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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.tools.nsc
package typechecker
import scala.collection.mutable
import scala.reflect.internal.util.{ BatchSourceFile, Statistics }
import mutable.ListBuffer
import symtab.Flags._
// 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 Modes with Adaptations with Tags {
self: Analyzer =>
import global._
import definitions._
import TypersStats._
import patmat.DefaultOverrideMatchAttachment
final def forArgMode(fun: Tree, mode: Int) =
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.HashMap[Tree, Tree]
final val shortenImports = false
def resetTyper() {
//println("resetTyper called")
resetContexts()
resetImplicits()
transformed.clear()
}
object UnTyper extends Traverser {
override def traverse(tree: Tree) = {
if (tree != EmptyTree) tree.tpe = null
if (tree.hasSymbol) tree.symbol = NoSymbol
super.traverse(tree)
}
}
/* needed for experimental version where early types can be type arguments
class EarlyMap(clazz: Symbol) extends TypeMap {
def apply(tp: Type): Type = tp match {
case TypeRef(NoPrefix, sym, List()) if (sym hasFlag PRESUPER) =>
TypeRef(ThisType(clazz), sym, List())
case _ =>
mapOver(tp)
}
}
*/
sealed abstract class SilentResult[+T]
case class SilentTypeError(err: AbsTypeError) extends SilentResult[Nothing] { }
case class SilentResultValue[+T](value: T) extends SilentResult[T] { }
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 def isPastTyper = phase.id > currentRun.typerPhase.id
// To enable decent error messages when the typer crashes.
// TODO - this only catches trees which go through def typed,
// but there are all kinds of back ways - typedClassDef, etc. etc.
// Funnel everything through one doorway.
var lastTreeToTyper: Tree = EmptyTree
// when true:
// - we may virtualize matches (if -Xexperimental and there's a suitable __match in scope)
// - we synthesize PartialFunction implementations for `x => x match {...}` and `match {...}` when the expected type is PartialFunction
// this is disabled by: -Xoldpatmat or interactive compilation (we run it for scaladoc due to SI-5933)
private def newPatternMatching = opt.virtPatmat && !forInteractive //&& !forScaladoc && (phase.id < currentRun.uncurryPhase.id)
abstract class Typer(context0: Context) extends TyperDiagnostics with Adaptation with Tag with TyperContextErrors {
import context0.unit
import typeDebug.{ ptTree, ptBlock, ptLine }
import TyperErrorGen._
val infer = new Inferencer(context0) {
override def isCoercible(tp: Type, pt: Type): Boolean = undoLog undo { // #3281
tp.isError || pt.isError ||
context0.implicitsEnabled && // this condition prevents chains of views
inferView(EmptyTree, tp, pt, false) != EmptyTree
}
}
/** 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
def mkPositionalArg(argTree: Tree, paramName: Name) = argTree
def mkNamedArg(argTree: Tree, paramName: Name) = atPos(argTree.pos)(new AssignOrNamedArg(Ident(paramName), (argTree)))
var mkArg: (Tree, Name) => Tree = mkPositionalArg
// 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, false, context)
argResultsBuff += res
if (res != SearchFailure) {
argBuff += mkArg(res.tree, param.name)
} else {
mkArg = mkNamedArg // don't pass the default argument (if any) here, but start emitting named arguments for the following args
if (!param.hasDefault && !paramFailed) {
context.errBuffer.find(_.kind == ErrorKinds.Divergent) match {
case Some(divergentImplicit) =>
// 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(divergentImplicit)
context.condBufferFlush(_.kind == ErrorKinds.Divergent)
}
case None =>
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 inferView(tree: Tree, from: Type, to: Type, reportAmbiguous: Boolean): Tree =
inferView(tree, from, to, reportAmbiguous, 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 :: Nil, to), reportAmbiguous, true, context, 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.normalize
val tp1 = dropExistential(tp0)
if (tp1 eq tp0) tp else tp1
case _ => tp
}
/** Check that <code>tree</code> is a stable expression.
*
* @param tree ...
* @return ...
*/
def checkStable(tree: Tree): Tree = (
if (treeInfo.isExprSafeToInline(tree)) tree
else if (tree.isErrorTyped) tree
else UnstableTreeError(tree)
)
/** Would tree be a stable (i.e. a pure expression) if the type
* of its symbol was not volatile?
*/
protected def isStableExceptVolatile(tree: Tree) = {
tree.hasSymbol && tree.symbol != NoSymbol && tree.tpe.isVolatile &&
{ val savedTpe = tree.symbol.info
val savedSTABLE = tree.symbol getFlag STABLE
tree.symbol setInfo AnyRefClass.tpe
tree.symbol setFlag STABLE
val result = treeInfo.isExprSafeToInline(tree)
tree.symbol setInfo savedTpe
tree.symbol setFlag savedSTABLE
result
}
}
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 <code>tp</code> is not a subtype of itself.
*
* @param pos ...
* @param tp ...
* @return <code>true</code> if <code>tp</code> is not a subtype of itself.
*/
def checkNonCyclic(pos: Position, tp: Type): Boolean = {
def checkNotLocked(sym: Symbol) = {
sym.initialize
sym.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 TypeBounds(lo, hi) =>
var ok = true
for (t <- lo) ok = ok & checkNonCyclic(pos, t)
ok
*/
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, 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.tpe = 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 <code>tree</code> does not refer to private
* components unless itself is wrapped in something private
* (<code>owner</code> tells where the type occurs).
*
* @param owner ...
* @param tree ...
* @return ...
*/
def privates[T <: Tree](owner: Symbol, tree: T): T =
check(owner, EmptyScope, WildcardType, tree)
/** Check that type <code>tree</code> does not refer to entities
* defined in scope <code>scope</code>.
*
* @param scope ...
* @param pt ...
* @param tree ...
* @return ...
*/
def locals[T <: Tree](scope: Scope, pt: Type, tree: T): T =
check(NoSymbol, scope, pt, 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 (!phase.erasedTypes) { // 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.isLocal && !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.normalize
} else t
case SingleType(_, sym) =>
checkNoEscape(sym)
t
case _ =>
t
})
}
}
def reenterValueParams(vparamss: List[List[ValDef]]) {
for (vparams <- vparamss)
for (vparam <- vparams)
vparam.symbol = context.scope enter vparam.symbol
}
def reenterTypeParams(tparams: List[TypeDef]): List[Symbol] =
for (tparam <- tparams) yield {
tparam.symbol = context.scope enter tparam.symbol
tparam.symbol.deSkolemize
}
/** The qualifying class
* of a this or super with prefix <code>qual</code>.
* 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 typerReportAnyContextErrors[T](c: Context)(f: Typer => T): T = {
val res = f(newTyper(c))
if (c.hasErrors)
context.issue(c.errBuffer.head)
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
final val xtypes = false
/** 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 <code>tree</code> require a stable type?
*/
private def isStableContext(tree: Tree, mode: Int, pt: Type) =
isNarrowable(tree.tpe) && ((mode & (EXPRmode | LHSmode)) == EXPRmode) &&
(xtypes ||
(pt.isStable ||
(mode & QUALmode) != 0 && !tree.symbol.isConstant ||
pt.typeSymbol.isAbstractType && pt.bounds.lo.isStable && !(tree.tpe <:< pt)) ||
pt.typeSymbol.isRefinementClass && !(tree.tpe <:< pt))
/** 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 (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.
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(nme.PACKAGEkw)
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)
}
/** Is `sym` defined in package object of package `pkg`?
*/
private def isInPackageObject(sym: Symbol, pkg: Symbol) = {
def isInPkgObj(sym: Symbol) =
!sym.owner.isPackage && {
sym.owner.isPackageObjectClass &&
sym.owner.owner == pkg ||
pkg.isInitialized && {
// need to be careful here to not get a cyclic reference during bootstrap
val pkgobj = pkg.info.member(nme.PACKAGEkw)
pkgobj.isInitialized &&
(pkgobj.info.member(sym.name).alternatives contains sym)
}
}
pkg.isPackageClass && {
if (sym.isOverloaded) sym.alternatives forall isInPkgObj
else isInPkgObj(sym)
}
}
/** Post-process an identifier or selection node, performing the following:
* 1. Check that non-function pattern expressions are stable
* 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.
*/
private def stabilize(tree: Tree, pre: Type, mode: Int, pt: Type): Tree = {
if (tree.symbol.isOverloaded && !inFunMode(mode))
inferExprAlternative(tree, pt)
val sym = tree.symbol
def fail() = NotAValueError(tree, sym)
if (tree.isErrorTyped) tree
else if ((mode & (PATTERNmode | FUNmode)) == PATTERNmode && tree.isTerm) { // (1)
if (sym.isValue) {
val tree1 = checkStable(tree)
// A module reference in a pattern has type Foo.type, not "object Foo"
if (sym.isModule && !sym.isMethod) tree1 setType singleType(pre, sym)
else tree1
}
else fail()
} else if ((mode & (EXPRmode | QUALmode)) == EXPRmode && !sym.isValue && !phase.erasedTypes) { // (2)
fail()
} else {
if (sym.isStable && pre.isStable && !isByNameParamType(tree.tpe) &&
(isStableContext(tree, mode, pt) || sym.isModule && !sym.isMethod))
tree.setType(singleType(pre, sym))
// 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.
else if ( tree.symbol.name == nme.getClass_
&& tree.tpe.params.isEmpty
// 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.
&& pre.typeSymbol.isPublic)
tree setType MethodType(Nil, getClassReturnType(pre))
else
tree
}
}
private def isNarrowable(tpe: Type): Boolean = unwrapWrapperTypes(tpe) match {
case TypeRef(_, _, _) | RefinedType(_, _) => true
case _ => !phase.erasedTypes
}
/**
* @param tree ...
* @param mode ...
* @param pt ...
* @return ...
*/
def stabilizeFun(tree: Tree, mode: Int, pt: Type): Tree = {
val sym = tree.symbol
val pre = tree match {
case Select(qual, _) => qual.tpe
case _ => NoPrefix
}
if (tree.tpe.isInstanceOf[MethodType] && pre.isStable && sym.tpe.params.isEmpty &&
(isStableContext(tree, mode, pt) || sym.isModule))
tree.setType(MethodType(List(), singleType(pre, sym))) // TODO: should this be a NullaryMethodType?
else 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.errBuffer.head)
} else 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, true, false, context) != SearchFailure
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"
var raw = featureDesc + " " + req + " be enabled\n" +
"by making the implicit value language." + featureName + " visible."
if (!(currentRun.reportedFeature contains featureTrait))
raw += "\nThis can be achieved by adding the import clause 'import scala.language." + featureName + "'\n" +
"or by setting the compiler option -language:" + featureName + ".\n" +
"See the Scala docs for value scala.language." + featureName + " for a discussion\n" +
"why the feature " + req + " be explicitly enabled."
currentRun.reportedFeature += featureTrait
val msg = raw 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: Int, pt: Type, original: Tree = EmptyTree): Tree = {
def adaptToImplicitMethod(mt: MethodType): Tree = {
if (context.undetparams.nonEmpty) { // (9) -- should revisit dropped condition `(mode & POLYmode) == 0`
// 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)
return setError(tree)
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)
}) match {
case SilentResultValue(result) =>
result
case _ =>
debuglog("fallback on implicits: " + tree + "/" + resetAllAttrs(original))
val tree1 = typed(resetAllAttrs(original), mode, WildcardType)
tree1.tpe = addAnnotations(tree1, tree1.tpe)
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 && !meth.isTermMacro && isFunctionType(pt)) { // (4.2)
debuglog("eta-expanding " + tree + ":" + tree.tpe + " to " + pt)
checkParamsConvertible(tree, tree.tpe)
val tree0 = etaExpand(context.unit, tree, this)
// println("eta "+tree+" ---> "+tree0+":"+tree0.tpe+" undet: "+context.undetparams+ " mode: "+Integer.toHexString(mode))
if (context.undetparams.nonEmpty) {
// #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)
instantiate(typed(tree0, mode, WildcardType), mode, pt)
} else
typed(tree0, mode, pt)
} else if (!meth.isConstructor && mt.params.isEmpty) { // (4.3)
adapt(typed(Apply(tree, List()) setPos tree.pos), mode, pt, original)
} else if (context.implicitsEnabled) {
MissingArgsForMethodTpeError(tree, meth)
} else {
setError(tree)
}
}
def adaptType(): Tree = {
if (inFunMode(mode)) {
// todo. the commented line below makes sense for 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
// tree setType tree.tpe.normalize
tree
} else if (tree.hasSymbol && !tree.symbol.typeParams.isEmpty && !inHKMode(mode) &&
!(tree.symbol.isJavaDefined && context.unit.isJava)) { // (7)
// @M When not typing a higher-kinded type ((mode & HKmode) == 0)
// 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?
MissingTypeParametersError(tree)
} else if ( // (7.1) @M: check kind-arity
// @M: removed check for tree.hasSymbol and replace tree.symbol by tree.tpe.symbol (TypeTree's must also be checked here, and they don't directly have a symbol)
(inHKMode(mode)) &&
// @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!)
!sameLength(tree.tpe.typeParams, pt.typeParams) &&
!(tree.tpe.typeSymbol == AnyClass ||
tree.tpe.typeSymbol == NothingClass ||
pt == WildcardType)) {
// Check that the actual kind arity (tree.symbol.typeParams.length) conforms to the expected
// kind-arity (pt.typeParams.length). Full checks are done in checkKindBounds in Infer.
// 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).
KindArityMismatchError(tree, pt)
} else tree match { // (6)
case TypeTree() => tree
case _ => TypeTree(tree.tpe) setOriginal tree
}
}
/**
* To deal with the type slack between actual (run-time) types and statically known types, for each abstract type T,
* reflect its variance as a skolem that is upper-bounded by T (covariant position), or lower-bounded by T (contravariant).
*
* Consider the following example:
*
* class AbsWrapperCov[+A]
* case class Wrapper[B](x: Wrapped[B]) extends AbsWrapperCov[B]
*
* def unwrap[T](x: AbsWrapperCov[T]): Wrapped[T] = x match {
* case Wrapper(wrapped) => // Wrapper's type parameter must not be assumed to be equal to T, it's *upper-bounded* by it
* wrapped // : Wrapped[_ <: T]
* }
*
* this method should type check if and only if Wrapped is covariant in its type parameter
*
* when inferring Wrapper's type parameter B from x's type AbsWrapperCov[T],
* we must take into account that x's actual type is AbsWrapperCov[Tactual] forSome {type Tactual <: T}
* as AbsWrapperCov is covariant in A -- in other words, we must not assume we know T exactly, all we know is its upper bound
*
* since method application is the only way to generate this slack between run-time and compile-time types (TODO: right!?),
* we can simply replace skolems that represent method type parameters as seen from the method's body
* by other skolems that are (upper/lower)-bounded by that type-parameter skolem
* (depending on the variance position of the skolem in the statically assumed type of the scrutinee, pt)
*
* see test/files/../t5189*.scala
*/
def adaptConstrPattern(): Tree = { // (5)
def hasUnapplyMember(tp: Type) = reallyExists(unapplyMember(tp))
val overloadedExtractorOfObject = tree.symbol filter (sym => hasUnapplyMember(sym.tpe))
// if the tree's symbol's type does not define an extractor, maybe the tree's type does
// this is the case when we encounter an arbitrary tree as the target of an unapply call (rather than something that looks like a constructor call)
// (for now, this only happens due to wrapClassTagUnapply, but when we support parameterized extractors, it will become more common place)
val extractor = overloadedExtractorOfObject orElse unapplyMember(tree.tpe)
if (extractor != NoSymbol) {
// if we did some ad-hoc overloading resolution, update the tree's symbol
// do not update the symbol if the tree's symbol's type does not define an unapply member
// (e.g. since it's some method that returns an object with an unapply member)
if (overloadedExtractorOfObject != NoSymbol)
tree setSymbol overloadedExtractorOfObject
tree.tpe match {
case OverloadedType(pre, alts) => tree.tpe = overloadedType(pre, alts filter (alt => hasUnapplyMember(alt.tpe)))
case _ =>
}
val unapply = unapplyMember(extractor.tpe)
val clazz = unapplyParameterType(unapply)
if (unapply.isCase && clazz.isCase && !(clazz.ancestors exists (_.isCase))) {
// convert synthetic unapply of case class to case class constructor
val prefix = tree.tpe.prefix
val tree1 = TypeTree(clazz.primaryConstructor.tpe.asSeenFrom(prefix, clazz.owner))
.setOriginal(tree)
val skolems = new mutable.ListBuffer[TypeSymbol]
object variantToSkolem extends VariantTypeMap {
def apply(tp: Type) = mapOver(tp) match {
case TypeRef(NoPrefix, tpSym, Nil) if variance != 0 && tpSym.isTypeParameterOrSkolem && tpSym.owner.isTerm =>
val bounds = if (variance == 1) TypeBounds.upper(tpSym.tpe) else TypeBounds.lower(tpSym.tpe)
// origin must be the type param so we can deskolemize
val skolem = context.owner.newGADTSkolem(unit.freshTypeName("?"+tpSym.name), tpSym, bounds)
// println("mapping "+ tpSym +" to "+ skolem + " : "+ bounds +" -- pt= "+ pt +" in "+ context.owner +" at "+ context.tree )
skolems += skolem
skolem.tpe
case tp1 => tp1
}
}
// have to open up the existential and put the skolems in scope
// can't simply package up pt in an ExistentialType, because that takes us back to square one (List[_ <: T] == List[T] due to covariance)
val ptSafe = variantToSkolem(pt) // TODO: pt.skolemizeExistential(context.owner, tree) ?
