Merge pull request #641 from dotty-staging/change/early-annotations

Evaluate annotations in Namer

Author: odersky

src/dotty/tools/dotc/typer/Namer.scala

@@ -15,6 +15,7 @@ import annotation.tailrec
 import ErrorReporting._
 import tpd.ListOfTreeDecorator
 import config.Printers._
+import Annotations._
 import language.implicitConversions
 
 trait NamerContextOps { this: Context =>
@@ -495,8 +496,23 @@ class Namer { typer: Typer =>
       completeInCreationContext(denot)
     }
 
-    def completeInCreationContext(denot: SymDenotation): Unit =
+    protected def addAnnotations(denot: SymDenotation): Unit = original match {
+      case original: untpd.MemberDef =>
+        for (annotTree <- untpd.modsDeco(original).mods.annotations) {
+          val cls = typedAheadAnnotation(annotTree)
+          val ann = Annotation.deferred(cls, implicit ctx => typedAnnotation(annotTree))
+          denot.addAnnotation(ann)
+        }
+      case _ =>
+    }
+
+    /** Intentionally left without `implicit ctx` parameter. We need
+     *  to pick up the context at the point where the completer was created.
+     */
+    def completeInCreationContext(denot: SymDenotation): Unit = {
       denot.info = typeSig(denot.symbol)
+      addAnnotations(denot)
+    }
   }
 
   class ClassCompleter(cls: ClassSymbol, original: TypeDef)(ictx: Context) extends Completer(original)(ictx) {
@@ -563,6 +579,7 @@ class Namer { typer: Typer =>
 
       index(rest)(inClassContext(selfInfo))
       denot.info = ClassInfo(cls.owner.thisType, cls, parentRefs, decls, selfInfo)
+      addAnnotations(denot)
       cls.setApplicableFlags(
         (NoInitsInterface /: impl.body)((fs, stat) => fs & defKind(stat)))
     }
@@ -586,6 +603,13 @@ class Namer { typer: Typer =>
   def typedAheadExpr(tree: Tree, pt: Type = WildcardType)(implicit ctx: Context): tpd.Tree =
     typedAheadImpl(tree, pt)(ctx retractMode Mode.PatternOrType)
 
+  def typedAheadAnnotation(tree: Tree)(implicit ctx: Context): Symbol = tree match {
+    case Apply(fn, _) => typedAheadAnnotation(fn)
+    case TypeApply(fn, _) => typedAheadAnnotation(fn)
+    case Select(qual, nme.CONSTRUCTOR) => typedAheadAnnotation(qual)
+    case New(tpt) => typedAheadType(tpt).tpe.classSymbol
+  }
+
   /** Enter and typecheck parameter list */
   def completeParams(params: List[MemberDef])(implicit ctx: Context) = {
     index(params)

src/dotty/tools/dotc/typer/ReTyper.scala

@@ -72,9 +72,7 @@ class ReTyper extends Typer {
   override def tryInsertApplyOrImplicit(tree: Tree, pt: ProtoType)(fallBack: (Tree, TyperState) => Tree)(implicit ctx: Context): Tree =
     fallBack(tree, ctx.typerState)
 
-  override def addTypedModifiersAnnotations(mdef: untpd.MemberDef, sym: Symbol)(implicit ctx: Context): Unit =
-    () // was: typedModifiers(Modifiers(sym), sym)
-       // but annotations are not transformed after typer, so no use to check them.
+  override def completeAnnotations(mdef: untpd.MemberDef, sym: Symbol)(implicit ctx: Context): Unit = ()
 
   override def ensureConstrCall(cls: ClassSymbol, parents: List[Tree])(implicit ctx: Context): List[Tree] =
     parents

src/dotty/tools/dotc/typer/Typer.scala

@@ -860,15 +860,11 @@ class Typer extends Namer with TypeAssigner with Applications with Implicits wit
     assignType(cpy.Alternative(tree)(trees1), trees1)
   }
 
-  def addTypedModifiersAnnotations(mdef: untpd.MemberDef, sym: Symbol)(implicit ctx: Context): Unit = {
-    val mods1 = typedModifiers(untpd.modsDeco(mdef).mods, sym)
-    for (tree <- mods1.annotations) sym.addAnnotation(Annotation(tree))
-  }
-
-  def typedModifiers(mods: untpd.Modifiers, sym: Symbol)(implicit ctx: Context): Modifiers = track("typedModifiers") {
-    val annotations1 = mods.annotations mapconserve typedAnnotation
-    if (annotations1 eq mods.annotations) mods.asInstanceOf[Modifiers]
-    else Modifiers(mods.flags, mods.privateWithin, annotations1)
+  def completeAnnotations(mdef: untpd.MemberDef, sym: Symbol)(implicit ctx: Context): Unit = {
+    // necessary to force annotation trees to be computed.
+    sym.annotations.foreach(_.tree)
+    // necessary in order to mark the typed ahead annotations as definitiely typed:
+    untpd.modsDeco(mdef).mods.annotations.mapconserve(typedAnnotation)
   }
 
   def typedAnnotation(annot: untpd.Tree)(implicit ctx: Context): Tree = track("typedAnnotation") {
@@ -877,7 +873,7 @@ class Typer extends Namer with TypeAssigner with Applications with Implicits wit
 
   def typedValDef(vdef: untpd.ValDef, sym: Symbol)(implicit ctx: Context) = track("typedValDef") {
     val ValDef(name, tpt, _) = vdef
-    addTypedModifiersAnnotations(vdef, sym)
+    completeAnnotations(vdef, sym)
     val tpt1 = typedType(tpt)
     val rhs1 = vdef.rhs match {
       case rhs @ Ident(nme.WILDCARD) => rhs withType tpt1.tpe
@@ -888,7 +884,7 @@ class Typer extends Namer with TypeAssigner with Applications with Implicits wit
 
   def typedDefDef(ddef: untpd.DefDef, sym: Symbol)(implicit ctx: Context) = track("typedDefDef") {
     val DefDef(name, tparams, vparamss, tpt, _) = ddef
-    addTypedModifiersAnnotations(ddef, sym)
+    completeAnnotations(ddef, sym)
     val tparams1 = tparams mapconserve (typed(_).asInstanceOf[TypeDef])
     val vparamss1 = vparamss nestedMapconserve (typed(_).asInstanceOf[ValDef])
     if (sym is Implicit) checkImplicitParamsNotSingletons(vparamss1)
@@ -900,7 +896,7 @@ class Typer extends Namer with TypeAssigner with Applications with Implicits wit
 
   def typedTypeDef(tdef: untpd.TypeDef, sym: Symbol)(implicit ctx: Context): Tree = track("typedTypeDef") {
     val TypeDef(name, rhs) = tdef
-    addTypedModifiersAnnotations(tdef, sym)
+    completeAnnotations(tdef, sym)
     val _ = typedType(rhs) // unused, typecheck only to remove from typedTree
     assignType(cpy.TypeDef(tdef)(name, TypeTree(sym.info), Nil), sym)
   }
@@ -916,7 +912,7 @@ class Typer extends Namer with TypeAssigner with Applications with Implicits wit
         result
       }
 
-    addTypedModifiersAnnotations(cdef, cls)
+    completeAnnotations(cdef, cls)
     val constr1 = typed(constr).asInstanceOf[DefDef]
     val parentsWithClass = ensureFirstIsClass(parents mapconserve typedParent, cdef.pos.toSynthetic)
     val parents1 = ensureConstrCall(cls, parentsWithClass)(superCtx)