/* NSC -- new scala compiler
* Copyright 2005 LAMP/EPFL
* @author Martin Odersky
*/
// $Id$
//todo: rewrite or disllow new T where T is a mixin (currently: <init> not a member of T)
package scala.tools.nsc.typechecker
import symtab.Flags._
import util.HashSet
import scala.tools.nsc.util.Position
import scala.collection.mutable.{HashMap, ListBuffer}
/** Methods to create symbols and to enter them into scopes. */
trait Typers requires Analyzer {
import global._
import definitions._
import posAssigner.atPos
var appcnt = 0
var idcnt = 0
var selcnt = 0
var implcnt = 0
var impltime = 0l
final val xviews = true
private val transformed = new HashMap[Tree, Tree]
private val superDefs = new HashMap[Symbol, ListBuffer[Tree]]
def resetTyper: unit = {
resetContexts
transformed.clear
superDefs .clear
}
def newTyper(context: Context): Typer = new Typer(context)
object UnTyper extends Traverser {
override def traverse(tree: Tree) = {
if (tree != EmptyTree) tree.tpe = null;
if (tree.hasSymbol) tree.symbol = NoSymbol;
super.traverse(tree)
}
}
class Typer(context0: Context) {
import context0.unit
val infer = new Inferencer(context0) {
override def isCoercible(tp: Type, pt: Type): boolean = (
tp.isError || pt.isError ||
context0.implicitsEnabled && // this condition prevents chains of views
inferView(Position.NOPOS, tp, pt, false) != EmptyTree
)
}
private def inferView(pos: int, from: Type, to: Type, reportAmbiguous: boolean): Tree = {
if (settings.debug.value) log("infer view from "+from+" to "+to);//debug
if (phase.erasedTypes) EmptyTree
else from match {
case MethodType(_, _) => EmptyTree
case OverloadedType(_, _) => EmptyTree
case PolyType(_, _) => EmptyTree
case _ => inferImplicit(pos, functionType(List(from), to), true, reportAmbiguous)
}
}
private def inferView(pos: int, from: Type, name: Name, tp: Type, reportAmbiguous: boolean): Tree = {
val to = refinedType(List(WildcardType), NoSymbol)
val psym = (if (name.isTypeName) to.symbol.newAbstractType(pos, name)
else to.symbol.newValue(pos, name)) setInfo tp
to.decls.enter(psym)
inferView(pos, from, to, reportAmbiguous)
}
import infer._
private var namerCache: Namer = null
def namer = {
if (namerCache == null || namerCache.context != context) namerCache = new Namer(context)
namerCache
}
private var context = context0
/** Mode constants
*/
val NOmode = 0x000
val EXPRmode = 0x001; // these 3 modes are mutually exclusive.
val PATTERNmode = 0x002
val TYPEmode = 0x004
val SCCmode = 0x008; // orthogonal to above. When set we are
// in the this or super constructor call of a constructor.
val FUNmode = 0x10; // orthogonal to above. When set
// we are looking for a method or constructor
val POLYmode = 0x020; // orthogonal to above. When set
// expression types can be polymorphic.
val QUALmode = 0x040; // orthogonal to above. When set
// expressions may be packages and
// Java statics modules.
val TAPPmode = 0x080; // Set for the function/type constructor part
// of a type application. When set we do not
// decompose PolyTypes.
val SUPERCONSTRmode = 0x100; // Set for the `super' in a superclass constructor call
// super.<init>
val SNDTRYmode = 0x200; // indicates that an application is typed for the 2nd
// time. In that case functions may no longer be
// be coerced with implicit views.
val LHSmode = 0x400; // Set for the left-hand side of an assignment
private val stickyModes: int = EXPRmode | PATTERNmode | TYPEmode
/** Report a type error.
* @param pos The position where to report the error
* @param ex The exception that caused the error */
def reportTypeError(pos: int, ex: TypeError): unit = ex match {
case CyclicReference(sym, info: TypeCompleter) =>
context.unit.error(pos,
info.tree match {
case ValDef(_, _, tpt, _) if (tpt.tpe == null) =>
"recursive "+sym+" needs type"
case DefDef(_, _, _, _, tpt, _) if (tpt.tpe == null) =>
(if (sym.owner.isClass && sym.owner.info.member(sym.name).hasFlag(OVERLOADED)) "overloaded "
else "recursive ")+sym+" needs result type"
case _ =>
ex.getMessage()
})
case _ =>
context.error(pos, ex.getMessage())
}
/** Check that tree is a stable expression.
*/
def checkStable(tree: Tree): Tree =
if (treeInfo.isPureExpr(tree) || tree.tpe.isError) tree
else errorTree(tree, "stable identifier required, but "+tree+" found.")
/** Check that type `tp' is not a subtype of itself.
*/
def checkNonCyclic(pos: int, tp: Type): boolean = {
def checkNotLocked(sym: Symbol): boolean = {
sym.initialize
if (sym hasFlag LOCKED) {
error(pos, "cyclic aliasing or subtyping involving "+sym); false
} else true
}
tp match {
case TypeRef(pre, sym, args) =>
(checkNotLocked(sym)) && (
!sym.isAliasType && !sym.isAbstractType ||
checkNonCyclic(pos, pre.memberInfo(sym).subst(sym.typeParams, args), sym)
)
case SingleType(pre, sym) =>
checkNotLocked(sym)
case st: SubType =>
checkNonCyclic(pos, st.supertype)
case ct: CompoundType =>
var p = ct.parents
while (!p.isEmpty && checkNonCyclic(pos, p.head)) p = p.tail
p.isEmpty
case _ =>
true
}
}
def checkNonCyclic(pos: int, tp: Type, lockedSym: Symbol): boolean = {
lockedSym.setFlag(LOCKED)
val result = checkNonCyclic(pos, tp)
lockedSym.resetFlag(LOCKED)
result
}
def checkNonCyclic(sym: Symbol): unit =
if (!checkNonCyclic(sym.pos, sym.tpe)) sym.setInfo(ErrorType);
def checkNonCyclic(defn: Tree, tpt: Tree): unit = {
if (!checkNonCyclic(defn.pos, tpt.tpe, defn.symbol)) {
tpt.tpe = ErrorType
defn.symbol.setInfo(ErrorType)
}
}
def checkParamsConvertible(pos: int, tpe: Type): unit = tpe match {
case MethodType(formals, restpe) =>
if (formals exists (.symbol.==(ByNameParamClass)))
error(pos, "methods with `=>'-parameters cannot be converted to function values");
if (formals exists (.symbol.==(RepeatedParamClass)))
error(pos, "methods with `*'-parameters cannot be converted to function values");
checkParamsConvertible(pos, restpe)
case _ =>
}
/** 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 badSymbol: Symbol = _
/** Check that type `tree' does not refer to private components unless itself is wrapped
* in something private (`owner' tells where the type occurs). */
def privates[T <: Tree](owner: Symbol, tree: T): T = {
check(owner, EmptyScope, tree)
}
/** Check that type `tree' does not refer to entities defined in scope `scope'. */
def locals[T <: Tree](scope: Scope, pt: Type, tree: T): T =
if (isFullyDefined(pt)) tree setType pt else check(NoSymbol, scope, tree)
def check[T <: Tree](owner: Symbol, scope: Scope, tree: T): T = {
this.owner = owner
this.scope = scope
badSymbol = NoSymbol
assert(tree.tpe != null, tree);//debug
apply(tree.tpe)
if (badSymbol == NoSymbol) tree
else {
error(tree.pos,
(if (badSymbol.hasFlag(PRIVATE)) "private " else "") + badSymbol +
" escapes its defining scope as part of type "+tree.tpe)
setError(tree)
}
}
override def apply(t: Type): Type = {
def checkNoEscape(sym: Symbol): unit = {
if (sym.hasFlag(PRIVATE)) {
var o = owner
while (o != NoSymbol && o != sym.owner && !o.isLocal && !o.hasFlag(PRIVATE))
o = o.owner
if (o == sym.owner) badSymbol = sym
} else if (sym.owner.isTerm) {
val e = scope.lookupEntry(sym.name)
if (e != null && e.sym == sym && e.owner == scope && !e.sym.isTypeParameterOrSkolem)
badSymbol = e.sym
}
}
if (badSymbol == NoSymbol)
t match {
case TypeRef(_, sym, _) => checkNoEscape(sym)
case SingleType(_, sym) => checkNoEscape(sym)
case _ =>
}
mapOver(t)
}
}
def reenterValueParams(vparamss: List[List[ValDef]]): unit =
for (val vparams <- vparamss; val vparam <- vparams) context.scope enter vparam.symbol
def reenterTypeParams(tparams: List[AbsTypeDef]): List[Symbol] =
for (val tparam <- tparams) yield {
context.scope enter tparam.symbol;
tparam.symbol.deSkolemize
}
/** The qualifying class of a this or super with prefix `qual' */
def qualifyingClassContext(tree: Tree, qual: Name): Context = {
if (qual.isEmpty) {
if (context.enclClass.owner.isPackageClass)
error(tree.pos, ""+tree+" can be used only in a class, object, or template")
context.enclClass
} else {
var c = context.enclClass
while (c != NoContext && c.owner.name != qual) c = c.outer.enclClass
if (c == NoContext) error(tree.pos, ""+qual+" is not an enclosing class")
c
}
}
/** 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. */
private def stabilize(tree: Tree, pre: Type, mode: int, pt: Type): Tree = {
if (tree.symbol.hasFlag(OVERLOADED) && (mode & FUNmode) == 0)
inferExprAlternative(tree, pt)
val sym = tree.symbol
if (tree.tpe.isError) tree
else if ((mode & (PATTERNmode | FUNmode)) == PATTERNmode && tree.isTerm) { // (1)
checkStable(tree)
} else if ((mode & (EXPRmode | QUALmode)) == EXPRmode && !sym.isValue) { // (2)
errorTree(tree, ""+sym+" is not a value")
} else if (sym.isStable && pre.isStable && tree.tpe.symbol != ByNameParamClass &&
(pt.isStable || (mode & QUALmode) != 0 && !sym.isConstant ||
sym.isModule && !sym.isMethod)) {
tree.setType(singleType(pre, sym))
} else tree
}
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 &&
(pt.isStable || (mode & QUALmode) != 0 && !sym.isConstant || sym.isModule)) {
assert(sym.tpe.paramTypes.isEmpty);
tree.setType(MethodType(List(), singleType(pre, sym)))
} else tree
}
/** Perform the following adaptations of expression, pattern or type `tree' wrt to
* given mode `mode' and given prototype `pt':
* (0) Convert expressions with constant types to literals
* (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 a class type that serves as a constructor in a pattern as follows:
* (5.1) If this type refers to a case class, set tree's type to the unique
* instance of its primary constructor that is a subtype of the expected type.