val freeVars = skolems.toList
// use "tree" for the context, not context.tree: don't make another CaseDef context,
// as instantiateTypeVar's bounds would end up there
val ctorContext = context.makeNewScope(tree, context.owner)
freeVars foreach ctorContext.scope.enter
newTyper(ctorContext).infer.inferConstructorInstance(tree1, clazz.typeParams, ptSafe)
// simplify types without losing safety,
// so that error messages don't unnecessarily refer to skolems
val extrapolate = new ExistentialExtrapolation(freeVars) extrapolate (_: Type)
val extrapolated = tree1.tpe match {
case MethodType(ctorArgs, res) => // ctorArgs are actually in a covariant position, since this is the type of the subpatterns of the pattern represented by this Apply node
ctorArgs foreach (p => p.info = extrapolate(p.info)) // no need to clone, this is OUR method type
copyMethodType(tree1.tpe, ctorArgs, extrapolate(res))
case tp => tp
}
// once the containing CaseDef has been type checked (see typedCase),
// tree1's remaining type-slack skolems will be deskolemized (to the method type parameter skolems)
tree1 setType extrapolated
} else {
tree
}
} else {
CaseClassConstructorError(tree)
}
}
def insertApply(): Tree = {
assert(!inHKMode(mode), modeString(mode)) //@M
val qual = adaptToName(tree, nme.apply) match {
case id @ Ident(_) =>
val pre = if (id.symbol.owner.isPackageClass) id.symbol.owner.thisType
else if (id.symbol.owner.isClass)
context.enclosingSubClassContext(id.symbol.owner).prefix
else NoPrefix
stabilize(id, pre, EXPRmode | QUALmode, WildcardType)
case sel @ Select(qualqual, _) =>
stabilize(sel, qualqual.tpe, EXPRmode | QUALmode, WildcardType)
case other =>
other
}
typedPos(tree.pos, mode, pt) {
Select(qual setPos tree.pos.makeTransparent, nme.apply)
}
}
// begin adapt
tree.tpe match {
case atp @ AnnotatedType(_, _, _) if canAdaptAnnotations(tree, mode, pt) => // (-1)
adaptAnnotations(tree, mode, pt)
case ct @ ConstantType(value) if inNoModes(mode, TYPEmode | FUNmode) && (ct <:< pt) && !forScaladoc && !forInteractive => // (0)
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)
case OverloadedType(pre, alts) if !inFunMode(mode) => // (1)
inferExprAlternative(tree, pt)
adapt(tree, mode, pt, original)
case NullaryMethodType(restpe) => // (2)
adapt(tree setType restpe, mode, pt, original)
case TypeRef(_, ByNameParamClass, List(arg)) if ((mode & EXPRmode) != 0) => // (2)
adapt(tree setType arg, mode, pt, original)
case tr @ TypeRef(_, sym, _) if sym.isAliasType && tr.normalize.isInstanceOf[ExistentialType] &&
((mode & (EXPRmode | LHSmode)) == EXPRmode) =>
adapt(tree setType tr.normalize.skolemizeExistential(context.owner, tree), mode, pt, original)
case et @ ExistentialType(_, _) if ((mode & (EXPRmode | LHSmode)) == EXPRmode) =>
adapt(tree setType et.skolemizeExistential(context.owner, tree), mode, pt, original)
case PolyType(tparams, restpe) if inNoModes(mode, TAPPmode | PATTERNmode | HKmode) => // (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 mt.isImplicit && ((mode & (EXPRmode | FUNmode | LHSmode)) == EXPRmode) => // (4.1)
adaptToImplicitMethod(mt)
case mt: MethodType if (((mode & (EXPRmode | FUNmode | LHSmode)) == EXPRmode) &&
(context.undetparams.isEmpty || inPolyMode(mode))) && !(tree.symbol != null && tree.symbol.isTermMacro) =>
instantiateToMethodType(mt)
case _ =>
def shouldInsertApply(tree: Tree) = inAllModes(mode, EXPRmode | FUNmode) && (tree.tpe match {
case _: MethodType | _: OverloadedType | _: PolyType => false
case _ => applyPossible
})
def applyPossible = {
def applyMeth = member(adaptToName(tree, nme.apply), nme.apply)
dyna.acceptsApplyDynamic(tree.tpe) || (
if ((mode & TAPPmode) != 0)
tree.tpe.typeParams.isEmpty && applyMeth.filter(!_.tpe.typeParams.isEmpty) != NoSymbol
else
applyMeth.filter(_.tpe.paramSectionCount > 0) != NoSymbol
)
}
if (tree.isType)
adaptType()
else if (
inExprModeButNot(mode, FUNmode) && !tree.isDef && // typechecking application
tree.symbol != null && tree.symbol.isTermMacro && // of a macro
!tree.attachments.get[SuppressMacroExpansionAttachment.type].isDefined)
macroExpand(this, tree, mode, pt)
else if ((mode & (PATTERNmode | FUNmode)) == (PATTERNmode | FUNmode))
adaptConstrPattern()
else if (shouldInsertApply(tree))
insertApply()
else if (!context.undetparams.isEmpty && !inPolyMode(mode)) { // (9)
assert(!inHKMode(mode), modeString(mode)) //@M
if (inExprModeButNot(mode, FUNmode) && pt.typeSymbol == UnitClass)
instantiateExpectingUnit(tree, mode)
else
instantiate(tree, mode, pt)
} else if (tree.tpe <:< pt) {
tree
} else {
def fallBack: Tree = {
if (inPatternMode(mode)) {
if ((tree.symbol ne null) && tree.symbol.isModule)
inferModulePattern(tree, pt)
if (isPopulated(tree.tpe, approximateAbstracts(pt)))
return tree
}
val tree1 = constfold(tree, pt) // (10) (11)
if (tree1.tpe <:< pt) adapt(tree1, mode, pt, original)
else {
if (inExprModeButNot(mode, FUNmode)) {
pt.normalize match {
case TypeRef(_, sym, _) =>
// note: was if (pt.typeSymbol == UnitClass) but this leads to a potentially
// infinite expansion if pt is constant type ()
if (sym == UnitClass && tree.tpe <:< AnyClass.tpe) { // (12)
if (settings.warnValueDiscard.value)
context.unit.warning(tree.pos, "discarded non-Unit value")
return typedPos(tree.pos, mode, pt) {
Block(List(tree), Literal(Constant()))
}
} else if (isNumericValueClass(sym) && isNumericSubType(tree.tpe, pt)) {
if (settings.warnNumericWiden.value)
context.unit.warning(tree.pos, "implicit numeric widening")
return typedPos(tree.pos, mode, pt) {
Select(tree, "to" + sym.name)
}
}
case AnnotatedType(_, _, _) if canAdaptAnnotations(tree, mode, pt) => // (13)
return typed(adaptAnnotations(tree, mode, pt), mode, pt)
case _ =>
}
if (!context.undetparams.isEmpty) {
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)
val coercion = inferView(tree, tree.tpe, pt, true)
// convert forward views of delegate types into closures wrapped around
// the delegate's apply method (the "Invoke" method, which was translated into apply)
if (forMSIL && coercion != null && isCorrespondingDelegate(tree.tpe, pt)) {
val meth: Symbol = tree.tpe.member(nme.apply)
debuglog("replacing forward delegate view with: " + meth + ":" + meth.tpe)
return typed(Select(tree, meth), mode, pt)
}
if (coercion != EmptyTree) {
def msg = "inferred view from " + tree.tpe + " to " + pt + " = " + coercion + ":" + coercion.tpe
if (settings.logImplicitConv.value)
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)
if (silentContext.hasErrors) context.issue(silentContext.errBuffer.head) else return res
}
}
}
if (settings.debug.value) {
log("error tree = " + tree)
if (settings.explaintypes.value) explainTypes(tree.tpe, pt)
}
val found = tree.tpe
if (!found.isErroneous && !pt.isErroneous) {
if ((!context.reportErrors && isPastTyper) || tree.attachments.get[MacroExpansionAttachment].isDefined) {
val (bound, req) = pt match {
case ExistentialType(qs, tpe) => (qs, tpe)
case _ => (Nil, pt)
}
val boundOrSkolems = bound ++ pt.skolemsExceptMethodTypeParams
if (boundOrSkolems.nonEmpty) {
// 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).
//
log("recovering from existential or skolem type error in tree \n" + tree + "\nwith type " + tree.tpe + "\n expected type = " + pt + "\n context = " + context.tree)
return adapt(tree, mode, deriveTypeWithWildcards(boundOrSkolems)(pt))
}
}
// create an actual error
AdaptTypeError(tree, found, pt)
}
setError(tree)
}
}
fallBack
}
}
}
def instantiate(tree: Tree, mode: Int, 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: Int): Tree = {
val savedUndetparams = context.undetparams
silent(_.instantiate(tree, mode, UnitClass.tpe)) match {
case SilentResultValue(t) => t
case _ =>
context.undetparams = savedUndetparams
val valueDiscard = atPos(tree.pos)(Block(List(instantiate(tree, mode, WildcardType)), Literal(Constant())))
typed(valueDiscard, mode, UnitClass.tpe)
}
}
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.widen.normalize 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.value)
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) {
silent(_ => doAdapt(pt)) match {
case SilentResultValue(result) if result != qual =>
result
case _ =>
debuglog("fallback on implicits in adaptToArguments: "+qual+" . "+name)
doAdapt(WildcardType)
}
} else
doAdapt(pt)
}
/** 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: Int, 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, mode)) match {
case SilentResultValue(xs) =>
val args = xs.asInstanceOf[List[Tree]]
if (args exists (_.isErrorTyped))
reportError
else
adaptToArguments(qual, name, args, WildcardType, reportAmbiguous, saveErrors)
case _ =>
reportError
}
case _ =>
reportError
}
}
silent(_.adaptToMember(qual, HasMember(name), false)) match {
case SilentResultValue(res) => res
case SilentTypeError(err) => onError({if (reportAmbiguous) { context.issue(err) }; 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 typePrimaryConstrBody(clazz : Symbol, cbody: Tree, tparams: List[Symbol], enclTparams: List[Symbol], vparamss: List[List[ValDef]]): Tree = {
// XXX: see about using the class's symbol....
enclTparams foreach (sym => context.scope.enter(sym))
namer.enterValueParams(vparamss)
typed(cbody)
}
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 $where" +
"\nThis restriction is planned to be removed in subsequent releases.")
/**
* Deeply traverses the tree in search of constructs that are not allowed
* in value classes (at any nesting level).
*
* All restrictions this object imposes are probably not fundamental but require
* fair amount of work and testing. We are conservative for now when it comes
* to allowing language features to interact with value classes.
* */
object checkEphemeralDeep extends Traverser {
override def traverse(tree: Tree): Unit = if (isValueClass) {
tree match {
case _: ModuleDef =>
//see https://issues.scala-lang.org/browse/SI-6359
implRestriction(tree, "nested object")
//see https://issues.scala-lang.org/browse/SI-6444
//see https://issues.scala-lang.org/browse/SI-6463
case _: ClassDef =>
implRestriction(tree, "nested class")
case Select(sup @ Super(qual, mix), selector) if selector != nme.CONSTRUCTOR && qual.symbol == clazz && mix != tpnme.EMPTY =>
//see https://issues.scala-lang.org/browse/SI-6483
implRestriction(sup, "qualified super reference")
case _ =>
}
super.traverse(tree)
}
}
for (stat <- body) {
def notAllowed(what: String) = unit.error(stat.pos, s"$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_))
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.info.decls.toList.filter(acc => acc.isMethod && acc.isParamAccessor) match {
case List(acc) =>
def isUnderlyingAcc(sym: Symbol) =
sym == acc || acc.hasAccessorFlag && sym == acc.accessed
if (acc.accessBoundary(clazz) != rootMirror.RootClass)
unit.error(acc.pos, "value class needs to have a publicly accessible val parameter")
else if (acc.tpe.typeSymbol.isDerivedValueClass)
unit.error(acc.pos, "value class may not wrap another user-defined value class")
checkEphemeral(clazz, body filterNot (stat => isUnderlyingAcc(stat.symbol)))
case x =>
unit.error(clazz.pos, "value class needs to have exactly one public val parameter")
}
}
for (tparam <- clazz.typeParams)
if (tparam hasAnnotation definitions.SpecializedClass)
unit.error(tparam.pos, "type parameter of value class may not be specialized")
}
def parentTypes(templ: Template): List[Tree] =
if (templ.parents.isEmpty) List(atPos(templ.pos)(TypeTree(AnyRefClass.tpe)))
else try {
val clazz = context.owner
// Normalize supertype and mixins so that supertype is always a class, not a trait.
