Merge pull request #8624 from dotty-staging/tasty/single-methodtype-tag

Remove variants of METHODtype tasty tag

Author: odersky

compiler/src/dotty/tools/dotc/core/tasty/TastyPrinter.scala

@@ -86,11 +86,10 @@ class TastyPrinter(bytes: Array[Byte])(implicit ctx: Context) {
               printName(); printTree(); printTrees()
             case RETURN | HOLE =>
               printNat(); printTrees()
-            case METHODtype | ERASEDMETHODtype |
-                 GIVENMETHODtype | ERASEDGIVENMETHODtype | IMPLICITMETHODtype |
-                 POLYtype | TYPELAMBDAtype =>
+            case METHODtype | POLYtype | TYPELAMBDAtype =>
               printTree()
-              until(end) { printName(); printTree() }
+              while (currentAddr.index < end.index && !isModifierTag(nextByte)) { printTree(); printName(); }
+              printTrees()
             case PARAMtype =>
               printNat(); printNat()
             case _ =>

compiler/src/dotty/tools/dotc/core/tasty/TreePickler.scala

@@ -259,7 +259,7 @@ class TreePickler(pickler: TastyPickler) {
       writeByte(BYNAMEtype)
       pickleType(tpe.underlying)
     case tpe: HKTypeLambda =>
-      pickleMethodic(TYPELAMBDAtype, tpe)
+      pickleMethodic(TYPELAMBDAtype, tpe, EmptyFlags)
     case tpe: MatchType =>
       writeByte(MATCHtype)
       withLength {
@@ -268,26 +268,27 @@ class TreePickler(pickler: TastyPickler) {
         tpe.cases.foreach(pickleType(_))
       }
     case tpe: PolyType if richTypes =>
-      pickleMethodic(POLYtype, tpe)
+      pickleMethodic(POLYtype, tpe, EmptyFlags)
     case tpe: MethodType if richTypes =>
-      val tag = methodTypeTag(
-        isContextual = tpe.isContextualMethod,
-        isImplicit = tpe.isImplicitMethod && !tpe.isContextualMethod,
-        isErased = tpe.isErasedMethod)
-      pickleMethodic(tag, tpe)
+      var mods = EmptyFlags
+      if tpe.isContextualMethod then mods |= Given
+      else if tpe.isImplicitMethod then mods |= Implicit
+      if tpe.isErasedMethod then mods |= Erased
+      pickleMethodic(METHODtype, tpe, mods)
     case tpe: ParamRef =>
       assert(pickleParamRef(tpe), s"orphan parameter reference: $tpe")
     case tpe: LazyRef =>
       pickleType(tpe.ref)
   }
 
-  def pickleMethodic(tag: Int, tpe: LambdaType)(implicit ctx: Context): Unit = {
+  def pickleMethodic(tag: Int, tpe: LambdaType, mods: FlagSet)(implicit ctx: Context): Unit = {
     writeByte(tag)
     withLength {
       pickleType(tpe.resultType, richTypes = true)
       tpe.paramNames.lazyZip(tpe.paramInfos).foreach { (name, tpe) =>
-        pickleName(name); pickleType(tpe)
+        pickleType(tpe); pickleName(name)
       }
+      if (mods != EmptyFlags) pickleFlags(mods, tpe.isTermLambda)
     }
   }
 

compiler/src/dotty/tools/dotc/core/tasty/TreeUnpickler.scala

@@ -210,17 +210,30 @@ class TreeUnpickler(reader: TastyReader,
 
 // ------ Reading types -----------------------------------------------------
 
-    /** Read names in an interleaved sequence of (parameter) names and types/bounds */
-    def readParamNames(end: Addr): List[Name] =
-      until(end) {
-        val name = readName()
-        skipTree()
-        name
-      }
-
-    /** Read types or bounds in an interleaved sequence of (parameter) names and types/bounds */
-    def readParamTypes[T <: Type](end: Addr)(implicit ctx: Context): List[T] =
-      until(end) { readNat(); readType().asInstanceOf[T] }
+    /** Read names in an interleaved sequence of types/bounds and (parameter) names,
+     *  possibly followed by a sequence of modifiers.
+     */
+    def readParamNamesAndMods(end: Addr): (List[Name], FlagSet) =
+      val names =
+        collectWhile(currentAddr != end && !isModifierTag(nextByte)) {
+          skipTree()
+          readName()
+        }
+      var mods = EmptyFlags
+      while currentAddr != end do // avoid boxing the mods
+        readByte() match
+          case IMPLICIT => mods |= Implicit
+          case ERASED   => mods |= Erased
+          case GIVEN    => mods |= Given
+      (names, mods)
+
+    /** Read `n` parameter types or bounds which are interleaved with names */
+    def readParamTypes[T <: Type](n: Int)(implicit ctx: Context): List[T] =
+      if n == 0 then Nil
+      else
+        val t = readType().asInstanceOf[T]
+        readNat() // skip name
+        t :: readParamTypes(n - 1)
 
