTypes)
if (sameSourceFile)
psym addChild context.owner
else
pending += ParentSealedInheritanceError(parent, psym)
val parentTypeOfThis = parent.tpe.dealias.typeOfThis
if (!(selfType <:< parentTypeOfThis) &&
!phase.erasedTypes &&
!context.owner.isSynthetic && // don't check synthetic concrete classes for virtuals (part of DEVIRTUALIZE)
!selfType.isErroneous &&
!parent.tpe.isErroneous)
{
pending += ParentSelfTypeConformanceError(parent, selfType)
if (settings.explaintypes) explainTypes(selfType, parentTypeOfThis)
}
if (parents exists (p => p != parent && p.tpe.typeSymbol == psym && !psym.isError))
pending += ParentInheritedTwiceError(parent, psym)
validateDynamicParent(psym, parent.pos)
}
if (!parents.isEmpty && parents.forall(!_.isErrorTyped)) {
val superclazz = parents.head.tpe.typeSymbol
for (p <- parents) validateParentClass(p, superclazz)
}
pending.foreach(ErrorUtils.issueTypeError)
}
def checkFinitary(classinfo: ClassInfoType) {
val clazz = classinfo.typeSymbol
for (tparam <- clazz.typeParams) {
if (classinfo.expansiveRefs(tparam) contains tparam) {
val newinfo = ClassInfoType(
classinfo.parents map (_.instantiateTypeParams(List(tparam), List(AnyRefTpe))),
classinfo.decls,
clazz)
clazz.setInfo {
clazz.info match {
case PolyType(tparams, _) => PolyType(tparams, newinfo)
case _ => newinfo
}
}
FinitaryError(tparam)
}
}
}
def typedClassDef(cdef: ClassDef): Tree = {
val clazz = cdef.symbol
val typedMods = typedModifiers(cdef.mods)
assert(clazz != NoSymbol, cdef)
reenterTypeParams(cdef.tparams)
val tparams1 = cdef.tparams mapConserve (typedTypeDef)
val impl1 = newTyper(context.make(cdef.impl, clazz, newScope)).typedTemplate(cdef.impl, typedParentTypes(cdef.impl))
val impl2 = finishMethodSynthesis(impl1, clazz, context)
if (clazz.isTrait && clazz.info.parents.nonEmpty && clazz.info.firstParent.typeSymbol == AnyClass)
checkEphemeral(clazz, impl2.body)
if ((clazz isNonBottomSubClass ClassfileAnnotationClass) && (clazz != ClassfileAnnotationClass)) {
if (!clazz.owner.isPackageClass)
unit.error(clazz.pos, "inner classes cannot be classfile annotations")
else restrictionWarning(cdef.pos, unit,
"""|subclassing Classfile does not
|make your annotation visible at runtime. If that is what
|you want, you must write the annotation class in Java.""".stripMargin)
}
if (!isPastTyper) {
for (ann <- clazz.getAnnotation(DeprecatedAttr)) {
val m = companionSymbolOf(clazz, context)
if (m != NoSymbol)
m.moduleClass.addAnnotation(AnnotationInfo(ann.atp, ann.args, List()))
}
}
treeCopy.ClassDef(cdef, typedMods, cdef.name, tparams1, impl2)
.setType(NoType)
}
def typedModuleDef(mdef: ModuleDef): Tree = {
// initialize all constructors of the linked class: the type completer (Namer.methodSig)
// might add default getters to this object. example: "object T; class T(x: Int = 1)"
val linkedClass = companionSymbolOf(mdef.symbol, context)
if (linkedClass != NoSymbol)
linkedClass.info.decl(nme.CONSTRUCTOR).alternatives foreach (_.initialize)
val clazz = mdef.symbol.moduleClass
val typedMods = typedModifiers(mdef.mods)
assert(clazz != NoSymbol, mdef)
val noSerializable = (
(linkedClass eq NoSymbol)
|| linkedClass.isErroneous
|| !linkedClass.isSerializable
|| clazz.isSerializable
)
val impl1 = newTyper(context.make(mdef.impl, clazz, newScope)).typedTemplate(mdef.impl, {
typedParentTypes(mdef.impl) ++ (
if (noSerializable) Nil
else {
clazz.makeSerializable()
List(TypeTree(SerializableTpe) setPos clazz.pos.focus)
}
)
})
val impl2 = finishMethodSynthesis(impl1, clazz, context)
if (settings.isScala211 && mdef.symbol == PredefModule)
ensurePredefParentsAreInSameSourceFile(impl2)
treeCopy.ModuleDef(mdef, typedMods, mdef.name, impl2) setType NoType
}
private def ensurePredefParentsAreInSameSourceFile(template: Template) = {
val parentSyms = template.parents map (_.symbol) filterNot (_ == AnyRefClass)
if (parentSyms exists (_.associatedFile != PredefModule.associatedFile))
unit.error(template.pos, s"All parents of Predef must be defined in ${PredefModule.associatedFile}.")
}
/** In order to override this in the TreeCheckers Typer so synthetics aren't re-added
* all the time, it is exposed here the module/class typing methods go through it.
* ...but it turns out it's also the ideal spot for namer/typer coordination for
* the tricky method synthesis scenarios, so we'll make it that.
*/
protected def finishMethodSynthesis(templ: Template, clazz: Symbol, context: Context): Template = {
addSyntheticMethods(templ, clazz, context)
}
/** For flatMapping a list of trees when you want the DocDefs and Annotated
* to be transparent.
*/
def rewrappingWrapperTrees(f: Tree => List[Tree]): Tree => List[Tree] = {
case dd @ DocDef(comment, defn) => f(defn) map (stat => DocDef(comment, stat) setPos dd.pos)
case Annotated(annot, defn) => f(defn) map (stat => Annotated(annot, stat))
case tree => f(tree)
}
protected def enterSyms(txt: Context, trees: List[Tree]) = {
var txt0 = txt
for (tree <- trees) txt0 = enterSym(txt0, tree)
}
protected def enterSym(txt: Context, tree: Tree): Context =
if (txt eq context) namer enterSym tree
else newNamer(txt) enterSym tree
/** <!-- 2 --> Check that inner classes do not inherit from Annotation
*/
def typedTemplate(templ0: Template, parents1: List[Tree]): Template = {
val templ = templ0
// please FIXME: uncommenting this line breaks everything
// val templ = treeCopy.Template(templ0, templ0.body, templ0.self, templ0.parents)
val clazz = context.owner
clazz.annotations.map(_.completeInfo())
if (templ.symbol == NoSymbol)
templ setSymbol clazz.newLocalDummy(templ.pos)
val self1 = templ.self match {
case vd @ ValDef(_, _, tpt, EmptyTree) =>
val tpt1 = checkNoEscaping.privates(
clazz.thisSym,
treeCopy.TypeTree(tpt).setOriginal(tpt) setType vd.symbol.tpe
)
copyValDef(vd)(tpt = tpt1, rhs = EmptyTree) setType NoType
}
// was:
// val tpt1 = checkNoEscaping.privates(clazz.thisSym, typedType(tpt))
// treeCopy.ValDef(vd, mods, name, tpt1, EmptyTree) setType NoType
// but this leads to cycles for existential self types ==> #2545
if (self1.name != nme.WILDCARD)
context.scope enter self1.symbol
val selfType = (
if (clazz.isAnonymousClass && !phase.erasedTypes)
intersectionType(clazz.info.parents, clazz.owner)
else
clazz.typeOfThis
)
// the following is necessary for templates generated later
assert(clazz.info.decls != EmptyScope, clazz)
val body1 = pluginsEnterStats(this, templ.body)
enterSyms(context.outer.make(templ, clazz, clazz.info.decls), body1)
if (!templ.isErrorTyped) // if `parentTypes` has invalidated the template, don't validate it anymore
validateParentClasses(parents1, selfType)
if (clazz.isCase)
validateNoCaseAncestor(clazz)
if (clazz.isTrait && hasSuperArgs(parents1.head))
ConstrArgsInParentOfTraitError(parents1.head, clazz)
if ((clazz isSubClass ClassfileAnnotationClass) && !clazz.isTopLevel)
unit.error(clazz.pos, "inner classes cannot be classfile annotations")
if (!phase.erasedTypes && !clazz.info.resultType.isError) // @S: prevent crash for duplicated type members
checkFinitary(clazz.info.resultType.asInstanceOf[ClassInfoType])
val body2 = {
val body2 =
if (isPastTyper || reporter.hasErrors) body1
else body1 flatMap rewrappingWrapperTrees(namer.addDerivedTrees(Typer.this, _))
val primaryCtor = treeInfo.firstConstructor(body2)
val primaryCtor1 = primaryCtor match {
case DefDef(_, _, _, _, _, Block(earlyVals :+ global.pendingSuperCall, unit)) =>
val argss = superArgs(parents1.head) getOrElse Nil
val pos = wrappingPos(parents1.head.pos, primaryCtor :: argss.flatten).makeTransparent
val superCall = atPos(pos)(PrimarySuperCall(argss))
deriveDefDef(primaryCtor)(block => Block(earlyVals :+ superCall, unit) setPos pos) setPos pos
case _ => primaryCtor
}
body2 mapConserve { case `primaryCtor` => primaryCtor1; case stat => stat }
}
val body3 = typedStats(body2, templ.symbol)
if (clazz.info.firstParent.typeSymbol == AnyValClass)
validateDerivedValueClass(clazz, body3)
if (clazz.isTrait) {
for (decl <- clazz.info.decls if decl.isTerm && decl.isEarlyInitialized) {
unit.warning(decl.pos, "Implementation restriction: early definitions in traits are not initialized before the super class is initialized.")
