Macro annotation that processes inlined tree crashes under `-Ycheck:all`

Compiler version

3.3.1-RC1-bin-20230216-2507577-NIGHTLY

Minimized code

Consider the following macro definition (the macro annotation extracts the number v that is applied to locally in inlineMethod):

import scala.annotation.MacroAnnotation
import scala.quoted.*

class annotation extends MacroAnnotation:
  def transform(using Quotes)(tree: quotes.reflect.Definition) =
    import quotes.reflect.*

    tree match
      case tree: ClassDef =>
        val List(DefDef(name, paramss, tpt, Some(body))) = tree.body: @unchecked

        val rhs = body match
          case Inlined(_, _, Block(List(Apply(_ /* `locally` */, List(rhs))), _)) => rhs

        val method = DefDef.copy(tree.body.head)(name, paramss, tpt, Some(rhs.changeOwner(tree.body.head.symbol)))

        List(ClassDef.copy(tree)(tree.name, tree.constructor, tree.parents, tree.self, List(method)))

Macro call site:

transparent inline def inlineMethod(v: Int) =
  locally(v)
  0

@annotation
class Test:
  def method = inlineMethod(42)

Output

When compiling with -Ycheck:all, the compiler crashes; otherwise, the code compiles. It seems that the transparent inline method is crucial to produce the crash.

