Revert some of ade53a1. Use completer factory methods.

Scalameta et al need to be able to customize the
type completer behavior, so we must use factory methods
to instantiate them, rather than instantiating the classes
directly.

Author: adriaanm

src/compiler/scala/tools/nsc/typechecker/MethodSynthesis.scala

@@ -146,26 +146,26 @@ trait MethodSynthesis {
         // if there's no field symbol, the ValDef tree receives the getter symbol and thus is not a synthetic
         if (fieldSym != NoSymbol) {
           context.unit.synthetics(getterSym) = getter.derivedTree(getterSym)
-          getterSym setInfo new namer.AccessorTypeCompleter(tree, tree.tpt.isEmpty, isBean = false, isSetter = false)
-        } else getterSym setInfo new namer.ValTypeCompleter(tree)
+          getterSym setInfo namer.accessorTypeCompleter(tree, tree.tpt.isEmpty, isBean = false, isSetter = false)
+        } else getterSym setInfo namer.valTypeCompleter(tree)
 
         enterInScope(getterSym)
 
         if (getter.needsSetter) {
           val setter = Setter(tree)
           val setterSym = setter.createSym
           context.unit.synthetics(setterSym) = setter.derivedTree(setterSym)
-          setterSym setInfo new namer.AccessorTypeCompleter(tree, tree.tpt.isEmpty, isBean = false, isSetter = true)
+          setterSym setInfo namer.accessorTypeCompleter(tree, tree.tpt.isEmpty, isBean = false, isSetter = true)
           enterInScope(setterSym)
         }
 
         // TODO: delay emitting the field to the fields phase (except for private[this] vals, which only get a field and no accessors)
         if (fieldSym != NoSymbol) {
-          fieldSym setInfo new namer.ValTypeCompleter(tree)
+          fieldSym setInfo namer.valTypeCompleter(tree)
           enterInScope(fieldSym)
         }
       } else {
-        getterSym setInfo new namer.ValTypeCompleter(tree)
+        getterSym setInfo namer.valTypeCompleter(tree)
         enterInScope(getterSym)
       }
 
@@ -208,11 +208,11 @@ trait MethodSynthesis {
           sym
         }
 
-        val getterCompleter = new namer.AccessorTypeCompleter(tree, missingTpt, isBean = true, isSetter = false)
+        val getterCompleter = namer.accessorTypeCompleter(tree, missingTpt, isBean = true, isSetter = false)
         enterInScope(deriveBeanAccessor(if (hasBeanProperty) "get" else "is") setInfo getterCompleter)
 
         if (tree.mods.isMutable) {
-          val setterCompleter = new namer.AccessorTypeCompleter(tree, missingTpt, isBean = true, isSetter = true)
+          val setterCompleter = namer.accessorTypeCompleter(tree, missingTpt, isBean = true, isSetter = true)
           enterInScope(deriveBeanAccessor("set") setInfo setterCompleter)
         }
       }

src/compiler/scala/tools/nsc/typechecker/Namers.scala

@@ -105,7 +105,7 @@ trait Namers extends MethodSynthesis {
 
     def enterValueParams(vparamss: List[List[ValDef]]): List[List[Symbol]] =
       mmap(vparamss) { param =>
-        enterInScope(assignMemberSymbol(param, mask = ValueParameterFlags)) setInfo new MonoTypeCompleter(param)
+        enterInScope(assignMemberSymbol(param, mask = ValueParameterFlags)) setInfo monoTypeCompleter(param)
       }
 
     protected def owner       = context.owner
@@ -337,10 +337,8 @@ trait Namers extends MethodSynthesis {
       }
     }
 
-    def createImportSymbol(tree: Import) = {
-      val importNamer = namerOf(tree.symbol)
-      NoSymbol.newImport(tree.pos) setInfo new importNamer.ImportTypeCompleter(tree)
-    }
+    def createImportSymbol(tree: Import) =
+      NoSymbol.newImport(tree.pos) setInfo (namerOf(tree.symbol) importTypeCompleter tree)
 