}
}
treeCopy.Template(templ, parents1, self1, body3) setType clazz.tpe_*
}
/** Remove definition annotations from modifiers (they have been saved
* into the symbol's `annotations` in the type completer / namer)
*
* However reification does need annotation definitions to proceed.
* Unfortunately, AnnotationInfo doesn't provide enough info to reify it in general case.
* The biggest problem is with the "atp: Type" field, which cannot be reified in some situations
* that involve locally defined annotations. See more about that in Reifiers.scala.
*
* That's why the original tree gets saved into `original` field of AnnotationInfo (happens elsewhere).
* The field doesn't get pickled/unpickled and exists only during a single compilation run.
* This simultaneously allows us to reify annotations and to preserve backward compatibility.
*/
def typedModifiers(mods: Modifiers): Modifiers =
mods.copy(annotations = Nil) setPositions mods.positions
def typedValDef(vdef: ValDef): ValDef = {
val sym = vdef.symbol
val valDefTyper = {
val maybeConstrCtx =
if ((sym.isParameter || sym.isEarlyInitialized) && sym.owner.isConstructor) context.makeConstructorContext
else context
newTyper(maybeConstrCtx.makeNewScope(vdef, sym))
}
valDefTyper.typedValDefImpl(vdef)
}
// use typedValDef instead. this version is called after creating a new context for the ValDef
private def typedValDefImpl(vdef: ValDef) = {
val sym = vdef.symbol.initialize
val typedMods = typedModifiers(vdef.mods)
sym.annotations.map(_.completeInfo())
val tpt1 = checkNoEscaping.privates(sym, typedType(vdef.tpt))
checkNonCyclic(vdef, tpt1)
if (sym.hasAnnotation(definitions.VolatileAttr) && !sym.isMutable)
VolatileValueError(vdef)
val rhs1 =
if (vdef.rhs.isEmpty) {
if (sym.isVariable && sym.owner.isTerm && !sym.isLazy && !isPastTyper)
LocalVarUninitializedError(vdef)
vdef.rhs
} else {
val tpt2 = if (sym.hasDefault) {
// When typechecking default parameter, replace all type parameters in the expected type by Wildcard.
// This allows defining "def foo[T](a: T = 1)"
val tparams = sym.owner.skipConstructor.info.typeParams
val subst = new SubstTypeMap(tparams, tparams map (_ => WildcardType)) {
override def matches(sym: Symbol, sym1: Symbol) =
if (sym.isSkolem) matches(sym.deSkolemize, sym1)
else if (sym1.isSkolem) matches(sym, sym1.deSkolemize)
else super[SubstTypeMap].matches(sym, sym1)
}
// allow defaults on by-name parameters
if (sym hasFlag BYNAMEPARAM)
if (tpt1.tpe.typeArgs.isEmpty) WildcardType // during erasure tpt1 is Function0
else subst(tpt1.tpe.typeArgs(0))
else subst(tpt1.tpe)
} else tpt1.tpe
transformedOrTyped(vdef.rhs, EXPRmode | BYVALmode, tpt2)
}
treeCopy.ValDef(vdef, typedMods, vdef.name, tpt1, checkDead(rhs1)) setType NoType
}
/** Enter all aliases of local parameter accessors.
*/
def computeParamAliases(clazz: Symbol, vparamss: List[List[ValDef]], rhs: Tree) {
debuglog(s"computing param aliases for $clazz:${clazz.primaryConstructor.tpe}:$rhs")
val pending = ListBuffer[AbsTypeError]()
// !!! This method is redundant with other, less buggy ones.
def decompose(call: Tree): (Tree, List[Tree]) = call match {
case _ if call.isErrorTyped => // e.g. SI-7636
(call, Nil)
case Apply(fn, args) =>
// an object cannot be allowed to pass a reference to itself to a superconstructor
// because of initialization issues; SI-473, SI-3913, SI-6928.
foreachSubTreeBoundTo(args, clazz) { tree =>
if (tree.symbol.isModule)
pending += SuperConstrReferenceError(tree)
tree match {
case This(qual) =>
pending += SuperConstrArgsThisReferenceError(tree)
case _ => ()
}
}
val (superConstr, preArgs) = decompose(fn)
val params = fn.tpe.params
// appending a dummy tree to represent Nil for an empty varargs (is this really necessary?)
val applyArgs = if (args.length < params.length) args :+ EmptyTree else args take params.length
assert(sameLength(applyArgs, params) || call.isErrorTyped,
s"arity mismatch but call is not error typed: $clazz (params=$params, args=$applyArgs)")
(superConstr, preArgs ::: applyArgs)
case Block(_ :+ superCall, _) =>
decompose(superCall)
case _ =>
(call, Nil)
}
val (superConstr, superArgs) = decompose(rhs)
assert(superConstr.symbol ne null, superConstr)//debug
def superClazz = superConstr.symbol.owner
def superParamAccessors = superClazz.constrParamAccessors
// associate superclass paramaccessors with their aliases
if (superConstr.symbol.isPrimaryConstructor && !superClazz.isJavaDefined && sameLength(superParamAccessors, superArgs)) {
for ((superAcc, superArg @ Ident(name)) <- superParamAccessors zip superArgs) {
if (mexists(vparamss)(_.symbol == superArg.symbol)) {
val alias = (
superAcc.initialize.alias
orElse (superAcc getter superAcc.owner)
filter (alias => superClazz.info.nonPrivateMember(alias.name) == alias)
)
if (alias.exists && !alias.accessed.isVariable && !isRepeatedParamType(alias.accessed.info)) {
val ownAcc = clazz.info decl name suchThat (_.isParamAccessor) match {
case acc if !acc.isDeferred && acc.hasAccessorFlag => acc.accessed
case acc => acc
}
ownAcc match {
case acc: TermSymbol if !acc.isVariable =>
debuglog(s"$acc has alias ${alias.fullLocationString}")
acc setAlias alias
case _ =>
}
}
}
}
}
pending.foreach(ErrorUtils.issueTypeError)
}
// Check for SI-4842.
private def checkSelfConstructorArgs(ddef: DefDef, clazz: Symbol) {
val pending = ListBuffer[AbsTypeError]()
ddef.rhs match {
case Block(stats, expr) =>
val selfConstructorCall = stats.headOption.getOrElse(expr)
foreachSubTreeBoundTo(List(selfConstructorCall), clazz) {
case tree @ This(qual) =>
pending += SelfConstrArgsThisReferenceError(tree)
case _ => ()
}
case _ =>
}
pending.foreach(ErrorUtils.issueTypeError)
}
/**
* Run the provided function for each sub tree of `trees` that
* are bound to a symbol with `clazz` as a base class.
*
* @param f This function can assume that `tree.symbol` is non null
*/
private def foreachSubTreeBoundTo[A](trees: List[Tree], clazz: Symbol)(f: Tree => Unit): Unit =
for {
tree <- trees
subTree <- tree
} {
val sym = subTree.symbol
if (sym != null && sym.info.baseClasses.contains(clazz))
f(subTree)
}
/** Check if a structurally defined method violates implementation restrictions.
* A method cannot be called if it is a non-private member of a refinement type
* and if its parameter's types are any of:
* - the self-type of the refinement
* - a type member of the refinement
* - an abstract type declared outside of the refinement.
* - an instance of a value class
* Furthermore, the result type may not be a value class either
*/
def checkMethodStructuralCompatible(ddef: DefDef): Unit = {
val meth = ddef.symbol
def parentString = meth.owner.parentSymbols filterNot (_ == ObjectClass) match {
case Nil => ""
case xs => xs.map(_.nameString).mkString(" (of ", " with ", ")")
}
def fail(pos: Position, msg: String): Boolean = {
unit.error(pos, msg)
false
}
/* Have to examine all parameters in all lists.
