Rename erasedParams to paramErasureStatuses

# Conflicts:
#	compiler/src/dotty/tools/dotc/ast/TreeInfo.scala

Author: odersky

compiler/src/dotty/tools/dotc/ast/tpd.scala

@@ -301,7 +301,7 @@ object tpd extends Trees.Instance[Type] with TypedTreeInfo {
               assert(vparams.hasSameLengthAs(tp.paramNames) && vparams.head.isTerm)
               (vparams.asInstanceOf[List[TermSymbol]], remaining1)
             case nil =>
-              (tp.paramNames.lazyZip(tp.paramInfos).lazyZip(tp.erasedParams).map(valueParam), Nil)
+              (tp.paramNames.lazyZip(tp.paramInfos).lazyZip(tp.paramErasureStatuses).map(valueParam), Nil)
         val (rtp, paramss) = recur(tp.instantiate(vparams.map(_.termRef)), remaining1)
         (rtp, vparams :: paramss)
       case _ =>

compiler/src/dotty/tools/dotc/core/TypeComparer.scala

@@ -2387,7 +2387,7 @@ class TypeComparer(@constructorOnly initctx: Context) extends ConstraintHandling
         formals2.isEmpty
     }
     // If methods have erased parameters, then the erased parameters must match
-    val erasedValid = (!tp1.hasErasedParams && !tp2.hasErasedParams) || (tp1.erasedParams == tp2.erasedParams)
+    val erasedValid = (!tp1.hasErasedParams && !tp2.hasErasedParams) || (tp1.paramErasureStatuses == tp2.paramErasureStatuses)
 
     erasedValid && loop(tp1.paramInfos, tp2.paramInfos)
   }

compiler/src/dotty/tools/dotc/core/TypeErasure.scala

@@ -697,7 +697,7 @@ class TypeErasure(sourceLanguage: SourceLanguage, semiEraseVCs: Boolean, isConst
         val (names, formals0) = if tp.hasErasedParams then
           tp.paramNames
             .zip(tp.paramInfos)
-            .zip(tp.erasedParams)
+            .zip(tp.paramErasureStatuses)
             .collect{ case (param, isErased) if !isErased => param }
             .unzip
         else (tp.paramNames, tp.paramInfos)

compiler/src/dotty/tools/dotc/core/Types.scala

@@ -3931,7 +3931,7 @@ object Types extends TypeUtils {
           case tp: MethodType =>
             val params = if (hasErasedParams)
               tp.paramInfos
-                .zip(tp.erasedParams)
+                .zip(tp.paramErasureStatuses)
                 .collect { case (param, isErased) if !isErased => param }
             else tp.paramInfos
             resultSignature.prependTermParams(params, sourceLanguage)
@@ -4163,7 +4163,7 @@ object Types extends TypeUtils {
     final override def isContextualMethod: Boolean =
       companion.eq(ContextualMethodType)
 
-    def erasedParams(using Context): List[Boolean] =
+    def paramErasureStatuses(using Context): List[Boolean] =
       paramInfos.map(p => p.hasAnnotation(defn.ErasedParamAnnot))
 
     def nonErasedParamCount(using Context): Int =

compiler/src/dotty/tools/dotc/quoted/Interpreter.scala

@@ -127,8 +127,8 @@ class Interpreter(pos: SrcPos, classLoader0: ClassLoader)(using Context):
       case fnType: MethodType =>
         val argTypes = fnType.paramInfos
         assert(argss.head.size == argTypes.size)
-        val nonErasedArgs = argss.head.lazyZip(fnType.erasedParams).collect { case (arg, false) => arg }.toList
-        val nonErasedArgTypes = fnType.paramInfos.lazyZip(fnType.erasedParams).collect { case (arg, false) => arg }.toList
+        val nonErasedArgs = argss.head.lazyZip(fnType.paramErasureStatuses).collect { case (arg, false) => arg }.toList
+        val nonErasedArgTypes = fnType.paramInfos.lazyZip(fnType.paramErasureStatuses).collect { case (arg, false) => arg }.toList
         assert(nonErasedArgs.size == nonErasedArgTypes.size)
         interpretArgsGroup(nonErasedArgs, nonErasedArgTypes) ::: interpretArgs(argss.tail, fnType.resType)
       case fnType: AppliedType if defn.isContextFunctionType(fnType) =>

compiler/src/dotty/tools/dotc/transform/Erasure.scala

@@ -583,6 +583,17 @@ object Erasure {
       checkNotErasedClass(tree)
     end checkNotErased
 