     /** All PackageClassInfoTypes come from here. */
     def createPackageSymbol(pos: Position, pid: RefTree): Symbol = {
@@ -430,8 +428,7 @@ trait Namers extends MethodSynthesis {
 
     def enterModuleDef(tree: ModuleDef) = {
       val sym = enterModuleSymbol(tree)
-      val mcsNamer = namerOf(sym)
-      sym.moduleClass setInfo new mcsNamer.ModuleClassTypeCompleter(tree)
+      sym.moduleClass setInfo namerOf(sym).moduleClassTypeCompleter(tree)
       sym setInfo completerOf(tree)
       validateCompanionDefs(tree)
       sym
@@ -684,8 +681,7 @@ trait Namers extends MethodSynthesis {
       }
 
     def completerOf(tree: MemberDef): TypeCompleter = {
-      val treeNamer = namerOf(tree.symbol)
-      val mono = new treeNamer.MonoTypeCompleter(tree)
+      val mono = namerOf(tree.symbol) monoTypeCompleter tree
       val tparams = treeInfo.typeParameters(tree)
       if (tparams.isEmpty) mono
       else {
@@ -1081,7 +1077,7 @@ trait Namers extends MethodSynthesis {
 
       val sym = (
         if (hasType || hasName) {
-          owner.typeOfThis = if (hasType) new SelfTypeCompleter(tpt) else owner.tpe_*
+          owner.typeOfThis = if (hasType) selfTypeCompleter(tpt) else owner.tpe_*
           val selfSym = owner.thisSym setPos self.pos
           if (hasName) selfSym setName name else selfSym
         }
@@ -1175,7 +1171,7 @@ trait Namers extends MethodSynthesis {
       val res = GenPolyType(tparams0, resultType)
       val pluginsTp = pluginsTypeSig(res, typer, cdef, WildcardType)
 
-      // Already assign the type to the class symbol (MonoTypeCompleter will do it again).
+      // Already assign the type to the class symbol (monoTypeCompleter will do it again).
       // Allows isDerivedValueClass to look at the info.
       clazz setInfo pluginsTp
       if (clazz.isDerivedValueClass) {
@@ -1189,7 +1185,7 @@ trait Namers extends MethodSynthesis {
 
     private def moduleSig(mdef: ModuleDef): Type = {
       val moduleSym = mdef.symbol
-      // The info of both the module and the moduleClass symbols need to be assigned. MonoTypeCompleter assigns
+      // The info of both the module and the moduleClass symbols need to be assigned. monoTypeCompleter assigns
       // the result of typeSig to the module symbol. The module class info is assigned here as a side-effect.
       val result = templateSig(mdef.impl)
       val pluginsTp = pluginsTypeSig(result, typer, mdef, WildcardType)
@@ -1589,7 +1585,7 @@ trait Namers extends MethodSynthesis {
                 // (a val's name ends in a " ", so can't compare to def)
                 val overridingSym = if (isGetter) vdef.symbol else vdef.symbol.getterIn(valOwner)
 
-                // We're called from an AccessorTypeCompleter, which is completing the info for the accessor's symbol,
+                // We're called from an accessorTypeCompleter, which is completing the info for the accessor's symbol,
                 // which may or may not be `vdef.symbol` (see isGetter above)
                 val overridden = safeNextOverriddenSymbol(overridingSym)
 
@@ -1732,7 +1728,7 @@ trait Namers extends MethodSynthesis {
     }
 
     /**
-     * TypeSig is invoked by MonoTypeCompleters. It returns the type of a definition which
+     * TypeSig is invoked by monoTypeCompleters. It returns the type of a definition which
      * is then assigned to the corresponding symbol (typeSig itself does not need to assign
      * the type to the symbol, but it can if necessary).
      */
@@ -1923,6 +1919,11 @@ trait Namers extends MethodSynthesis {
     }
   }
 
+  @deprecated("Instantiate TypeCompleterBase (for monomorphic, non-wrapping completer) or CompleterWrapper directly.", "2.12.2")
+  def mkTypeCompleter(t: Tree)(c: Symbol => Unit) = new TypeCompleterBase(t) {
+    def completeImpl(sym: Symbol) = c(sym)
+  }
+
   // NOTE: only meant for monomorphic definitions,
   // do not use to wrap existing completers (see CompleterWrapper for that)
   abstract class TypeCompleterBase[T <: Tree](val tree: T) extends LockingTypeCompleter with FlagAgnosticCompleter