Open Kordyjan opened 11 months ago
nicolasstucki
commented
11 months ago Up to 3.3.2-RC1-bin-20230705-13f877b-NIGHTLY - xcheck-macros assertion fail about missing position
I did not manage to reproduce this one. I get the same failure that is in the details.
Kordyjan
commented
11 months ago I fixed the ranges in the original comment.
WojciechMazur
commented
11 months ago It might be possible that it's related to https://github.com/lampepfl/dotty/issues/18257 based on JsonCodecMakerNewTypeSpec test which defined recursive jsons. Altough there is was either failing or crashing with stack overflow depending on the complexity of match type.
nicolasstucki
commented
11 months ago The missing position was fixed in #18178.
nicolasstucki
commented
11 months ago I have no insight on the LazyRef.ref assertion failure.
WojciechMazur
commented
7 months ago The compilation crash is still present in the latest 3.5.0-RC1-nightly. The code that triggers the crash is a single test https://github.com/plokhotnyuk/jsoniter-scala/blob/84d57daeada31c0cce2631489e6d7c71e57be37e/jsoniter-scala-macros/shared/src/test/scala-3/com/github/plokhotnyuk/jsoniter_scala/macros/JsonCodecMakerNewTypeSpec.scala#L97-L205 One of the reasons for the crash is the used recursive match type - this kind of constructs are not allowed. It's reproduction can be found in here https://github.com/scala/scala3/issues/18257#issuecomment-1777010537 - however what's important in this form it leads to infinite loop instead of crash. The one thing that Scala compiler should do is to detect and break the cycle early. The recursive match type detection works only for simpler types, but in the complex ones, as the one in jsoniter, we never get any hints from compiler what goes wrong.
Actually in many cases the match type recursion would be reported as error, however, there are some cases when we get crash with no errors, eg. this one leads to stack overflow and no context about recursion being involved when the recursion match is defined in call-by-name block
import scala.collection.mutable
trait JsonValueCodec[T]
trait JsonReader
trait JsonWriter
def verifySerDeser[T](codec: JsonValueCodec[T], obj: T, json: String): Unit = ???
def test(block: => Unit) = ???
def Test = test{
type JsonPrimitive = String | Int | Double | Boolean | None.type
type Rec[JA[_], JO[_], A] = A match { // FIXME: remove this workaround after adding support of recursive types
case JsonPrimitive => JsonPrimitive | JA[Rec[JA, JO, JsonPrimitive]] | JO[Rec[JA, JO, JsonPrimitive]]
case _ => A | JA[Rec[JA, JO, A]] | JO[Rec[JA, JO, A]]
}
type Json = Rec[[A] =>> mutable.Buffer[A], [A] =>> mutable.Map[String, A], JsonPrimitive]
type JsonObject = mutable.Map[String, Json]
type JsonArray = mutable.Buffer[Json]
val jsonCodec: JsonValueCodec[Json] = new JsonValueCodec[Json] {
val nullValue: Json = None
}
def obj(values: (String, Json)*): Json = ???
def arr(values: Json*): Json = mutable.ArrayBuffer[Json](values: _*)
verifySerDeser(
jsonCodec,
arr("VVV", 1.2, true, obj("WWW" -> None, "XXX" -> 777)),
"""["VVV",1.2,true,{"WWW":null,"XXX":777}]"""
)
}
Compiler version
Everything after 3.3.1.
3.3.2-RC1-bin-20230530-28915c4-NIGHTLY-3.3.2-RC1-bin-20230630-c629090-NIGHTLY-xcheck-macroserror from3.3.2-RC1-bin-20230703-0a21ecf-NIGHTLY- typer crashReproduction
Output (click arrow to expand)
Up to
3.3.2-RC1-bin-20230630-c629090-NIGHTLY-xcheck-macrosassertion fail about missing position From3.3.2-RC1-bin-20230703-0a21ecf-NIGHTLY: