Re-fix skipping match analysis & inlining

Author: dwijnand

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

@@ -35,13 +35,6 @@ class PatternMatcher extends MiniPhase {
 
   override def runsAfter: Set[String] = Set(ElimRepeated.name)
 
-  private val InInlinedCode = new util.Property.Key[Boolean]
-  private def inInlinedCode(using Context) = ctx.property(InInlinedCode).getOrElse(false)
-
-  override def prepareForInlined(tree: Inlined)(using Context): Context =
-    if inInlinedCode then ctx
-    else ctx.fresh.setProperty(InInlinedCode, true)
-
   override def transformMatch(tree: Match)(using Context): Tree =
     if (tree.isInstanceOf[InlineMatch]) tree
     else {
@@ -53,13 +46,10 @@ class PatternMatcher extends MiniPhase {
         case rt => tree.tpe
       val translated = new Translator(matchType, this).translateMatch(tree)
 
-      if !inInlinedCode then
+      // Skip analysis on inlined code (eg pos/i19157)
+      if !tpd.enclosingInlineds.nonEmpty then
         // check exhaustivity and unreachability
         SpaceEngine.checkMatch(tree)
-      else
-        // only check exhaustivity, as inlining may generate unreachable code 
-        // like in i19157.scala
-        SpaceEngine.checkMatchExhaustivityOnly(tree)
 
       translated.ensureConforms(matchType)
     }

compiler/src/dotty/tools/dotc/transform/patmat/Space.scala

@@ -901,9 +901,6 @@ object SpaceEngine {
   }
 
   def checkMatch(m: Match)(using Context): Unit =
-    checkMatchExhaustivityOnly(m)
-    if reachabilityCheckable(m.selector) then checkReachability(m)
-  
-  def checkMatchExhaustivityOnly(m: Match)(using Context): Unit =
     if exhaustivityCheckable(m.selector) then checkExhaustivity(m)
+    if reachabilityCheckable(m.selector) then checkReachability(m)
 }