* (5.2) Otherwise, if this type is a subtype of scala.Seq[A], set trees' type
* to a method type from a repeated parameter sequence type A* to the expected type.
* (6) Convert all other types to TypeTree nodes.
* (7) When in TYPEmode nut not FUNmode, check that types are fully parameterized
* (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 a view
* If all this fails, error
*/
// def adapt(tree: Tree, mode: int, pt: Type): Tree = {
protected def adapt(tree: Tree, mode: int, pt: Type): Tree = tree.tpe match {
case ct @ ConstantType(value) if ((mode & TYPEmode) == 0 && (ct <:< pt)) => // (0)
copy.Literal(tree, value)
case OverloadedType(pre, alts) if ((mode & FUNmode) == 0) => // (1)
inferExprAlternative(tree, pt);
adapt(tree, mode, pt)
case PolyType(List(), restpe) => // (2)
adapt(tree setType restpe, mode, pt)
case TypeRef(_, sym, List(arg))
if ((mode & EXPRmode) != 0 && sym == ByNameParamClass) => // (2)
adapt(tree setType arg, mode, pt)
case PolyType(tparams, restpe) if ((mode & TAPPmode) == 0) => // (3)
val tparams1 = cloneSymbols(tparams)
val tree1 = if (tree.isType) tree
else TypeApply(tree, tparams1 map (tparam =>
TypeTree(tparam.tpe) setOriginal tree /* setPos tree.pos */)) setPos tree.pos
context.undetparams = context.undetparams ::: tparams1
adapt(tree1 setType restpe.substSym(tparams, tparams1), mode, pt)
case mt: ImplicitMethodType if ((mode & (EXPRmode | FUNmode | LHSmode)) == EXPRmode) => // (4.1)
val tree1 =
if (!context.undetparams.isEmpty & (mode & POLYmode) == 0) { // (9)
val tparams = context.undetparams
context.undetparams = List()
inferExprInstance(tree, tparams, pt)
adapt(tree, mode, pt)
} else tree
typed(applyImplicitArgs(tree1), mode, pt)
case mt: MethodType
if (((mode & (EXPRmode | FUNmode)) == EXPRmode) &&
(context.undetparams.isEmpty || (mode & POLYmode) != 0)) =>
if (!tree.symbol.isConstructor && pt != WildcardType && isCompatible(mt, pt) &&
(pt <:< functionType(mt.paramTypes map (t => WildcardType), WildcardType))) { // (4.2)
if (settings.debug.value) log("eta-expanding "+tree+":"+tree.tpe+" to "+pt)
checkParamsConvertible(tree.pos, tree.tpe);
typed(etaExpand(tree), mode, pt)
} else if (!tree.symbol.isConstructor && mt.paramTypes.isEmpty) { // (4.3)
adapt(typed(Apply(tree, List()) setPos tree.pos), mode, pt)
} else {
if (context.implicitsEnabled) {
if (settings.migrate.value && !tree.symbol.isConstructor && isCompatible(mt, pt))
error(tree.pos, migrateMsg + " method can be converted to function only if an expected function type is given");
else
error(tree.pos, "missing arguments for "+tree.symbol+tree.symbol.locationString+
(if (tree.symbol.isConstructor) ""
else ";\nprefix this method with `&' if you want to treat it as a partially applied function"))
}
setError(tree)
}
case _ =>
if (tree.isType) {
val clazz = tree.tpe.symbol
if ((mode & PATTERNmode) != 0) { // (5)
if (tree.tpe.isInstanceOf[MethodType]) {
tree // everything done already
} else {
clazz.initialize
if (clazz.hasFlag(CASE)) { // (5.1)
val tree1 = TypeTree(clazz.primaryConstructor.tpe.asSeenFrom(tree.tpe.prefix, clazz.owner)) setOriginal tree
try {
inferConstructorInstance(tree1, clazz.typeParams, pt)
} catch {
case npe : NullPointerException =>
logError("CONTEXT: " + context . unit . source .dbg(tree.pos), npe);
throw npe;
case fe : FatalError =>
logError("CONTEXT: " + context . unit . source .dbg(tree.pos), fe);
throw fe;
case t : Throwable =>
logError("CONTEXT: " + context . unit . source .dbg(tree.pos), t);
throw t;
}
tree1
} else if (clazz.isSubClass(SeqClass)) { // (5.2)
pt.baseType(clazz).baseType(SeqClass) match {
case TypeRef(pre, seqClass, args) =>
tree.setType(MethodType(List(typeRef(pre, RepeatedParamClass, args)), pt))
case NoType =>
errorTree(tree, "expected pattern type "+pt +
" does not conform to sequence "+clazz)
case ErrorType =>
setError(tree)
}
} else {
if (!tree.tpe.isError)
error(tree.pos, ""+clazz+" is neither a case class nor a sequence class")
setError(tree)
}
}
} else if ((mode & FUNmode) != 0) {
tree
} else if (tree.hasSymbol && !tree.symbol.typeParams.isEmpty) { // (7)
errorTree(tree, ""+clazz+" takes type parameters")
} else tree match { // (6)
case TypeTree() => tree
case _ => TypeTree(tree.tpe) setOriginal(tree)
}
} else if ((mode & (EXPRmode | FUNmode)) == (EXPRmode | FUNmode) &&
!tree.tpe.isInstanceOf[MethodType] && !tree.tpe.isInstanceOf[OverloadedType] &&
((mode & TAPPmode) == 0 || tree.tpe.typeParams.isEmpty) &&
adaptToName(tree, nme.apply).tpe.nonLocalMember(nme.apply)
.filter(m => m.tpe.paramSectionCount > 0) != NoSymbol) { // (8)
typed(atPos(tree.pos)(Select(adaptToName(tree, nme.apply), nme.apply)), mode, pt)
} else if (!context.undetparams.isEmpty & (mode & POLYmode) == 0) { // (9)
val tparams = context.undetparams
context.undetparams = List()
inferExprInstance(tree, tparams, pt)
adapt(tree, mode, pt)
} else if (tree.tpe <:< pt) {
tree
} else {
val tree1 = constfold(tree, pt); // (10) (11)
if (tree1.tpe <:< pt) adapt(tree1, mode, pt)
else {
if ((mode & (EXPRmode | FUNmode)) == EXPRmode) {
pt match {
case TypeRef(_, sym, _) =>
// note: was if (pt.symbol == UnitClass) but this leads to a potentially
// infinite expansion if pt is constant type ()
if (sym == UnitClass && tree.tpe <:< AnyClass.tpe) // (12)
return typed(atPos(tree.pos)(Block(List(tree), Literal(()))), mode, pt)
case _ =>
}
if (context.implicitsEnabled && !tree.tpe.isError && !pt.isError) {
// (13); the condition prevents chains of views
if (settings.debug.value) log("inferring view from "+tree.tpe+" to "+pt)
val coercion = inferView(tree.pos, tree.tpe, pt, true)
if (coercion != EmptyTree) {
if (settings.debug.value) log("inferred view from "+tree.tpe+" to "+pt+" = "+coercion+":"+coercion.tpe)
return typed(Apply(coercion, List(tree)) setPos tree.pos, mode, pt)
}
}
}
if (settings.debug.value) log("error tree = "+tree)
typeErrorTree(tree, tree.tpe, pt)
}
}
}
// System.out.println("adapt "+tree+":"+tree.tpe+", mode = "+mode+", pt = "+pt)
// adapt(tree, mode, pt)
// }
def adaptToMember(qual: Tree, name: Name, tp: Type): Tree = {
val qtpe = qual.tpe.widen;
if (qual.isTerm && (qual.symbol == null || qual.symbol.isValue) &&
!phase.erasedTypes && !qtpe.isError && !tp.isError &&
qtpe.symbol != AllRefClass && qtpe.symbol != AllClass && qtpe != WildcardType) {
val coercion = inferView(qual.pos, qtpe, name, tp, true)
if (coercion != EmptyTree)
typedQualifier(atPos(qual.pos)(Apply(coercion, List(qual))))
else qual
} else qual
}
def adaptToName(qual: Tree, name: Name) =
if (qual.tpe.nonLocalMember(name) != NoSymbol) qual
else adaptToMember(qual, name, WildcardType)
private def completeParentType(tpt: Tree, tparams: List[Symbol], enclTparams: List[Symbol], vparamss: List[List[ValDef]], superargs: List[Tree]): Type = {
enclTparams foreach context.scope.enter
namer.enterValueParams(context.owner, vparamss)
val newTree = New(tpt)
.setType(PolyType(tparams, appliedType(tpt.tpe, tparams map (.tpe))))