var supertpt = typedTypeConstructor(templ.parents.head)
val firstParent = supertpt.tpe.typeSymbol
var mixins = templ.parents.tail map typedType
// If first parent is a trait, make it first mixin and add its superclass as first parent
while ((supertpt.tpe.typeSymbol ne null) && supertpt.tpe.typeSymbol.initialize.isTrait) {
val supertpt1 = typedType(supertpt)
if (!supertpt1.isErrorTyped) {
mixins = supertpt1 :: mixins
supertpt = TypeTree(supertpt1.tpe.firstParent) setPos supertpt.pos.focus
}
}
if (supertpt.tpe.typeSymbol == AnyClass && firstParent.isTrait)
supertpt.tpe = AnyRefClass.tpe
// Determine
// - supertparams: Missing type parameters from supertype
// - supertpe: Given supertype, polymorphic in supertparams
val supertparams = if (supertpt.hasSymbol) supertpt.symbol.typeParams else List()
var supertpe = supertpt.tpe
if (!supertparams.isEmpty)
supertpe = PolyType(supertparams, appliedType(supertpe, supertparams map (_.tpeHK)))
// A method to replace a super reference by a New in a supercall
def transformSuperCall(scall: Tree): Tree = (scall: @unchecked) match {
case Apply(fn, args) =>
treeCopy.Apply(scall, transformSuperCall(fn), args map (_.duplicate))
case Select(Super(_, _), nme.CONSTRUCTOR) =>
treeCopy.Select(
scall,
atPos(supertpt.pos.focus)(New(TypeTree(supertpe)) setType supertpe),
nme.CONSTRUCTOR)
}
treeInfo.firstConstructor(templ.body) match {
case constr @ DefDef(_, _, _, vparamss, _, cbody @ Block(cstats, cunit)) =>
// Convert constructor body to block in environment and typecheck it
val (preSuperStats, superCall) = {
val (stats, rest) = cstats span (x => !treeInfo.isSuperConstrCall(x))
(stats map (_.duplicate), if (rest.isEmpty) EmptyTree else rest.head.duplicate)
}
val cstats1 = if (superCall == EmptyTree) preSuperStats else preSuperStats :+ superCall
val cbody1 = treeCopy.Block(cbody, preSuperStats, superCall match {
case Apply(_, _) if supertparams.nonEmpty => transformSuperCall(superCall)
case _ => cunit.duplicate
})
val outercontext = context.outer
assert(clazz != NoSymbol, templ)
val cscope = outercontext.makeNewScope(constr, outercontext.owner)
val cbody2 = newTyper(cscope) // called both during completion AND typing.
.typePrimaryConstrBody(clazz,
cbody1, supertparams, clazz.unsafeTypeParams, vparamss map (_.map(_.duplicate)))
superCall match {
case Apply(_, _) =>
val sarg = treeInfo.firstArgument(superCall)
if (sarg != EmptyTree && supertpe.typeSymbol != firstParent)
ConstrArgsInTraitParentTpeError(sarg, firstParent)
if (!supertparams.isEmpty)
supertpt = TypeTree(cbody2.tpe) setPos supertpt.pos.focus
case _ =>
if (!supertparams.isEmpty)
MissingTypeArgumentsParentTpeError(supertpt)
}
val preSuperVals = treeInfo.preSuperFields(templ.body)
if (preSuperVals.isEmpty && preSuperStats.nonEmpty)
debugwarn("Wanted to zip empty presuper val list with " + preSuperStats)
else
map2(preSuperStats, preSuperVals)((ldef, gdef) => gdef.tpt.tpe = ldef.symbol.tpe)
case _ =>
if (!supertparams.isEmpty)
MissingTypeArgumentsParentTpeError(supertpt)
}
/* experimental: early types as type arguments
val hasEarlyTypes = templ.body exists (treeInfo.isEarlyTypeDef)
val earlyMap = new EarlyMap(clazz)
List.mapConserve(supertpt :: mixins){ tpt =>
val tpt1 = checkNoEscaping.privates(clazz, tpt)
if (hasEarlyTypes) tpt1 else tpt1 setType earlyMap(tpt1.tpe)
}
*/
//Console.println("parents("+clazz") = "+supertpt :: mixins);//DEBUG
// 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.
def fixDuplicates(remaining: List[Tree]): List[Tree] = remaining match {
case Nil => Nil
case x :: xs =>
val sym = x.symbol
x :: fixDuplicates(
if (isPossibleSyntheticParent(sym)) xs filterNot (_.symbol == sym)
else xs
)
}
fixDuplicates(supertpt :: mixins) mapConserve (tpt => checkNoEscaping.privates(clazz, 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
log("Type error calculating parents in template " + templ)
log("Error: " + ex)
ParentTypesError(templ, ex)
List(TypeTree(AnyRefClass.tpe))
}
/** <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) =
if (parent == DynamicClass) checkFeature(parent.pos, 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)
if (psym.hasDeprecatedInheritanceAnnotation) {
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 (context.unit.source.file == psym.sourceFile)
psym addChild context.owner
else
pending += ParentSealedInheritanceError(parent, psym)
if (!(selfType <:< parent.tpe.typeOfThis) &&
!phase.erasedTypes &&
!context.owner.isSynthetic && // don't check synthetic concrete classes for virtuals (part of DEVIRTUALIZE)
!settings.noSelfCheck.value && // setting to suppress this very check
!selfType.isErroneous &&
!parent.tpe.isErroneous)
{
//Console.println(context.owner);//DEBUG
//Console.println(context.owner.unsafeTypeParams);//DEBUG
//Console.println(List.fromArray(context.owner.info.closure));//DEBUG
pending += ParentSelfTypeConformanceError(parent, selfType)
if (settings.explaintypes.value) explainTypes(selfType, parent.tpe.typeOfThis)
}
if (parents exists (p => p != parent && p.tpe.typeSymbol == psym && !psym.isError))
pending += ParentInheritedTwiceError(parent, psym)
validateDynamicParent(psym)
}
if (!parents.isEmpty && parents.forall(!_.isErrorTyped)) {
val superclazz = parents.head.tpe.typeSymbol
for (p <- parents) validateParentClass(p, superclazz)
}
/*
if (settings.Xshowcls.value != "" &&
settings.Xshowcls.value == context.owner.fullName)
println("INFO "+context.owner+
", baseclasses = "+(context.owner.info.baseClasses map (_.fullName))+
", lin = "+(context.owner.info.baseClasses map (context.owner.thisType.baseType)))
*/
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(AnyRefClass.tpe))),
classinfo.decls,
clazz)
clazz.setInfo {
clazz.info match {
case PolyType(tparams, _) => PolyType(tparams, newinfo)
case _ => newinfo
}
}
FinitaryError(tparam)
}
}
}
/**
* @param cdef ...
* @return ...
*/
def typedClassDef(cdef: ClassDef): Tree = {
// attributes(cdef)
val clazz = cdef.symbol
val typedMods = typedModifiers(cdef.mods)
assert(clazz != NoSymbol, cdef)
reenterTypeParams(cdef.tparams)
val tparams1 = cdef.tparams mapConserve (typedTypeDef)
val impl1 = typerReportAnyContextErrors(context.make(cdef.impl, clazz, newScope)) {
_.typedTemplate(cdef.impl, parentTypes(cdef.impl))
}
val impl2 = finishMethodSynthesis(impl1, clazz, context)
if (clazz.isTrait && clazz.info.parents.nonEmpty && clazz.info.firstParent.normalize.typeSymbol == AnyClass)
checkEphemeral(clazz, impl2.body)
if ((clazz != ClassfileAnnotationClass) &&
(clazz isNonBottomSubClass ClassfileAnnotationClass))
restrictionWarning(cdef.pos, unit,
"subclassing Classfile does not\n"+
"make your annotation visible at runtime. If that is what\n"+
"you want, you must write the annotation class in Java.")
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)
}
/**
* @param mdef ...
* @return ...
*/
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 = typerReportAnyContextErrors(context.make(mdef.impl, clazz, newScope)) {
_.typedTemplate(mdef.impl, {
parentTypes(mdef.impl) ++ (
if (noSerializable) Nil
else {
clazz.makeSerializable()
List(TypeTree(SerializableClass.tpe) setPos clazz.pos.focus)
}
)
})
}
val impl2 = finishMethodSynthesis(impl1, clazz, context)
treeCopy.ModuleDef(mdef, typedMods, mdef.name, impl2) setType NoType
}
/** 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)
/**
* @param templ ...
* @param parents1 ...
* <li> <!-- 2 -->
* Check that inner classes do not inherit from Annotation
* </li>
* @return ...
*/
def typedTemplate(templ: Template, parents1: List[Tree]): Template = {
val clazz = context.owner
// complete lazy annotations
val annots = clazz.annotations
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)
enterSyms(context.outer.make(templ, clazz, clazz.info.decls), templ.body)
validateParentClasses(parents1, selfType)
if (clazz.isCase)
validateNoCaseAncestor(clazz)
if ((clazz isSubClass ClassfileAnnotationClass) && !clazz.owner.isPackageClass)
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 body =
if (isPastTyper || reporter.hasErrors) templ.body
else templ.body flatMap rewrappingWrapperTrees(namer.addDerivedTrees(Typer.this, _))
val body1 = typedStats(body, templ.symbol)
if (clazz.info.firstParent.typeSymbol == AnyValClass)
validateDerivedValueClass(clazz, body1)
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, body1) 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
/**
* @param vdef ...
* @return ...
*/
def typedValDef(vdef: ValDef): ValDef = {
// attributes(vdef)
val sym = vdef.symbol.initialize
val typer1 = constrTyperIf(sym.isParameter && sym.owner.isConstructor)
val typedMods = typedModifiers(vdef.mods)
// complete lazy annotations
val annots = sym.annotations
var tpt1 = checkNoEscaping.privates(sym, typer1.typedType(vdef.tpt))
checkNonCyclic(vdef, tpt1)
if (sym.hasAnnotation(definitions.VolatileAttr)) {
if (!sym.isMutable)
VolatileValueError(vdef)
else if (sym.isFinal)
FinalVolatileVarError(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
newTyper(typer1.context.make(vdef, sym)).transformedOrTyped(vdef.rhs, EXPRmode | BYVALmode, tpt2)
}
treeCopy.ValDef(vdef, typedMods, vdef.name, tpt1, checkDead(rhs1)) setType NoType
}
/** Enter all aliases of local parameter accessors.
*
* @param clazz ...
* @param vparamss ...
* @param rhs ...
