Fix #4758: Revert "New phase for entering annotations"

compiler/src/dotty/tools/dotc/typer/FrontEnd.scala

@@ -55,12 +55,6 @@ class FrontEnd extends Phase {
     typr.println("entered: " + unit.source)
   }
 
-  def enterAnnotations(implicit ctx: Context) = monitor("annotating") {
-    val unit = ctx.compilationUnit
-    ctx.typer.annotate(unit.untpdTree :: Nil)
-    typr.println("annotated: " + unit.source)
-  }
-
   def typeCheck(implicit ctx: Context) = monitor("typechecking") {
     val unit = ctx.compilationUnit
     unit.tpdTree = ctx.typer.typedExpr(unit.untpdTree)
@@ -91,7 +85,6 @@ class FrontEnd extends Phase {
       enterSyms(remaining.head)
       remaining = remaining.tail
     }
-    unitContexts.foreach(enterAnnotations(_))
     unitContexts.foreach(typeCheck(_))
     record("total trees after typer", ast.Trees.ntrees)
     unitContexts.map(_.compilationUnit).filterNot(discardAfterTyper)

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

@@ -687,90 +687,14 @@ class Namer { typer: Typer =>
     ctxWithStats
   }
 
-  /** Add all annotations of definitions in `stats` to the defined symbols */
-  def annotate(stats: List[Tree])(implicit ctx: Context): Unit = {
-    def recur(stat: Tree): Unit = stat match {
-      case pcl: PackageDef =>
-        annotate(pcl.stats)
-      case stat: untpd.MemberDef =>
-        stat.getAttachment(SymOfTree) match {
-          case Some(sym) =>
-            sym.infoOrCompleter match {
-              case info: Completer if !defn.isPredefClass(sym.owner) =>
-                // Annotate Predef methods only when they are completed;
-                // This is necessary to break a cyclic dependence between `Predef`
-                // and `deprecated` in test `compileStdLib`.
-                addAnnotations(sym, stat)(info.creationContext)
-              case _ =>
-                // Annotations were already added as part of the symbol's completion
-            }
-          case none =>
-            assert(stat.typeOpt.exists, i"no symbol for $stat")
-        }
-      case stat: untpd.Thicket =>
-        stat.trees.foreach(recur)
-      case _ =>
-    }
-
-    for (stat <- stats) recur(expanded(stat))
-  }
-
-  /** Add annotations of `stat` to `sym`.
-   *  This method can be called twice on a symbol (e.g. once
-   *  during the `annotate` phase and then again during completion).
-   *  Therefore, care needs to be taken not to add annotations again
-   *  that are already added to the symbol.
-   */
-  def addAnnotations(sym: Symbol, stat: MemberDef)(implicit ctx: Context) = {
-    // (1) The context in which an annotation of a top-level class or module is evaluated
-    // is the closest enclosing context which has the enclosing package as owner.
-    // (2) The context in which an annotation for any other symbol is evaluated is the
-    // closest enclosing context which has the owner of the class enclosing the symbol as owner.
-    // E.g in
-    //
-    //     package p
-    //     import a.b
-    //     class C {
-    //       import d.e
-    //       @ann m() ...
-    //     }
-    //
-    // `@ann` is evaluated in the context just outside `C`, where the `a.b`
-    // import is visible but the `d.e` import is forgotten. This measure is necessary
-    // in order to avoid cycles.
-    lazy val annotCtx = {
-      var target = sym.owner.lexicallyEnclosingClass
-      if (!target.is(PackageClass)) target = target.owner
-      var c = ctx
-      while (c.owner != target) c = c.outer
-      c
-    }
-
-    for (annotTree <- untpd.modsDeco(stat).mods.annotations) {
-      val cls = typedAheadAnnotationClass(annotTree)(annotCtx)
-      if (sym.unforcedAnnotation(cls).isEmpty) {
-        val ann = Annotation.deferred(cls, implicit ctx => typedAheadAnnotation(annotTree))
-        sym.addAnnotation(ann)
-        if (cls == defn.ForceInlineAnnot && sym.is(Method, butNot = Accessor))
-          sym.setFlag(Inline)
-      }
-    }
-  }
-
-  def indexAndAnnotate(stats: List[Tree])(implicit ctx: Context): Context = {
-    val localCtx = index(stats)
-    annotate(stats)
-    localCtx
-  }
-
-  /** Index and annotate symbols in `tree` while asserting the `lateCompile` flag.
+  /** Index symbols in `tree` while asserting the `lateCompile` flag.
    *  This will cause any old top-level symbol with the same fully qualified
    *  name as a newly created symbol to be replaced.
    */
   def lateEnter(tree: Tree)(implicit ctx: Context) = {
     val saved = lateCompile
     lateCompile = true
-    try indexAndAnnotate(tree :: Nil) finally lateCompile = saved
+    try index(tree :: Nil) finally lateCompile = saved
   }
 