*/
def paramssTypes(tp: Type): List[List[Type]] = tp match {
case mt @ MethodType(_, restpe) => mt.paramTypes :: paramssTypes(restpe)
case PolyType(_, restpe) => paramssTypes(restpe)
case _ => Nil
}
def resultType = meth.tpe_*.finalResultType
def nthParamPos(n1: Int, n2: Int) =
try ddef.vparamss(n1)(n2).pos catch { case _: IndexOutOfBoundsException => meth.pos }
def failStruct(pos: Position, what: String, where: String = "Parameter type") =
fail(pos, s"$where in structural refinement may not refer to $what")
foreachWithIndex(paramssTypes(meth.tpe)) { (paramList, listIdx) =>
foreachWithIndex(paramList) { (paramType, paramIdx) =>
val sym = paramType.typeSymbol
def paramPos = nthParamPos(listIdx, paramIdx)
/* Not enough to look for abstract types; have to recursively check the bounds
* of each abstract type for more abstract types. Almost certainly there are other
* exploitable type soundness bugs which can be seen by bounding a type parameter
* by an abstract type which itself is bounded by an abstract type.
*/
def checkAbstract(tp0: Type, what: String): Boolean = {
def check(sym: Symbol): Boolean = !sym.isAbstractType || {
log(s"""checking $tp0 in refinement$parentString at ${meth.owner.owner.fullLocationString}""")
( (!sym.hasTransOwner(meth.owner) && failStruct(paramPos, "an abstract type defined outside that refinement", what))
|| (!sym.hasTransOwner(meth) && failStruct(paramPos, "a type member of that refinement", what))
|| checkAbstract(sym.info.bounds.hi, "Type bound")
)
}
tp0.dealiasWidenChain forall (t => check(t.typeSymbol))
}
checkAbstract(paramType, "Parameter type")
if (sym.isDerivedValueClass)
failStruct(paramPos, "a user-defined value class")
if (paramType.isInstanceOf[ThisType] && sym == meth.owner)
failStruct(paramPos, "the type of that refinement (self type)")
}
}
if (resultType.typeSymbol.isDerivedValueClass)
failStruct(ddef.tpt.pos, "a user-defined value class", where = "Result type")
}
def typedDefDef(ddef: DefDef): DefDef = {
val meth = ddef.symbol.initialize
reenterTypeParams(ddef.tparams)
reenterValueParams(ddef.vparamss)
// for `val` and `var` parameter, look at `target` meta-annotation
if (!isPastTyper && meth.isPrimaryConstructor) {
for (vparams <- ddef.vparamss; vd <- vparams) {
if (vd.mods.isParamAccessor) {
namer.validateParam(vd)
}
}
}
val tparams1 = ddef.tparams mapConserve typedTypeDef
val vparamss1 = ddef.vparamss mapConserve (_ mapConserve typedValDef)
meth.annotations.map(_.completeInfo())
for (vparams1 <- vparamss1; vparam1 <- vparams1 dropRight 1)
if (isRepeatedParamType(vparam1.symbol.tpe))
StarParamNotLastError(vparam1)
val tpt1 = checkNoEscaping.privates(meth, typedType(ddef.tpt))
checkNonCyclic(ddef, tpt1)
ddef.tpt.setType(tpt1.tpe)
val typedMods = typedModifiers(ddef.mods)
var rhs1 =
if (ddef.name == nme.CONSTRUCTOR && !ddef.symbol.hasStaticFlag) { // need this to make it possible to generate static ctors
if (!meth.isPrimaryConstructor &&
(!meth.owner.isClass ||
meth.owner.isModuleClass ||
meth.owner.isAnonOrRefinementClass))
InvalidConstructorDefError(ddef)
typed(ddef.rhs)
} else if (meth.isMacro) {
// typechecking macro bodies is sort of unconventional
// that's why we employ our custom typing scheme orchestrated outside of the typer
transformedOr(ddef.rhs, typedMacroBody(this, ddef))
} else {
transformedOrTyped(ddef.rhs, EXPRmode, tpt1.tpe)
}
if (meth.isClassConstructor && !isPastTyper && !meth.owner.isSubClass(AnyValClass)) {
// At this point in AnyVal there is no supercall, which will blow up
// in computeParamAliases; there's nothing to be computed for Anyval anyway.
if (meth.isPrimaryConstructor)
computeParamAliases(meth.owner, vparamss1, rhs1)
else
checkSelfConstructorArgs(ddef, meth.owner)
}
if (tpt1.tpe.typeSymbol != NothingClass && !context.returnsSeen && rhs1.tpe.typeSymbol != NothingClass)
rhs1 = checkDead(rhs1)
if (!isPastTyper && meth.owner.isClass &&
meth.paramss.exists(ps => ps.exists(_.hasDefault) && isRepeatedParamType(ps.last.tpe)))
StarWithDefaultError(meth)
if (!isPastTyper) {
val allParams = meth.paramss.flatten
for (p <- allParams) {
for (n <- p.deprecatedParamName) {
if (allParams.exists(p1 => p1.name == n || (p != p1 && p1.deprecatedParamName.exists(_ == n))))
DeprecatedParamNameError(p, n)
}
}
if (meth.isStructuralRefinementMember)
checkMethodStructuralCompatible(ddef)
if (meth.isImplicit && !meth.isSynthetic) meth.info.paramss match {
case List(param) :: _ if !param.isImplicit =>
checkFeature(ddef.pos, ImplicitConversionsFeature, meth.toString)
case _ =>
}
}
treeCopy.DefDef(ddef, typedMods, ddef.name, tparams1, vparamss1, tpt1, rhs1) setType NoType
}
def typedTypeDef(tdef: TypeDef): TypeDef =
typerWithCondLocalContext(context.makeNewScope(tdef, tdef.symbol))(tdef.tparams.nonEmpty) {
_.typedTypeDefImpl(tdef)
}
// use typedTypeDef instead. this version is called after creating a new context for the TypeDef
private def typedTypeDefImpl(tdef: TypeDef): TypeDef = {
tdef.symbol.initialize
reenterTypeParams(tdef.tparams)
val tparams1 = tdef.tparams mapConserve typedTypeDef
val typedMods = typedModifiers(tdef.mods)
tdef.symbol.annotations.map(_.completeInfo())
// @specialized should not be pickled when compiling with -no-specialize
if (settings.nospecialization && currentRun.compiles(tdef.symbol)) {
tdef.symbol.removeAnnotation(definitions.SpecializedClass)
tdef.symbol.deSkolemize.removeAnnotation(definitions.SpecializedClass)
}
val rhs1 = checkNoEscaping.privates(tdef.symbol, typedType(tdef.rhs))
checkNonCyclic(tdef.symbol)
if (tdef.symbol.owner.isType)
rhs1.tpe match {
case TypeBounds(lo1, hi1) if (!(lo1 <:< hi1)) => LowerBoundError(tdef, lo1, hi1)
case _ => ()
}
if (tdef.symbol.isDeferred && tdef.symbol.info.isHigherKinded)
checkFeature(tdef.pos, HigherKindsFeature)
treeCopy.TypeDef(tdef, typedMods, tdef.name, tparams1, rhs1) setType NoType
}
private def enterLabelDef(stat: Tree) {
stat match {
case ldef @ LabelDef(_, _, _) =>
if (ldef.symbol == NoSymbol)
ldef.symbol = namer.enterInScope(
context.owner.newLabel(ldef.name, ldef.pos) setInfo MethodType(List(), UnitTpe))
case _ =>
}
}
def typedLabelDef(ldef: LabelDef): LabelDef = {
if (!nme.isLoopHeaderLabel(ldef.symbol.name) || isPastTyper) {
val restpe = ldef.symbol.tpe.resultType
val rhs1 = typed(ldef.rhs, restpe)
ldef.params foreach (param => param setType param.symbol.tpe)
deriveLabelDef(ldef)(_ => rhs1) setType restpe
}
else {
val initpe = ldef.symbol.tpe.resultType
val rhs1 = typed(ldef.rhs)
val restpe = rhs1.tpe
if (restpe == initpe) { // stable result, no need to check again
ldef.params foreach (param => param setType param.symbol.tpe)
treeCopy.LabelDef(ldef, ldef.name, ldef.params, rhs1) setType restpe
} else {
context.scope.unlink(ldef.symbol)
val sym2 = namer.enterInScope(
context.owner.newLabel(ldef.name, ldef.pos) setInfo MethodType(List(), restpe))
val LabelDef(_, _, rhs1) = resetAttrs(ldef)
val rhs2 = typed(rhs1, restpe)
ldef.params foreach (param => param setType param.symbol.tpe)
deriveLabelDef(ldef)(_ => rhs2) setSymbol sym2 setType restpe
}
}
}
def typedBlock(block0: Block, mode: Mode, pt: Type): Block = {
val syntheticPrivates = new ListBuffer[Symbol]
try {
namer.enterSyms(block0.stats)
val block = treeCopy.Block(block0, pluginsEnterStats(this, block0.stats), block0.expr)
for (stat <- block.stats) enterLabelDef(stat)
if (phaseId(currentPeriod) <= currentRun.typerPhase.id) {
// This is very tricky stuff, because we are navigating the Skylla and Charybdis of
// anonymous classes and what to return from them here. On the one hand, we cannot admit
// every non-private member of an anonymous class as a part of the structural type of the
// enclosing block. This runs afoul of the restriction that a structural type may not
// refer to an enclosing type parameter or abstract types (which in turn is necessitated
// by what can be done in Java reflection). On the other hand, making every term member
// private conflicts with private escape checking - see ticket #3174 for an example.