val tree = typed(atPos(tpt.pos)(Apply(Select(newTree, nme.CONSTRUCTOR), superargs)))
if (settings.debug.value) log("superconstr "+tree+" co = "+context.owner);//debug
tree.tpe
}
/*
def completeParentType(tpt: Tree, templ: Template): Tree =
if (tpt.hasSymbol) {
val tparams = tpt.symbol.typeParams
if (!tparams.isEmpty) {
val constr @ DefDef(_, _, _, vparamss, _, rhs) = treeInfo.firstConstructor(templ.body)
val Apply(_, superargs) = treeInfo.superCall(rhs, tpt.symbol.name)
val outercontext = context.outer
TypeTree(
newTyper(outercontext.makeNewScope(constr, outercontext.owner))
.completeParentType(
tpt,
tparams,
context.owner.unsafeTypeParams,
vparamss map (.map(.duplicate.asInstanceOf[ValDef])),
superargs map (.duplicate))) setPos tpt.pos
} else tpt
} else tpt
*/
def parentTypes(templ: Template): List[Tree] = try {
if (templ.parents.isEmpty) List()
else {
var supertpt = typedTypeConstructor(templ.parents.head)
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.symbol != null && supertpt.tpe.symbol.initialize.isTrait) {
mixins = typedType(supertpt) :: mixins
supertpt = TypeTree(supertpt.tpe.parents.head) setOriginal supertpt /* setPos supertpt.pos */
}
if (supertpt.hasSymbol) {
val tparams = supertpt.symbol.typeParams
if (!tparams.isEmpty) {
val constr @ DefDef(_, _, _, vparamss, _, Apply(_, superargs)) =
treeInfo.firstConstructor(templ.body)
val outercontext = context.outer
supertpt = TypeTree(
newTyper(outercontext.makeNewScope(constr, outercontext.owner))
.completeParentType(
supertpt,
tparams,
context.owner.unsafeTypeParams,
vparamss map (.map(.duplicate.asInstanceOf[ValDef])),
superargs map (.duplicate))) setOriginal supertpt /* setPos supertpt.pos */
}
}
//System.out.println("parents("+context.owner+") = "+supertpt :: mixins);//DEBUG
List.mapConserve(supertpt :: mixins)(tpt => checkNoEscaping.privates(context.owner, tpt))
}
} catch {
case ex: TypeError =>
reportTypeError(templ.pos, ex)
List(TypeTree(AnyRefClass.tpe))
}
/** Check that
* - all parents are class types,
* - first parent cluss is not a mixin; following classes are mixins,
* - final classes are not inherited,
* - sealed classes are only inherited by classes which are
* nested within definition of base class, or that occur within same
* statement sequence,
* - self-type of current class is a subtype of self-type of each parent class.
* - no two parents define same symbol.
*/
def validateParentClasses(parents: List[Tree], selfType: Type): unit = {
def validateParentClass(parent: Tree, superclazz: Symbol): unit = {
if (!parent.tpe.isError) {
val psym = parent.tpe.symbol.initialize
if (!psym.isClass)
error(parent.pos, "class type expected")
else if (psym != superclazz)
if (psym.isTrait) {
val ps = psym.info.parents
if (!ps.isEmpty && !superclazz.isSubClass(ps.head.symbol))
error(parent.pos, "illegal inheritance; super"+superclazz+
"\n is not a subclass of the super"+ps.head.symbol+
"\n of the mixin " + psym);
} else if (settings.migrate.value) {
error(parent.pos, migrateMsg+psym+" needs to be a declared as a trait")
}else {
error(parent.pos, ""+psym+" needs to be a trait be mixed in")
}
else if (psym.hasFlag(FINAL))
error(parent.pos, "illegal inheritance from final class")
else if (!phase.erasedTypes && psym.isSealed &&
context.unit.source.file != psym.sourceFile)
error(parent.pos, "illegal inheritance from sealed "+psym)
if (!(selfType <:< parent.tpe.typeOfThis) && !phase.erasedTypes) {
//System.out.println(context.owner);//DEBUG
//System.out.println(context.owner.unsafeTypeParams);//DEBUG
//System.out.println(List.fromArray(context.owner.info.closure));//DEBUG
error(parent.pos, "illegal inheritance;\n self-type "+
selfType+" does not conform to "+parent +
"'s selftype "+parent.tpe.typeOfThis)
if (settings.explaintypes.value) explainTypes(selfType, parent.tpe.typeOfThis)
}
if (parents exists (p => p != parent && p.tpe.symbol == psym && !psym.isError))
error(parent.pos, ""+psym+" is inherited twice")
}
}
if (!parents.head.tpe.isError)
for (val p <- parents) validateParentClass(p, parents.head.tpe.symbol)
}
def typedClassDef(cdef: ClassDef): Tree = {
val clazz = cdef.symbol
reenterTypeParams(cdef.tparams)
val tparams1 = List.mapConserve(cdef.tparams)(typedAbsTypeDef)
val tpt1 = checkNoEscaping.privates(clazz.thisSym, typedType(cdef.tpt))
val impl1 = newTyper(context.make(cdef.impl, clazz, new Scope()))
.typedTemplate(cdef.impl, parentTypes(cdef.impl))
val impl2 = addSyntheticMethods(impl1, clazz, context.unit)
val ret = copy.ClassDef(cdef, cdef.mods, cdef.name, tparams1, tpt1, impl2)
.setType(NoType)
ret
}
def typedModuleDef(mdef: ModuleDef): Tree = {
//System.out.println("sourcefile of " + mdef.symbol + "=" + mdef.symbol.sourceFile);
val clazz = mdef.symbol.moduleClass
val impl1 = newTyper(context.make(mdef.impl, clazz, new Scope()))
.typedTemplate(mdef.impl, parentTypes(mdef.impl))
val impl2 = addSyntheticMethods(impl1, clazz, context.unit)
copy.ModuleDef(mdef, mdef.mods, mdef.name, impl2) setType NoType
}
def addGetterSetter(stat: Tree): List[Tree] = stat match {
case ValDef(mods, name, tpt, rhs) if !(mods hasFlag LOCAL) && !stat.symbol.isModuleVar =>
val vdef = copy.ValDef(stat, mods | PRIVATE | LOCAL, nme.getterToLocal(name), tpt, rhs)
val value = vdef.symbol
val getter = if (mods hasFlag DEFERRED) value else value.getter(value.owner)
assert(getter != NoSymbol, getter);//debug
val getterDef: DefDef = {
val result = DefDef(getter, vparamss =>
if (mods hasFlag DEFERRED) EmptyTree
else typed(atPos(vdef.pos)(Select(This(value.owner), value)), EXPRmode, value.tpe))
result.tpt.asInstanceOf[TypeTree] setOriginal tpt /* setPos tpt.pos */
checkNoEscaping.privates(getter, result.tpt)
result
}
def setterDef: DefDef = {
val setter = value.owner.info.decl(nme.getterToSetter(getter.name));
assert(setter != NoSymbol, getter);//debug
atPos(vdef.pos)(
DefDef(setter, vparamss =>
if (mods hasFlag DEFERRED) EmptyTree
else typed(Assign(Select(This(value.owner), value),
Ident(vparamss.head.head)))))
}
val gs = if (mods hasFlag MUTABLE) List(getterDef, setterDef)
else List(getterDef)
if (mods hasFlag DEFERRED) gs else vdef :: gs
case DocDef(comment, defn) =>
addGetterSetter(defn) map (stat => DocDef(comment, stat))
case Attributed(attr, defn) =>
addGetterSetter(defn) map (stat => Attributed(attr.duplicate, stat))
case _ =>
List(stat)
}
def typedTemplate(templ: Template, parents1: List[Tree]): Template = {
val clazz = context.owner
if (templ.symbol == NoSymbol) templ setSymbol clazz.newLocalDummy(templ.pos)
val selfType =
if (clazz.isAnonymousClass && !phase.erasedTypes)
intersectionType(clazz.info.parents, clazz.owner)
else if (settings.Xgadt.value) clazz.typeOfThis.asSeenFrom(context.prefix, clazz)
else clazz.typeOfThis
// the following is necessary for templates generated later
new Namer(context.outer.make(templ, clazz, clazz.info.decls)).enterSyms(templ.body)
validateParentClasses(parents1, selfType);
