Merge pull request #1693 from dotty-staging/add-annotations-phase

Add annotations phase

Author: odersky

compiler/src/dotty/tools/dotc/ast/Trees.scala

@@ -32,7 +32,7 @@ object Trees {
   /** Property key for trees with documentation strings attached */
   val DocComment = new Property.Key[Comment]
 
-   @sharable private var nextId = 0 // for debugging
+  @sharable private var nextId = 0 // for debugging
 
   type LazyTree = AnyRef     /* really: Tree | Lazy[Tree] */
   type LazyTreeList = AnyRef /* really: List[Tree] | Lazy[List[Tree]] */

compiler/src/dotty/tools/dotc/core/Contexts.scala

@@ -216,8 +216,8 @@ object Contexts {
             else if (isNonEmptyScopeContext) scope.implicitDecls
             else Nil
           val outerImplicits =
-            if (isImportContext && importInfo.hiddenRoot.exists)
-              outer.implicits exclude importInfo.hiddenRoot
+            if (isImportContext && importInfo.unimported.exists)
+              outer.implicits exclude importInfo.unimported
             else
               outer.implicits
           if (implicitRefs.isEmpty) outerImplicits
@@ -422,9 +422,18 @@ object Contexts {
     final def withOwner(owner: Symbol): Context =
       if (owner ne this.owner) fresh.setOwner(owner) else this
 
-    override def toString =
+    final def withProperty[T](key: Key[T], value: Option[T]): Context =
+      if (property(key) == value) this
+      else value match {
+        case Some(v) => fresh.setProperty(key, v)
+        case None => fresh.dropProperty(key)
+      }
+
+    override def toString = {
+      def iinfo(implicit ctx: Context) = if (ctx.importInfo == null) "" else i"${ctx.importInfo.selectors}%, %"
       "Context(\n" +
-      (outersIterator map ( ctx => s"  owner = ${ctx.owner}, scope = ${ctx.scope}") mkString "\n")
+      (outersIterator map ( ctx => s"  owner = ${ctx.owner}, scope = ${ctx.scope}, import = ${iinfo(ctx)}") mkString "\n")
+    }
   }
 
   /** A condensed context provides only a small memory footprint over
@@ -468,6 +477,9 @@ object Contexts {
     def setProperty[T](key: Key[T], value: T): this.type =
       setMoreProperties(moreProperties.updated(key, value))
 
+    def dropProperty(key: Key[_]): this.type =
+      setMoreProperties(moreProperties - key)
+
     def setPhase(pid: PhaseId): this.type = setPeriod(Period(runId, pid))
     def setPhase(phase: Phase): this.type = setPeriod(Period(runId, phase.start, phase.end))
 

compiler/src/dotty/tools/dotc/core/Definitions.scala

@@ -650,6 +650,13 @@ class Definitions {
   def isTupleClass(cls: Symbol) = isVarArityClass(cls, tpnme.Tuple)
   def isProductClass(cls: Symbol) = isVarArityClass(cls, tpnme.Product)
 
+  val predefClassNames: Set[Name] =
+    Set("Predef$", "DeprecatedPredef", "LowPriorityImplicits").map(_.toTypeName)
+
+  /** Is `cls` the predef module class, or a class inherited by Predef? */
+  def isPredefClass(cls: Symbol) =
+    (cls.owner eq ScalaPackageClass) && predefClassNames.contains(cls.name)
+
   val StaticRootImportFns = List[() => TermRef](
     () => JavaLangPackageVal.termRef,
     () => ScalaPackageVal.termRef

compiler/src/dotty/tools/dotc/core/Phases.scala

@@ -26,7 +26,10 @@ trait Phases {
 
   def phasesStack: List[Phase] =
     if ((this eq NoContext) || !phase.exists) Nil
-    else phase :: outersIterator.dropWhile(_.phase == phase).next.phasesStack
+    else {
+      val rest = outersIterator.dropWhile(_.phase == phase)
+      phase :: (if (rest.hasNext) rest.next.phasesStack else Nil)
+    }
 
