Tweak setInfo and do not warn on return of arg

src/reflect/scala/reflect/api/Internals.scala

@@ -530,7 +530,7 @@ trait Internals { self: Universe =>
     /** Set symbol's type signature to given type.
      *  @return the symbol itself
      */
-    def setInfo[S <: Symbol](sym: S, tpe: Type): S
+    def setInfo[S <: Symbol](sym: S, tpe: Type): sym.type
 
     /** Set symbol's annotations to given annotations `annots`.
      */

src/reflect/scala/reflect/internal/ReificationSupport.scala

@@ -60,7 +60,7 @@ trait ReificationSupport { self: SymbolTable =>
     def setAnnotations[S <: Symbol](sym: S, annots: List[AnnotationInfo]): S =
       sym.setAnnotations(annots)
 
-    def setInfo[S <: Symbol](sym: S, tpe: Type): S =
+    def setInfo[S <: Symbol](sym: S, tpe: Type): sym.type =
       sym.setInfo(tpe).markAllCompleted()
 
     def mkThis(sym: Symbol): Tree = self.This(sym)

src/reflect/scala/reflect/internal/TreeInfo.scala

@@ -356,10 +356,12 @@ abstract class TreeInfo {
    *  where the op is an assignment operator.
    */
   def isThisTypeResult(tree: Tree): Boolean = tree match {
-    case Applied(fun @ Select(receiver, op), _, _) =>
+    case Applied(fun @ Select(receiver, op), _, argss) =>
       tree.tpe match {
-        case ThisType(sym) => sym == receiver.symbol
-        case SingleType(_, sym) => sym == receiver.symbol
+        case ThisType(sym) =>
+          sym == receiver.symbol
+        case SingleType(p, sym) =>
+          sym == receiver.symbol || argss.exists(_.exists(sym == _.symbol))
         case _ =>
           def check(sym: Symbol): Boolean =
             (sym == receiver.symbol) || {

test/files/neg/nonunit-statement.scala

@@ -189,3 +189,11 @@ final class ArrayOops[A](private val xs: Array[A]) extends AnyVal {
     }
   }
 }
+class Depends {
+  def f[A](a: A): a.type = a
+  def g() = {
+    val d = new Depends
+    f(d)
+    ()
+  }
+}

test/files/pos/skunky-expansion.scala

@@ -0,0 +1,31 @@
+// scalac: -Werror -Wnonunit-statement
+//
+import scala.reflect.macros._
+import scala.reflect.api.TypeCreator
+
+abstract trait Encoder[A] extends scala.AnyRef;
+object StringContextOps extends scala.AnyRef {
+  class StringOpsMacros(c: scala.reflect.macros.whitebox.Context) extends scala.AnyRef {
+    def sql_impl(argSeq: StringOpsMacros.this.c.universe.Tree*): AnyRef = {
+      val EncoderType: StringOpsMacros.this.c.universe.Type = StringOpsMacros.this.c.universe.typeOf[Encoder[_]](({
+        val $u: StringOpsMacros.this.c.universe.type = StringOpsMacros.this.c.universe;
+        val $m: $u.Mirror = StringOpsMacros.this.c.universe.rootMirror;
+        $u.TypeTag.apply[Encoder[_]]($m, {
+          final class $typecreator1 extends TypeCreator {
+            def apply[U <: scala.reflect.api.Universe with Singleton]($m$untyped: scala.reflect.api.Mirror[U]): U#Type = {
+              val $u: U = $m$untyped.universe;
+              val $m: $u.Mirror = $m$untyped.asInstanceOf[$u.Mirror];
+              val symdef$EncoderType1: $u.Symbol = $u.internal.reificationSupport.newNestedSymbol($u.internal.reificationSupport.selectTerm($u.internal.reificationSupport.selectType($m.staticModule("StringContextOps").asModule.moduleClass, "StringOpsMacros"), "sql_impl"), $u.TermName.apply("EncoderType"), $u.NoPosition, $u.internal.reificationSupport.FlagsRepr.apply(549755813888L), false);
+              val symdef$_$11: $u.Symbol = $u.internal.reificationSupport.newNestedSymbol(symdef$EncoderType1, $u.TypeName.apply("_$1"), $u.NoPosition, $u.internal.reificationSupport.FlagsRepr.apply(34359738384L), false);
+              $u.internal.reificationSupport.setInfo[$u.Symbol](symdef$EncoderType1, $u.NoType);
+              $u.internal.reificationSupport.setInfo[$u.Symbol](symdef$_$11, $u.internal.reificationSupport.TypeBounds($m.staticClass("scala.Nothing").asType.toTypeConstructor, $m.staticClass("scala.Any").asType.toTypeConstructor));
+              $u.internal.reificationSupport.ExistentialType(scala.collection.immutable.List.apply[$u.Symbol](symdef$_$11), $u.internal.reificationSupport.TypeRef($u.internal.reificationSupport.thisPrefix($m.EmptyPackageClass), $m.staticClass("Encoder"), scala.collection.immutable.List.apply[$u.Type]($u.internal.reificationSupport.TypeRef($u.NoPrefix, symdef$_$11, scala.collection.immutable.Nil))))
+            }
+          };
+          new $typecreator1()
+        })
+      }: StringOpsMacros.this.c.universe.TypeTag[Encoder[_]]));
+      argSeq.head
+    }
+  }
+}

test/files/pos/skunky.scala

@@ -0,0 +1,15 @@
+// scalac: -Werror -Wnonunit-statement
+
+import scala.reflect.macros._
+
+trait Encoder[A]
+
+object StringContextOps {
+  class StringOpsMacros(val c: whitebox.Context) {
+    import c.universe._
+    def sql_impl(argSeq: Tree*): Tree = {
+      val EncoderType = typeOf[Encoder[_]]
+      argSeq.head
+    }
+  }
+}