val body1 = typedStats(templ.body flatMap addGetterSetter, templ.symbol)
copy.Template(templ, parents1, body1) setType clazz.tpe
}
def typedValDef(vdef: ValDef): ValDef = {
val sym = vdef.symbol
val typer1 = if (sym.hasFlag(PARAM) && sym.owner.isConstructor)
newTyper(context.makeConstructorContext)
else this
var tpt1 = checkNoEscaping.privates(sym, typer1.typedType(vdef.tpt))
checkNonCyclic(vdef, tpt1)
val rhs1 =
if (vdef.rhs.isEmpty) {
if (sym.isVariable && sym.owner.isTerm && phase.id <= currentRun.typerPhase.id)
error(vdef.pos, "local variables must be initialized")
vdef.rhs
} else {
newTyper(context.make(vdef, sym)).transformedOrTyped(vdef.rhs, tpt1.tpe)
}
copy.ValDef(vdef, vdef.mods, vdef.name, tpt1, rhs1) setType NoType
}
/** Enter all aliases of local parameter accessors. */
def computeParamAliases(clazz: Symbol, vparamss: List[List[ValDef]], rhs: Tree): unit = {
if (settings.debug.value) log("computing param aliases for "+clazz+":"+clazz.primaryConstructor.tpe+":"+rhs);//debug
def decompose(call: Tree): Pair[Tree, List[Tree]] = call match {
case Apply(fn, args) =>
val Pair(superConstr, args1) = decompose(fn)
val formals = fn.tpe.paramTypes
val args2 = if (formals.isEmpty || formals.last.symbol != RepeatedParamClass) args
else args.take(formals.length - 1) ::: List(EmptyTree)
if (args2.length != formals.length) assert(false, "mismatch "+clazz+" "+formals+" "+args2);//debug
Pair(superConstr, args1 ::: args2)
case Block(stats, expr) =>
decompose(stats.head)
case _ =>
Pair(call, List())
}
val Pair(superConstr, superArgs) = decompose(rhs)
assert(superConstr.symbol != null);//debug
if (superConstr.symbol.isPrimaryConstructor) {
val superClazz = superConstr.symbol.owner
if (!superClazz.hasFlag(JAVA)) {
val superParamAccessors = superClazz.constrParamAccessors
if (superParamAccessors.length != superArgs.length) {
System.out.println(""+superClazz+":"+superClazz.info.decls.toList.filter(.hasFlag(PARAMACCESSOR)))
assert(false, "mismatch: "+superParamAccessors+";"+rhs+";"+superClazz.info.decls); //debug
}
List.map2(superParamAccessors, superArgs) { (superAcc, superArg) =>
superArg match {
case Ident(name) =>
if (vparamss.exists(.exists(vp => vp.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(.hasFlag(PARAMACCESSOR))
if (ownAcc hasFlag ACCESSOR) ownAcc = ownAcc.accessed
if (settings.debug.value) log(""+ownAcc+" has alias "+alias + alias.locationString);//debug
ownAcc.asInstanceOf[TermSymbol].setAlias(alias)
}
}
case _ =>
}
}
()
}
}
}
def typedDefDef(ddef: DefDef): DefDef = {
val meth = ddef.symbol
def checkPrecedes(tree: Tree): unit = tree match {
case Block(stat :: _, _) => checkPrecedes(stat)
case Apply(fun, _) =>
if (fun.symbol.isConstructor &&
fun.symbol.owner == meth.owner && fun.symbol.pos >= meth.pos)
error(fun.pos, "called constructor must precede calling constructor");
case _ =>
}
def typedSuperCall(tree: Tree): Tree = {
val result = typed(tree, EXPRmode | SCCmode, UnitClass.tpe)
checkPrecedes(result)
result
}
reenterTypeParams(ddef.tparams)
reenterValueParams(ddef.vparamss)
val tparams1 = List.mapConserve(ddef.tparams)(typedAbsTypeDef)
val vparamss1 = List.mapConserve(ddef.vparamss)(vparams1 =>
List.mapConserve(vparams1)(typedValDef))
for (val vparams <- vparamss1; val vparam <- vparams) {
checkNoEscaping.locals(context.scope, WildcardType, vparam.tpt); ()
}
var tpt1 =
checkNoEscaping.locals(context.scope, WildcardType,
checkNoEscaping.privates(meth,
typedType(ddef.tpt)))
checkNonCyclic(ddef, tpt1)
val rhs1 =
if (ddef.name == nme.CONSTRUCTOR) {
if (!meth.hasFlag(SYNTHETIC) &&
!(meth.owner.isClass ||
meth.owner.isModuleClass ||
meth.owner.isAnonymousClass ||
meth.owner.isRefinementClass))
error(ddef.pos, "constructor definition not allowed here "+meth.owner);//debug
val result = ddef.rhs match {
case Block(stat :: stats, expr) =>
val stat1 = typedSuperCall(stat)
newTyper(context.makeConstructorSuffixContext).typed(
copy.Block(ddef.rhs, stats, expr), UnitClass.tpe) match {
case block1 @ Block(stats1, expr1) =>
copy.Block(block1, stat1 :: stats1, expr1)
}
case _ =>
typedSuperCall(ddef.rhs)
}
if (meth.isPrimaryConstructor && !phase.erasedTypes && reporter.errors == 0)
computeParamAliases(meth.owner, vparamss1, result)
result
} else transformedOrTyped(ddef.rhs, tpt1.tpe)
copy.DefDef(ddef, ddef.mods, ddef.name, tparams1, vparamss1, tpt1, rhs1) setType NoType
}
def typedAbsTypeDef(tdef: AbsTypeDef): AbsTypeDef = {
val lo1 = checkNoEscaping.privates(tdef.symbol, typedType(tdef.lo))
val hi1 = checkNoEscaping.privates(tdef.symbol, typedType(tdef.hi))
checkNonCyclic(tdef.symbol)
if (!(lo1.tpe <:< hi1.tpe))
error(tdef.pos,
"lower bound "+lo1.tpe+" does not conform to upper bound "+hi1.tpe)
copy.AbsTypeDef(tdef, tdef.mods, tdef.name, lo1, hi1) setType NoType
}
def typedAliasTypeDef(tdef: AliasTypeDef): AliasTypeDef = {
reenterTypeParams(tdef.tparams)
val tparams1 = List.mapConserve(tdef.tparams)(typedAbsTypeDef)
val rhs1 = checkNoEscaping.privates(tdef.symbol, typedType(tdef.rhs))
checkNonCyclic(tdef.symbol)
copy.AliasTypeDef(tdef, tdef.mods, tdef.name, tparams1, rhs1) setType NoType
}
private def enterLabelDef(stat: Tree): unit = stat match {
case ldef @ LabelDef(_, _, _) =>
if (ldef.symbol == NoSymbol)
ldef.symbol = namer.enterInScope(
context.owner.newLabel(ldef.pos, ldef.name) setInfo MethodType(List(), UnitClass.tpe))
case _ =>
}
def typedLabelDef(ldef: LabelDef): LabelDef = {
val restpe = ldef.symbol.tpe.resultType
val rhs1 = typed(ldef.rhs, restpe)
ldef.params foreach (param => param.tpe = param.symbol.tpe)
copy.LabelDef(ldef, ldef.name, ldef.params, rhs1) setType restpe
}
def typedBlock(block: Block, mode: int, pt: Type): Block = {
namer.enterSyms(block.stats)
block.stats foreach enterLabelDef
val stats1 = typedStats(block.stats, context.owner)
val expr1 = typed(block.expr, mode & ~(FUNmode | QUALmode), pt)
val block1 = copy.Block(block, stats1, expr1)
.setType(if (treeInfo.isPureExpr(block)) expr1.tpe else expr1.tpe.deconst)
if (isFullyDefined(pt)) block1
else { //todo: correct?
if (block1.tpe.symbol.isAnonymousClass)
block1 setType intersectionType(block1.tpe.parents, block1.tpe.symbol.owner)
checkNoEscaping.locals(context.scope, pt, block1)
}
}
def typedCase(cdef: CaseDef, pattpe: Type, pt: Type): CaseDef = {
val pat1: Tree = typedPattern(cdef.pat, pattpe)
val guard1: Tree = if (cdef.guard == EmptyTree) EmptyTree
else typed(cdef.guard, BooleanClass.tpe)
var body1: Tree = typed(cdef.body, pt)
if (!context.savedTypeBounds.isEmpty) {
context.restoreTypeBounds
// the following is a hack to make the pattern matcher work
body1 =
typed {
atPos(body1.pos) {
TypeApply(Select(body1, Any_asInstanceOf), List(TypeTree(pt)))
}
}
}
copy.CaseDef(cdef, pat1, guard1, body1) setType body1.tpe
}
def typedCases(tree: Tree, cases: List[CaseDef], pattp0: Type, pt: Type): List[CaseDef] = {
var pattp = pattp0
List.mapConserve(cases) ( cdef =>
newTyper(context.makeNewScope(cdef, context.owner)).typedCase(cdef, pattp, pt))
/* not yet!