   /** Execute `op` at given phase */
   def atPhase[T](phase: Phase)(op: Context => T): T =

compiler/src/dotty/tools/dotc/printing/RefinedPrinter.scala

@@ -614,14 +614,12 @@ class RefinedPrinter(_ctx: Context) extends PlainPrinter(_ctx) {
       (sym.allOverriddenSymbols exists (_ is TypeParam))
 
   override def toText(sym: Symbol): Text = {
-    if (sym.isImport) {
-      def importString(tree: untpd.Tree) = s"import ${tree.show}"
+    if (sym.isImport)
       sym.infoOrCompleter match {
-        case info: Namer#Completer => return importString(info.original)
-        case info: ImportType => return importString(info.expr)
+        case info: Namer#Completer => return info.original.show
+        case info: ImportType => return s"import $info.expr.show"
         case _ =>
       }
-    }
     if (sym.is(ModuleClass))
       kindString(sym) ~~ (nameString(sym.name.stripModuleClassSuffix) + idString(sym))
     else

compiler/src/dotty/tools/dotc/repl/CompilingInterpreter.scala

@@ -6,7 +6,7 @@ import java.io.{
   File, PrintWriter, PrintStream, StringWriter, Writer, OutputStream,
   ByteArrayOutputStream => ByteOutputStream
 }
-import java.lang.{Class, ClassLoader}
+import java.lang.{Class, ClassLoader, Thread, System, StringBuffer}
 import java.net.{URL, URLClassLoader}
 
 import scala.collection.immutable.ListSet

compiler/src/dotty/tools/dotc/repl/InterpreterLoop.scala

@@ -4,7 +4,7 @@ package repl
 
 import java.io.{BufferedReader, File, FileReader, PrintWriter}
 import java.io.IOException
-import java.lang.{ClassLoader, System}
+import java.lang.{ClassLoader, System, Thread}
 import scala.concurrent.{Future, Await}
 import scala.concurrent.duration.Duration
 import reporting.Reporter

compiler/src/dotty/tools/dotc/transform/CollectEntryPoints.scala

@@ -9,7 +9,6 @@ import dotty.tools.dotc.core.Symbols.NoSymbol
 import scala.annotation.tailrec
 import dotty.tools.dotc.core._
 import Symbols._
-import scala.Some
 import dotty.tools.dotc.transform.TreeTransforms.{NXTransformations, TransformerInfo, TreeTransform, TreeTransformer}
 import dotty.tools.dotc.ast.tpd
 import dotty.tools.dotc.core.Contexts.Context

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

@@ -44,6 +44,12 @@ 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)
@@ -69,8 +75,9 @@ class FrontEnd extends Phase {
     }
     unitContexts foreach (parse(_))
     record("parsedTrees", ast.Trees.ntrees)
-    unitContexts foreach (enterSyms(_))
-    unitContexts foreach (typeCheck(_))
+    unitContexts.foreach(enterSyms(_))
+    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/ImportInfo.scala

@@ -95,14 +95,22 @@ class ImportInfo(symf: => Symbol, val selectors: List[untpd.Tree], val isRootImp
   /** The root import symbol hidden by this symbol, or NoSymbol if no such symbol is hidden.
    *  Note: this computation needs to work even for un-initialized import infos, and
    *  is not allowed to force initialization.
+   *
+   *  TODO: Once we have fully bootstrapped, I would prefer if we expressed
+   *  unimport with an `override` modifier, and generalized it to all imports.
+   *  I believe this would be more transparent than the curren set of conditions. E.g.
+   *
+   *      override import Predef.{any2stringAdd => _, StringAdd => _, _} // disables String +
+   *      override import java.lang.{}                                   // disables all imports
    */
-  lazy val hiddenRoot: Symbol = {
-    val sym = site.termSymbol
-    def hasMaskingSelector = selectors exists {
+  lazy val unimported: Symbol = {
+    lazy val sym = site.termSymbol
+    val hasMaskingSelector = selectors exists {
       case Thicket(_ :: Ident(nme.WILDCARD) :: Nil) => true
       case _ => false
     }
-    if ((defn.RootImportTypes exists (_.symbol == sym)) && hasMaskingSelector) sym else NoSymbol
+    if (hasMaskingSelector && defn.RootImportTypes.exists(_.symbol == sym)) sym
+    else NoSymbol
   }
 
