Fix a bug where QuoteMatcher does not compare nested erased params

Author: zeptometer

compiler/src/scala/quoted/runtime/impl/QuoteMatcher.scala

@@ -383,11 +383,14 @@ object QuoteMatcher {
             case scrutinee @ DefDef(_, paramss1, tpt1, _) =>
               pattern match
                 case pattern @ DefDef(_, paramss2, tpt2, _) =>
-                  def matchErasedParams(scrutinee: DefDef, pattern: DefDef): optional[MatchingExprs] =
-                    (scrutinee.tpe.widenTermRefExpr, pattern.tpe.widenTermRefExpr) match
+                  def matchErasedParams(sctype: Type, pttype: Type): optional[MatchingExprs] =
+                    (sctype, pttype) match
                       case (sctpe: MethodType, pttpe: MethodType) =>
-                        if sctpe.erasedParams.sameElements(pttpe.erasedParams) then matched else notMatched
-                      case _ => notMatched
+                        if sctpe.erasedParams.sameElements(pttpe.erasedParams) then
+                          matchErasedParams(sctpe.resType, pttpe.resType)
+                        else
+                          notMatched
+                      case _ => matched
 
                   def matchParamss(scparamss: List[ParamClause], ptparamss: List[ParamClause])(using Env): optional[(Env, MatchingExprs)] =
                     (scparamss, ptparamss) match {
@@ -400,7 +403,7 @@ object QuoteMatcher {
                       case _ => notMatched
                     }
 
-                  val ematch = matchErasedParams(scrutinee, pattern)
+                  val ematch = matchErasedParams(scrutinee.tpe.widenTermRefExpr, pattern.tpe.widenTermRefExpr)
                   val (pEnv, pmatch) = matchParamss(paramss1, paramss2)
                   val defEnv = pEnv + (scrutinee.symbol -> pattern.symbol)
 

tests/run-custom-args/run-macros-erased/i17105.check

@@ -1 +1,2 @@
 case erased: [erased case]
+case erased nested: -10

tests/run-custom-args/run-macros-erased/i17105/Macro_1.scala

@@ -8,4 +8,13 @@ def testExprImpl(body: Expr[Any])(using Quotes): Expr[String] =
       Expr("This case should not match")
     case '{ def erasedfn(erased y: String) = "placeholder"; $a(erasedfn): String } =>
       '{ $a((erased z: String) => "[erased case]") }
+    case '{
+      def erasedfn(a: Int)(b: Int): Int = a
+      $y(erasedfn): String
+    } => Expr("This should not match")
+    case '{
+      def erasedfn(a: Int)(erased b: Int): Int = a
+      $y(erasedfn): String
+    } =>
+      '{ $y((a: Int) => (erased b: Int) => -a) }
     case _ => Expr("not matched")

tests/run-custom-args/run-macros-erased/i17105/Test_2.scala

@@ -1,2 +1,3 @@
 @main def Test: Unit =
   println("case erased: " + testExpr { def erasedfn1(erased x: String) = "placeholder"; erasedfn1("arg1")})
+  println("case erased nested: " + testExpr { def erasedfn2(p: Int)(erased q: Int) = p; erasedfn2(10)(0).toString() })