*/
def computeParamAliases(clazz: Symbol, vparamss: List[List[ValDef]], rhs: Tree) {
debuglog(s"computing param aliases for $clazz:${clazz.primaryConstructor.tpe}:$rhs")
def decompose(call: Tree): (Tree, List[Tree]) = call match {
case Apply(fn, args) =>
val (superConstr, args1) = decompose(fn)
val params = fn.tpe.params
val args2 = if (params.isEmpty || !isRepeatedParamType(params.last.tpe)) args
else args.take(params.length - 1) :+ EmptyTree
assert(sameLength(args2, params) || call.isErrorTyped, "mismatch " + clazz + " " + (params map (_.tpe)) + " " + args2)//debug
(superConstr, args1 ::: args2)
case Block(stats, expr) if !stats.isEmpty =>
decompose(stats.last)
case _ =>
(call, List())
}
val (superConstr, superArgs) = decompose(rhs)
assert(superConstr.symbol ne null, superConstr)//debug
val pending = ListBuffer[AbsTypeError]()
// an object cannot be allowed to pass a reference to itself to a superconstructor
// because of initialization issues; bug #473
foreachSubTreeBoundTo(superArgs, clazz) { tree =>
if (tree.symbol.isModule)
pending += SuperConstrReferenceError(tree)
tree match {
case This(qual) =>
pending += SuperConstrArgsThisReferenceError(tree)
case _ => ()
}
}
if (superConstr.symbol.isPrimaryConstructor) {
val superClazz = superConstr.symbol.owner
if (!superClazz.isJavaDefined) {
val superParamAccessors = superClazz.constrParamAccessors
if (sameLength(superParamAccessors, superArgs)) {
for ((superAcc, superArg @ Ident(name)) <- superParamAccessors zip superArgs) {
if (vparamss.exists(_.exists(_.symbol == superArg.symbol))) {
var alias = superAcc.initialize.alias
if (alias == NoSymbol)
alias = superAcc.getter(superAcc.owner)
if (alias != NoSymbol &&
superClazz.info.nonPrivateMember(alias.name) != alias)
alias = NoSymbol
if (alias != NoSymbol) {
var ownAcc = clazz.info.decl(name).suchThat(_.isParamAccessor)
if ((ownAcc hasFlag ACCESSOR) && !ownAcc.isDeferred)
ownAcc = ownAcc.accessed
if (!ownAcc.isVariable && !alias.accessed.isVariable) {
debuglog("" + ownAcc + " has alias "+alias.fullLocationString) //debug
ownAcc.asInstanceOf[TermSymbol].setAlias(alias)
}
}
}
}
}
}
}
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 fail(pos: Position, msg: String) = unit.error(pos, msg)
val tp: Type = meth.tpe match {
case mt @ MethodType(_, _) => mt
case NullaryMethodType(restpe) => restpe // TODO_NMT: drop NullaryMethodType from resultType?
case PolyType(_, restpe) => restpe
case _ => NoType
}
def nthParamPos(n: Int) = ddef.vparamss match {
case xs :: _ if xs.length > n => xs(n).pos
case _ => meth.pos
}
def failStruct(pos: Position, what: String, where: String = "Parameter") =
fail(pos, s"$where type in structural refinement may not refer to $what")
foreachWithIndex(tp.paramTypes) { (paramType, idx) =>
val sym = paramType.typeSymbol
def paramPos = nthParamPos(idx)
if (sym.isAbstractType) {
if (!sym.hasTransOwner(meth.owner))
failStruct(paramPos, "an abstract type defined outside that refinement")
else if (!sym.hasTransOwner(meth))
failStruct(paramPos, "a type member of that refinement")
}
if (sym.isDerivedValueClass)
failStruct(paramPos, "a user-defined value class")
if (paramType.isInstanceOf[ThisType] && sym == meth.owner)
failStruct(paramPos, "the type of that refinement (self type)")
}
if (tp.resultType.typeSymbol.isDerivedValueClass)
failStruct(ddef.tpt.pos, "a user-defined value class", where = "Result")
}
def typedUseCase(useCase: UseCase) {
def stringParser(str: String): syntaxAnalyzer.Parser = {
val file = new BatchSourceFile(context.unit.source.file, str) {
override def positionInUltimateSource(pos: Position) = {
pos.withSource(context.unit.source, useCase.pos.start)
}
}
val unit = new CompilationUnit(file)
new syntaxAnalyzer.UnitParser(unit)
}
val trees = stringParser(useCase.body+";").nonLocalDefOrDcl
val enclClass = context.enclClass.owner
def defineAlias(name: Name) =
if (context.scope.lookup(name) == NoSymbol) {
lookupVariable(name.toString.substring(1), enclClass) match {
case Some(repl) =>
silent(_.typedTypeConstructor(stringParser(repl).typ())) match {
case SilentResultValue(tpt) =>
val alias = enclClass.newAliasType(name.toTypeName, useCase.pos)
val tparams = cloneSymbolsAtOwner(tpt.tpe.typeSymbol.typeParams, alias)
val newInfo = genPolyType(tparams, appliedType(tpt.tpe, tparams map (_.tpe)))
alias setInfo newInfo
context.scope.enter(alias)
case _ =>
}
case _ =>
}
}
for (tree <- trees; t <- tree)
t match {
case Ident(name) if name startsWith '$' => defineAlias(name)
case _ =>
}
useCase.aliases = context.scope.toList
namer.enterSyms(trees)
typedStats(trees, NoSymbol)
useCase.defined = context.scope.toList filterNot (useCase.aliases contains _)
if (settings.debug.value)
useCase.defined foreach (sym => println("defined use cases: %s:%s".format(sym, sym.tpe)))
}
/**
* @param ddef ...
* @return ...
*/
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)
// complete lazy annotations
val annots = meth.annotations
for (vparams1 <- vparamss1; vparam1 <- vparams1 dropRight 1)
if (isRepeatedParamType(vparam1.symbol.tpe))
StarParamNotLastError(vparam1)
var 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.isTermMacro) {
// 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){
_.typedTypeDef0(tdef)
}
// call typedTypeDef instead
// a TypeDef with type parameters must always be type checked in a new scope
private def typedTypeDef0(tdef: TypeDef): TypeDef = {
tdef.symbol.initialize
reenterTypeParams(tdef.tparams)
val tparams1 = tdef.tparams mapConserve typedTypeDef
val typedMods = typedModifiers(tdef.mods)
// complete lazy annotations
val annots = tdef.symbol.annotations
// @specialized should not be pickled when compiling with -no-specialize
if (settings.nospecialization.value && 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(), UnitClass.tpe))
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.tpe = 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.tpe = 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 rhs2 = typed(resetAllAttrs(ldef.rhs), restpe)
ldef.params foreach (param => param.tpe = param.symbol.tpe)
deriveLabelDef(ldef)(_ => rhs2) setSymbol sym2 setType restpe
}
}
}
/**
* @param block ...
* @param mode ...
* @param pt ...
* @return ...
*/
def typedBlock(block: Block, mode: Int, pt: Type): Block = {
val syntheticPrivates = new ListBuffer[Symbol]
try {
namer.enterSyms(block.stats)
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)
}
}
/**
* @param cdef ...
* @param pattpe ...
* @param pt ...
* @return ...
*/
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 setType pat1.tpe.finalResultType
if (forInteractive) {
for (bind @ Bind(name, _) <- cdef.pat)
if (name.toTermName != nme.WILDCARD && bind.symbol != null && bind.symbol != NoSymbol)
namer.enterIfNotThere(bind.symbol)
}
val guard1: Tree = if (cdef.guard == EmptyTree) EmptyTree
else typed(cdef.guard, BooleanClass.tpe)
var body1: Tree = typed(cdef.body, pt)
val contextWithTypeBounds = context.nextEnclosing(_.tree.isInstanceOf[CaseDef])
if (contextWithTypeBounds.savedTypeBounds.nonEmpty) {
body1.tpe = contextWithTypeBounds restoreTypeBounds body1.tpe
// 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))
body1 = typedPos(body1.pos)(gen.mkCast(body1, pt.normalize))
}
// body1 = checkNoEscaping.locals(context.scope, pt, body1)
val treeWithSkolems = treeCopy.CaseDef(cdef, pat1, guard1, body1) setType body1.tpe
new TypeMapTreeSubstituter(deskolemizeGADTSkolems).traverse(treeWithSkolems)
treeWithSkolems // now without skolems, actually
}
// undo adaptConstrPattern's evil deeds, as they confuse the old pattern matcher
// the flags are used to avoid accidentally deskolemizing unrelated skolems of skolems
object deskolemizeGADTSkolems extends TypeMap {
def apply(tp: Type): Type = mapOver(tp) match {
case TypeRef(pre, sym, args) if sym.isGADTSkolem =>
typeRef(NoPrefix, sym.deSkolemize, args)
case tp1 => tp1
}
}
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: Int, tpe: Type): CaseDef = deriveCaseDef(cdef)(adapt(_, mode, tpe))
def ptOrLub(tps: List[Type], pt: Type ) = if (isFullyDefined(pt)) (pt, false) else weakLub(tps map (_.deconst))
def ptOrLubPacked(trees: List[Tree], pt: Type) = if (isFullyDefined(pt)) (pt, false) else weakLub(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: Int, pt: Type, tree: Tree = EmptyTree): Match = {
val selector1 = checkDead(typed(selector, EXPRmode | BYVALmode, WildcardType))
val selectorTp = packCaptured(selector1.tpe.widen).skolemizeExistential(context.owner, selector)
val casesTyped = typedCases(cases, selectorTp, pt)
val (resTp, needAdapt) =
if (opt.virtPatmat) ptOrLubPacked(casesTyped, pt)
else ptOrLub(casesTyped map (_.tpe), pt)
val casesAdapted = if (!needAdapt) casesTyped else casesTyped map (adaptCase(_, mode, resTp))
treeCopy.Match(tree, selector1, casesAdapted) setType resTp
}
// match has been typed -- virtualize it if we're feeling experimental
// (virtualized matches are expanded during type checking so they have the full context available)
// otherwise, do nothing: matches are translated during phase `patmat` (unless -Xoldpatmat)
def virtualizedMatch(match_ : Match, mode: Int, pt: Type) = {
import patmat.{vpmName, PureMatchTranslator, OptimizingMatchTranslator}
// TODO: add fallback __match sentinel to predef
val matchStrategy: Tree =
if (!(newPatternMatching && opt.experimental && 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), EXPRmode, WildcardType), reportAmbiguousErrors = false) match {
case SilentResultValue(ms) => ms
case _ => 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 a match specified by `cases`
// Match(EmptyTree, cases) ==> new PartialFunction { def apply<OrElse>(params) = `translateMatch('`(param1,...,paramN)` match { cases }')` }
// for fresh params, the selector of the match we'll translated simply gathers those in a tuple
// NOTE: restricted to PartialFunction -- leave Function trees if the expected type does not demand a partial function
class MatchFunTyper(tree: Tree, cases: List[CaseDef], mode: Int, pt0: Type) {
// TODO: remove FunctionN support -- this is currently designed so that it can emit FunctionN and PartialFunction subclasses
// however, we should leave Function nodes until Uncurry so phases after typer can still detect normal Function trees
// we need to synthesize PartialFunction impls, though, to avoid nastiness in Uncurry in transforming&duplicating generated pattern matcher trees
// TODO: remove PartialFunction support from UnCurry
private val pt = deskolemizeGADTSkolems(pt0)
private val targs = pt.normalize.typeArgs
private val arity = if (isFunctionType(pt)) targs.length - 1 else 1 // TODO pt should always be a (Partial)Function, right?