   override def toString = {

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

@@ -528,18 +528,96 @@ class Namer { typer: Typer =>
       }
     }
 
-    stats foreach expand
+    stats.foreach(expand)
     mergeCompanionDefs()
     val ctxWithStats = (ctx /: stats) ((ctx, stat) => indexExpanded(stat)(ctx))
     createCompanionLinks(ctxWithStats)
     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 = typedAheadAnnotation(annotTree)(annotCtx)
+      if (sym.unforcedAnnotation(cls).isEmpty) {
+        val ann = Annotation.deferred(cls, implicit ctx => typedAnnotation(annotTree))
+        sym.addAnnotation(ann)
+        if (cls == defn.InlineAnnot && sym.is(Method, butNot = Accessor))
+          sym.setFlag(Inline)
+      }
+    }
+  }
+
+  def indexAndAnnotate(stats: List[Tree])(implicit ctx: Context): Context = {
+    val localCtx = index(stats)
+    annotate(stats)
+    localCtx
+  }
+
   /** The completer of a symbol defined by a member def or import (except ClassSymbols) */
   class Completer(val original: Tree)(implicit ctx: Context) extends LazyType {
 
     protected def localContext(owner: Symbol) = ctx.fresh.setOwner(owner).setTree(original)
 
+    /** The context with which this completer was created */
+    def creationContext = ctx
+
     protected def typeSig(sym: Symbol): Type = original match {
       case original: ValDef =>
         if (sym is Module) moduleValSig(sym)
@@ -572,19 +650,6 @@ class Namer { typer: Typer =>
       completeInCreationContext(denot)
     }
 
-    protected def addAnnotations(denot: SymDenotation): Unit = original match {
-      case original: untpd.MemberDef =>
-        var hasInlineAnnot = false
-        for (annotTree <- untpd.modsDeco(original).mods.annotations) {
-          val cls = typedAheadAnnotation(annotTree)
-          val ann = Annotation.deferred(cls, implicit ctx => typedAnnotation(annotTree))
-          denot.addAnnotation(ann)
-          if (cls == defn.InlineAnnot && denot.is(Method, butNot = Accessor))
-            denot.setFlag(Inline)
-        }
-      case _ =>
-    }
-
     private def addInlineInfo(denot: SymDenotation) = original match {
       case original: untpd.DefDef if denot.isInlineMethod =>
         Inliner.registerInlineInfo(
@@ -598,7 +663,10 @@ class Namer { typer: Typer =>
      *  to pick up the context at the point where the completer was created.
      */
     def completeInCreationContext(denot: SymDenotation): Unit = {
-      addAnnotations(denot)
+      original match {
+        case original: MemberDef => addAnnotations(denot.symbol, original)
+        case _ =>
+      }
       addInlineInfo(denot)
       denot.info = typeSig(denot.symbol)
       Checking.checkWellFormed(denot.symbol)
@@ -742,7 +810,7 @@ class Namer { typer: Typer =>
         ok
       }
 
-      addAnnotations(denot)
+      addAnnotations(denot.symbol, original)
 
       val selfInfo =
         if (self.isEmpty) NoType
@@ -765,9 +833,10 @@ 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)
       symbolOfTree(constr).ensureCompleted()
 
-      index(rest)(inClassContext(selfInfo))
+      indexAndAnnotate(rest)(inClassContext(selfInfo))
 
       val tparamAccessors = decls.filter(_ is TypeParamAccessor).toList
       val parentTypes = ensureFirstIsClass(parents.map(checkedParentType(_, tparamAccessors)))
@@ -790,7 +859,7 @@ class Namer { typer: Typer =>
       case Some(ttree) => ttree
       case none =>
         val ttree = typer.typed(tree, pt)
-        xtree.pushAttachment(TypedAhead, ttree)
+        xtree.putAttachment(TypedAhead, ttree)
         ttree
     }
   }
@@ -810,7 +879,7 @@ class Namer { typer: Typer =>
 
   /** Enter and typecheck parameter list */
   def completeParams(params: List[MemberDef])(implicit ctx: Context) = {
-    index(params)
+    indexAndAnnotate(params)
     for (param <- params) typedAheadExpr(param)
   }
 
@@ -990,7 +1059,7 @@ 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.
-    index(tparams)
+    indexAndAnnotate(tparams)
     if (isConstructor) sym.owner.typeParams.foreach(_.ensureCompleted())
     for (tparam <- tparams) typedAheadExpr(tparam)
 

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

@@ -72,6 +72,7 @@ class ReTyper extends Typer {
   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)(fallBack: (Tree, TyperState) => Tree)(implicit ctx: Context): Tree =
     fallBack(tree, ctx.typerState)