cdef.pat match {
case Literal(Constant(null)) =>
if (!(pattp <:< NonNullClass.tpe))
pattp = intersectionType(List(pattp, NonNullClass.tpe), context.owner)
case _ =>
}
result
*/
}
def typedFunction(fun: Function, mode: int, pt: Type): Tree = {
def decompose(pt: Type): Triple[Symbol, List[Type], Type] =
if (isFunctionType(pt)
||
pt.symbol == PartialFunctionClass &&
fun.vparams.length == 1 && fun.body.isInstanceOf[Match])
Triple(pt.symbol, pt.typeArgs.init, pt.typeArgs.last)
else
Triple(FunctionClass(fun.vparams.length), fun.vparams map (x => NoType), WildcardType)
val Triple(clazz, argpts, respt) =
decompose(if (pt.symbol isSubClass CodeClass) pt.typeArgs.head else pt)
if (fun.vparams.length != argpts.length)
errorTree(fun, "wrong number of parameters; expected = "+argpts.length)
else {
val vparamSyms = List.map2(fun.vparams, argpts) { (vparam, argpt) =>
if (vparam.tpt.isEmpty)
vparam.tpt.tpe =
if (argpt == NoType || argpt == WildcardType) {
error(vparam.pos, "missing parameter type"); ErrorType
}
else argpt
namer.enterSym(vparam)
vparam.symbol
}
val vparams = List.mapConserve(fun.vparams)(typedValDef)
for (val vparam <- vparams) {
checkNoEscaping.locals(context.scope, WildcardType, vparam.tpt); ()
}
val body = checkNoEscaping.locals(context.scope, respt, typed(fun.body, respt))
val formals = vparamSyms map (.tpe)
val restpe = body.tpe.deconst
val funtpe = typeRef(clazz.tpe.prefix, clazz, formals ::: List(restpe))
val fun1 = copy.Function(fun, vparams, checkNoEscaping.locals(context.scope, restpe, body))
.setType(funtpe)
if (pt.symbol isSubClass CodeClass) {
val liftPoint = Apply(Select(Ident(CodeModule), nme.lift_), List(fun1))
typed(atPos(fun.pos)(liftPoint))
} else fun1
}
}
def typedRefinement(stats: List[Tree]): List[Tree] = {
namer.enterSyms(stats)
for (val stat <- stats) stat.symbol setFlag OVERRIDE
typedStats(stats, NoSymbol)
}
def typedStats(stats: List[Tree], exprOwner: Symbol): List[Tree] = {
val inBlock = exprOwner == context.owner
val result =
List.mapConserve(stats) { stat =>
if (context.owner.isRefinementClass && !treeInfo.isDeclaration(stat))
errorTree(stat, "only declarations allowed here")
stat match {
case imp @ Import(_, _) =>
context = context.makeNewImport(imp)
stat.symbol.initialize
EmptyTree
case _ =>
(if (!inBlock && (!stat.isDef || stat.isInstanceOf[LabelDef]))
newTyper(context.make(stat, exprOwner)) else this).typed(stat)
}
}
val scope = if (inBlock) context.scope else context.owner.info.decls;
var e = scope.elems;
while (e != null && e.owner == scope) {
if (!e.sym.hasFlag(LOCAL)) {
var e1 = scope.lookupNextEntry(e);
while (e1 != null && e1.owner == scope) {
if (!e1.sym.hasFlag(LOCAL) &&
(e.sym.isType || inBlock || (e.sym.tpe matches e1.sym.tpe)))
error(e.sym.pos, ""+e1.sym+" is defined twice");
e1 = scope.lookupNextEntry(e1);
}
}
e = e.next
}
result
}
protected def typed1(tree: Tree, mode: int, pt: Type): Tree = {
def funmode = mode & stickyModes | FUNmode | POLYmode
def ptOrLub(tps: List[Type]) = if (isFullyDefined(pt)) pt else lub(tps)
def typedTypeApply(fun: Tree, args: List[Tree]): Tree = fun.tpe match {
case OverloadedType(pre, alts) =>
inferPolyAlternatives(fun, args.length)
typedTypeApply(fun, args)
case PolyType(tparams, restpe) if (tparams.length != 0) =>
if (tparams.length == args.length) {
val targs = args map (.tpe)
checkBounds(tree.pos, tparams, targs, "")
copy.TypeApply(tree, fun, args) setType restpe.subst(tparams, targs)
} else {
errorTree(tree, "wrong number of type parameters for "+treeSymTypeMsg(fun))
}
case ErrorType =>
setError(tree)
case _ =>
errorTree(tree, treeSymTypeMsg(fun)+" does not take type parameters.")
}
def typedArg(arg: Tree, pt: Type): Tree = {
val argTyper = if ((mode & SCCmode) != 0) newTyper(context.makeConstructorContext)
else this
argTyper.typed(arg, mode & stickyModes, pt)
}
def typedArgs(args: List[Tree]) =
List.mapConserve(args)(arg => typedArg(arg, WildcardType))
def typedApply(fun0: Tree, args: List[Tree]): Tree = {
var fun = fun0;
if (fun.hasSymbol && (fun.symbol hasFlag OVERLOADED)) {
// preadapt symbol to number of arguments given
val argtypes = args map (arg => AllClass.tpe)
val pre = fun.symbol.tpe.prefix
val sym = fun.symbol filter (alt =>
isApplicable(context.undetparams, pre.memberType(alt), argtypes, pt))
if (sym != NoSymbol)
fun = adapt(fun setSymbol sym setType pre.memberType(sym), funmode, WildcardType)
}
fun.tpe match {
case OverloadedType(pre, alts) =>
val args1 = typedArgs(args)
inferMethodAlternative(fun, context.undetparams, args1 map (.tpe.deconst), pt)
typedApply(adapt(fun, funmode, WildcardType), args1)
case MethodType(formals0, restpe) =>
val formals = formalTypes(formals0, args.length)
if (formals.length != args.length) {
//System.out.println(""+formals.length+" "+args.length);//DEBUG
errorTree(tree, "wrong number of arguments for "+treeSymTypeMsg(fun))
} else {
val tparams = context.undetparams
context.undetparams = List()
if (tparams.isEmpty) {
val args1 = List.map2(args, formals)(typedArg)
def ifPatternSkipFormals(tp: Type) = tp match {
case MethodType(_, rtp) if ((mode & PATTERNmode) != 0) => rtp
case _ => tp
}
constfold(copy.Apply(tree, fun, args1).setType(ifPatternSkipFormals(restpe)))
} else {
assert((mode & PATTERNmode) == 0); // this case cannot arise for patterns
val lenientTargs = protoTypeArgs(tparams, formals, restpe, pt)
val strictTargs = List.map2(lenientTargs, tparams)((targ, tparam) =>
if (targ == WildcardType) tparam.tpe else targ)
def typedArgToPoly(arg: Tree, formal: Type): Tree = {
val lenientPt = formal.subst(tparams, lenientTargs)
val arg1 = typedArg(arg, lenientPt)
val argtparams = context.undetparams
context.undetparams = List()
if (!argtparams.isEmpty) {
val strictPt = formal.subst(tparams, strictTargs)
inferArgumentInstance(arg1, argtparams, strictPt, lenientPt)
}
arg1
}
val args1 = List.map2(args, formals)(typedArgToPoly)
if (args1 exists (.tpe.isError)) setError(tree)
else {
if (settings.debug.value) log("infer method inst "+fun+", tparams = "+tparams+", args = "+args1.map(.tpe)+", pt = "+pt+", lobounds = "+tparams.map(.tpe.bounds.lo));//debug
val undetparams = inferMethodInstance(fun, tparams, args1, pt)
val result = typedApply(fun, args1)
context.undetparams = undetparams
result
}
}
}
case ErrorType =>
setError(tree)
case _ =>
errorTree(tree, ""+fun+" does not take parameters")
}
}
def tryTypedArgs(args: List[Tree]) = {
val reportGeneralErrors = context.reportGeneralErrors
val reportAmbiguousErrors = context.reportAmbiguousErrors
try {
context.reportGeneralErrors = false
context.reportAmbiguousErrors = false
typedArgs(args)
} catch {
case ex: TypeError =>
null
} finally {
context.reportGeneralErrors = reportGeneralErrors
context.reportAmbiguousErrors = reportAmbiguousErrors
}
}
/** Try to apply function to arguments; if it does not work try to insert an implicit
* conversion
*/
def tryTypedApply(fun: Tree, args: List[Tree]): Tree = {
val reportGeneralErrors = context.reportGeneralErrors
try {
context.reportGeneralErrors = false
typedApply(fun, args)
} catch {
case ex: TypeError =>
val Select(qual, name) = fun
val args1 = tryTypedArgs(args map UnTyper.apply)
context.reportGeneralErrors = reportGeneralErrors
val qual1 = if (args1 == null || pt.isError) qual
else adaptToMember(qual, name, MethodType(args1 map (.tpe), pt))
val tree1 = Apply(Select(qual1, name) setPos fun.pos, args map UnTyper.apply) setPos tree.pos
typed1(tree1, mode | SNDTRYmode, pt)
} finally {
context.reportGeneralErrors = reportGeneralErrors
}
}
/** Attribute a selection where `tree' is `qual.name'.
* `qual' is already attributed.
*/
def typedSelect(qual: Tree, name: Name): Tree = {
val sym =
if (tree.symbol != NoSymbol) {
if (phase.erasedTypes && qual.isInstanceOf[Super]) qual.tpe = tree.symbol.owner.tpe
if (false && settings.debug.value) { // todo: replace by settings.check.value?
val alts = qual.tpe.member(tree.symbol.name).alternatives
if (!(alts exists (alt =>
alt == tree.symbol || alt.isTerm && (alt.tpe matches tree.symbol.tpe))))
assert(false, "symbol "+tree.symbol+tree.symbol.locationString+" not in "+alts+" of "+qual.tpe+
"\n members = "+qual.tpe.members+
"\n type history = "+qual.tpe.symbol.infosString+
"\n phase = "+phase)
}
tree.symbol
} else qual.tpe match {
case ThisType(clazz) if (clazz == context.enclClass.owner) =>
qual.tpe.member(name)
case _ =>
qual.tpe.nonLocalMember(name)
}
if (sym == NoSymbol) {
val qual1 = adaptToName(qual, name)
if (qual1 ne qual) return typed(copy.Select(tree, qual1, name), mode, pt)
}
if (sym.info == NoType) {
if (settings.debug.value) System.err.println("qual = "+qual+":"+qual.tpe+"\nSymbol="+qual.tpe.symbol+"\nsymbol-info = "+qual.tpe.symbol.info+"\nscope-id = "+qual.tpe.symbol.info.decls.hashCode()+"\nmembers = "+qual.tpe.members+"\nfound = "+sym)
if (!qual.tpe.widen.isError)
if (context.unit == null) assert(false, "("+qual+":"+qual.tpe+")."+name)
error(tree.pos,
decode(name)+" is not a member of "+qual.tpe.widen +
(if (Position.line(context.unit.source, qual.pos) <
Position.line(context.unit.source, tree.pos))
"\npossible cause: maybe a semicolon is missing before `"+name+"'?" else ""))
setError(tree)
} else {
val tree1 = tree match {
case Select(_, _) => copy.Select(tree, qual, name)
case SelectFromTypeTree(_, _) => copy.SelectFromTypeTree(tree, qual, name)
}
stabilize(checkAccessible(tree1, sym, qual.tpe, qual), qual.tpe, mode, pt)
}
}
/** Attribute an identifier consisting of a simple name or an outer reference.
