NoClassDefFoundError with multi-stage macros #9484
Description
This requires 4 separate source files which are compiled together in a single run:
The top level in Test.scala calls a macro in Q:
object Test extends App {
Q.f()
}The second level in Q.scala has the macro implementation which uses LC:
import scala.quoted._
object Q {
inline def f(): Any = ${ fExpr }
def fExpr(using QuoteContext): Expr[Any] = { new LC; Expr(1) }
}L.scala defines LC and an unrelated object L which is not referenced anywhere but references another macro in C. This code is used at the same staging level as Q.scala but has to be in a separate compilation unit to trigger the bug:
import scala.quoted._
object L {
val m = C.m
}
class LCThe third level in C.scala contains the macro that is referenced by L:
import scala.quoted._
object C {
inline def m: Any = ${ mExpr }
def mExpr(using qctx: QuoteContext): Expr[Any] = Expr(1)
}In 0.26.0-RC1 this fails with:
[error] -- Error: /mnt/c/Users/szeiger/code/dottyquery/src/main/scala/dottyquery/Test.scala:2:5
[error] 2 | Q.f()
[error] | ^^^^^
[error] | Exception occurred while executing macro expansion.
[error] | java.lang.NoClassDefFoundError: LC
[error] | at Q$.fExpr(Q.scala:5)
[error] |
[error] | This location contains code that was inlined from Test.scala:2
When all definitions are moved into a named package (instead of the default package) it causes a compiler crash with a stack trace instead of reporting an error, but the cause is the same NoClassDefFoundError.