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/* NSC -- new scala compiler
* Copyright 2005 LAMP/EPFL
* @author Martin Odersky
*/
// $Id$
package scala.tools.nsc.typechecker;
import scala.tools.util.Position;
import symtab.Flags._;
/** Methods to create symbols and to enter them into scopes. */
trait Namers: Analyzer {
import global._;
class NamerPhase(prev: Phase) extends StdPhase(prev) {
def name = "namer";
val global: Namers.this.global.type = Namers.this.global;
def apply(unit: CompilationUnit): unit =
new Namer(startContext.make(unit)).enterSyms(unit.body);
}
class Namer(context: Context) {
val typer = new Typer(context);
private def doubleDefError(pos: int, sym: Symbol): unit =
context.unit.error(pos,
sym.name.toString() + " is already defined as " +
(if ((sym.rawflags & CASE) != 0) "case class " + sym.name else sym.toString()));
private def updatePosFlags(sym: Symbol, pos: int, mods: int): Symbol = {
val sym1 = if (sym.isExternal && !sym.isPackage) sym
else { doubleDefError(pos, sym); sym.cloneSymbol }
sym1.pos = pos;
val oldflags = sym1.rawflags & (INITIALIZED | LOCKED);
val newflags = mods & ~(INITIALIZED | LOCKED);
sym1.rawflags = oldflags | newflags;
if (sym1.isModule)
updatePosFlags(sym1.moduleClass, pos, (mods & MODULE2CLASSFLAGS) | MODULE | FINAL);
sym1
}
private def enterInScope(pos: int, sym: Symbol): Symbol = {
if (!(sym.isMethod && sym.owner.isClass)) {
val prev = context.scope.lookupEntry(sym.name);
if (prev != null && prev.owner == context.scope && !prev.sym.isMethod)
doubleDefError(pos, prev.sym);
}
context.scope enter sym;
sym
}
private def enterPackageSymbol(pos: int, name: Name): Symbol = {
val p: Symbol = context.scope.lookup(name);
if (p.isPackage && context.scope == p.owner.info.decls) {
p.pos = pos; p.moduleClass.pos = pos; p
} else {
enterInScope(pos, context.owner.newPackage(pos, name))
}
}
private def enterClassSymbol(pos: int, mods: int, name: Name): Symbol = {
val c: Symbol = context.scope.lookup(name);
if (c.isType && context.scope == c.owner.info.decls) {
updatePosFlags(c, pos, mods)
} else {
enterInScope(pos, context.owner.newClass(pos, name).setFlag(mods))
}
}
private def enterModuleSymbol(pos: int, mods: int, name: Name): Symbol = {
val m: Symbol = context.scope.lookup(name);
if (m.isModule && context.scope == m.owner.info.decls) {
updatePosFlags(m, pos, mods)
} else {
val newm = context.owner.newModule(pos, name);
newm.setFlag(mods);
newm.moduleClass.setFlag(mods);
enterInScope(pos, newm)
}
}
private def enterCaseFactorySymbol(pos: int, mods: int, name: Name): Symbol = {
val m: Symbol = context.scope.lookup(name);
if (m.isModule && context.scope == m.owner.info.decls) {
updatePosFlags(m, pos, mods)
} else {
enterInScope(pos, context.owner.newMethod(pos, name).setFlag(mods))
}
}
def enterSyms(trees: List[Tree]): unit =
for (val tree <- trees) enterSym(tree);
def enterSym(tree: Tree): Symbol = {
def finishWith(tparams: List[AbsTypeDef]) = {
val ltype = typer.typeCompleter(tree);
def makeParam(tparam: AbsTypeDef): Symbol =
tree.symbol.newTypeParameter(tparam.pos, tparam.name);
tree.symbol.setInfo(
if (tparams.isEmpty) ltype
else new LazyPolyType(tparams map makeParam, ltype))
}
def finish = finishWith(List());
if (tree.symbol != null) tree.symbol
else {
val owner = context.owner;
tree match {
case PackageDef(name, stats) =>
tree.symbol = enterPackageSymbol(tree.pos, name);
val namer = new Namer(
context.make(tree, tree.symbol.moduleClass, tree.symbol.info.decls));
stats map namer.enterSym;
tree.symbol
case ClassDef(mods, name, tparams, _, _) =>
if ((mods & (CASE | ABSTRACT)) == CASE) { // enter case factory method.
tree.symbol = enterCaseFactorySymbol(
tree.pos, mods & ACCESSFLAGS | CASE, name.toTermName);
finishWith(tparams);
}
tree.symbol = enterClassSymbol(tree.pos, mods, name);
val constr = tree.symbol.newConstructor(tree.pos)
.setFlag(tree.symbol.rawflags & CONSTRFLAGS)
.setInfo(typer.typeCompleter(tree));
tree.symbol.info.decls enter constr;
finishWith(tparams)
case ModuleDef(mods, name, _, _) =>
tree.symbol = enterModuleSymbol(tree.pos, mods, name);
tree.symbol.moduleClass.setInfo(typer.typeCompleter(tree));
finish
case ValDef(mods, name, tp, rhs) =>
tree.symbol = enterInScope(tree.pos, owner.newValue(tree.pos, name).setFlag(mods));
finish
case DefDef(mods, nme.CONSTRUCTOR, tparams, vparams, tp, rhs) =>
if (!(owner.isClass && context.scope == owner.info.decls) ||
owner.isModuleClass || owner.isAnonymousClass || owner.isRefinementClass)
context.unit.error(tree.pos, "constructor definition not allowed here");
tree.symbol = enterInScope(tree.pos, owner.newConstructor(tree.pos))
.setFlag(mods | owner.rawflags & CONSTRFLAGS);
finishWith(tparams)
case DefDef(mods, name, tparams, _, _, _) =>
tree.symbol = enterInScope(tree.pos, owner.newMethod(tree.pos, name)).setFlag(mods);
finishWith(tparams)
case AbsTypeDef(mods, name, _, _) =>
tree.symbol = enterInScope(tree.pos, owner.newAbstractType(tree.pos, name));
finish
case AliasTypeDef(mods, name, tparams, _) =>
tree.symbol = enterInScope(tree.pos, owner.newAliasType(tree.pos, name));
finishWith(tparams)
case Attributed(_, defn) =>
enterSym(defn)
case DocDef(_, defn) =>
enterSym(defn)
case Import(expr, selectors) =>
tree.symbol = NoSymbol.newImport(tree.pos);
finish
case _ =>
NoSymbol
}
}
}
}
}
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