* @param tree The tree representing the identifier.
* @param name The name of the identifier.
* Transformations: (1) Prefix class members with this.
* (2) Change imported symbols to selections
*/
def typedIdent(name: Name): Tree = {
def ambiguousError(msg: String) =
error(tree.pos, "reference to "+name+" is ambiguous;\n"+msg)
var defSym: Symbol = tree.symbol; // the directly found symbol
var pre: Type = NoPrefix; // the prefix type of defSym, if a class member
var qual: Tree = EmptyTree; // the qualififier tree if transformed tree is a select
if (defSym == NoSymbol) {
var defEntry: ScopeEntry = null; // the scope entry of defSym, if defined in a local scope
var cx = context
while (defSym == NoSymbol && cx != NoContext) {
//if (phase.name == "uncurry") System.out.println("typing " + name + " " + cx.owner + " " + (if (cx.enclClass == null) "null" else cx.enclClass.owner));//DEBUG
pre = cx.enclClass.prefix
defEntry = cx.scope.lookupEntry(name)
if (defEntry != null && defEntry.sym.tpe != NoType) {
defSym = defEntry.sym
} else {
cx = cx.enclClass
defSym = pre.member(name) filter (
sym => sym.tpe != NoType && context.isAccessible(sym, pre, false))
if (defSym == NoSymbol) cx = cx.outer
}
}
val symDepth = if (defEntry == null) cx.depth
else cx.depth - (cx.scope.nestingLevel - defEntry.owner.nestingLevel)
var impSym: Symbol = NoSymbol; // the imported symbol
var imports = context.imports; // impSym != NoSymbol => it is imported from imports.head
while (impSym == NoSymbol && !imports.isEmpty && imports.head.depth > symDepth) {
impSym = imports.head.importedSymbol(name)
if (impSym == NoSymbol) imports = imports.tail
}
// detect ambiguous definition/import,
// update `defSym' to be the final resolved symbol,
// update `pre' to be `sym's prefix type in case it is an imported member,
// and compute value of:
// imported symbols take precedence over package-owned symbols in different
// compilation units
if (defSym.tpe != NoType && impSym.tpe != NoType &&
defSym.owner.isPackageClass &&
(!currentRun.compiles(defSym) ||
context.unit != null && defSym.sourceFile != context.unit.source.file))
defSym = NoSymbol
if (defSym.tpe != NoType) {
if (impSym.tpe != NoType)
ambiguousError(
"it is both defined in "+defSym.owner +
" and imported subsequently by \n"+imports.head)
else if (!defSym.owner.isClass || defSym.owner.isPackageClass || defSym.isTypeParameterOrSkolem)
pre = NoPrefix
else
qual = atPos(tree.pos)(gen.mkQualifier(pre))
} else {
if (impSym.tpe != NoType) {
var impSym1 = NoSymbol
var imports1 = imports.tail
def ambiguousImport() = {
if (!(imports.head.qual.tpe =:= imports1.head.qual.tpe))
ambiguousError(
"it is imported twice in the same scope by\n"+imports.head + "\nand "+imports1.head)
}
while (!imports1.isEmpty &&
(!imports.head.isExplicitImport(name) ||
imports1.head.depth == imports.head.depth)) {
var impSym1 = imports1.head.importedSymbol(name)
if (impSym1 != NoSymbol) {
if (imports1.head.isExplicitImport(name)) {
if (imports.head.isExplicitImport(name) ||
imports1.head.depth != imports.head.depth) ambiguousImport()
impSym = impSym1;
imports = imports1
} else if (!imports.head.isExplicitImport(name) &&
imports1.head.depth == imports.head.depth) ambiguousImport()
}
imports1 = imports1.tail
}
defSym = impSym
qual = imports.head.qual
pre = qual.tpe
} else {
if (settings.debug.value) {
log(context.imports);//debug
}
error(tree.pos, "not found: "+decode(name))
defSym = context.owner.newErrorSymbol(name)
}
}
}
if (defSym.owner.isPackageClass) pre = defSym.owner.thisType
val tree1 = if (qual == EmptyTree) tree
else atPos(tree.pos)(Select(qual, name));
// atPos necessary because qualifier might come from startContext
stabilize(checkAccessible(tree1, defSym, pre, qual), pre, mode, pt)
}
// begin typed1
val sym: Symbol = tree.symbol
if (sym != null) sym.initialize
//if (settings.debug.value && tree.isDef) log("typing definition of "+sym);//DEBUG
tree match {
case PackageDef(name, stats) =>
val stats1 = newTyper(context.make(tree, sym.moduleClass, sym.info.decls))
.typedStats(stats, NoSymbol)
copy.PackageDef(tree, name, stats1) setType NoType
case cdef @ ClassDef(_, _, _, _, _) =>
newTyper(context.makeNewScope(tree, sym)).typedClassDef(cdef)
case mdef @ ModuleDef(_, _, _) =>
newTyper(context.make(tree, sym.moduleClass)).typedModuleDef(mdef)
case vdef @ ValDef(_, _, _, _) =>
typedValDef(vdef)
case ddef @ DefDef(_, _, _, _, _, _) =>
newTyper(context.makeNewScope(tree, sym)).typedDefDef(ddef)
case tdef @ AbsTypeDef(_, _, _, _) =>
newTyper(context.makeNewScope(tree, sym)).typedAbsTypeDef(tdef)
case tdef @ AliasTypeDef(_, _, _, _) =>
newTyper(context.makeNewScope(tree, sym)).typedAliasTypeDef(tdef)
case ldef @ LabelDef(_, _, _) =>
var lsym = ldef.symbol
var typer1 = this
if (lsym == NoSymbol) { // labeldef is part of template
typer1 = newTyper(context.makeNewScope(tree, context.owner))
typer1.enterLabelDef(ldef)
}
typer1.typedLabelDef(ldef)
case Attributed(attr, defn) =>
val attr1 = typed(attr, AttributeClass.tpe)
val attrInfo = attr1 match {
case Apply(Select(New(tpt), nme.CONSTRUCTOR), args) =>
Pair(tpt.tpe, args map {
case Literal(value) =>
value
case arg =>
error(arg.pos, "attribute argument needs to be a constant; found: "+arg)
null
})
}
if (attrInfo != null) {
val attributed =
if (defn.symbol.isModule) defn.symbol.moduleClass else defn.symbol;
attributed.attributes = attributed.attributes ::: List(attrInfo)
}
typed(defn, mode, pt)
case DocDef(comment, defn) => {
val ret = typed(defn, mode, pt)
if (onlyPresentation) comments(defn . symbol) = comment;
ret
}
case block @ Block(_, _) =>
newTyper(context.makeNewScope(tree, context.owner))
.typedBlock(block, mode, pt)
case Sequence(elems) =>
val elems1 = List.mapConserve(elems)(elem => typed(elem, mode, pt))
copy.Sequence(tree, elems1) setType pt
case Alternative(alts) =>
val alts1 = List.mapConserve(alts)(alt => typed(alt, mode, pt))
copy.Alternative(tree, alts1) setType pt
case Star(elem) =>
val elem1 = typed(elem, mode, pt)
copy.Star(tree, elem1) setType pt
case Bind(name, body) =>
var vble = tree.symbol
if (vble == NoSymbol) vble = context.owner.newValue(tree.pos, name)
if (vble.name != nme.WILDCARD) namer.enterInScope(vble)
val body1 = typed(body, mode, pt)
vble.setInfo(if (treeInfo.isSequenceValued(body)) seqType(body1.tpe) else body1.tpe)
copy.Bind(tree, name, body1) setSymbol vble setType body1.tpe; // buraq, was: pt
case ArrayValue(elemtpt, elems) =>
val elemtpt1 = typedType(elemtpt)
val elems1 = List.mapConserve(elems)(elem => typed(elem, mode, elemtpt1.tpe))
copy.ArrayValue(tree, elemtpt1, elems1)
.setType(if (isFullyDefined(pt) && !phase.erasedTypes) pt
else appliedType(ArrayClass.typeConstructor, List(elemtpt1.tpe)))
case fun @ Function(_, _) =>
/*
newTyper(context.makeNewScope(tree, context.owner)).typedFunction(fun, mode, pt)
*/
tree.symbol = context.owner.newValue(tree.pos, nme.ANON_FUN_NAME)
.setFlag(SYNTHETIC).setInfo(NoType)
newTyper(context.makeNewScope(tree, tree.symbol)).typedFunction(fun, mode, pt)
case Assign(lhs, rhs) =>
def isGetter(sym: Symbol) = sym.info match {
case PolyType(List(), _) => sym.owner.isClass && !sym.isStable
case _: ImplicitMethodType => sym.owner.isClass && !sym.isStable
case _ => false
}
val lhs1 = typed(lhs, EXPRmode | LHSmode, WildcardType)
val varsym = lhs1.symbol
if (varsym != null && isGetter(varsym)) {
lhs1 match {
case Select(qual, name) =>
typed(
Apply(
Select(qual, nme.getterToSetter(name)) setPos lhs.pos,
List(rhs)) setPos tree.pos, mode, pt)
}
} else if (varsym != null && (varsym.isVariable || varsym.isValue && phase.erasedTypes)) {
val rhs1 = typed(rhs, lhs1.tpe)
copy.Assign(tree, lhs1, rhs1) setType UnitClass.tpe
} else {