     /** Read reference to definition and return symbol created at that definition */
     def readSymRef()(implicit ctx: Context): Symbol = symbolAt(readAddr())
@@ -290,14 +303,14 @@ class TreeUnpickler(reader: TastyReader,
         val end = readEnd()
 
         def readMethodic[N <: Name, PInfo <: Type, LT <: LambdaType]
-            (companion: LambdaTypeCompanion[N, PInfo, LT], nameMap: Name => N): LT = {
+            (companionOp: FlagSet => LambdaTypeCompanion[N, PInfo, LT], nameMap: Name => N): LT = {
           val result = typeAtAddr.getOrElse(start, {
               val nameReader = fork
               nameReader.skipTree() // skip result
               val paramReader = nameReader.fork
-              val paramNames = nameReader.readParamNames(end).map(nameMap)
-              companion(paramNames)(
-                pt => registeringType(pt, paramReader.readParamTypes[PInfo](end)),
+              val (paramNames, mods) = nameReader.readParamNamesAndMods(end)
+              companionOp(mods)(paramNames.map(nameMap))(
+                pt => registeringType(pt, paramReader.readParamTypes[PInfo](paramNames.length)),
                 pt => readType())
             })
           goto(end)
@@ -361,19 +374,17 @@ class TreeUnpickler(reader: TastyReader,
             case MATCHtype =>
               MatchType(readType(), readType(), until(end)(readType()))
             case POLYtype =>
-              readMethodic(PolyType, _.toTypeName)
+              readMethodic(_ => PolyType, _.toTypeName)
             case METHODtype =>
-              readMethodic(MethodType, _.toTermName)
-            case ERASEDMETHODtype =>
-              readMethodic(ErasedMethodType, _.toTermName)
-            case GIVENMETHODtype =>
-              readMethodic(ContextualMethodType, _.toTermName)
-            case ERASEDGIVENMETHODtype =>
-              readMethodic(ErasedContextualMethodType, _.toTermName)
-            case IMPLICITMETHODtype =>
-              readMethodic(ImplicitMethodType, _.toTermName)
+              def methodTypeCompanion(mods: FlagSet): MethodTypeCompanion =
+                if mods.is(Implicit) then ImplicitMethodType
+                else if mods.isAllOf(Erased | Given) then ErasedContextualMethodType
+                else if mods.is(Given) then ContextualMethodType
+                else if mods.is(Erased) then ErasedMethodType
+                else MethodType
+              readMethodic(methodTypeCompanion, _.toTermName)
             case TYPELAMBDAtype =>
-              readMethodic(HKTypeLambda, _.toTypeName)
+              readMethodic(_ => HKTypeLambda, _.toTypeName)
             case PARAMtype =>
               readTypeRef() match {
                 case binder: LambdaType => binder.paramRefs(readNat())