+    def checkPureErased(tree: untpd.Tree, isArgument: Boolean)(using Context): Unit =
+      if false then inContext(preErasureCtx):
+        if tpd.isPureExpr(tree.asInstanceOf[tpd.Tree]) then
+          val tree1 = tree.asInstanceOf[tpd.Tree]
+          println(i"$tree1 is pure, ${tree1.tpe.widen}")
+        else
+          def what =
+            if isArgument then "argument to erased parameter"
+            else "right-hand-side of erased value"
+          report.error(em"$what fails to be a pure expression", tree.srcPos)
+
     private def checkNotErasedClass(tp: Type, tree: untpd.Tree)(using Context): Unit = tp match
       case JavaArrayType(et) =>
         checkNotErasedClass(et, tree)
@@ -848,7 +859,12 @@ object Erasure {
       val origFunType = origFun.tpe.widen(using preErasureCtx)
       val ownArgs = origFunType match
         case mt: MethodType if mt.hasErasedParams =>
-          args.zip(mt.erasedParams).collect { case (arg, false) => arg }
+          args.lazyZip(mt.paramErasureStatuses).flatMap: (arg, isErased) =>
+            if isErased then
+              checkPureErased(arg, isArgument = true)
+              Nil
+            else
+              arg :: Nil
         case _ => args
       val fun1 = typedExpr(fun, AnyFunctionProto)
       fun1.tpe.widen match
@@ -916,7 +932,9 @@ object Erasure {
       }
 
     override def typedValDef(vdef: untpd.ValDef, sym: Symbol)(using Context): Tree =
-      if (sym.isEffectivelyErased) erasedDef(sym)
+      if sym.isEffectivelyErased then
+        checkPureErased(vdef.rhs, isArgument = false)
+        erasedDef(sym)
       else
         checkNotErasedClass(sym.info, vdef)
         super.typedValDef(untpd.cpy.ValDef(vdef)(
@@ -928,6 +946,7 @@ object Erasure {
      */
     override def typedDefDef(ddef: untpd.DefDef, sym: Symbol)(using Context): Tree =
       if sym.isEffectivelyErased || sym.name.is(BodyRetainerName) then
+        checkPureErased(ddef.rhs, isArgument = false)
         erasedDef(sym)
       else
         checkNotErasedClass(sym.info.finalResultType, ddef)

compiler/src/dotty/tools/dotc/transform/PostTyper.scala

@@ -408,7 +408,7 @@ class PostTyper extends MacroTransform with InfoTransformer { thisPhase =>
         case app: Apply =>
           val methType = app.fun.tpe.widen.asInstanceOf[MethodType]
           if (methType.hasErasedParams)
-            for (arg, isErased) <- app.args.lazyZip(methType.erasedParams) do
+            for (arg, isErased) <- app.args.lazyZip(methType.paramErasureStatuses) do
               if isErased then
                 if methType.isResultDependent then
                   Checking.checkRealizable(arg.tpe, arg.srcPos, "erased argument")
@@ -475,15 +475,15 @@ class PostTyper extends MacroTransform with InfoTransformer { thisPhase =>
         case tree: ValDef =>
           annotateExperimentalCompanion(tree.symbol)
           registerIfHasMacroAnnotations(tree)
-          checkErasedDef(tree)
+          //checkErasedDef(tree)
           Checking.checkPolyFunctionType(tree.tpt)
           val tree1 = cpy.ValDef(tree)(tpt = makeOverrideTypeDeclared(tree.symbol, tree.tpt))
           if tree1.removeAttachment(desugar.UntupledParam).isDefined then
             checkStableSelection(tree.rhs)
           processValOrDefDef(super.transform(tree1))
         case tree: DefDef =>
           registerIfHasMacroAnnotations(tree)
-          checkErasedDef(tree)
+          //checkErasedDef(tree)
           Checking.checkPolyFunctionType(tree.tpt)
           annotateContextResults(tree)
           val tree1 = cpy.DefDef(tree)(tpt = makeOverrideTypeDeclared(tree.symbol, tree.tpt))