if (!lhs1.tpe.isError) error(tree.pos, "assignment to non-variable ")
setError(tree)
}
case If(cond, thenp, elsep) =>
val cond1 = typed(cond, BooleanClass.tpe)
if (elsep.isEmpty) {
val thenp1 = typed(thenp, UnitClass.tpe)
copy.If(tree, cond1, thenp1, elsep) setType UnitClass.tpe
} else {
val thenp1 = typed(thenp, pt)
val elsep1 = typed(elsep, pt)
copy.If(tree, cond1, thenp1, elsep1) setType ptOrLub(List(thenp1.tpe, elsep1.tpe))
}
case Match(selector, cases) =>
val selector1 = typed(selector)
val cases1 = typedCases(tree, cases, selector1.tpe.widen, pt)
copy.Match(tree, selector1, cases1) setType ptOrLub(cases1 map (.tpe))
case Return(expr) =>
val enclFun = if (tree.symbol != NoSymbol) tree.symbol else context.owner.enclMethod
if (!enclFun.isMethod || enclFun.isConstructor)
errorTree(tree, "return outside method definition")
else if (!context.owner.isInitialized)
errorTree(tree, "method "+context.owner+" has return statement; needs result type")
else {
val expr1: Tree = typed(expr, enclFun.tpe.finalResultType)
copy.Return(tree, expr1) setSymbol enclFun setType AllClass.tpe
}
case Try(block, catches, finalizer) =>
val block1 = typed(block, pt)
val catches1 = typedCases(tree, catches, ThrowableClass.tpe, pt)
val finalizer1 = if (finalizer.isEmpty) finalizer
else typed(finalizer, UnitClass.tpe)
copy.Try(tree, block1, catches1, finalizer1)
.setType(ptOrLub(block1.tpe :: (catches1 map (.tpe))))
case Throw(expr) =>
val expr1 = typed(expr, ThrowableClass.tpe)
copy.Throw(tree, expr1) setType AllClass.tpe
case New(tpt: Tree) =>
var tpt1 = typedTypeConstructor(tpt)
if (tpt1.hasSymbol && !tpt1.symbol.typeParams.isEmpty) {
context.undetparams = cloneSymbols(tpt1.symbol.typeParams)
tpt1 = TypeTree()
.setOriginal(tpt1) /* .setPos(tpt1.pos) */
.setType(appliedType(tpt1.tpe, context.undetparams map (.tpe)))
}
if (tpt1.tpe.symbol hasFlag ABSTRACT)
error(tree.pos, ""+tpt1.tpe.symbol+" is abstract; cannot be instantiated")
copy.New(tree, tpt1).setType(tpt1.tpe)
case Typed(expr, Function(List(), EmptyTree)) =>
val expr1 = typed1(expr, mode, pt);
expr1.tpe match {
case MethodType(formals, _) =>
adapt(expr1, mode, functionType(formals map (t => WildcardType), WildcardType))
case ErrorType =>
expr1
case _ =>
errorTree(expr1, "`&' must be applied to method type; cannot be applied to " + expr1.tpe)
}
case Typed(expr, tpt @ Ident(name)) if (name == nme.WILDCARD_STAR.toTypeName) =>
val expr1 = typed(expr, mode & stickyModes, seqType(pt))
expr1.tpe.baseType(SeqClass) match {
case TypeRef(_, _, List(elemtp)) =>
copy.Typed(tree, expr1, tpt setType elemtp) setType elemtp
case _ =>
setError(tree)
}
case Typed(expr, tpt) =>
val tpt1 = typedType(tpt)
val expr1 = typed(expr, mode & stickyModes, tpt1.tpe)
copy.Typed(tree, expr1, tpt1) setType tpt1.tpe
case TypeApply(fun, args) =>
val args1 = List.mapConserve(args)(typedType)
// do args first in order to maintain conext.undetparams on the function side.
typedTypeApply(typed(fun, funmode | TAPPmode, WildcardType), args1)
case Apply(Block(stats, expr), args) =>
typed1(Block(stats, Apply(expr, args)), mode, pt)
case Apply(fun, args) =>
val stableApplication = fun.symbol != null && fun.symbol.isMethod && fun.symbol.isStable
if (stableApplication && (mode & PATTERNmode) != 0) {
// treat stable function applications f() as expressions.
typed1(tree, mode & ~PATTERNmode | EXPRmode, pt)
} else {
val funpt = if ((mode & PATTERNmode) != 0) pt else WildcardType
var fun1 = typed(fun, funmode, funpt)
if (stableApplication) fun1 = stabilizeFun(fun1, mode, pt)
// if function is overloaded, filter all alternatives that match
// number of arguments and expected result type.
if (settings.debug.value) log("trans app "+fun1+":"+fun1.symbol+":"+fun1.tpe+" "+args);//DEBUG
if (util.Statistics.enabled) appcnt = appcnt + 1
if (xviews &&
fun1.isInstanceOf[Select] &&
!fun1.tpe.isInstanceOf[ImplicitMethodType] &&
(mode & (EXPRmode | SNDTRYmode)) == EXPRmode) tryTypedApply(fun1, args)
else typedApply(fun1, args)
}
case Super(qual, mix) =>
val Pair(clazz, selftype) =
if (tree.symbol != NoSymbol) {
Pair(tree.symbol, tree.symbol.thisType)
} else {
val clazzContext = qualifyingClassContext(tree, qual)
Pair(clazzContext.owner, clazzContext.prefix)
}
if (clazz == NoSymbol) setError(tree)
else {
val owntype =
if (mix.isEmpty)
if ((mode & SUPERCONSTRmode) != 0) clazz.info.parents.head
else intersectionType(clazz.info.parents)
else {
val ps = clazz.info.parents dropWhile (p => p.symbol.name != mix)
if (ps.isEmpty) {
if (settings.debug.value) System.out.println(clazz.info.parents map (.symbol.name));//debug
error(tree.pos, ""+mix+" does not name a base class of "+clazz)
ErrorType
} else ps.head
}
tree setSymbol clazz setType SuperType(selftype, owntype)
}
case This(qual) =>
val Pair(clazz, selftype) =
if (tree.symbol != NoSymbol) {
Pair(tree.symbol, tree.symbol.thisType)
} else {
val clazzContext = qualifyingClassContext(tree, qual)
Pair(clazzContext.owner, clazzContext.prefix)
}
if (clazz == NoSymbol) setError(tree)
else {
val owntype = if (pt.isStable || (mode & QUALmode) != 0) selftype
else selftype.singleDeref
tree setSymbol clazz setType owntype
}
case Select(qual @ Super(_, _), nme.CONSTRUCTOR) =>
val qual1 = typed(qual, EXPRmode | QUALmode | POLYmode | SUPERCONSTRmode, WildcardType)
// the qualifier type of a supercall constructor is its first parent class
typedSelect(qual1, nme.CONSTRUCTOR)
case Select(qual, name) =>
if (util.Statistics.enabled) selcnt = selcnt + 1
var qual1 = typedQualifier(qual)
if (name.isTypeName) qual1 = checkStable(qual1)
typedSelect(qual1, name)
case Ident(name) =>
idcnt = idcnt + 1
if (name == nme.WILDCARD && (mode & (PATTERNmode | FUNmode)) == PATTERNmode)
tree setType pt
else
typedIdent(name)
// todo: try with case Literal(Constant(()))
case Literal(value) =>
tree setType (
if (value.tag == UnitTag) UnitClass.tpe
else ConstantType(value))
case SingletonTypeTree(ref) =>
val ref1 = checkStable(typed(ref, EXPRmode | QUALmode, AnyRefClass.tpe))
tree setType ref1.tpe.resultType
case SelectFromTypeTree(qual, selector) =>
tree setType typedSelect(typedType(qual), selector).tpe
case CompoundTypeTree(templ: Template) =>
tree setType {
val parents1 = List.mapConserve(templ.parents)(typedType)
if (parents1 exists (.tpe.isError)) ErrorType
else {
val decls = new Scope()
val self = refinedType(parents1 map (.tpe), context.enclClass.owner, decls)
newTyper(context.make(templ, self.symbol, decls)).typedRefinement(templ.body)
self
}
}
case AppliedTypeTree(tpt, args) =>
val tpt1 = typed1(tpt, mode | FUNmode | TAPPmode, WildcardType)
val tparams = tpt1.symbol.typeParams
val args1 = List.mapConserve(args)(typedType)
if (tpt1.tpe.isError) {
setError(tree)
} else if (tparams.length == args1.length) {
val argtypes = args1 map (.tpe)
val owntype = if (tpt1.symbol.isClass) appliedType(tpt1.tpe, argtypes)
else tpt1.tpe.subst(tparams, argtypes)
TypeTree(owntype) setOriginal(tree) // setPos tree.pos
} else if (tparams.length == 0) {
errorTree(tree, ""+tpt1.tpe+" does not take type parameters")
} else {
//System.out.println("\{tpt1}:\{tpt1.symbol}:\{tpt1.symbol.info}")
if (settings.debug.value) System.out.println(""+tpt1+":"+tpt1.symbol+":"+tpt1.symbol.info);//debug
errorTree(tree, "wrong number of type arguments for "+tpt1.tpe+", should be "+tparams.length)
}
case _ =>
throw new Error("unexpected tree: "+tree);//debug
}
}
def typed(tree: Tree, mode: int, pt: Type): Tree =
try {
if (settings.debug.value) {
assert(pt != null, tree);//debug
//System.out.println("typing "+tree);//debug
}
val tree1 = if (tree.tpe != null) tree else typed1(tree, mode, pt)
//System.out.println("typed "+tree1+":"+tree1.tpe);//debug
val result = if (tree1.isEmpty) tree1 else adapt(tree1, mode, pt)