//
// The cleanest way forward is if we would find a way to suppress structural type checking
// for these members and maybe defer type errors to the places where members are called.
// But that would be a big refactoring and also a big departure from existing code. The
// probably safest fix for 2.8 is to keep members of an anonymous class that are not
// mentioned in a parent type private (as before) but to disable escape checking for code
// that's in the same anonymous class. That's what's done here.
//
// We really should go back and think hard whether we find a better way to address the
// problem of escaping idents on the one hand and well-formed structural types on the
// other.
block match {
case Block(List(classDef @ ClassDef(_, _, _, _)), Apply(Select(New(_), _), _)) =>
val classDecls = classDef.symbol.info.decls
val visibleMembers = pt match {
case WildcardType => classDecls.toList
case BoundedWildcardType(TypeBounds(lo, _)) => lo.members
case _ => pt.members
}
def matchesVisibleMember(member: Symbol) = visibleMembers exists { vis =>
(member.name == vis.name) &&
(member.tpe <:< vis.tpe.substThis(vis.owner, classDef.symbol))
}
// The block is an anonymous class definitions/instantiation pair
// -> members that are hidden by the type of the block are made private
val toHide = (
classDecls filter (member =>
member.isTerm
&& member.isPossibleInRefinement
&& member.isPublic
&& !matchesVisibleMember(member)
) map (member => member
resetFlag (PROTECTED | LOCAL)
setFlag (PRIVATE | SYNTHETIC_PRIVATE)
setPrivateWithin NoSymbol
)
)
syntheticPrivates ++= toHide
case _ =>
}
}
val stats1 = if (isPastTyper) block.stats else
block.stats.flatMap(stat => stat match {
case vd@ValDef(_, _, _, _) if vd.symbol.isLazy =>
namer.addDerivedTrees(Typer.this, vd)
case _ => stat::Nil
})
val stats2 = typedStats(stats1, context.owner)
val expr1 = typed(block.expr, mode &~ (FUNmode | QUALmode), pt)
treeCopy.Block(block, stats2, expr1)
.setType(if (treeInfo.isExprSafeToInline(block)) expr1.tpe else expr1.tpe.deconst)
} finally {
// enable escaping privates checking from the outside and recycle
// transient flag
syntheticPrivates foreach (_ resetFlag SYNTHETIC_PRIVATE)
}
}
def typedCase(cdef: CaseDef, pattpe: Type, pt: Type): CaseDef = {
// verify no _* except in last position
for (Apply(_, xs) <- cdef.pat ; x <- xs dropRight 1 ; if treeInfo isStar x)
StarPositionInPatternError(x)
// withoutAnnotations - see continuations-run/z1673.scala
// This adjustment is awfully specific to continuations, but AFAICS the
// whole AnnotationChecker framework is.
val pat1 = typedPattern(cdef.pat, pattpe.withoutAnnotations)
// When case classes have more than two parameter lists, the pattern ends
// up typed as a method. We only pattern match on the first parameter
// list, so substitute the final result type of the method, i.e. the type
// of the case class.
if (pat1.tpe.paramSectionCount > 0)
pat1 modifyType (_.finalResultType)
for (bind @ Bind(name, _) <- cdef.pat) {
val sym = bind.symbol
if (name.toTermName != nme.WILDCARD && sym != null) {
if (sym == NoSymbol) {
if (context.scope.lookup(name) == NoSymbol)
namer.enterInScope(context.owner.newErrorSymbol(name))
} else
namer.enterIfNotThere(sym)
}
}
val guard1: Tree = if (cdef.guard == EmptyTree) EmptyTree
else typed(cdef.guard, BooleanTpe)
var body1: Tree = typed(cdef.body, pt)
if (context.enclosingCaseDef.savedTypeBounds.nonEmpty) {
body1 modifyType context.enclosingCaseDef.restoreTypeBounds
// insert a cast if something typechecked under the GADT constraints,
// 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)) {
log(s"Adding cast to pattern because ${body1.tpe} does not conform to expected type $pt")
body1 = typedPos(body1.pos)(gen.mkCast(body1, pt.dealiasWiden))
}
}
// body1 = checkNoEscaping.locals(context.scope, pt, body1)
treeCopy.CaseDef(cdef, pat1, guard1, body1) setType body1.tpe
}
def typedCases(cases: List[CaseDef], pattp: Type, pt: Type): List[CaseDef] =
cases mapConserve { cdef =>
newTyper(context.makeNewScope(cdef, context.owner)).typedCase(cdef, pattp, pt)
}
def adaptCase(cdef: CaseDef, mode: Mode, tpe: Type): CaseDef = deriveCaseDef(cdef)(adapt(_, mode, tpe))
def packedTypes(trees: List[Tree]): List[Type] = trees map (c => packedType(c, context.owner).deconst)
// takes untyped sub-trees of a match and type checks them
def typedMatch(selector: Tree, cases: List[CaseDef], mode: Mode, pt: Type, tree: Tree = EmptyTree): Match = {
val selector1 = checkDead(typedByValueExpr(selector))
val selectorTp = packCaptured(selector1.tpe.widen).skolemizeExistential(context.owner, selector)
val casesTyped = typedCases(cases, selectorTp, pt)
def finish(cases: List[CaseDef], matchType: Type) =
treeCopy.Match(tree, selector1, cases) setType matchType
if (isFullyDefined(pt))
finish(casesTyped, pt)
else packedTypes(casesTyped) match {
case packed if sameWeakLubAsLub(packed) => finish(casesTyped, lub(packed))
case packed =>
val lub = weakLub(packed)
finish(casesTyped map (adaptCase(_, mode, lub)), lub)
}
}
// match has been typed -- virtualize it during type checking so the full context is available
def virtualizedMatch(match_ : Match, mode: Mode, pt: Type) = {
import patmat.{ vpmName, PureMatchTranslator }
// TODO: add fallback __match sentinel to predef
val matchStrategy: Tree =
if (!(settings.Xexperimental && context.isNameInScope(vpmName._match))) null // fast path, avoiding the next line if there's no __match to be seen
else newTyper(context.makeImplicit(reportAmbiguousErrors = false)).silent(_.typed(Ident(vpmName._match)), reportAmbiguousErrors = false) orElse (_ => null)
if (matchStrategy ne null) // virtualize
typed((new PureMatchTranslator(this.asInstanceOf[patmat.global.analyzer.Typer] /*TODO*/, matchStrategy)).translateMatch(match_), mode, pt)
else
match_ // will be translated in phase `patmat`
}
/** synthesize and type check a PartialFunction implementation based on the match in `tree`
*
* `param => sel match { cases }` becomes:
*
* new AbstractPartialFunction[$argTp, $matchResTp] {
* def applyOrElse[A1 <: $argTp, B1 >: $matchResTp]($param: A1, default: A1 => B1): B1 =
* $selector match { $cases }
* def isDefinedAt(x: $argTp): Boolean =
* $selector match { $casesTrue }
* }
*
* TODO: it would be nicer to generate the tree specified above at once and type it as a whole,
* there are two gotchas:
* - matchResTp may not be known until we've typed the match (can only use resTp when it's fully defined),
* - if we typed the match in isolation first, you'd know its result type, but would have to re-jig the owner structure
* - could we use a type variable for matchResTp and backpatch it?