compiler/src/dotty/tools/dotc/typer/EtaExpansion.scala

@@ -300,9 +300,9 @@ object EtaExpansion extends LiftImpure {
     val body = Apply(lifted, ids)
     if (mt.isContextualMethod) body.setApplyKind(ApplyKind.Using)
     val fn =
-      if (mt.isContextualMethod) new untpd.FunctionWithMods(params, body, Modifiers(Given), mt.erasedParams)
-      else if (mt.isImplicitMethod) new untpd.FunctionWithMods(params, body, Modifiers(Implicit), mt.erasedParams)
-      else if (mt.hasErasedParams) new untpd.FunctionWithMods(params, body, Modifiers(), mt.erasedParams)
+      if (mt.isContextualMethod) new untpd.FunctionWithMods(params, body, Modifiers(Given), mt.paramErasureStatuses)
+      else if (mt.isImplicitMethod) new untpd.FunctionWithMods(params, body, Modifiers(Implicit), mt.paramErasureStatuses)
+      else if (mt.hasErasedParams) new untpd.FunctionWithMods(params, body, Modifiers(), mt.paramErasureStatuses)
       else untpd.Function(params, body)
     if (defs.nonEmpty) untpd.Block(defs.toList map (untpd.TypedSplice(_)), fn) else fn
   }

compiler/src/dotty/tools/dotc/typer/Typer.scala

@@ -1761,7 +1761,7 @@ class Typer(@constructorOnly nestingLevel: Int = 0) extends Namer
       if (mt.isParamDependent)
         report.error(em"$mt is an illegal function type because it has inter-parameter dependencies", tree.srcPos)
       // Restart typechecking if there are erased classes that we want to mark erased
-      if mt.erasedParams.zip(mt.paramInfos.map(_.isErasedClass)).exists((paramErased, classErased) => classErased && !paramErased) then
+      if mt.paramErasureStatuses.zip(mt.paramInfos.map(_.isErasedClass)).exists((paramErased, classErased) => classErased && !paramErased) then
         val newParams = params3.zipWithConserve(mt.paramInfos.map(_.isErasedClass)) { (arg, isErasedClass) =>
           if isErasedClass then arg.withAddedFlags(Erased) else arg
         }
@@ -3788,7 +3788,7 @@ class Typer(@constructorOnly nestingLevel: Int = 0) extends Namer
     }
 
     val erasedParams = pt match {
-      case defn.PolyFunctionOf(mt: MethodType) => mt.erasedParams
+      case defn.PolyFunctionOf(mt: MethodType) => mt.paramErasureStatuses
       case _ => paramTypes.map(_ => false)
     }
 

compiler/src/scala/quoted/runtime/impl/QuoteMatcher.scala

@@ -448,7 +448,7 @@ class QuoteMatcher(debug: Boolean) {
                   def matchErasedParams(sctype: Type, pttype: Type): optional[MatchingExprs] =
                     (sctype, pttype) match
                       case (sctpe: MethodType, pttpe: MethodType) =>
-                        if sctpe.erasedParams.sameElements(pttpe.erasedParams) then
+                        if sctpe.paramErasureStatuses.sameElements(pttpe.paramErasureStatuses) then
                           matchErasedParams(sctpe.resType, pttpe.resType)
                         else
                           notMatched