Relativize path in SourceFile annotation

Author: nicolasstucki

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

@@ -335,7 +335,14 @@ class PostTyper extends MacroTransform with IdentityDenotTransformer { thisPhase
                && ctx.compilationUnit.source.exists
                && sym != defn.SourceFileAnnot
             then
-              sym.addAnnotation(Annotation.makeSourceFile(ctx.compilationUnit.source.file.path))
+              val jpath = ctx.compilationUnit.source.file.jpath.normalize
+              val sourceroot =
+                java.nio.file.Paths.get(ctx.settings.sourceroot.value)
+                .toAbsolutePath
+                .normalize
+              val relativePath =
+                if jpath.isAbsolute then sourceroot.relativize(jpath) else jpath
+              sym.addAnnotation(Annotation.makeSourceFile(relativePath.toString))
           else (tree.rhs, sym.info) match
             case (rhs: LambdaTypeTree, bounds: TypeBounds) =>
               VarianceChecker.checkLambda(rhs, bounds)