Remove code duplication between Namer, ClassfileParser and UnPickler

Author: DarkDimius

src/dotty/tools/dotc/core/Symbols.scala

@@ -161,6 +161,15 @@ trait Symbols { this: Context =>
           owner.thisType, modcls, parents, decls, TermRef.withSymAndName(owner.thisType, module, name)),
         privateWithin, coord, assocFile)
 
+  def synthesizeCompanionMethod(name: TermName, ret: SymDenotation, owner: SymDenotation)(implicit ctx: Context) = {
+    if(owner.exists && ret.exists) ctx.newSymbol(
+      owner = owner.symbol,
+      name = name,
+      flags = Flags.Synthetic | Flags.Private,
+      info = ExprType(ret.typeRef))
+    else NoSymbol
+  }
+
   /** Create a package symbol with associated package class
    *  from its non-info fields and a lazy type for loading the package's members.
    */

src/dotty/tools/dotc/core/pickling/ClassfileParser.scala

@@ -130,19 +130,14 @@ class ClassfileParser(
     for (i <- 0 until in.nextChar) parseMember(method = true)
     classInfo = parseAttributes(classRoot.symbol, classInfo)
     if (isAnnotation) addAnnotationConstructor(classInfo)
-    if (classRoot.exists) syntecizeCompanionMethod(nme.COMPANION_CLASS_METHOD, classRoot, moduleRoot)
+    val companionClassMethod = ctx.synthesizeCompanionMethod(nme.COMPANION_CLASS_METHOD, classRoot, moduleRoot)
+    if (companionClassMethod.exists) companionClassMethod.entered
+
 
     setClassInfo(classRoot, classInfo)
     setClassInfo(moduleRoot, staticInfo)
   }
 
-  def syntecizeCompanionMethod(name: TermName, ret: SymDenotation, owner: SymDenotation)(implicit ctx: Context) = {
-    if(owner.exists) ctx.newSymbol(
-      owner = owner.symbol,
-      name = name,
-      flags = Flags.Synthetic | Flags.Private,
-      info = ExprType(ret.typeRef)).entered
-  }
 
   /** Add type parameters of enclosing classes */
   def addEnclosingTParams()(implicit ctx: Context): Unit = {

src/dotty/tools/dotc/core/pickling/UnPickler.scala

@@ -120,12 +120,9 @@ object UnPickler {
     if (!(denot.flagsUNSAFE is JavaModule)) ensureConstructor(denot.symbol.asClass, decls)
     if (denot.flagsUNSAFE is Module) {
       val scalacCompanion = denot.classSymbol.scalacLinkedClass
-      if (scalacCompanion.exists)
-      ctx.newSymbol(
-        owner = denot.classSymbol,
-        name = nme.COMPANION_CLASS_METHOD,
-        flags = Flags.Synthetic | Flags.Private,
-        info = ExprType(scalacCompanion.typeRef)).entered
+      val companionClassMethod = ctx.synthesizeCompanionMethod(nme.COMPANION_CLASS_METHOD, scalacCompanion, denot.classSymbol)
+      if (companionClassMethod.exists)
+        companionClassMethod.entered
     }
 
     denot.info = ClassInfo(denot.owner.thisType, denot.classSymbol, parentRefs, decls, ost)

src/dotty/tools/dotc/typer/Namer.scala

@@ -432,18 +432,10 @@ class Namer { typer: Typer =>
     }
 
     def createLinks(classTree: TypeDef, moduleTree: TypeDef)(implicit ctx: Context) = {
-      val claz = ctx.denotNamed(classTree.name.encode)
-      val modl = ctx.denotNamed(moduleTree.name.encode)
-      ctx.newSymbol(
-        owner = modl.symbol,
-        name = nme.COMPANION_CLASS_METHOD,
-        flags = Flags.Synthetic | Flags.Private,
-        info = ExprType(claz.symbol.typeRef)).entered
-      ctx.newSymbol(
-        owner = claz.symbol,
-        name = nme.COMPANION_MODULE_METHOD,
-        flags = Flags.Synthetic | Flags.Private,
-        info = ExprType(modl.symbol.typeRef)).entered
+      val claz = ctx.denotNamed(classTree.name.encode).symbol
+      val modl = ctx.denotNamed(moduleTree.name.encode).symbol
+      ctx.synthesizeCompanionMethod(nme.COMPANION_CLASS_METHOD, claz, modl).entered
+      ctx.synthesizeCompanionMethod(nme.COMPANION_MODULE_METHOD, modl, claz).entered
     }
 
     def createCompanionLinks(implicit ctx: Context): Unit = {