   def missingType(sym: Symbol, modifier: String)(implicit ctx: Context) = {
@@ -822,6 +746,19 @@ class Namer { typer: Typer =>
       else completeInCreationContext(denot)
     }
 
+    protected def addAnnotations(sym: Symbol): Unit = original match {
+      case original: untpd.MemberDef =>
+        lazy val annotCtx = annotContext(original, sym)
+        for (annotTree <- untpd.modsDeco(original).mods.annotations) {
+          val cls = typedAheadAnnotationClass(annotTree)(annotCtx)
+          val ann = Annotation.deferred(cls, implicit ctx => typedAnnotation(annotTree))
+          sym.addAnnotation(ann)
+          if (cls == defn.ForceInlineAnnot && sym.is(Method, butNot = Accessor))
+            sym.setFlag(Inline)
+        }
+      case _ =>
+    }
+
     private def addInlineInfo(sym: Symbol) = original match {
       case original: untpd.DefDef if sym.isInlineableMethod =>
         Inliner.registerInlineInfo(
@@ -836,10 +773,7 @@ class Namer { typer: Typer =>
      */
     def completeInCreationContext(denot: SymDenotation): Unit = {
       val sym = denot.symbol
-      original match {
-        case original: MemberDef => addAnnotations(sym, original)
-        case _ =>
-      }
+      addAnnotations(sym)
       addInlineInfo(sym)
       denot.info = typeSig(sym)
       Checking.checkWellFormed(sym)
@@ -955,7 +889,7 @@ class Namer { typer: Typer =>
         }
       }
 
-      addAnnotations(denot.symbol, original)
+      addAnnotations(denot.symbol)
 
       val selfInfo =
         if (self.isEmpty) NoType
@@ -978,9 +912,7 @@ class Namer { typer: Typer =>
       // accessors, that's why the constructor needs to be completed before
       // the parent types are elaborated.
       index(constr)
-      annotate(constr :: params)
-
-      indexAndAnnotate(rest)(ctx.inClassContext(selfInfo))
+      index(rest)(ctx.inClassContext(selfInfo))
       symbolOfTree(constr).ensureCompleted()
 
       val parentTypes = ensureFirstIsClass(parents.map(checkedParentType(_)), cls.pos)
@@ -1025,7 +957,7 @@ class Namer { typer: Typer =>
 
   /** Enter and typecheck parameter list */
   def completeParams(params: List[MemberDef])(implicit ctx: Context) = {
-    indexAndAnnotate(params)
+    index(params)
     for (param <- params) typedAheadExpr(param)
   }
 
@@ -1222,7 +1154,7 @@ class Namer { typer: Typer =>
     //   3. Info of CP is computed (to be copied to DP).
     //   4. CP is completed.
     //   5. Info of CP is copied to DP and DP is completed.
-    indexAndAnnotate(tparams)
+    index(tparams)
     if (isConstructor) sym.owner.typeParams.foreach(_.ensureCompleted())
     for (tparam <- tparams) typedAheadExpr(tparam)
 

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

@@ -91,7 +91,6 @@ class ReTyper extends Typer with ReChecking {
   override def localTyper(sym: Symbol) = this
 
   override def index(trees: List[untpd.Tree])(implicit ctx: Context) = ctx
-  override def annotate(trees: List[untpd.Tree])(implicit ctx: Context) = ()
 
   override def tryInsertApplyOrImplicit(tree: Tree, pt: ProtoType, locked: TypeVars)(fallBack: => Tree)(implicit ctx: Context): Tree =
     fallBack