private val ptRes = if (targs.isEmpty) WildcardType else targs.last // may not be fully defined
private val isPartial = pt.typeSymbol == PartialFunctionClass
assert(isPartial)
private val anonClass = context.owner.newAnonymousFunctionClass(tree.pos)
private val funThis = This(anonClass)
anonClass addAnnotation AnnotationInfo(SerialVersionUIDAttr.tpe, List(Literal(Constant(0))), List())
def deriveFormals =
if (targs.isEmpty) Nil
else targs.init
def mkParams(methodSym: Symbol, formals: List[Type] = deriveFormals) =
if (formals.isEmpty || !formals.forall(isFullyDefined)) { MissingParameterTypeAnonMatchError(tree, pt); Nil }
else methodSym newSyntheticValueParams formals
def mkSel(params: List[Symbol]) =
if (params.isEmpty) EmptyTree
else {
val ids = params map (p => Ident(p.name))
atPos(tree.pos.focusStart) { if (arity == 1) ids.head else gen.mkTuple(ids) }
}
import CODE._
// need to duplicate the cases before typing them to generate the apply method, or the symbols will be all messed up
val casesTrue = if (isPartial) cases map (c => deriveCaseDef(c)(x => atPos(x.pos.focus)(TRUE_typed)).duplicate.asInstanceOf[CaseDef]) else Nil
// println("casesTrue "+ casesTrue)
def parentsPartial(targs: List[Type]) = addSerializable(appliedType(AbstractPartialFunctionClass.typeConstructor, targs))
def applyMethod = {
// rig the show so we can get started typing the method body -- later we'll correct the infos...
anonClass setInfo ClassInfoType(addSerializable(ObjectClass.tpe, pt), newScope, anonClass)
val methodSym = anonClass.newMethod(nme.apply, tree.pos, if(isPartial) (FINAL | OVERRIDE) else FINAL)
val paramSyms = mkParams(methodSym)
val selector = mkSel(paramSyms)
if (selector eq EmptyTree) EmptyTree
else {
methodSym setInfoAndEnter MethodType(paramSyms, AnyClass.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 _)
val match_ = methodBodyTyper.typedMatch(gen.mkUnchecked(selector), cases, mode, ptRes)
val resTp = match_.tpe
val methFormals = paramSyms map (_.tpe)
val parents = (
if (isPartial) parentsPartial(List(methFormals.head, resTp))
else addSerializable(abstractFunctionType(methFormals, resTp))
)
anonClass setInfo ClassInfoType(parents, newScope, anonClass)
methodSym setInfoAndEnter MethodType(paramSyms, resTp)
DefDef(methodSym, methodBodyTyper.virtualizedMatch(match_, mode, resTp))
}
}
// def applyOrElse[A1 <: A, B1 >: B](x: A1, default: A1 => B1): B1 =
def applyOrElseMethodDef = {
// 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(parentsPartial(targs), newScope, anonClass)
val methodSym = anonClass.newMethod(nme.applyOrElse, tree.pos, FINAL | OVERRIDE)
// create the parameter that corresponds to the function's parameter
val List(argTp) = deriveFormals
val A1 = methodSym newTypeParameter(newTypeName("A1")) setInfo TypeBounds.upper(argTp)
val paramSyms@List(x) = mkParams(methodSym, List(A1.tpe))
val selector = mkSel(paramSyms)
if (selector eq EmptyTree) EmptyTree
else {
// applyOrElse's default parameter:
val B1 = methodSym newTypeParameter(newTypeName("B1")) setInfo TypeBounds.empty //lower(resTp)
val default = methodSym newValueParameter(newTermName("default"), tree.pos.focus, SYNTHETIC) setInfo functionType(List(A1.tpe), B1.tpe)
val paramSyms = List(x, default)
methodSym setInfoAndEnter 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 _)
val match_ = methodBodyTyper.typedMatch(gen.mkUnchecked(selector), cases, mode, ptRes)
val resTp = match_.tpe
anonClass setInfo ClassInfoType(parentsPartial(List(argTp, resTp)), newScope, anonClass)
B1 setInfo TypeBounds.lower(resTp)
anonClass.info.decls enter methodSym // methodSym's info need not change (B1's bound has been updated instead)
match_ setType B1.tpe
// the default uses applyOrElse's first parameter since the scrut's type has been widened
val body = methodBodyTyper.virtualizedMatch(match_ updateAttachment DefaultOverrideMatchAttachment(REF(default) APPLY (REF(x))), mode, B1.tpe)
DefDef(methodSym, body)
}
}
def isDefinedAtMethod = {
val methodSym = anonClass.newMethod(nme.isDefinedAt, tree.pos.makeTransparent, FINAL)
val paramSyms = mkParams(methodSym)
val selector = mkSel(paramSyms)
if (selector eq EmptyTree) EmptyTree
else {
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 _)
methodSym setInfoAndEnter MethodType(paramSyms, BooleanClass.tpe)
val match_ = methodBodyTyper.typedMatch(gen.mkUnchecked(selector), casesTrue, mode, BooleanClass.tpe)
val body = methodBodyTyper.virtualizedMatch(match_ updateAttachment DefaultOverrideMatchAttachment(FALSE_typed), mode, BooleanClass.tpe)
DefDef(methodSym, body)
}
}
lazy val members = if (isPartial) {
// 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 (targs forall (_ <:< AnyClass.tpe)) List(applyOrElseMethodDef, isDefinedAtMethod)
else List(applyMethod, isDefinedAtMethod)
} else List(applyMethod)
def translated =
if (members.head eq EmptyTree) setError(tree)
else {
val typedBlock = typedPos(tree.pos, mode, pt) {
Block(ClassDef(anonClass, NoMods, ListOfNil, ListOfNil, members, tree.pos.focus), atPos(tree.pos.focus)(New(anonClass.tpe)))
}
// Don't leak implementation details into the type, see SI-6575
if (isPartial && !typedBlock.isErrorTyped)
typedPos(tree.pos, mode, pt) {
Typed(typedBlock, TypeTree(typedBlock.tpe baseType PartialFunctionClass))
}
else typedBlock
}
}
// Function(params, Match(sel, cases)) ==> new <Partial>Function { def apply<OrElse>(params) = `translateMatch('sel match { cases }')` }
class MatchFunTyperBetaReduced(fun: Function, sel: Tree, cases: List[CaseDef], mode: Int, pt: Type) extends MatchFunTyper(fun, cases, mode, pt) {
override def deriveFormals =
fun.vparams map { p => if(p.tpt.tpe == null) typedType(p.tpt).tpe else p.tpt.tpe }
// the only difference from the super class is that we must preserve the names of the parameters
override def mkParams(methodSym: Symbol, formals: List[Type] = deriveFormals) =
(fun.vparams, formals).zipped map { (p, tp) =>
methodSym.newValueParameter(p.name, p.pos.focus, SYNTHETIC) setInfo tp
}
override def mkSel(params: List[Symbol]) = sel.duplicate
}
/**
* @param fun ...
* @param mode ...
* @param pt ...
* @return ...
*/
private def typedFunction(fun: Function, mode: Int, pt: Type): Tree = {
val numVparams = fun.vparams.length
if (numVparams > definitions.MaxFunctionArity)
return MaxFunctionArityError(fun)
def decompose(pt: Type): (Symbol, List[Type], Type) =
if ((isFunctionType(pt) || (pt.typeSymbol == PartialFunctionClass && numVparams == 1 && fun.body.isInstanceOf[Match])) && // see bug901 for a reason why next conditions are needed
( pt.normalize.typeArgs.length - 1 == numVparams
|| fun.vparams.exists(_.tpt.isEmpty)
))
(pt.typeSymbol, pt.normalize.typeArgs.init, pt.normalize.typeArgs.last)
else
(FunctionClass(numVparams), fun.vparams map (x => NoType), WildcardType)
val (clazz, argpts, respt) = decompose(pt)
if (argpts.lengthCompare(numVparams) != 0)
WrongNumberOfParametersError(fun, argpts)
else {
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, forFunMode(mode), pt)) match {
case SilentResultValue(fn1) if context.undetparams.isEmpty =>
// 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 _ =>
}
case _ =>
}
MissingParameterTypeError(fun, vparam, pt)
ErrorType
}
if (!vparam.tpt.pos.isDefined) vparam.tpt setPos vparam.pos.focus
}
}
fun.body match {
// later phase indicates scaladoc is calling (where shit is messed up, I tell you)
// -- so fall back to old patmat, which is more forgiving
case Match(sel, cases) if (sel ne EmptyTree) && newPatternMatching && (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)
(new outerTyper.MatchFunTyperBetaReduced(fun, sel, cases, mode, pt)).translated
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)
// for (vparam <- vparams) {
// checkNoEscaping.locals(context.scope, WildcardType, vparam.tpt); ()
// }
val formals = vparamSyms map (_.tpe)
val body1 = typed(fun.body, respt)
val restpe = packedType(body1, fun.symbol).deconst.resultType
val funtpe = typeRef(clazz.tpe.prefix, clazz, formals :+ restpe)
// body = checkNoEscaping.locals(context.scope, restpe, body)
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) {
val member = stat.symbol
if (!(context.owner.ancestors forall
(bc => member.matchingSymbol(bc, context.owner.thisType) == NoSymbol))) {
member setFlag OVERRIDE
}
}
}
}
def typedImport(imp : Import) : Import = (transformed remove imp) match {
case Some(imp1: Import) => imp1
case _ => log("unhandled import: "+imp+" in "+unit); imp
}
private def isWarnablePureExpression(tree: Tree) = tree match {
case EmptyTree | Literal(Constant(())) => false
case _ =>
!tree.isErrorTyped && (treeInfo isExprSafeToInline tree) && {
val sym = tree.symbol
(sym == null) || !(sym.isModule || sym.isLazy) || {
debuglog("'Pure' but side-effecting expression in statement position: " + tree)
false
}
}
}
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.makeNewImport(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.typed(stat, EXPRmode | BYVALmode, WildcardType))
if (treeInfo.isSelfOrSuperConstrCall(result)) {
context.inConstructorSuffix = true
if (treeInfo.isSelfConstrCall(result) && result.symbol.pos.pointOrElse(0) >= exprOwner.enclMethod.pos.pointOrElse(0))
ConstructorsOrderError(stat)
}
if (isWarnablePureExpression(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.hasLocalFlag && (
(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.hasDefaultFlag &&
!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
for (sym <- scope)
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.hasDefaultFlag && 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: Int, newmode: Int, pt: Type): Tree = {
val typedMode = onlyStickyModes(mode) | newmode
val t = withCondConstrTyper((mode & SCCmode) != 0)(_.typed(arg, typedMode, pt))
checkDead.inMode(typedMode, t)
}
def typedArgs(args: List[Tree], mode: Int) =
args mapConserve (arg => typedArg(arg, mode, 0, WildcardType))
/** Type trees in `args0` against corresponding expected type in `adapted0`.