Error and Stack Trace

```scala *** error while checking Test.scala after phase inlining *** java.util.NoSuchElementException: head of empty list while running Ycheck on Test.scala java.util.NoSuchElementException: head of empty list while compiling Test.scala, TestMacro.scala [error] ## Exception when compiling 2 sources [error] java.util.NoSuchElementException: head of empty list [error] scala.collection.immutable.Nil$.head(List.scala:662) [error] scala.collection.immutable.Nil$.head(List.scala:661) [error] dotty.tools.dotc.transform.YCheckPositions$$anon$1.traverse(YCheckPositions.scala:45) [error] dotty.tools.dotc.ast.Trees$Instance$TreeTraverser.apply(Trees.scala:1660) [error] dotty.tools.dotc.ast.Trees$Instance$TreeTraverser.apply(Trees.scala:1660) [error] dotty.tools.dotc.ast.Trees$Instance$TreeAccumulator.foldOver(Trees.scala:1620) [error] dotty.tools.dotc.ast.Trees$Instance$TreeTraverser.traverseChildren(Trees.scala:1661) [error] dotty.tools.dotc.transform.YCheckPositions$$anon$1.traverse(YCheckPositions.scala:53) [error] dotty.tools.dotc.ast.Trees$Instance$TreeTraverser.apply(Trees.scala:1660) [error] dotty.tools.dotc.ast.Trees$Instance$TreeTraverser.apply(Trees.scala:1660) [error] dotty.tools.dotc.ast.Trees$Instance$TreeAccumulator.fold$1(Trees.scala:1532) [error] dotty.tools.dotc.ast.Trees$Instance$TreeAccumulator.apply(Trees.scala:1534) [error] dotty.tools.dotc.ast.Trees$Instance$TreeAccumulator.foldOver(Trees.scala:1627) [error] dotty.tools.dotc.ast.Trees$Instance$TreeTraverser.traverseChildren(Trees.scala:1661) [error] dotty.tools.dotc.transform.YCheckPositions$$anon$1.traverse(YCheckPositions.scala:53) [error] dotty.tools.dotc.ast.Trees$Instance$TreeTraverser.apply(Trees.scala:1660) [error] dotty.tools.dotc.ast.Trees$Instance$TreeTraverser.apply(Trees.scala:1660) [error] dotty.tools.dotc.ast.Trees$Instance$TreeAccumulator.foldOver(Trees.scala:1624) [error] dotty.tools.dotc.ast.Trees$Instance$TreeTraverser.traverseChildren(Trees.scala:1661) [error] dotty.tools.dotc.transform.YCheckPositions$$anon$1.traverse(YCheckPositions.scala:53) [error] dotty.tools.dotc.ast.Trees$Instance$TreeTraverser.apply(Trees.scala:1660) [error] dotty.tools.dotc.ast.Trees$Instance$TreeTraverser.apply(Trees.scala:1660) [error] dotty.tools.dotc.ast.Trees$Instance$TreeAccumulator.fold$1(Trees.scala:1532) [error] dotty.tools.dotc.ast.Trees$Instance$TreeAccumulator.apply(Trees.scala:1534) [error] dotty.tools.dotc.ast.Trees$Instance$TreeAccumulator.foldOver(Trees.scala:1633) [error] dotty.tools.dotc.ast.Trees$Instance$TreeTraverser.traverseChildren(Trees.scala:1661) [error] dotty.tools.dotc.transform.YCheckPositions$$anon$1.traverse(YCheckPositions.scala:53) [error] dotty.tools.dotc.transform.YCheckPositions.checkPostCondition(YCheckPositions.scala:58) [error] dotty.tools.dotc.transform.TreeChecker$Checker.typedUnadapted$$anonfun$1(TreeChecker.scala:412) [error] scala.runtime.function.JProcedure1.apply(JProcedure1.java:15) [error] scala.runtime.function.JProcedure1.apply(JProcedure1.java:10) [error] scala.collection.immutable.List.foreach(List.scala:333) [error] dotty.tools.dotc.transform.TreeChecker$Checker.typedUnadapted(TreeChecker.scala:412) [error] dotty.tools.dotc.typer.Typer.typed(Typer.scala:3077) [error] dotty.tools.dotc.typer.Typer.typed(Typer.scala:3081) [error] dotty.tools.dotc.transform.TreeChecker$Checker.typed(TreeChecker.scala:378) [error] dotty.tools.dotc.typer.Typer.typedExpr(Typer.scala:3193) [error] dotty.tools.dotc.transform.TreeChecker.check(TreeChecker.scala:126) [error] dotty.tools.dotc.transform.TreeChecker.run(TreeChecker.scala:106) [error] dotty.tools.dotc.core.Phases$Phase.runOn$$anonfun$1(Phases.scala:324) [error] scala.collection.immutable.List.map(List.scala:246) [error] dotty.tools.dotc.core.Phases$Phase.runOn(Phases.scala:328) [error] dotty.tools.dotc.Run.runPhases$1$$anonfun$1(Run.scala:247) [error] scala.runtime.function.JProcedure1.apply(JProcedure1.java:15) [error] scala.runtime.function.JProcedure1.apply(JProcedure1.java:10) [error] scala.collection.ArrayOps$.foreach$extension(ArrayOps.scala:1321) [error] dotty.tools.dotc.Run.runPhases$1(Run.scala:263) [error] dotty.tools.dotc.Run.compileUnits$$anonfun$1(Run.scala:271) [error] dotty.tools.dotc.Run.compileUnits$$anonfun$adapted$1(Run.scala:280) [error] dotty.tools.dotc.util.Stats$.maybeMonitored(Stats.scala:67) [error] dotty.tools.dotc.Run.compileUnits(Run.scala:280) [error] dotty.tools.dotc.Run.compileUnits(Run.scala:201) [error] dotty.tools.dotc.Driver.finish(Driver.scala:56) [error] dotty.tools.dotc.Driver.doCompile(Driver.scala:36) [error] dotty.tools.xsbt.CompilerBridgeDriver.run(CompilerBridgeDriver.java:88) [error] dotty.tools.xsbt.CompilerBridge.run(CompilerBridge.java:22) ```

Note that I'm not entirely certain whether extracting a subtree of an Inlined node using Inlined(_, _, Block(List(Apply(_, List(rhs))), _)) is legal, but I think it should be (how else would you get the tree to process it further).

scala / scala3