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

@@ -659,7 +659,7 @@ class Typer extends Namer
   }
 
   def typedBlockStats(stats: List[untpd.Tree])(implicit ctx: Context): (Context, List[tpd.Tree]) =
-    (indexAndAnnotate(stats), typedStats(stats, ctx.owner))
+    (index(stats), typedStats(stats, ctx.owner))
 
   def typedBlock(tree: untpd.Block, pt: Type)(implicit ctx: Context) = track("typedBlock") {
     val (exprCtx, stats1) = typedBlockStats(tree.stats)
@@ -1270,7 +1270,7 @@ class Typer extends Namer
 
   def typedLambdaTypeTree(tree: untpd.LambdaTypeTree)(implicit ctx: Context): Tree = track("typedLambdaTypeTree") {
     val LambdaTypeTree(tparams, body) = tree
-    indexAndAnnotate(tparams)
+    index(tparams)
     val tparams1 = tparams.mapconserve(typed(_).asInstanceOf[TypeDef])
     val body1 = typedType(tree.body)
     assignType(cpy.LambdaTypeTree(tree)(tparams1, body1), tparams1, body1)
@@ -1339,20 +1339,26 @@ class Typer extends Namer
     assignType(cpy.Alternative(tree)(trees1), trees1)
   }
 
+  /** The context to be used for an annotation of `mdef`.
+   *  This should be the context enclosing `mdef`, or if `mdef` defines a parameter
+   *  the context enclosing the owner of `mdef`.
+   *  Furthermore, we need to evaluate annotation arguments in an expression context,
+   *  since classes defined in a such arguments should not be entered into the
+   *  enclosing class.
+   */
+  def annotContext(mdef: untpd.Tree, sym: Symbol)(implicit ctx: Context): Context = {
+    def isInner(owner: Symbol) = owner == sym || sym.is(Param) && owner == sym.owner
+    val c = ctx.outersIterator.dropWhile(c => isInner(c.owner)).next()
+    c.property(ExprOwner) match {
+      case Some(exprOwner) if c.owner.isClass => c.exprContext(mdef, exprOwner)
+      case _ => c
+    }
+  }
+
   def completeAnnotations(mdef: untpd.MemberDef, sym: Symbol)(implicit ctx: Context): Unit = {
     // necessary to force annotation trees to be computed.
     sym.annotations.foreach(_.ensureCompleted)
-    lazy val annotCtx = {
-      val c = ctx.outersIterator.dropWhile(_.owner == sym).next()
-      c.property(ExprOwner) match {
-        case Some(exprOwner) if c.owner.isClass =>
-          // We need to evaluate annotation arguments in an expression context, since
-          // classes defined in a such arguments should not be entered into the
-          // enclosing class.
-          c.exprContext(mdef, exprOwner)
-        case _ => c
-      }
-    }
+    lazy val annotCtx = annotContext(mdef, sym)
     // necessary in order to mark the typed ahead annotations as definitely typed:
     untpd.modsDeco(mdef).mods.annotations.foreach(typedAnnotation(_)(annotCtx))
   }

compiler/src/dotty/tools/repl/ReplFrontEnd.scala

@@ -21,7 +21,6 @@ private[repl] class REPLFrontEnd extends FrontEnd {
 
     val unitContext = ctx.fresh.setCompilationUnit(units.head)
     enterSyms(unitContext)
-    enterAnnotations(unitContext)
     typeCheck(unitContext)
     List(unitContext.compilationUnit)
   }

tests/neg/i3702.scala → tests/pos/i3702.scala

@@ -2,7 +2,7 @@ object test {
   class annot extends scala.annotation.Annotation
   def foo = {
     def bar(i: Int): Int = i
-    @annot class Silly {} // error: not found
+    @annot class Silly {} // used to be: not found, but now ok after backing out of 2b12868070be50fb70
     bar(5)
   }
 }

tests/pos/i4758/Test1.scala

@@ -0,0 +1,4 @@
+package foo.bar
+
+class Bar extends annotation.StaticAnnotation
+

tests/pos/i4758/Test2.scala

@@ -0,0 +1,7 @@
+package foo
+
+import foo.bar.Bar
+
+@Bar
+class Foo extends annotation.StaticAnnotation
+

tests/pos/i4758/Test3.scala

@@ -0,0 +1,3 @@
+package object foo {
+  @Foo class Hello
+}