* - occurrences of `this` in `cases` or `sel` must resolve to the this of the class originally enclosing the match,
* not of the anonymous partial function subclass
*
* an alternative TODO: add partial function AST node or equivalent and get rid of this synthesis --> do everything in uncurry (or later)
* however, note that pattern matching codegen is designed to run *before* uncurry
*/
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.dealiasWiden.typeArgs
// if targs.head isn't fully defined, we can't translate --> error
targs match {
case argTp :: _ if isFullyDefined(argTp) => // ok
case _ => // uh-oh
MissingParameterTypeAnonMatchError(tree, pt)
return setError(tree)
}
// NOTE: resTp still might not be fully defined
val argTp :: resTp :: Nil = targs
// targs must conform to Any for us to synthesize an applyOrElse (fallback to apply otherwise -- typically for @cps annotated targs)
val targsValidParams = targs forall (_ <:< AnyTpe)
val anonClass = context.owner newAnonymousFunctionClass tree.pos addAnnotation SerialVersionUIDAnnotation
import CODE._
val Match(sel, cases) = tree
// need to duplicate the cases before typing them to generate the apply method, or the symbols will be all messed up
val casesTrue = cases map (c => deriveCaseDef(c)(x => atPos(x.pos.focus)(TRUE)).duplicate.asInstanceOf[CaseDef])
// must generate a new tree every time
def selector: Tree = gen.mkUnchecked(
if (sel != EmptyTree) sel.duplicate
else atPos(tree.pos.focusStart)(
// SI-6925: subsume type of the selector to `argTp`
// we don't want/need the match to see the `A1` type that we must use for variance reasons in the method signature
//
// this failed: replace `selector` by `Typed(selector, TypeTree(argTp))` -- as it's an upcast, this should never fail,
// `(x: A1): A` doesn't always type check, even though `A1 <: A`, due to singleton types (test/files/pos/t4269.scala)
// hence the cast, which will be erased in posterasure
// (the cast originally caused extremely weird types to show up
// in test/scaladoc/run/SI-5933.scala because `variantToSkolem` was missing `tpSym.initialize`)
gen.mkCastPreservingAnnotations(Ident(paramName), argTp)
))
def mkParam(methodSym: Symbol, tp: Type = argTp) =
methodSym.newValueParameter(paramName, paramPos.focus, SYNTHETIC) setInfo tp
def mkDefaultCase(body: Tree) =
atPos(tree.pos.makeTransparent) {
CaseDef(Bind(nme.DEFAULT_CASE, Ident(nme.WILDCARD)), body)
}
// `def applyOrElse[A1 <: $argTp, B1 >: $matchResTp](x: A1, default: A1 => B1): B1 =
// ${`$selector match { $cases; case default$ => default(x) }`
def applyOrElseMethodDef = {
val methodSym = anonClass.newMethod(nme.applyOrElse, tree.pos, FINAL | OVERRIDE)
// create the parameter that corresponds to the function's parameter
val A1 = methodSym newTypeParameter (newTypeName("A1")) setInfo TypeBounds.upper(argTp)
val x = mkParam(methodSym, A1.tpe)
// applyOrElse's default parameter:
val B1 = methodSym newTypeParameter (newTypeName("B1")) setInfo TypeBounds.empty
val default = methodSym newValueParameter (newTermName("default"), tree.pos.focus, SYNTHETIC) setInfo functionType(List(A1.tpe), B1.tpe)
val paramSyms = List(x, default)
methodSym setInfo polyType(List(A1, B1), MethodType(paramSyms, B1.tpe))
val methodBodyTyper = newTyper(context.makeNewScope(context.tree, methodSym))
// should use the DefDef for the context's tree, but it doesn't exist yet (we need the typer we're creating to create it)
paramSyms foreach (methodBodyTyper.context.scope enter _)
// First, type without the default case; only the cases provided
// by the user are typed. The LUB of these becomes `B`, the lower
// bound of `B1`, which in turn is the result type of the default
// case
val match0 = methodBodyTyper.typedMatch(selector, cases, mode, resTp)
val matchResTp = match0.tpe
B1 setInfo TypeBounds.lower(matchResTp) // patch info
// the default uses applyOrElse's first parameter since the scrut's type has been widened
val match_ = {
val defaultCase = methodBodyTyper.typedCase(
mkDefaultCase(methodBodyTyper.typed1(REF(default) APPLY (REF(x)), mode, B1.tpe).setType(B1.tpe)), argTp, B1.tpe)
treeCopy.Match(match0, match0.selector, match0.cases :+ defaultCase)
}
match_ setType B1.tpe
// SI-6187 Do you really want to know? Okay, here's what's going on here.
//
// Well behaved trees satisfy the property:
//
// typed(tree) == typed(resetAttrs(typed(tree))
//
// Trees constructed without low-level symbol manipulation get this for free;
// references to local symbols are cleared by `ResetAttrs`, but bind to the
// corresponding symbol in the re-typechecked tree. But PartialFunction synthesis
// doesn't play by these rules.
//
// During typechecking of method bodies, references to method type parameter from
// the declared types of the value parameters should bind to a fresh set of skolems,
// which have been entered into scope by `Namer#methodSig`. A comment therein:
//
// "since the skolemized tparams are in scope, the TypeRefs in vparamSymss refer to skolemized tparams"
//
// But, if we retypecheck the reset `applyOrElse`, the TypeTree of the `default`
// parameter contains no type. Somehow (where?!) it recovers a type that is _almost_ okay:
// `A1 => B1`. But it should really be `A1&0 => B1&0`. In the test, run/t6187.scala, this
// difference results in a type error, as `default.apply(x)` types as `B1`, which doesn't
// conform to the required `B1&0`
//
// I see three courses of action.
//
// 1) synthesize a `asInstanceOf[B1]` below (I tried this first. But... ewwww.)
// 2) install an 'original' TypeTree that will used after ResetAttrs (the solution below)
// 3) Figure out how the almost-correct type is recovered on re-typechecking, and
// substitute in the skolems.
//
// For 2.11, we'll probably shift this transformation back a phase or two, so macros
// won't be affected. But in any case, we should satisfy retypecheckability.
//
val originals: Map[Symbol, Tree] = {
def typedIdent(sym: Symbol) = methodBodyTyper.typedType(Ident(sym), mode)
val A1Tpt = typedIdent(A1)
val B1Tpt = typedIdent(B1)
Map(
x -> A1Tpt,
default -> gen.scalaFunctionConstr(List(A1Tpt), B1Tpt)
)
}
def newParam(param: Symbol): ValDef = {
val vd = ValDef(param, EmptyTree)
val tt @ TypeTree() = vd.tpt
tt setOriginal (originals(param) setPos param.pos.focus)
vd
}
val rhs = methodBodyTyper.virtualizedMatch(match_, mode, B1.tpe)
val defdef = newDefDef(methodSym, rhs)(vparamss = mapParamss(methodSym)(newParam), tpt = TypeTree(B1.tpe))
(defdef, matchResTp)
}
// `def isDefinedAt(x: $argTp): Boolean = ${`$selector match { $casesTrue; case default$ => false } }`
def isDefinedAtMethod = {
val methodSym = anonClass.newMethod(nme.isDefinedAt, tree.pos.makeTransparent, FINAL)
val paramSym = mkParam(methodSym)
val methodBodyTyper = newTyper(context.makeNewScope(context.tree, methodSym)) // should use the DefDef for the context's tree, but it doesn't exist yet (we need the typer we're creating to create it)
methodBodyTyper.context.scope enter paramSym
methodSym setInfo MethodType(List(paramSym), BooleanTpe)
val defaultCase = mkDefaultCase(FALSE)
val match_ = methodBodyTyper.typedMatch(selector, casesTrue :+ defaultCase, mode, BooleanTpe)
DefDef(methodSym, methodBodyTyper.virtualizedMatch(match_, mode, BooleanTpe))
}
// only used for @cps annotated partial functions
// `def apply(x: $argTp): $matchResTp = $selector match { $cases }`
def applyMethod = {
val methodSym = anonClass.newMethod(nme.apply, tree.pos, FINAL | OVERRIDE)
val paramSym = mkParam(methodSym)
methodSym setInfo MethodType(List(paramSym), AnyTpe)
val methodBodyTyper = newTyper(context.makeNewScope(context.tree, methodSym))
// should use the DefDef for the context's tree, but it doesn't exist yet (we need the typer we're creating to create it)
methodBodyTyper.context.scope enter paramSym
val match_ = methodBodyTyper.typedMatch(selector, cases, mode, resTp)
val matchResTp = match_.tpe
methodSym setInfo MethodType(List(paramSym), matchResTp) // patch info
(DefDef(methodSym, methodBodyTyper.virtualizedMatch(match_, mode, matchResTp)), matchResTp)
}
def parents(resTp: Type) = addSerializable(appliedType(AbstractPartialFunctionClass.typeConstructor, List(argTp, resTp)))
val members = {
val (applyMeth, matchResTp) = {
// rig the show so we can get started typing the method body -- later we'll correct the infos...
// targs were type arguments for PartialFunction, so we know they will work for AbstractPartialFunction as well
anonClass setInfo ClassInfoType(parents(resTp), newScope, anonClass)
// somehow @cps annotations upset the typer when looking at applyOrElse's signature, but not apply's
// TODO: figure out the details (T @cps[U] is not a subtype of Any, but then why does it work for the apply method?)
if (targsValidParams) applyOrElseMethodDef
else applyMethod
}
// patch info to the class's definitive info
anonClass setInfo ClassInfoType(parents(matchResTp), newScope, anonClass)
List(applyMeth, isDefinedAtMethod)
}
members foreach (m => anonClass.info.decls enter m.symbol)
val typedBlock = typedPos(tree.pos, mode, pt) {
Block(ClassDef(anonClass, NoMods, ListOfNil, members, tree.pos.focus), atPos(tree.pos.focus)(
Apply(Select(New(Ident(anonClass.name).setSymbol(anonClass)), nme.CONSTRUCTOR), List())
))
}
if (typedBlock.isErrorTyped) typedBlock
else // Don't leak implementation details into the type, see SI-6575
typedPos(tree.pos, mode, pt) {
Typed(typedBlock, TypeTree(typedBlock.tpe baseType PartialFunctionClass))
}
}
/** Synthesize and type check the implementation of a type with a Single Abstract Method
*
* `{ (p1: T1, ..., pN: TN) => body } : S`
*
* expands to (where `S` is the expected type that defines a single abstract method named `apply`)
*
* `{
* def apply$body(p1: T1, ..., pN: TN): T = body
* new S {
* def apply(p1: T1, ..., pN: TN): T = apply$body(p1,..., pN)
* }
* }`
*
* If 'T' is not fully defined, it is inferred by type checking
* `apply$body` without a result type before type checking the block.
* The method's inferred result type is used instead of T`. [See test/files/pos/sammy_poly.scala]
*
* The `apply` method is identified by the argument `sam`; `S` corresponds to the argument `samClassTp`,
* and `resPt` is derived from `samClassTp` -- it may be fully defined, or not...
*
* The function's body is put in a method outside of the class definition to enforce scoping.
* S's members should not be in scope in `body`.
*
* The restriction on implicit arguments (neither S's constructor, nor sam may take an implicit argument list),
* is largely to keep the implementation of type inference (the computation of `samClassTpFullyDefined`) simple.
*
* NOTE: it would be nicer to not have to type check `apply$body` separately when `T` is not fully defined.
* However T must be fully defined before we type the instantiation, as it'll end up as a parent type,
* which must be fully defined. Would be nice to have some kind of mechanism to insert type vars in a block of code,
* and have the instantiation of the first occurrence propagate to the rest of the block.
*/
def synthesizeSAMFunction(sam: Symbol, fun: Function, resPt: Type, samClassTp: Type, mode: Mode): Tree = {
// assert(fun.vparams forall (vp => isFullyDefined(vp.tpt.tpe))) -- by construction, as we take them from sam's info
val sampos = fun.pos
// if the expected sam type is fully defined, use it for the method's result type
// otherwise, NoType, so that type inference will determine the method's result type
// resPt is syntactically contained in samClassTp, so if the latter is fully defined, so is the former
// ultimately, we want to fully define samClassTp as it is used as the superclass of our anonymous class
val samDefTp = if (isFullyDefined(resPt)) resPt else NoType
val bodyName = newTermName(sam.name + "$body")
// `def '${sam.name}\$body'($p1: $T1, ..., $pN: $TN): $resPt = $body`
val samBodyDef =
DefDef(NoMods,
bodyName,
Nil,
List(fun.vparams.map(_.duplicate)), // must duplicate as we're also using them for `samDef`
TypeTree(samDefTp) setPos sampos.focus,
fun.body)
// If we need to enter the sym for the body def before type checking the block,
// we'll create a nested context, as explained below.
var nestedTyper = this
// Type check body def before classdef to fully determine samClassTp (if necessary).
// As `samClassTp` determines a parent type for the class,
// we can't type check `block` in one go unless `samClassTp` is fully defined.
val samClassTpFullyDefined =
if (isFullyDefined(samClassTp)) samClassTp
else try {
// This creates a symbol for samBodyDef with a type completer that'll be triggered immediately below.
// The symbol is entered in the same scope used for the block below, and won't thus be reentered later.
// It has to be a new scope, though, or we'll "get ambiguous reference to overloaded definition" [pos/sammy_twice.scala]
// makeSilent: [pos/nonlocal-unchecked.scala -- when translation all functions to sams]
val nestedCtx = enterSym(context.makeNewScope(context.tree, context.owner).makeSilent(), samBodyDef)
nestedTyper = newTyper(nestedCtx)
// NOTE: this `samBodyDef.symbol.info` runs the type completer set up by the enterSym above
val actualSamType = samBodyDef.symbol.info
// we're trying to fully define the type arguments for this type constructor
val samTyCon = samClassTp.typeSymbol.typeConstructor
// the unknowns
val tparams = samClassTp.typeSymbol.typeParams
// ... as typevars
val tvars = tparams map freshVar
// 1. Recover partial information:
// - derive a type from samClassTp that has the corresponding tparams for type arguments that aren't fully defined
// - constrain typevars to be equal to type args that are fully defined
val samClassTpMoreDefined = appliedType(samTyCon,
(samClassTp.typeArgs, tparams, tvars).zipped map {
case (a, _, tv) if isFullyDefined(a) => tv =:= a; a
case (_, p, _) => p.typeConstructor
})
// the method type we're expecting the synthesized sam to have, based on the expected sam type,
// where fully defined type args to samClassTp have been preserved,
// with the unknown args replaced by their corresponding type param
val expectedSamType = samClassTpMoreDefined.memberInfo(sam)
// 2. make sure the body def's actual type (formals and result) conforms to
// sam's expected type (in terms of the typevars that represent the sam's class's type params)
actualSamType <:< expectedSamType.substituteTypes(tparams, tvars)
// solve constraints tracked by tvars
val targs = solvedTypes(tvars, tparams, tparams map varianceInType(sam.info), upper = false, lubDepth(sam.info :: Nil))
debuglog(s"sam infer: $samClassTp --> ${appliedType(samTyCon, targs)} by $actualSamType <:< $expectedSamType --> $targs for $tparams")
// a fully defined samClassTp
appliedType(samTyCon, targs)
} catch {
case _: NoInstance | _: TypeError =>
devWarning(sampos, s"Could not define type $samClassTp using ${samBodyDef.symbol.rawInfo} <:< ${samClassTp memberInfo sam} (for $sam)")
samClassTp
}
// `final override def ${sam.name}($p1: $T1, ..., $pN: $TN): $resPt = ${sam.name}\$body'($p1, ..., $pN)`
val samDef =
DefDef(Modifiers(FINAL | OVERRIDE | SYNTHETIC),
sam.name.toTermName,
Nil,
List(fun.vparams),
TypeTree(samBodyDef.tpt.tpe) setPos sampos.focus,
Apply(Ident(bodyName), fun.vparams map (p => Ident(p.name)))
)
val serializableParentAddendum =
if (typeIsSubTypeOfSerializable(samClassTp)) Nil
else List(TypeTree(SerializableTpe))
val classDef =
ClassDef(Modifiers(FINAL), tpnme.ANON_FUN_NAME, tparams = Nil,
gen.mkTemplate(
parents = TypeTree(samClassTpFullyDefined) :: serializableParentAddendum,
self = emptyValDef,
constrMods = NoMods,
vparamss = ListOfNil,
body = List(samDef),
superPos = sampos.focus
)
)
// type checking the whole block, so that everything is packaged together nicely
// and we don't have to create any symbols by hand
val block =
nestedTyper.typedPos(sampos, mode, samClassTpFullyDefined) {
Block(
samBodyDef,
classDef,
Apply(Select(New(Ident(tpnme.ANON_FUN_NAME)), nme.CONSTRUCTOR), Nil)
)
}
classDef.symbol addAnnotation SerialVersionUIDAnnotation
block
}
/** Type check a function literal.
*
* Based on the expected type pt, potentially synthesize an instance of
* - PartialFunction,
* - a type with a Single Abstract Method (under -Xexperimental for now).
*/
private def typedFunction(fun: Function, mode: Mode, pt: Type): Tree = {
val numVparams = fun.vparams.length
val FunctionSymbol =
if (numVparams > definitions.MaxFunctionArity) NoSymbol
else FunctionClass(numVparams)
/* The Single Abstract Member of pt, unless pt is the built-in function type of the expected arity,
* as `(a => a): Int => Int` should not (yet) get the sam treatment.