//System.out.println("adapted "+tree1+":"+tree1.tpe+" to "+pt);//debug
result
} catch {
case ex: TypeError =>
//System.out.println("caught "+ex+" in typed");//DEBUG
reportTypeError(tree.pos, ex)
setError(tree)
case ex: Throwable =>
if (settings.debug.value)
System.out.println("exception when typing "+tree+", pt = "+pt)
if (context != null && context.unit != null && context.unit.source != null && tree != null)
logError("AT: " + context.unit.source.dbg(tree.pos), ex);
throw(ex)
}
def atOwner(owner: Symbol): Typer =
new Typer(context.make(context.tree, owner))
def atOwner(tree: Tree, owner: Symbol): Typer =
new Typer(context.make(tree, owner))
/** Types expression or definition `tree' */
def typed(tree: Tree): Tree =
typed(tree, EXPRmode, WildcardType)
/** Types expression `tree' with given prototype `pt' */
def typed(tree: Tree, pt: Type): Tree =
typed(tree, EXPRmode, pt)
/** Types qualifier `tree' of a select node. E.g. is tree occurs in acontext like `tree.m'. */
def typedQualifier(tree: Tree): Tree =
typed(tree, EXPRmode | QUALmode | POLYmode, WildcardType)
/** Types function part of an application */
def typedOperator(tree: Tree): Tree =
typed(tree, EXPRmode | FUNmode | POLYmode | TAPPmode, WildcardType)
/** Types a pattern with prototype `pt' */
def typedPattern(tree: Tree, pt: Type): Tree =
typed(tree, PATTERNmode, pt)
/** Types a (fully parameterized) type tree */
def typedType(tree: Tree): Tree =
typed(tree, TYPEmode, WildcardType)
/** Types a type constructor tree used in a new or supertype */
def typedTypeConstructor(tree: Tree): Tree = {
val result = typed(tree, TYPEmode | FUNmode, WildcardType)
if (!phase.erasedTypes && result.tpe.isInstanceOf[TypeRef] && !result.tpe.prefix.isStable)
error(tree.pos, ""+result.tpe.prefix+" is not a legal prefix for a constructor")
result
}
def computeType(tree: Tree): Type = {
val tree1 = typed(tree)
transformed(tree) = tree1
tree1.tpe
}
def transformedOrTyped(tree: Tree, pt: Type): Tree = transformed.get(tree) match {
case Some(tree1) => transformed -= tree; tree1
case None => typed(tree, pt)
}
/*
def convertToTypeTree(tree: Tree): Tree = tree match {
case TypeTree() => tree
case _ => TypeTree(tree.tpe)
}
*/
/* -- Views --------------------------------------------------------------- */
private def depoly(tp: Type): Type = tp match {
case PolyType(tparams, restpe) => restpe.subst(tparams, tparams map (t => WildcardType))
case _ => tp
}
private def containsError(tp: Type): boolean = tp match {
case PolyType(tparams, restpe) => containsError(restpe)
case MethodType(formals, restpe) => (formals exists (.isError)) || containsError(restpe)
case _ => tp.isError
}
/** Try to construct a typed tree from given implicit info with given expected type
* @param pos Position for error reporting
* @param info The given implicit info describing the implicit definition
* @param pt The expected type
* @param isLocal Is implicit definition visible without prefix?
* @returns A typed tree if the implicit info can be made to conform to `pt', EmptyTree otherwise.
* @pre info.tpe does not contain an error
*/
private def typedImplicit(pos: int, info: ImplicitInfo, pt: Type, isLocal: boolean): Tree =
if (isCompatible(depoly(info.tpe), pt)) {
val tree = Ident(info.name) setPos pos
def fail(reason: String, sym1: Symbol, sym2: Symbol): Tree = {
if (settings.debug.value)
log(""+tree+" is not a valid implicit value because:\n"+reason + sym1+" "+sym2);
EmptyTree
}
try {
if (!isLocal) tree setSymbol info.sym
val tree1 = typed1(tree, EXPRmode, pt)
if (settings.debug.value) log("typed implicit "+tree1+":"+tree1.tpe+", pt = "+pt);
val tree2 = adapt(tree1, EXPRmode, pt)
if (settings.debug.value) log("adapted implicit "+tree1.symbol+":"+tree2.tpe+" to "+pt);
if (!tree2.tpe.isError && info.sym == tree1.symbol) tree2
else fail("syms differ: ", tree1.symbol, info.sym)
} catch {
case ex: TypeError => fail(ex.getMessage(), NoSymbol, NoSymbol)
}
} else EmptyTree
/** Infer implicit argument or view
* @param pos position for error reporting
* @param pt the expected type of the implicit
* @param isView are we searching for a view? (this affects the error message)
* @param reportAmbiguous should ambiguous errors be reported? False iff we search for a view
* to find out whether one type is coercible to another (@see isCoercible)
*/
private def inferImplicit(pos: int, pt: Type, isView: boolean, reportAmbiguous: boolean): Tree = {
if (util.Statistics.enabled) implcnt = implcnt + 1
val startTime = if (util.Statistics.enabled) System.currentTimeMillis() else 0l
val tc = newTyper(context.makeImplicit(reportAmbiguous))
def ambiguousError(info1: ImplicitInfo, info2: ImplicitInfo) =
error(
pos,
"ambiguous implicit value:\n" +
" both "+info1.sym + info1.sym.locationString+" of type "+info1.tpe+
"\n and "+info2.sym + info2.sym.locationString+" of type "+info2.tpe+
(if (isView) "\n are possible conversion functions from "+ pt.typeArgs(0)+" to "+pt.typeArgs(1)
else "\n match expected type "+pt))
/** Search list of implicit info lists for one matching prototype `pt'
* If found return a tree from found implicit info which is typed with expected type `pt'.
* Otherwise return EmptyTree
* @param implicitInfoss The given list of lists of implicit infos
* @isLocal Is implicit definition visible without prefix?
* If this is the case then symbols in preceding lists shadow
* symbols of the same name in succeeding lists.
*/
def searchImplicit(implicitInfoss: List[List[ImplicitInfo]], isLocal: boolean): Tree = {
def isSubClassOrObject(sym1: Symbol, sym2: Symbol) = {
(sym1 isSubClass sym2) ||
sym1.isModuleClass && sym2.isModuleClass &&
(sym1.sourceModule.linkedClass isSubClass sym2.sourceModule.linkedClass)
}
def improves(info1: ImplicitInfo, info2: ImplicitInfo) =
(info2 == NoImplicitInfo) ||
(info1 != NoImplicitInfo) &&
isSubClassOrObject(info1.sym.owner, info2.sym.owner) &&
isStrictlyBetter(info1.tpe, info2.tpe)
val shadowed = new HashSet[Name](8)
def isApplicable(info: ImplicitInfo): boolean =
!containsError(info.tpe) &&
!(isLocal && shadowed.contains(info.name)) &&
tc.typedImplicit(pos, info, pt, isLocal) != EmptyTree
def applicableInfos(is: List[ImplicitInfo]) = {
val result = is filter isApplicable
if (isLocal)
for (val i <- is) shadowed addEntry i.name
result
}
val applicable = List.flatten(implicitInfoss map applicableInfos)
val best = (NoImplicitInfo /: applicable) ((best, alt) => if (improves(alt, best)) alt else best)
val competing = applicable dropWhile (alt => best == alt || improves(best, alt))
if (best == NoImplicitInfo) EmptyTree
else {
if (!competing.isEmpty) ambiguousError(best, competing.head)
tc.typedImplicit(pos, best, pt, isLocal)
}
}
def implicitsOfType(tp: Type): List[List[ImplicitInfo]] = {
val tp1 = if (isFunctionType(tp)) intersectionType(tp.typeArgs.reverse) else tp
tp1.baseClasses map implicitsOfClass
}
def implicitsOfClass(clazz: Symbol): List[ImplicitInfo] = (
clazz.initialize.linkedModule.moduleClass.info.members.toList.filter(.hasFlag(IMPLICIT)) map
(sym => new ImplicitInfo(sym.name, clazz.linkedModule.tpe, sym))
)
var tree = searchImplicit(context.implicitss, true)
if (tree == EmptyTree) tree = searchImplicit(implicitsOfType(pt.widen), false)
if (util.Statistics.enabled) impltime = impltime + System.currentTimeMillis() - startTime
tree
}
def applyImplicitArgs(tree: Tree): Tree = tree.tpe match {
case MethodType(formals, _) =>
def implicitArg(pt: Type) = {
val arg = inferImplicit(tree.pos, pt, false, true)
if (arg != EmptyTree) arg
else errorTree(tree, "no implicit argument matching parameter type "+pt+" was found.")
}
Apply(tree, formals map implicitArg) setPos tree.pos
case ErrorType =>
tree
}
}
}