From 5a4fe8988c7c011554fef0c31777f74642914486 Mon Sep 17 00:00:00 2001
From: Nicolas Stucki <nicolas.stucki@gmail.com>
Date: Tue, 12 May 2020 16:48:03 +0200
Subject: [PATCH] Fix #8520: Add Reflection.Symbol.typeMembers

---
 .../tastyreflect/ReflectionCompilerInterface.scala  |  6 ++++++
 library/src/scala/tasty/Reflection.scala            |  8 ++++++++
 .../src/scala/tasty/reflect/CompilerInterface.scala |  6 ++++++
 tests/run-macros/i8520.check                        |  3 +++
 tests/run-macros/i8520/Macro_1.scala                | 13 +++++++++++++
 tests/run-macros/i8520/Test_2.scala                 |  9 +++++++++
 6 files changed, 45 insertions(+)
 create mode 100644 tests/run-macros/i8520.check
 create mode 100644 tests/run-macros/i8520/Macro_1.scala
 create mode 100644 tests/run-macros/i8520/Test_2.scala

diff --git a/compiler/src/dotty/tools/dotc/tastyreflect/ReflectionCompilerInterface.scala b/compiler/src/dotty/tools/dotc/tastyreflect/ReflectionCompilerInterface.scala
index c2bb1173aced..60527714850a 100644
--- a/compiler/src/dotty/tools/dotc/tastyreflect/ReflectionCompilerInterface.scala
+++ b/compiler/src/dotty/tools/dotc/tastyreflect/ReflectionCompilerInterface.scala
@@ -1732,6 +1732,12 @@ class ReflectionCompilerInterface(val rootContext: core.Contexts.Context) extend
       case sym if isMethod(sym) && sym.name.toString == name => sym.asTerm
     }.toList
 
+  def Symbol_typeMembers(self: Symbol)(using ctx: Context): List[Symbol] =
+    self.unforcedDecls.filter(_.isType)
+
+  def Symbol_typeMember(self: Symbol)(name: String)(using ctx: Context): Symbol =
+    self.unforcedDecls.find(sym => sym.name == name.toTypeName)
+
   def Symbol_classMethods(self: Symbol)(using ctx: Context): List[Symbol] =
     self.typeRef.decls.iterator.collect {
       case sym if isMethod(sym) => sym.asTerm
diff --git a/library/src/scala/tasty/Reflection.scala b/library/src/scala/tasty/Reflection.scala
index d3f6e63719b7..b6f881f4584c 100644
--- a/library/src/scala/tasty/Reflection.scala
+++ b/library/src/scala/tasty/Reflection.scala
@@ -2219,6 +2219,14 @@ class Reflection(private[scala] val internal: CompilerInterface) { self =>
     def classMethods(using ctx: Context): List[Symbol] =
       internal.Symbol_classMethods(sym)
 
+    /** Type member directly declared in the class */
+    def typeMembers(using ctx: Context): List[Symbol] =
+      internal.Symbol_typeMembers(sym)
+
+    /** Type member with the given name directly declared in the class */
+    def typeMember(name: String)(using ctx: Context): Symbol =
+      internal.Symbol_typeMember(sym)(name)
+
     /** Get named non-private methods declared or inherited */
     def method(name: String)(using ctx: Context): List[Symbol] =
       internal.Symbol_method(sym)(name)
diff --git a/library/src/scala/tasty/reflect/CompilerInterface.scala b/library/src/scala/tasty/reflect/CompilerInterface.scala
index 55ac971e4ffb..d8ae349f6594 100644
--- a/library/src/scala/tasty/reflect/CompilerInterface.scala
+++ b/library/src/scala/tasty/reflect/CompilerInterface.scala
@@ -1308,6 +1308,12 @@ trait CompilerInterface {
   /** Get all non-private methods declared or inherited */
   def Symbol_methods(self: Symbol)(using ctx: Context): List[Symbol]
 
+  /** Type member directly declared in the class */
+  def Symbol_typeMembers(self: Symbol)(using ctx: Context): List[Symbol]
+
+  /** Type member with the given name directly declared in the class */
+  def Symbol_typeMember(self: Symbol)(name: String)(using ctx: Context): Symbol
+
   /** The symbols of each type parameter list and value parameter list of this
    *  method, or Nil if this isn't a method.
    */
diff --git a/tests/run-macros/i8520.check b/tests/run-macros/i8520.check
new file mode 100644
index 000000000000..ef34dd33b1e3
--- /dev/null
+++ b/tests/run-macros/i8520.check
@@ -0,0 +1,3 @@
+List((A,+))
+List((B,-))
+List((C, ))
diff --git a/tests/run-macros/i8520/Macro_1.scala b/tests/run-macros/i8520/Macro_1.scala
new file mode 100644
index 000000000000..7ad9e353bb35
--- /dev/null
+++ b/tests/run-macros/i8520/Macro_1.scala
@@ -0,0 +1,13 @@
+import scala.quoted._
+
+inline def test[T[_]]: Unit = ${ testExpr[T] }
+
+def testExpr[T[_]: Type](using QuoteContext): Expr[Unit] = {
+  import qctx.tasty._
+  def variance(f: Flags) =
+     if f.is(Flags.Covariant) then "+"
+     else if f.is(Flags.Contravariant) then "-"
+     else " "
+  val t = '[T].unseal.tpe.typeSymbol.typeMembers.map(x => (x.name, variance(x.flags)))
+  '{ println(${Expr(t.toString)}) }
+}
diff --git a/tests/run-macros/i8520/Test_2.scala b/tests/run-macros/i8520/Test_2.scala
new file mode 100644
index 000000000000..c2448eb71651
--- /dev/null
+++ b/tests/run-macros/i8520/Test_2.scala
@@ -0,0 +1,9 @@
+trait X[+A]
+trait Y[-B]
+trait Z[C]
+
+@main def Test = {
+  test[X]
+  test[Y]
+  test[Z]
+}