From b39fe3bbbaeeefacffab04e532918d832b2f3093 Mon Sep 17 00:00:00 2001
From: Nicolas Stucki <nicolas.stucki@gmail.com>
Date: Fri, 9 Apr 2021 11:09:13 +0200
Subject: [PATCH] Add `TermParamClause.isErased`

---
 compiler/src/scala/quoted/runtime/impl/QuotesImpl.scala | 2 ++
 library/src/scala/quoted/Quotes.scala                   | 2 ++
 tests/run-macros/i12021.check                           | 5 +++--
 tests/run-macros/i12021/Macro_1.scala                   | 8 +++++---
 tests/run-macros/i12021/Test_2.scala                    | 3 +++
 5 files changed, 15 insertions(+), 5 deletions(-)

diff --git a/compiler/src/scala/quoted/runtime/impl/QuotesImpl.scala b/compiler/src/scala/quoted/runtime/impl/QuotesImpl.scala
index efed80239b88..9a1df9d01f2d 100644
--- a/compiler/src/scala/quoted/runtime/impl/QuotesImpl.scala
+++ b/compiler/src/scala/quoted/runtime/impl/QuotesImpl.scala
@@ -1512,6 +1512,8 @@ class QuotesImpl private (using val ctx: Context) extends Quotes, QuoteUnpickler
           self.nonEmpty && self.head.symbol.is(dotc.core.Flags.Implicit)
         def isGiven: Boolean =
           self.nonEmpty && self.head.symbol.is(dotc.core.Flags.Given)
+        def isErased: Boolean =
+          self.nonEmpty && self.head.symbol.is(dotc.core.Flags.Erased)
     end TermParamClauseMethods
 
     type TypeParamClause = List[tpd.TypeDef]
diff --git a/library/src/scala/quoted/Quotes.scala b/library/src/scala/quoted/Quotes.scala
index d97be901355a..a864a4b3fd3b 100644
--- a/library/src/scala/quoted/Quotes.scala
+++ b/library/src/scala/quoted/Quotes.scala
@@ -2160,6 +2160,8 @@ trait Quotes { self: runtime.QuoteUnpickler & runtime.QuoteMatching =>
         def isImplicit: Boolean
         /** Is this a given parameter clause `(using X1, ..., Xn)` or `(using x1: X1, ..., xn: Xn)` */
         def isGiven: Boolean
+        /** Is this a erased parameter clause `(erased x1: X1, ..., xn: Xn)` */
+        def isErased: Boolean
     end TermParamClauseMethods
 
     /** A type parameter clause `[X1, ..., Xn]` */
diff --git a/tests/run-macros/i12021.check b/tests/run-macros/i12021.check
index dccff2b4e6a5..b244dce80b34 100644
--- a/tests/run-macros/i12021.check
+++ b/tests/run-macros/i12021.check
@@ -1,2 +1,3 @@
-X1: (i: scala.Int) isImplicit=true, isGiven=false
-X2: (i: scala.Int) isImplicit=false, isGiven=true
+X1: (i: scala.Int) isImplicit=true, isGiven=false, isErased=false
+X2: (i: scala.Int) isImplicit=false, isGiven=true, isErased=false
+X3: (i: scala.Int) isImplicit=false, isGiven=false, isErased=true
diff --git a/tests/run-macros/i12021/Macro_1.scala b/tests/run-macros/i12021/Macro_1.scala
index 89dcaaaf5634..4c10cf2ca17d 100644
--- a/tests/run-macros/i12021/Macro_1.scala
+++ b/tests/run-macros/i12021/Macro_1.scala
@@ -6,10 +6,12 @@ inline def inspect[A]: String =
 def inspect2[A: Type](using Quotes): Expr[String] = {
   import quotes.reflect.*
 
-  val DefDef(_, List(Nil, ps: TermParamClause), _, _) =
-    TypeRepr.of[A].typeSymbol.primaryConstructor.tree
+  val ps =
+    TypeRepr.of[A].typeSymbol.primaryConstructor.tree match
+      case DefDef(_, List(Nil, ps: TermParamClause), _, _) => ps
+      case DefDef(_, List(ps: TermParamClause), _, _) => ps
 
   val names = ps.params.map(p => s"${p.name}: ${p.tpt.show}").mkString("(", ", ", ")")
 
-  Expr(s"${Type.show[A]}: $names isImplicit=${ps.isImplicit}, isGiven=${ps.isGiven}")
+  Expr(s"${Type.show[A]}: $names isImplicit=${ps.isImplicit}, isGiven=${ps.isGiven}, isErased=${ps.isErased}")
 }
diff --git a/tests/run-macros/i12021/Test_2.scala b/tests/run-macros/i12021/Test_2.scala
index 96683b2c6583..17f74792ece4 100644
--- a/tests/run-macros/i12021/Test_2.scala
+++ b/tests/run-macros/i12021/Test_2.scala
@@ -1,8 +1,11 @@
+import scala.language.experimental.erasedDefinitions
 
 class X1(implicit i: Int)
 class X2(using i: Int)
+class X3(erased i: Int)
 
 @main def Test = {
   println(inspect[X1])
   println(inspect[X2])
+  println(inspect[X3])
 }
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