*
* The mode in which each argument is typed is derived from `mode` and
* whether the arg was originally by-name or var-arg (need `formals0` for that)
* the default is by-val, of course.
*
* (docs reverse-engineered -- AM)
*/
def typedArgs(args0: List[Tree], mode: Int, formals0: List[Type], adapted0: List[Type]): List[Tree] = {
val sticky = onlyStickyModes(mode)
def loop(args: List[Tree], formals: List[Type], adapted: List[Type]): List[Tree] = {
if (args.isEmpty || adapted.isEmpty) Nil
else {
// No formals left or * indicates varargs.
val isVarArgs = formals.isEmpty || formals.tail.isEmpty && isRepeatedParamType(formals.head)
val typedMode = sticky | (
if (isVarArgs) STARmode | BYVALmode
else if (isByNameParamType(formals.head)) 0
else BYVALmode
)
var tree = typedArg(args.head, mode, typedMode, adapted.head)
if (hasPendingMacroExpansions) tree = macroExpandAll(this, tree)
// formals may be empty, so don't call tail
tree :: loop(args.tail, formals drop 1, adapted.tail)
}
}
loop(args0, formals0, adapted0)
}
/** 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: Int, 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.hasSymbol && fun.symbol.isOverloaded) {
// remove alternatives with wrong number of parameters without looking at types.
// less expensive than including them in inferMethodAlternatvie (see below).
def shapeType(arg: Tree): Type = arg match {
case Function(vparams, body) =>
functionType(vparams map (vparam => AnyClass.tpe), shapeType(body))
case AssignOrNamedArg(Ident(name), rhs) =>
NamedType(name, shapeType(rhs))
case _ =>
NothingClass.tpe
}
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) {
val sym1 = sym filter (alt => {
// eliminate functions that would result from tupling transforms
// keeps alternatives with repeated params
hasExactlyNumParams(followApply(alt.tpe), argtypes.length) ||
// also keep alts which define at least one default
alt.tpe.paramss.exists(_.exists(_.hasDefault))
})
if (sym1 != NoSymbol) sym = sym1
}
if (sym == NoSymbol) fun
else adapt(fun setSymbol sym setType pre.memberType(sym), forFunMode(mode), WildcardType)
} else fun
}
val fun = preSelectOverloaded(fun0)
fun.tpe match {
case OverloadedType(pre, alts) =>
def handleOverloaded = {
val undetparams = context.extractUndetparams()
val argtpes = new ListBuffer[Type]
val amode = forArgMode(fun, mode)
val args1 = args map {
case arg @ AssignOrNamedArg(Ident(name), rhs) =>
// named args: only type the righthand sides ("unknown identifier" errors otherwise)
val rhs1 = typedArg(rhs, amode, BYVALmode, WildcardType)
argtpes += NamedType(name, rhs1.tpe.deconst)
// the assign is untyped; that's ok because we call doTypedApply
atPos(arg.pos) { new AssignOrNamedArg(arg.lhs, rhs1) }
case arg =>
val arg1 = typedArg(arg, amode, BYVALmode, WildcardType)
argtpes += arg1.tpe.deconst
arg1
}
context.undetparams = undetparams
if (context.hasErrors)
setError(tree)
else {
inferMethodAlternative(fun, undetparams, argtpes.toList, pt, varArgsOnly = treeInfo.isWildcardStarArgList(args))
doTypedApply(tree, adapt(fun, forFunMode(mode), WildcardType), args1, mode, pt)
}
}
handleOverloaded
case mt @ MethodType(params, _) =>
val paramTypes = mt.paramTypes
// repeat vararg as often as needed, remove by-name
val formals = formalTypes(paramTypes, args.length)
/** 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: Option[Tree] = {
// if 1 formal, 1 arg (a tuple), otherwise unmodified args
val tupleArgs = actualArgs(tree.pos.makeTransparent, args, formals.length)
if (!sameLength(tupleArgs, args) && !isUnitForVarArgs(args, params)) {
// 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)) match {
case SilentResultValue(t) =>
// Depending on user options, may warn or error here if
// a Unit or tuple was inserted.
Some(t) filter (tupledTree =>
!inExprModeButNot(mode, FUNmode)
|| tupledTree.symbol == null
|| checkValidAdaptation(tupledTree, args)
)
case _ =>
context.undetparams = savedUndetparams
None
}
} else None
}
/** Treats an application which uses named or default arguments.
* Also works if names + a vararg used: when names are used, the vararg
* parameter has to be specified exactly once. Note that combining varargs
* and defaults is ruled out by typedDefDef.
*/
def tryNamesDefaults: Tree = {
val lencmp = compareLengths(args, formals)
def checkNotMacro() = {
if (fun.symbol != null && fun.symbol.filter(sym => sym != null && sym.isTermMacro && !sym.isErroneous) != NoSymbol)
tryTupleApply getOrElse duplErrorTree(NamedAndDefaultArgumentsNotSupportedForMacros(tree, fun))
}
if (mt.isErroneous) duplErrTree
else if (inPatternMode(mode)) {
// #2064
duplErrorTree(WrongNumberOfArgsError(tree, fun))
} else if (lencmp > 0) {
tryTupleApply getOrElse duplErrorTree(TooManyArgsNamesDefaultsError(tree, fun))
} else if (lencmp == 0) {
// we don't need defaults. names were used, so this application is transformed
// into a block (@see transformNamedApplication in NamesDefaults)
val (namelessArgs, argPos) = removeNames(Typer.this)(args, params)
if (namelessArgs exists (_.isErroneous)) {
duplErrTree
} else if (!isIdentity(argPos) && !sameLength(formals, params))
// !isIdentity indicates that named arguments are used to re-order arguments
duplErrorTree(MultipleVarargError(tree))
else if (isIdentity(argPos) && !isNamedApplyBlock(fun)) {
// if there's no re-ordering, and fun is not transformed, no need to transform
// more than an optimization, e.g. important in "synchronized { x = update-x }"
checkNotMacro()
doTypedApply(tree, fun, namelessArgs, mode, pt)
} else {
checkNotMacro()
transformNamedApplication(Typer.this, mode, pt)(
treeCopy.Apply(tree, fun, namelessArgs), argPos)
}
} else {
// defaults are needed. they are added to the argument list in named style as
// calls to the default getters. Example:
// foo[Int](a)() ==> foo[Int](a)(b = foo$qual.foo$default$2[Int](a))
checkNotMacro()
val fun1 = transformNamedApplication(Typer.this, mode, pt)(fun, x => x)
if (fun1.isErroneous) duplErrTree
else {
assert(isNamedApplyBlock(fun1), fun1)
val NamedApplyInfo(qual, targs, previousArgss, _) = context.namedApplyBlockInfo.get._2
val blockIsEmpty = fun1 match {
case Block(Nil, _) =>
// if the block does not have any ValDef we can remove it. Note that the call to
// "transformNamedApplication" is always needed in order to obtain targs/previousArgss
context.namedApplyBlockInfo = None
true
case _ => false
}
val (allArgs, missing) = addDefaults(args, qual, targs, previousArgss, params, fun.pos.focus, context)
val funSym = fun1 match { case Block(_, expr) => expr.symbol }
val lencmp2 = compareLengths(allArgs, formals)
if (!sameLength(allArgs, args) && callToCompanionConstr(context, funSym)) {
duplErrorTree(ModuleUsingCompanionClassDefaultArgsErrror(tree))
} else if (lencmp2 > 0) {
removeNames(Typer.this)(allArgs, params) // #3818
duplErrTree
} else if (lencmp2 == 0) {
// useful when a default doesn't match parameter type, e.g. def f[T](x:T="a"); f[Int]()
val note = "Error occurred in an application involving default arguments."
if (!(context.diagnostic contains note)) context.diagnostic = note :: context.diagnostic
doTypedApply(tree, if (blockIsEmpty) fun else fun1, allArgs, mode, pt)
} else {
tryTupleApply getOrElse duplErrorTree(NotEnoughArgsError(tree, fun, missing))
}
}
}
}
if (!sameLength(formals, args) || // wrong nb of arguments
(args exists isNamed) || // uses a named argument
isNamedApplyBlock(fun)) { // fun was transformed to a named apply block =>
// integrate this application into the block
if (dyna.isApplyDynamicNamed(fun)) dyna.typedNamedApply(tree, fun, args, mode, pt)
else tryNamesDefaults
} else {
val tparams = context.extractUndetparams()
if (tparams.isEmpty) { // all type params are defined
def handleMonomorphicCall: Tree = {
// In order for checkDead not to be misled by the unfortunate special
// case of AnyRef#synchronized (which is implemented with signature T => T
// but behaves as if it were (=> T) => T) we need to know what is the actual
// target of a call. Since this information is no longer available from
// typedArg, it is recorded here.
checkDead.updateExpr(fun)
val args1 =
// no expected type when jumping to a match label -- anything goes (this is ok since we're typing the translation of well-typed code)
// ... except during erasure: we must take the expected type into account as it drives the insertion of casts!
