Merge pull request scala#2152 from retronym/topic/annotatedRetyping-2.10.1

SI-7163 backport of annotated retyping to 2.10.1

Author: adriaanm

src/compiler/scala/tools/nsc/typechecker/Typers.scala

@@ -4153,15 +4153,11 @@ trait Typers extends Modes with Adaptations with Tags {
         def resultingTypeTree(tpe: Type) = {
           // we need symbol-ful originals for reification
           // hence we go the extra mile to hand-craft tis guy
-          val original =
-            if (arg1.isType)
-              arg1 match {
-                case tt @ TypeTree() => Annotated(ann, tt.original)
-                // this clause is needed to correctly compile stuff like "new C @D" or "@(inline @getter)"
-                case _ => Annotated(ann, arg1)
-              }
-            else
-              tree
+          val original = arg1 match {
+            case tt @ TypeTree() => Annotated(ann, tt.original)
+            // this clause is needed to correctly compile stuff like "new C @D" or "@(inline @getter)"
+            case _ => Annotated(ann, arg1)
+          }
           original setType ann.tpe
           TypeTree(tpe) setOriginal original setPos tree.pos.focus
         }

test/files/pos/annotated-original/C_2.scala

@@ -0,0 +1,7 @@
+object Bug {
+  M.m {
+    def s = ""
+    M.m(s): @unchecked // error: macro has not been expanded.
+    ???
+  }
+}

test/files/pos/annotated-original/M_1.scala

@@ -0,0 +1,7 @@
+import language.experimental.macros
+import reflect.macros.Context
+
+object M {
+  def impl(c: Context)(a: c.Expr[Any]) = c.Expr[Any](c.resetLocalAttrs(a.tree))
+  def m(a: Any) = macro impl
+}

test/files/run/annotatedRetyping.check

@@ -0,0 +1,6 @@
+typing List(1, 2).map(((x) => {
+  val another = scala.Tuple2(t.nt, t.tr): @testAnn match {
+    case scala.Tuple2(_, _) => 1
+  };
+  x
+}))

test/files/run/annotatedRetyping.scala

@@ -0,0 +1,62 @@
+import scala.tools.partest._
+import scala.tools.nsc._
+
+object Test extends DirectTest {
+
+  override def extraSettings: String = "-usejavacp"
+
+  def code = """
+    class testAnn extends annotation.Annotation
+
+    object t {
+      def nt = 1
+      def tr = "a"
+    }
+
+    class Test {
+      List(1,2).map(x => {
+        val another = ((t.nt, t.tr): @testAnn) match { case (_, _) => 1 }
+        x
+      })
+    }
+  """.trim
+
+
+  // point of this test: type-check the "Annotated" tree twice. first time the analyzer plugin types it,
+  // second time the typer.
+
+  // bug was that typedAnnotated assigned a type to the Annotated tree. The second type check would consider
+  // the tree as alreadyTyped, which is not cool, the Annotated needs to be transformed into a Typed tree.
+
+  def show() {
+    val global = newCompiler()
+    import global._
+    import analyzer._
+    import collection.{mutable => m}
+
+    object analyzerPlugin extends AnalyzerPlugin {
+    val templates: m.Map[Symbol, (Template, Typer)] = m.Map()
+      override def pluginsTypeSig(tpe: Type, typer: Typer, defTree: Tree, pt: Type): Type = {
+        defTree match {
+          case impl: Template =>
+            templates += typer.context.owner -> (impl, typer)
+  
+          case dd: DefDef if dd.symbol.isPrimaryConstructor && templates.contains(dd.symbol.owner) =>
+            val (impl, templTyper) = templates(dd.symbol.owner)
+            for (stat <- impl.body.filterNot(_.isDef)) {
+              println("typing "+ stat)
+              val statsOwner = impl.symbol orElse templTyper.context.owner.newLocalDummy(impl.pos)
+              val tpr = analyzer.newTyper(templTyper.context.make(stat, statsOwner))
+              tpr.typed(stat)
+            }
+
+          case _ => 
+        }
+        tpe
+      }
+    }
+
+    addAnalyzerPlugin(analyzerPlugin)
+    compileString(global)(code)
+  }
+}