tasty/src/dotty/tools/tasty/TastyFormat.scala

@@ -160,17 +160,12 @@ Standard-Section: "ASTs" TopLevelStat*
                   BIND           Length boundName_NameRef bounds_Type              -- boundName @ bounds,  for type-variables defined in a type pattern
                   BYNAMEtype            underlying_Type                            -- => underlying
                   PARAMtype      Length binder_ASTRef paramNum_Nat                 -- A reference to parameter # paramNum in lambda type `binder`
-                  POLYtype       Length result_Type NamesTypes                     -- A polymorphic method type `[NamesTypes]result`, used in refinements
-                  METHODtype     Length result_Type NamesTypes                     -- A method type `(NamesTypes)result`, needed for refinements
-                  ERASEDMETHODtype      Length result_Type NamesTypes              -- A method type `erased (NamesTypes)result`, needed for refinements
-                  GIVENMETHODtype       Length result_Type NamesTypes              -- A method type `(using NamesTypes)result`, needed for refinements
-                  ERASEDGIVENMETHODtype Length result_Type NamesTypes              -- A method type `(using erased NamesTypes)result`, needed for refinements
-                  IMPLICITMETHODtype    Length result_Type NamesTypes              -- A method type `(implicit NamesTypes)result`, needed for refinements
-  // TODO: remove ERASEDIMPLICITMETHODtype
-                  TYPELAMBDAtype Length result_Type NamesTypes                     -- A type lambda `[NamesTypes] => result`
+                  POLYtype       Length result_Type TypesNames                     -- A polymorphic method type `[TypesNames]result`, used in refinements
+                  METHODtype     Length result_Type TypesNames Modifier*           -- A method type `(Modifier* TypesNames)result`, needed for refinements, with optional modifiers for the parameters
+                  TYPELAMBDAtype Length result_Type TypesNames                     -- A type lambda `[TypesNames] => result`
                   SHAREDtype            type_ASTRef                                -- link to previously serialized type
-  NamesTypes    = NameType*
-  NameType      = paramName_NameRef typeOrBounds_ASTRef                            -- `termName : type`  or  `typeName bounds`
+  TypesNames    = TypeName*
+  TypeName      = typeOrBounds_ASTRef paramName_NameRef                            -- (`termName`: `type`)  or  (`typeName` `bounds`)
 
   Modifier      = PRIVATE                                                          -- private
                   INTERNAL                                                         -- package private (not yet used)
@@ -254,7 +249,7 @@ Standard Section: "Comments" Comment*
 object TastyFormat {
 
   final val header: Array[Int] = Array(0x5C, 0xA1, 0xAB, 0x1F)
-  val MajorVersion: Int = 20
+  val MajorVersion: Int = 21
   val MinorVersion: Int = 0
 
   /** Tags used to serialize names, should update [[nameTagToString]] if a new constant is added */
@@ -305,6 +300,7 @@ object TastyFormat {
       case DEFAULTGETTER => "DEFAULTGETTER"
       case SUPERACCESSOR => "SUPERACCESSOR"
       case INLINEACCESSOR => "INLINEACCESSOR"
+      case BODYRETAINER => "BODYRETAINER"
       case OBJECTCLASS => "OBJECTCLASS"
       case SIGNED => "SIGNED"
       case id => s"NotANameTag($id)"
@@ -460,23 +456,10 @@ object TastyFormat {
   final val TYPEREFin = 175
 
   final val METHODtype = 180
-  final val ERASEDMETHODtype = 181
-  final val GIVENMETHODtype = 182
-  final val ERASEDGIVENMETHODtype = 183
-  final val IMPLICITMETHODtype = 184
 
   final val MATCHtype = 190
   final val MATCHtpt = 191
 
-  def methodTypeTag(isContextual: Boolean, isImplicit: Boolean, isErased: Boolean): Int = {
-    val implicitOffset =
-      if (isContextual) 2
-      else if (isImplicit) { assert(!isErased); 4 }
-      else 0
-    val erasedOffset = if (isErased) 1 else 0
-    METHODtype + erasedOffset + implicitOffset
-  }
-
   final val HOLE = 255
 
   final val firstNatTreeTag = SHAREDterm
@@ -680,10 +663,6 @@ object TastyFormat {
     case BYNAMEtpt => "BYNAMEtpt"
     case POLYtype => "POLYtype"
     case METHODtype => "METHODtype"
-    case ERASEDMETHODtype => "ERASEDMETHODtype"
-    case GIVENMETHODtype => "GIVENMETHODtype"
-    case ERASEDGIVENMETHODtype => "ERASEDGIVENMETHODtype"
-    case IMPLICITMETHODtype => "IMPLICITMETHODtype"
     case TYPELAMBDAtype => "TYPELAMBDAtype"
     case LAMBDAtpt => "LAMBDAtpt"
     case MATCHtype => "MATCHtype"
@@ -702,10 +681,7 @@ object TastyFormat {
     case VALDEF | DEFDEF | TYPEDEF | TYPEPARAM | PARAM | NAMEDARG | RETURN | BIND |
          SELFDEF | REFINEDtype | TERMREFin | TYPEREFin | HOLE => 1
     case RENAMED | PARAMtype => 2
-    case POLYtype | TYPELAMBDAtype |
-         METHODtype | ERASEDMETHODtype |
-         GIVENMETHODtype | ERASEDGIVENMETHODtype |
-         IMPLICITMETHODtype => -1
+    case POLYtype | TYPELAMBDAtype | METHODtype => -1
     case _ => 0
   }
 }