Merge pull request #14888 from dotty-staging/fix-12432

Disallow package names as types

Author: griggt

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

@@ -11,6 +11,7 @@ import printing.Printer
 import printing.Texts.Text
 import util.{Stats, Attachment, Property, SourceFile, NoSource, SrcPos, SourcePosition}
 import config.Config
+import config.Printers.overload
 import annotation.internal.sharable
 import annotation.unchecked.uncheckedVariance
 import annotation.constructorOnly
@@ -1729,7 +1730,9 @@ object Trees {
       val typer = ctx.typer
       val proto = FunProto(args, expectedType)
       val denot = receiver.tpe.member(method)
-      assert(denot.exists, i"no member $receiver . $method, members = ${receiver.tpe.decls}")
+      if !denot.exists then
+        overload.println(i"members = ${receiver.tpe.decls}")
+        report.error(i"no member $receiver . $method", receiver.srcPos)
       val selected =
         if (denot.isOverloaded) {
           def typeParamCount(tp: Type) = tp.widen match {

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

@@ -7,6 +7,7 @@ import core._
 import dotty.tools.dotc.typer.Checking
 import dotty.tools.dotc.typer.Inliner
 import dotty.tools.dotc.typer.VarianceChecker
+import typer.ErrorReporting.errorTree
 import Types._, Contexts._, Names._, Flags._, DenotTransformers._, Phases._
 import SymDenotations._, StdNames._, Annotations._, Trees._, Scopes._
 import Decorators._
@@ -263,6 +264,10 @@ class PostTyper extends MacroTransform with IdentityDenotTransformer { thisPhase
         case Select(qual, _) => check(qual)    // simple select _n
         case Apply(TypeApply(Select(qual, _), _), _) => check(qual) // generic select .apply[T](n)
 
+    def checkNotPackage(tree: Tree)(using Context): Tree =
+      if !tree.symbol.is(Package) then tree
+      else errorTree(tree, i"${tree.symbol} cannot be used as a type")
+
     override def transform(tree: Tree)(using Context): Tree =
       try tree match {
         // TODO move CaseDef case lower: keep most probable trees first for performance
@@ -273,21 +278,23 @@ class PostTyper extends MacroTransform with IdentityDenotTransformer { thisPhase
              case None =>
                ctx
           super.transform(tree)(using gadtCtx)
-        case tree: Ident if !tree.isType =>
-          if tree.symbol.is(Inline) && !Inliner.inInlineMethod then
-            ctx.compilationUnit.needsInlining = true
-          checkNoConstructorProxy(tree)
-          tree.tpe match {
-            case tpe: ThisType => This(tpe.cls).withSpan(tree.span)
-            case _ => tree
-          }
+        case tree: Ident =>
+          if tree.isType then
+            checkNotPackage(tree)
+          else
+            if tree.symbol.is(Inline) && !Inliner.inInlineMethod then
+              ctx.compilationUnit.needsInlining = true
+            checkNoConstructorProxy(tree)
+            tree.tpe match {
+              case tpe: ThisType => This(tpe.cls).withSpan(tree.span)
+              case _ => tree
+            }
         case tree @ Select(qual, name) =>
           if tree.symbol.is(Inline) then
             ctx.compilationUnit.needsInlining = true
-          if (name.isTypeName) {
+          if name.isTypeName then
             Checking.checkRealizable(qual.tpe, qual.srcPos)
-            withMode(Mode.Type)(super.transform(tree))
-          }
+            withMode(Mode.Type)(super.transform(checkNotPackage(tree)))
           else
             checkNoConstructorProxy(tree)
             transformSelect(tree, Nil)

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

@@ -262,7 +262,7 @@ class SyntheticMembers(thisPhase: DenotTransformer) {
       // compare primitive fields first, slow equality checks of non-primitive fields can be skipped when primitives differ
       val sortedAccessors = accessors.sortBy(accessor => if (accessor.info.typeSymbol.isPrimitiveValueClass) 0 else 1)
       val comparisons = sortedAccessors.map { accessor =>
-        This(clazz).select(accessor).equal(ref(thatAsClazz).select(accessor)) }
+        This(clazz).withSpan(ctx.owner.span.focus).select(accessor).equal(ref(thatAsClazz).select(accessor)) }
       var rhs = // this.x == this$0.x && this.y == x$0.y && that.canEqual(this)
         if comparisons.isEmpty then Literal(Constant(true)) else comparisons.reduceLeft(_ and _)
       val canEqualMeth = existingDef(defn.Product_canEqual, clazz)

tests/neg/i12432.scala

@@ -0,0 +1,4 @@
+
+case class i1 ( i1 : annotation ) // error // error
+class i2 ( a : scala.annotation ) // error
+