SpecializeNames: Duplicate scalac behaviour, sort tparams

Author: DarkDimius

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

@@ -236,7 +236,7 @@ object NameOps {
       case nme.clone_ => nme.clone_
     }
 
-    def specializedFor(returnType: Types.Type, args: List[Types.Type])(implicit ctx: Context): name.ThisName = {
+    def specializedFor(classTargs: List[Types.Type], classTargsNames: List[Name], methodTargs: List[Types.Type], methodTarsNames: List[Name])(implicit ctx: Context): name.ThisName = {
 
       def typeToTag(tp: Types.Type): Name = {
         tp.classSymbol match {
@@ -253,9 +253,12 @@ object NameOps {
         }
       }
 
+      val methodTags: Seq[Name] = (methodTargs zip methodTarsNames).sortBy(_._2).map(x => typeToTag(x._1))
+      val classTags: Seq[Name] = (classTargs zip classTargsNames).sortBy(_._2).map(x => typeToTag(x._1))
+
       name.fromName(name ++ nme.specializedTypeNames.prefix ++
-        args.map(typeToTag).foldRight(typeToTag(returnType))(_ ++ _) ++
-        nme.specializedTypeNames.suffix)
+        methodTags.fold(nme.EMPTY)(_ ++ _) ++ nme.specializedTypeNames.separator ++
+        classTags.fold(nme.EMPTY)(_ ++ _) ++ nme.specializedTypeNames.suffix)
     }
 
     /** If name length exceeds allowable limit, replace part of it by hash */

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

@@ -338,4 +338,27 @@ object Names {
       StringBuilder.newBuilder.mapResult(s => from.fromChars(s.toCharArray, 0, s.length))
     def apply(): Builder[Char, Name] = termNameBuilder
   }
+
+  implicit val NameOrdering: Ordering[Name] = new Ordering[Name] {
+    def compare(x: Name, y: Name): Int = {
+      if (x.isTermName && y.isTypeName) 1
+      else if (x.isTypeName && y.isTermName) -1
+      else if (x.start == y.start && x.length == y.length) 0
+      else {
+        val until = Math.min(x.length, y.length)
+        var i = 0
+
+        while (i < until && x(i) == y(i)) i = i + 1
+
+        if (i < until) {
+          if (x(i) < y(i)) -1
+          else /*(x(i) > y(i))*/ 1
+        } else {
+          if (x.length < y.length) 1
+          else if (x.length > y.length) -1
+          else 0 // shouldn't happen, but still
+        }
+      }
+    }
+  }
 }

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

@@ -559,7 +559,8 @@ object StdNames {
       final val Void: N    = "V"
       final val Object: N  = "L"
 
-      final val prefix: N = "$mc"
+      final val prefix: N = "$m"
+      final val separator: N = "c"
       final val suffix: N = "$sp"
     }
 

src/dotty/tools/dotc/transform/FunctionalInterfaces.scala

@@ -63,7 +63,12 @@ class FunctionalInterfaces extends MiniPhaseTransform {
         val m = tree.meth.tpe.widen.asInstanceOf[MethodType]
 
         if (shouldSpecialize(m)) {
-          val interfaceName = (functionName ++ m.paramTypes.length.toString).specializedFor(m.resultType, m.paramTypes)
+          val functionSymbol = tree.tpe.widenDealias.classSymbol
+          val names = ctx.atPhase(ctx.erasurePhase.prev) {
+            implicit ctx => functionSymbol.typeParams.map(_.name)
+          }
+          val interfaceName = (functionName ++ m.paramTypes.length.toString).specializedFor(m.paramTypes ::: m.resultType :: Nil, names, Nil, Nil)
+
           // symbols loaded from classpath aren't defined in periods earlier than when they where loaded
           val interface = ctx.withPhase(ctx.typerPhase).getClassIfDefined(functionPackage ++ interfaceName)
           if (interface.exists) {