*/
val sam =
if (!settings.Xexperimental || pt.typeSymbol == FunctionSymbol) NoSymbol
else samOf(pt)
/* The SAM case comes first so that this works:
* abstract class MyFun extends (Int => Int)
* (a => a): MyFun
*
* Note that the arity of the sam must correspond to the arity of the function.
*/
val samViable = sam.exists && sameLength(sam.info.params, fun.vparams)
val (argpts, respt) =
if (samViable) {
val samInfo = pt memberInfo sam
(samInfo.paramTypes, samInfo.resultType)
} else {
pt baseType FunctionSymbol match {
case TypeRef(_, FunctionSymbol, args :+ res) => (args, res)
case _ => (fun.vparams map (_ => if (pt == ErrorType) ErrorType else NoType), WildcardType)
}
}
if (!FunctionSymbol.exists)
MaxFunctionArityError(fun)
else if (argpts.lengthCompare(numVparams) != 0)
WrongNumberOfParametersError(fun, argpts)
else {
var issuedMissingParameterTypeError = false
foreach2(fun.vparams, argpts) { (vparam, argpt) =>
if (vparam.tpt.isEmpty) {
vparam.tpt.tpe =
if (isFullyDefined(argpt)) argpt
else {
fun match {
case etaExpansion(vparams, fn, args) =>
silent(_.typed(fn, mode.forFunMode, pt)) filter (_ => context.undetparams.isEmpty) map { fn1 =>
// if context.undetparams is not empty, the function was polymorphic,
// so we need the missing arguments to infer its type. See #871
//println("typing eta "+fun+":"+fn1.tpe+"/"+context.undetparams)
val ftpe = normalize(fn1.tpe) baseType FunctionClass(numVparams)
if (isFunctionType(ftpe) && isFullyDefined(ftpe))
return typedFunction(fun, mode, ftpe)
}
case _ =>
}
MissingParameterTypeError(fun, vparam, pt, withTupleAddendum = !issuedMissingParameterTypeError)
issuedMissingParameterTypeError = true
ErrorType
}
if (!vparam.tpt.pos.isDefined) vparam.tpt setPos vparam.pos.focus
}
}
fun.body match {
// translate `x => x match { <cases> }` : PartialFunction to
// `new PartialFunction { def applyOrElse(x, default) = x match { <cases> } def isDefinedAt(x) = ... }`
case Match(sel, cases) if (sel ne EmptyTree) && (pt.typeSymbol == PartialFunctionClass) =>
// go to outer context -- must discard the context that was created for the Function since we're discarding the function
// thus, its symbol, which serves as the current context.owner, is not the right owner
// you won't know you're using the wrong owner until lambda lift crashes (unless you know better than to use the wrong owner)
val outerTyper = newTyper(context.outer)
val p = fun.vparams.head
if (p.tpt.tpe == null) p.tpt setType outerTyper.typedType(p.tpt).tpe
outerTyper.synthesizePartialFunction(p.name, p.pos, fun.body, mode, pt)
// Use synthesizeSAMFunction to expand `(p1: T1, ..., pN: TN) => body`
// to an instance of the corresponding anonymous subclass of `pt`.
case _ if samViable =>
newTyper(context.outer).synthesizeSAMFunction(sam, fun, respt, pt, mode)
// regular Function
case _ =>
val vparamSyms = fun.vparams map { vparam =>
enterSym(context, vparam)
if (context.retyping) context.scope enter vparam.symbol
vparam.symbol
}
val vparams = fun.vparams mapConserve typedValDef
val formals = vparamSyms map (_.tpe)
val body1 = typed(fun.body, respt)
val restpe = packedType(body1, fun.symbol).deconst.resultType
val funtpe = appliedType(FunctionSymbol, formals :+ restpe: _*)
treeCopy.Function(fun, vparams, body1) setType funtpe
}
}
}
def typedRefinement(templ: Template) {
val stats = templ.body
namer.enterSyms(stats)
// need to delay rest of typedRefinement to avoid cyclic reference errors
unit.toCheck += { () =>
val stats1 = typedStats(stats, NoSymbol)
// this code kicks in only after typer, so `stats` will never be filled in time
// as a result, most of compound type trees with non-empty stats will fail to reify
// todo. investigate whether something can be done about this
val att = templ.attachments.get[CompoundTypeTreeOriginalAttachment].getOrElse(CompoundTypeTreeOriginalAttachment(Nil, Nil))
templ.removeAttachment[CompoundTypeTreeOriginalAttachment]
templ updateAttachment att.copy(stats = stats1)
for (stat <- stats1 if stat.isDef && stat.symbol.isOverridingSymbol)
stat.symbol setFlag OVERRIDE
}
}
def typedImport(imp : Import) : Import = (transformed remove imp) match {
case Some(imp1: Import) => imp1
case _ => log("unhandled import: "+imp+" in "+unit); imp
}
def typedStats(stats: List[Tree], exprOwner: Symbol): List[Tree] = {
val inBlock = exprOwner == context.owner
def includesTargetPos(tree: Tree) =
tree.pos.isRange && context.unit.exists && (tree.pos includes context.unit.targetPos)
val localTarget = stats exists includesTargetPos
def typedStat(stat: Tree): Tree = {
if (context.owner.isRefinementClass && !treeInfo.isDeclarationOrTypeDef(stat))
OnlyDeclarationsError(stat)
else
stat match {
case imp @ Import(_, _) =>
imp.symbol.initialize
if (!imp.symbol.isError) {
context = context.make(imp)
typedImport(imp)
} else EmptyTree
case _ =>
if (localTarget && !includesTargetPos(stat)) {
// skip typechecking of statements in a sequence where some other statement includes
// the targetposition
stat
} else {
val localTyper = if (inBlock || (stat.isDef && !stat.isInstanceOf[LabelDef])) {
this
} else newTyper(context.make(stat, exprOwner))
// XXX this creates a spurious dead code warning if an exception is thrown
// in a constructor, even if it is the only thing in the constructor.
val result = checkDead(localTyper.typedByValueExpr(stat))
if (treeInfo.isSelfOrSuperConstrCall(result)) {
context.inConstructorSuffix = true
if (treeInfo.isSelfConstrCall(result) && result.symbol.pos.pointOrElse(0) >= exprOwner.enclMethod.pos.pointOrElse(0))
ConstructorsOrderError(stat)
}
if (treeInfo.isPureExprForWarningPurposes(result)) context.warning(stat.pos,
"a pure expression does nothing in statement position; " +
"you may be omitting necessary parentheses"
)
result
}
}
}
/* 'accessor' and 'accessed' are so similar it becomes very difficult to
* follow the logic, so I renamed one to something distinct.
*/
def accesses(looker: Symbol, accessed: Symbol) = accessed.isLocalToThis && (
(accessed.isParamAccessor)
|| (looker.hasAccessorFlag && !accessed.hasAccessorFlag && accessed.isPrivate)
)
def checkNoDoubleDefs(stats: List[Tree]): Unit = {
val scope = if (inBlock) context.scope else context.owner.info.decls
var e = scope.elems
while ((e ne null) && e.owner == scope) {
var e1 = scope.lookupNextEntry(e)
while ((e1 ne null) && e1.owner == scope) {
if (!accesses(e.sym, e1.sym) && !accesses(e1.sym, e.sym) &&
(e.sym.isType || inBlock || (e.sym.tpe matches e1.sym.tpe)))
// default getters are defined twice when multiple overloads have defaults. an
// error for this is issued in RefChecks.checkDefaultsInOverloaded
if (!e.sym.isErroneous && !e1.sym.isErroneous && !e.sym.hasDefault &&
!e.sym.hasAnnotation(BridgeClass) && !e1.sym.hasAnnotation(BridgeClass)) {
log("Double definition detected:\n " +
((e.sym.getClass, e.sym.info, e.sym.ownerChain)) + "\n " +
((e1.sym.getClass, e1.sym.info, e1.sym.ownerChain)))
DefDefinedTwiceError(e.sym, e1.sym)
scope.unlink(e1) // need to unlink to avoid later problems with lub; see #2779
}
e1 = scope.lookupNextEntry(e1)
}
e = e.next
}
}
def addSynthetics(stats: List[Tree]): List[Tree] = {
val scope = if (inBlock) context.scope else context.owner.info.decls
var newStats = new ListBuffer[Tree]
var moreToAdd = true
while (moreToAdd) {
val initElems = scope.elems
// SI-5877 The decls of a package include decls of the package object. But we don't want to add
// the corresponding synthetics to the package class, only to the package object class.
def shouldAdd(sym: Symbol) =
inBlock || !context.isInPackageObject(sym, context.owner)
for (sym <- scope if shouldAdd(sym))
for (tree <- context.unit.synthetics get sym) {
newStats += typedStat(tree) // might add even more synthetics to the scope
context.unit.synthetics -= sym
}
// the type completer of a synthetic might add more synthetics. example: if the
// factory method of a case class (i.e. the constructor) has a default.
moreToAdd = scope.elems ne initElems
}
if (newStats.isEmpty) stats
else {
// put default getters next to the method they belong to,
// same for companion objects. fixes #2489 and #4036.
// [Martin] This is pretty ugly. I think we could avoid
// this code by associating defaults and companion objects
// with the original tree instead of the new symbol.
def matches(stat: Tree, synt: Tree) = (stat, synt) match {
// synt is default arg for stat
case (DefDef(_, statName, _, _, _, _), DefDef(mods, syntName, _, _, _, _)) =>
mods.hasDefault && syntName.toString.startsWith(statName.toString)
// synt is companion module
case (ClassDef(_, className, _, _), ModuleDef(_, moduleName, _)) =>
className.toTermName == moduleName
// synt is implicit def for implicit class (#6278)
case (ClassDef(cmods, cname, _, _), DefDef(dmods, dname, _, _, _, _)) =>
cmods.isImplicit && dmods.isImplicit && cname.toTermName == dname
case _ => false
}
def matching(stat: Tree): List[Tree] = {
val (pos, neg) = newStats.partition(synt => matches(stat, synt))
newStats = neg
pos.toList
}
(stats foldRight List[Tree]())((stat, res) => {
stat :: matching(stat) ::: res
}) ::: newStats.toList
}
}
val stats1 = stats mapConserve typedStat
if (phase.erasedTypes) stats1
else {
checkNoDoubleDefs(stats1)
addSynthetics(stats1)
}
}
def typedArg(arg: Tree, mode: Mode, newmode: Mode, pt: Type): Tree = {
val typedMode = mode.onlySticky | newmode
val t = withCondConstrTyper(mode.inSccMode)(_.typed(arg, typedMode, pt))
checkDead.inMode(typedMode, t)
}
def typedArgs(args: List[Tree], mode: Mode) =
args mapConserve (arg => typedArg(arg, mode, NOmode, WildcardType))
/** Does function need to be instantiated, because a missing parameter
* in an argument closure overlaps with an uninstantiated formal?
*/
def needsInstantiation(tparams: List[Symbol], formals: List[Type], args: List[Tree]) = {
def isLowerBounded(tparam: Symbol) = !tparam.info.bounds.lo.typeSymbol.isBottomClass
exists2(formals, args) {
case (formal, Function(vparams, _)) =>
(vparams exists (_.tpt.isEmpty)) &&
vparams.length <= MaxFunctionArity &&
(formal baseType FunctionClass(vparams.length) match {
case TypeRef(_, _, formalargs) =>
( exists2(formalargs, vparams)((formal, vparam) =>
vparam.tpt.isEmpty && (tparams exists formal.contains))
&& (tparams forall isLowerBounded)
)
case _ =>
false
})
case _ =>
false
}
}
/** Is `tree` a block created by a named application?
*/
def isNamedApplyBlock(tree: Tree) =
context.namedApplyBlockInfo exists (_._1 == tree)
def callToCompanionConstr(context: Context, calledFun: Symbol) = {
calledFun.isConstructor && {
val methCtx = context.enclMethod
(methCtx != NoContext) && {
val contextFun = methCtx.tree.symbol
contextFun.isPrimaryConstructor && contextFun.owner.isModuleClass &&
companionSymbolOf(calledFun.owner, context).moduleClass == contextFun.owner
}
}
}
def doTypedApply(tree: Tree, fun0: Tree, args: List[Tree], mode: Mode, pt: Type): Tree = {
// TODO_NMT: check the assumption that args nonEmpty
def duplErrTree = setError(treeCopy.Apply(tree, fun0, args))
def duplErrorTree(err: AbsTypeError) = { issue(err); duplErrTree }
def preSelectOverloaded(fun: Tree): Tree = {
if (fun.hasSymbolField && fun.symbol.isOverloaded) {
// remove alternatives with wrong number of parameters without looking at types.
// less expensive than including them in inferMethodAlternative (see below).
def shapeType(arg: Tree): Type = arg match {
case Function(vparams, body) =>
functionType(vparams map (_ => AnyTpe), shapeType(body))
case AssignOrNamedArg(Ident(name), rhs) =>
NamedType(name, shapeType(rhs))
case _ =>
NothingTpe
}
val argtypes = args map shapeType
val pre = fun.symbol.tpe.prefix
var sym = fun.symbol filter { alt =>
// must use pt as expected type, not WildcardType (a tempting quick fix to #2665)
// now fixed by using isWeaklyCompatible in exprTypeArgs
// TODO: understand why exactly -- some types were not inferred anymore (`ant clean quick.bin` failed)
// (I had expected inferMethodAlternative to pick up the slack introduced by using WildcardType here)
//
// @PP responds: I changed it to pass WildcardType instead of pt and only one line in
// trunk (excluding scalacheck, which had another) failed to compile. It was this line in
// Types: "refs = Array(Map(), Map())". I determined that inference fails if there are at
// least two invariant type parameters. See the test case I checked in to help backstop:
// pos/isApplicableSafe.scala.
isApplicableSafe(context.undetparams, followApply(pre memberType alt), argtypes, pt)
}
if (sym.isOverloaded) {
// eliminate functions that would result from tupling transforms
// keeps alternatives with repeated params
val sym1 = sym filter (alt =>
isApplicableBasedOnArity(pre memberType alt, argtypes.length, varargsStar = false, tuplingAllowed = false)
|| alt.tpe.params.exists(_.hasDefault)
)
if (sym1 != NoSymbol) sym = sym1
}
if (sym == NoSymbol) fun
else adapt(fun setSymbol sym setType pre.memberType(sym), mode.forFunMode, WildcardType)
} else fun
}
val fun = preSelectOverloaded(fun0)
fun.tpe match {
case OverloadedType(pre, alts) =>
def handleOverloaded = {
val undetparams = context.undetparams
val (args1, argTpes) = context.savingUndeterminedTypeParams() {
val amode = forArgMode(fun, mode)
def typedArg0(tree: Tree) = typedArg(tree, amode, BYVALmode, WildcardType)
args.map {
case arg @ AssignOrNamedArg(Ident(name), rhs) =>
// named args: only type the righthand sides ("unknown identifier" errors otherwise)
val rhs1 = typedArg0(rhs)
// the assign is untyped; that's ok because we call doTypedApply
val arg1 = treeCopy.AssignOrNamedArg(arg, arg.lhs, rhs1)
(arg1, NamedType(name, rhs1.tpe.deconst))
case arg @ treeInfo.WildcardStarArg(repeated) =>
val arg1 = typedArg0(arg)
(arg1, RepeatedType(arg1.tpe.deconst))
case arg =>
val arg1 = typedArg0(arg)
(arg1, arg1.tpe.deconst)
}.unzip
}
if (context.hasErrors)
setError(tree)
else {
inferMethodAlternative(fun, undetparams, argTpes, pt)
doTypedApply(tree, adapt(fun, mode.forFunMode, WildcardType), args1, mode, pt)
}
}
handleOverloaded
case mt @ MethodType(params, _) =>
val paramTypes = mt.paramTypes
// repeat vararg as often as needed, remove by-name
val argslen = args.length
val formals = formalTypes(paramTypes, argslen)
/* Try packing all arguments into a Tuple and apply `fun`
* to that. This is the last thing which is tried (after
* default arguments)
*/
def tryTupleApply: Tree = (
if (eligibleForTupleConversion(paramTypes, argslen) && !phase.erasedTypes) {
val tupleArgs = List(atPos(tree.pos.makeTransparent)(gen.mkTuple(args)))
// expected one argument, but got 0 or >1 ==> try applying to tuple
// the inner "doTypedApply" does "extractUndetparams" => restore when it fails
val savedUndetparams = context.undetparams
silent(_.doTypedApply(tree, fun, tupleArgs, mode, pt)) map { t =>
// Depending on user options, may warn or error here if
// a Unit or tuple was inserted.
val keepTree = (
!mode.typingExprNotFun
|| t.symbol == null
|| checkValidAdaptation(t, args)
)
if (keepTree) t else EmptyTree
} orElse { _ => context.undetparams = savedUndetparams ; EmptyTree }
}
else EmptyTree
)
/* Treats an application which uses named or default arguments.
* Also works if names + a vararg used: when names are used, the vararg