// I've exhausted all other semi-clean approaches I could think of in balancing GADT magic, SI-6145, CPS type-driven transforms and other existential trickiness
// (the right thing to do -- packing existential types -- runs into limitations in subtyping existential types,
// casting breaks SI-6145,
// not casting breaks GADT typing as it requires sneaking ill-typed trees past typer)
if (!phase.erasedTypes && fun.symbol.isLabel && treeInfo.isSynthCaseSymbol(fun.symbol))
typedArgs(args, forArgMode(fun, mode))
else
typedArgs(args, forArgMode(fun, mode), paramTypes, formals)
// instantiate dependent method types, must preserve singleton types where possible (stableTypeFor) -- example use case:
// val foo = "foo"; def precise(x: String)(y: x.type): x.type = {...}; val bar : foo.type = precise(foo)(foo)
// precise(foo) : foo.type => foo.type
val restpe = mt.resultType(args1 map (arg => gen.stableTypeFor(arg) getOrElse arg.tpe))
def ifPatternSkipFormals(tp: Type) = tp match {
case MethodType(_, rtp) if (inPatternMode(mode)) => rtp
case _ => tp
}
// Replace the Delegate-Chainer methods += and -= with corresponding
// + and - calls, which are translated in the code generator into
// Combine and Remove
if (forMSIL) {
fun match {
case Select(qual, name) =>
if (isSubType(qual.tpe, DelegateClass.tpe)
&& (name == encode("+=") || name == encode("-="))) {
val n = if (name == encode("+=")) nme.PLUS else nme.MINUS
val f = Select(qual, n)
// the compiler thinks, the PLUS method takes only one argument,
// but he thinks it's an instance method -> still two ref's on the stack
// -> translated by backend
val rhs = treeCopy.Apply(tree, f, args)
return typed(Assign(qual, rhs))
}
case _ => ()
}
}
/**
* This is translating uses of List() into Nil. This is less
* than ideal from a consistency standpoint, but it shouldn't be
* altered without due caution.
* ... this also causes bootstrapping cycles if List_apply is
* forced during kind-arity checking, so it is guarded by additional
* tests to ensure we're sufficiently far along.
*/
if (args.isEmpty && !forInteractive && fun.symbol.isInitialized && ListModule.hasCompleteInfo && (fun.symbol == List_apply))
atPos(tree.pos)(gen.mkNil setType restpe)
else
constfold(treeCopy.Apply(tree, fun, args1) setType ifPatternSkipFormals(restpe))
}
handleMonomorphicCall
} else if (needsInstantiation(tparams, formals, args)) {
//println("needs inst "+fun+" "+tparams+"/"+(tparams map (_.info)))
inferExprInstance(fun, tparams)
doTypedApply(tree, fun, args, mode, pt)
} else {
def handlePolymorphicCall = {
assert(!inPatternMode(mode), modeString(mode)) // this case cannot arise for patterns
val lenientTargs = protoTypeArgs(tparams, formals, mt.resultApprox, pt)
val strictTargs = map2(lenientTargs, tparams)((targ, tparam) =>
if (targ == WildcardType) tparam.tpeHK else targ)
var remainingParams = paramTypes
def typedArgToPoly(arg: Tree, formal: Type): Tree = { //TR TODO: cleanup
val lenientPt = formal.instantiateTypeParams(tparams, lenientTargs)
val newmode =
if (isByNameParamType(remainingParams.head)) POLYmode
else POLYmode | BYVALmode
if (remainingParams.tail.nonEmpty) remainingParams = remainingParams.tail
val arg1 = typedArg(arg, forArgMode(fun, mode), newmode, lenientPt)
val argtparams = context.extractUndetparams()
if (!argtparams.isEmpty) {
val strictPt = formal.instantiateTypeParams(tparams, strictTargs)
inferArgumentInstance(arg1, argtparams, strictPt, lenientPt)
arg1
} else arg1
}
val args1 = map2(args, formals)(typedArgToPoly)
if (args1 exists { _.isErrorTyped }) duplErrTree
else {
debuglog("infer method inst " + fun + ", tparams = " + tparams + ", args = " + args1.map(_.tpe) + ", pt = " + pt + ", lobounds = " + tparams.map(_.tpe.bounds.lo) + ", parambounds = " + tparams.map(_.info)) //debug
// define the undetparams which have been fixed by this param list, replace the corresponding symbols in "fun"
// returns those undetparams which have not been instantiated.
val undetparams = inferMethodInstance(fun, tparams, args1, pt)
val result = doTypedApply(tree, fun, args1, mode, pt)
context.undetparams = undetparams
result
}
}
handlePolymorphicCall
}
}
case SingleType(_, _) =>
doTypedApply(tree, fun setType fun.tpe.widen, args, mode, pt)
case ErrorType =>
if (!tree.isErrorTyped) setError(tree) else tree
// @H change to setError(treeCopy.Apply(tree, fun, args))
case otpe if inPatternMode(mode) && unapplyMember(otpe).exists =>
doTypedUnapply(tree, fun0, fun, args, mode, pt)
case _ =>
duplErrorTree(ApplyWithoutArgsError(tree, fun))
}
}
def doTypedUnapply(tree: Tree, fun0: Tree, fun: Tree, args: List[Tree], mode: Int, pt: Type): Tree = {
def duplErrTree = setError(treeCopy.Apply(tree, fun0, args))
def duplErrorTree(err: AbsTypeError) = { issue(err); duplErrTree }
val otpe = fun.tpe
if (args.length > MaxTupleArity)
return duplErrorTree(TooManyArgsPatternError(fun))
//
def freshArgType(tp: Type): (List[Symbol], Type) = tp match {
case MethodType(param :: _, _) =>
(Nil, param.tpe)
case PolyType(tparams, restpe) =>
createFromClonedSymbols(tparams, freshArgType(restpe)._2)((ps, t) => ((ps, t)))
// No longer used, see test case neg/t960.scala (#960 has nothing to do with it)
case OverloadedType(_, _) =>
OverloadedUnapplyError(fun)
(Nil, ErrorType)
case _ =>
UnapplyWithSingleArgError(fun)
(Nil, ErrorType)
}
val unapp = unapplyMember(otpe)
val unappType = otpe.memberType(unapp)
val argDummy = context.owner.newValue(nme.SELECTOR_DUMMY, fun.pos, SYNTHETIC) setInfo pt
val arg = Ident(argDummy) setType pt
val uncheckedTypeExtractor =
if (unappType.paramTypes.nonEmpty)
extractorForUncheckedType(tree.pos, unappType.paramTypes.head)
else None
if (!isApplicableSafe(Nil, unappType, List(pt), WildcardType)) {
//Console.println("UNAPP: need to typetest, arg.tpe = "+arg.tpe+", unappType = "+unappType)
val (freeVars, unappFormal) = freshArgType(unappType.skolemizeExistential(context.owner, tree))
val unapplyContext = context.makeNewScope(context.tree, context.owner)
freeVars foreach unapplyContext.scope.enter
val typer1 = newTyper(unapplyContext)
val pattp = typer1.infer.inferTypedPattern(tree, unappFormal, arg.tpe, canRemedy = uncheckedTypeExtractor.nonEmpty)
// turn any unresolved type variables in freevars into existential skolems
val skolems = freeVars map (fv => unapplyContext.owner.newExistentialSkolem(fv, fv))
arg.tpe = pattp.substSym(freeVars, skolems)
argDummy setInfo arg.tpe
}
// setType null is necessary so that ref will be stabilized; see bug 881
val fun1 = typedPos(fun.pos)(Apply(Select(fun setType null, unapp), List(arg)))
if (fun1.tpe.isErroneous) duplErrTree
else {
val resTp = fun1.tpe.finalResultType.normalize
val nbSubPats = args.length
val (formals, formalsExpanded) = extractorFormalTypes(resTp, nbSubPats, fun1.symbol)
if (formals == null) duplErrorTree(WrongNumberOfArgsError(tree, fun))
else {
val args1 = typedArgs(args, mode, formals, formalsExpanded)
// This used to be the following (failing) assert:
// assert(isFullyDefined(pt), tree+" ==> "+UnApply(fun1, args1)+", pt = "+pt)
// I modified as follows. See SI-1048.
val pt1 = if (isFullyDefined(pt)) pt else makeFullyDefined(pt)
val itype = glb(List(pt1, arg.tpe))
arg.tpe = pt1 // restore type (arg is a dummy tree, just needs to pass typechecking)
val unapply = UnApply(fun1, args1) setPos tree.pos setType itype
// if the type that the unapply method expects for its argument is uncheckable, wrap in classtag extractor
// skip if the unapply's type is not a method type with (at least, but really it should be exactly) one argument
// also skip if we already wrapped a classtag extractor (so we don't keep doing that forever)
if (uncheckedTypeExtractor.isEmpty || fun1.symbol.owner.isNonBottomSubClass(ClassTagClass)) unapply
else wrapClassTagUnapply(unapply, uncheckedTypeExtractor.get, unappType.paramTypes.head)
}
}
}
def wrapClassTagUnapply(uncheckedPattern: Tree, classTagExtractor: Tree, pt: Type): Tree = {
// TODO: disable when in unchecked match
// we don't create a new Context for a Match, so find the CaseDef, then go out one level and navigate back to the match that has this case
// val thisCase = context.nextEnclosing(_.tree.isInstanceOf[CaseDef])
// val unchecked = thisCase.outer.tree.collect{case Match(selector, cases) if cases contains thisCase => selector} match {
// case List(Typed(_, tpt)) if tpt.tpe hasAnnotation UncheckedClass => true
// case t => println("outer tree: "+ (t, thisCase, thisCase.outer.tree)); false
// }
// println("wrapClassTagUnapply"+ (!isPastTyper && infer.containsUnchecked(pt), pt, uncheckedPattern))
// println("wrap