Do not copy symbols in BodyAnnotations

Author: mbovel

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

@@ -146,19 +146,23 @@ class PostTyper extends MacroTransform with IdentityDenotTransformer { thisPhase
         ttm(tree)
 
     /** Transforms the given annotation tree. */
-    private def transformAnnot(annot: Tree)(using Context): Tree = {
+    private def transformAnnotTree(annot: Tree)(using Context): Tree = {
       val saved = inJavaAnnot
       inJavaAnnot = annot.symbol.is(JavaDefined)
       if (inJavaAnnot) checkValidJavaAnnotation(annot)
-      try transform(copySymbols(annot))
+      try transform(annot)
       finally inJavaAnnot = saved
     }
 
     private def transformAnnot(annot: Annotation)(using Context): Annotation =
-      annot.derivedAnnotation(transformAnnot(annot.tree))
+      val tree1 =
+        annot match
+          case _: BodyAnnotation => annot.tree
+          case _ => copySymbols(annot.tree)
+      annot.derivedAnnotation(transformAnnotTree(tree1))
 
     /** Transforms all annotations in the given type. */
-    private def transformAnnots(using Context) =
+    private def transformAnnotsIn(using Context) =
       new TypeMap:
         def apply(tp: Type) = tp match
           case tp @ AnnotatedType(parent, annot) =>
@@ -460,7 +464,7 @@ class PostTyper extends MacroTransform with IdentityDenotTransformer { thisPhase
           Checking.checkRealizable(tree.tpt.tpe, tree.srcPos, "SAM type")
           super.transform(tree)
         case tree @ Annotated(annotated, annot) =>
-          cpy.Annotated(tree)(transform(annotated), transformAnnot(annot))
+          cpy.Annotated(tree)(transform(annotated), transformAnnotTree(annot))
         case tree: AppliedTypeTree =>
           if (tree.tpt.symbol == defn.andType)
             Checking.checkNonCyclicInherited(tree.tpe, tree.args.tpes, EmptyScope, tree.srcPos)
@@ -482,7 +486,7 @@ class PostTyper extends MacroTransform with IdentityDenotTransformer { thisPhase
               report.error(em"type ${alias.tpe} outside bounds $bounds", tree.srcPos)
           super.transform(tree)
         case tree: TypeTree =>
-          tree.withType(transformAnnotsIn(tpe))
+          tree.withType(transformAnnotsIn(tree.tpe))
         case Typed(Ident(nme.WILDCARD), _) =>
           withMode(Mode.Pattern)(super.transform(tree))
             // The added mode signals that bounds in a pattern need not

tests/pos/annot-body.scala

@@ -0,0 +1,15 @@
+// This test checks that symbols in `BodyAnnotation` are not copied in
+// `transformAnnot` during `PostTyper`.
+
+package json
+
+trait Reads[A] {
+  def reads(a: Any): A
+}
+
+object JsMacroImpl {
+  inline def reads[A]: Reads[A] =
+    new Reads[A] { self =>
+      def reads(a: Any) = ???
+    }
+}