Crash during Erasure: assertion failed: missing outer accessor in object Main #19534
Assignees
Labels
area:metaprogramming:quotes
Issues related to quotes and splices
area:metaprogramming:reflection
Issues related to the quotes reflection API
itype:invalid
Comments
lihaoyi
added
itype:bug
itype:crash
stat:needs triage
|
Self contained reproduction, fails in every Scala 3 version: // defs_1.scala
package mainargs
import scala.annotation.ClassfileAnnotation
class arg() extends ClassfileAnnotation
class main() extends ClassfileAnnotation
class ParserForMethods[B](val mains: MethodMains[B])
object ParserForMethods {
inline def apply[B](base: B): ParserForMethods[B] = ${ Macros.parserForMethods[B]('base) }
}
case class MethodMains[B](value: Seq[MainData[Any, B]], base: () => B)
class MainData[T, B] private[mainargs] (val invokeRaw: (B, Seq[Any]) => T)
object MainData:
def create[T, B](invokeRaw: (B, Seq[Any]) => T) = new MainData(invokeRaw)// macros_1.scala
package mainargs
import scala.quoted._
object Macros {
private def mainAnnotation(using Quotes) = quotes.reflect.Symbol.requiredClass("mainargs.main")
private def argAnnotation(using Quotes) = quotes.reflect.Symbol.requiredClass("mainargs.arg")
def parserForMethods[B](base: Expr[B])(using Quotes, Type[B]): Expr[ParserForMethods[B]] = {
import quotes.reflect._
val allMethods = TypeRepr.of[B].typeSymbol.memberMethods
val annotatedMethodsWithMainAnnotations = allMethods
.flatMap { methodSymbol =>
methodSymbol.getAnnotation(mainAnnotation).map(methodSymbol -> _)
}
.sortBy(_._1.pos.map(_.start))
val mainDatas = Expr.ofList(annotatedMethodsWithMainAnnotations.map {
(annotatedMethod, mainAnnotationInstance) =>
createMainData[Any, B](annotatedMethod)
})
'{
new ParserForMethods[B](
MethodMains[B]($mainDatas, () => $base)
)
}
}
def createMainData[T: Type, B: Type](using
Quotes
)(method: quotes.reflect.Symbol): Expr[MainData[T, B]] = {
import quotes.reflect.*
val invokeRaw: Expr[(B, Seq[Any]) => T] = {
def callOf(args: Expr[Seq[Any]]) = call(method, '{ Seq(${ args }) }).asExprOf[T]
'{ ((b: B, params: Seq[Any]) => ${ callOf('{ params }) }) }
}
'{ MainData.create[T, B](${ invokeRaw }) }
}
private def call(using Quotes)(
method: quotes.reflect.Symbol,
argss: Expr[Seq[Seq[Any]]]
): Expr[_] = {
import quotes.reflect._
val paramss = method.paramSymss
val fct = Ref(method)
val accesses: List[List[Term]] = for (i <- paramss.indices.toList) yield {
for (j <- paramss(i).indices.toList) yield {
val tpe = paramss(i)(j).tree.asInstanceOf[ValDef].tpt.tpe
tpe.asType match
case '[t] => '{ $argss(${ Expr(i) })(${ Expr(j) }).asInstanceOf[t] }.asTerm
}
}
val base = Apply(fct, accesses.head)
val application: Apply = accesses.tail.foldLeft(base)((lhs, args) => Apply(lhs, args))
val expr = application.asExpr
expr
}
}// main_2.scala
import mainargs.*
trait CommandList {
@main
def list(@arg v: String) = v
}
object Main extends CommandList {
def main(args: Array[String]): Unit = ParserForMethods(this)
} |
WojciechMazur
added
area:metaprogramming:reflection
|
Thanks @WojciechMazur ! |
|
I suspect that the |
|
If we pass - val fct = Ref(method)
+ val fct = base.asTerm.select(methodSymbol) |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Compiler version
3.3.1
Minimized code
Repro steps from com-lihaoyi/mainargs#103
Output (click arrow to expand)
The text was updated successfully, but these errors were encountered: