Roll InstChecks into PostTyper

Move InstChecks functionality into PostTyper in order
to save a separate traversal.

Author: odersky

src/dotty/tools/dotc/Compiler.scala

@@ -39,7 +39,6 @@ class Compiler {
     List(
       List(new FrontEnd),
       List(new PostTyper),
-      List(new InstChecks),
       List(new FirstTransform,
            new SyntheticMethods),
       List(new Pickler), // Pickler needs to come last in a group since it should not pickle trees generated later

src/dotty/tools/dotc/core/SymDenotations.scala

@@ -210,6 +210,10 @@ object SymDenotations {
     /** Does this denotation have an annotation matching the given class symbol? */
     final def hasAnnotation(cls: Symbol)(implicit ctx: Context) =
       dropOtherAnnotations(annotations, cls).nonEmpty
+      
+    /** Apply transform `f` to all annotations of this denotation */
+    final def transformAnnotations(f: Annotation => Annotation)(implicit ctx: Context): Unit = 
+      annotations = annotations.mapConserve(f)
 
     /** Optionally, the annotation matching the given class symbol */
     final def getAnnotation(cls: Symbol)(implicit ctx: Context): Option[Annotation] =

src/dotty/tools/dotc/transform/FirstTransform.scala

@@ -35,10 +35,6 @@ class FirstTransform extends MiniPhaseTransform with IdentityDenotTransformer wi
   import ast.tpd._
 
   override def phaseName = "firstTransform"
-  
-  override def runsAfter = Set(classOf[typer.InstChecks]) 
-    // This phase makes annotations disappear in types, so InstChecks should
-    // run before so that it can get at all annotations.
 
   def transformInfo(tp: Type, sym: Symbol)(implicit ctx: Context): Type = tp
 

src/dotty/tools/dotc/transform/PostTyper.scala

@@ -7,7 +7,7 @@ import scala.collection.{ mutable, immutable }
 import ValueClasses._
 import scala.annotation.tailrec
 import core._
-import typer.InstChecks
+import typer.ErrorReporting._
 import Types._, Contexts._, Constants._, Names._, NameOps._, Flags._, DenotTransformers._
 import SymDenotations._, Symbols._, StdNames._, Annotations._, Trees._, Scopes._, Denotations._
 import util.Positions._
@@ -22,6 +22,8 @@ import Symbols._, TypeUtils._
  *      public parameter field in a superclass to a forwarder to the superclass
  *      field (corresponding = super class field is initialized with subclass field)
  *      (@see ForwardParamAccessors)
+ *      
+ *  (3) Check that `New` nodes can be instantiated, and that annotations are valid
  *  
  *  The reason for making this a macro transform is that some functions (in particular
  *  super and protected accessors and instantiation checks) are naturally top-down and
@@ -44,28 +46,89 @@ class PostTyper extends MacroTransform with IdentityDenotTransformer  { thisTran
 
   val superAcc = new SuperAccessors(thisTransformer)
   val paramFwd = new ParamForwarding(thisTransformer)
-//  val instChecks = new InstChecks
+
+  /** Check that `tp` refers to a nonAbstract class
+   *  and that the instance conforms to the self type of the created class.
+   */
+  private def checkInstantiable(tp: Type, pos: Position)(implicit ctx: Context): Unit =
+    tp.underlyingClassRef(refinementOK = false) match {
+      case tref: TypeRef =>
+        val cls = tref.symbol
+        if (cls.is(AbstractOrTrait))
+          ctx.error(d"$cls is abstract; cannot be instantiated", pos)
+        if (!cls.is(Module)) {
+          val selfType = tp.givenSelfType.asSeenFrom(tref.prefix, cls.owner)
+          if (selfType.exists && !(tp <:< selfType))
+            ctx.error(d"$tp does not conform to its self type $selfType; cannot be instantiated")
+        }
+      case _ =>
+    }
+  
+  private def newPart(tree: Tree): Option[New] = methPart(tree) match {
+    case Select(nu: New, _) => Some(nu)
+    case _ => None
+  }
+  
+  private def checkValidJavaAnnotation(annot: Tree)(implicit ctx: Context): Unit = {
+    // TODO fill in
+  }
 
   class PostTyperTransformer extends Transformer {
+    
+    private var inJavaAnnot: Boolean = false
+    
+    private var parentNews: Set[New] = Set()
+    
+    private def transformAnnot(annot: Tree)(implicit ctx: Context): Tree = {
+      val saved = inJavaAnnot
+      inJavaAnnot = annot.symbol is JavaDefined
+      if (inJavaAnnot) checkValidJavaAnnotation(annot)
+      try transform(annot)
+      finally inJavaAnnot = saved
+    }
+    
+    private def transformAnnot(annot: Annotation)(implicit ctx: Context): Annotation =
+      annot.derivedAnnotation(transformAnnot(annot.tree))
+    
+    private def transformAnnots(tree: MemberDef)(implicit ctx: Context): Unit =
+      tree.symbol.transformAnnotations(transformAnnot)
 
     override def transform(tree: Tree)(implicit ctx: Context): Tree =
       try tree match {
         case impl: Template =>
-          def trans(impl: Template) = 
-            cpy.Template(impl)(body = transformStats(impl.body, impl.symbol))
-          paramFwd.forwardParamAccessors(superAcc.wrapTemplate(impl)(trans))
+          val saved = parentNews
+          parentNews ++= impl.parents.flatMap(newPart)
+          try 
+            paramFwd.forwardParamAccessors(
+              superAcc.wrapTemplate(impl)(
+                super.transform(_).asInstanceOf[Template]))
+          finally parentNews = saved
         case tree @ TypeApply(sel: Select, args) =>
-          val sel1 = superAcc.transformSelect(super.transform(sel), args)
-          if (superAcc.isProtectedAccessor(sel1)) sel1 else cpy.TypeApply(tree)(sel1, args)
+          val args1 = transform(args)
+          val sel1 = superAcc.transformSelect(super.transform(sel), args1)
+          if (superAcc.isProtectedAccessor(sel1)) sel1 else cpy.TypeApply(tree)(sel1, args1)
         case sel: Select =>
           superAcc.transformSelect(super.transform(sel), Nil)
-        case tree: DefDef =>
-          superAcc.wrapDefDef(tree)(cpy.DefDef(tree)(rhs = transform(tree.rhs)))
-        case tree: Assign =>
+        case tree @ Assign(sel: Select, _) =>
           superAcc.transformAssign(super.transform(tree))
-//        case tree: Apply if tree.symbol.isConstructor =>
-//          instChecks.checkInstantiable(tree)
-//          super.transform(tree)
+        case tree: DefDef =>
+          transformAnnots(tree)
+          superAcc.wrapDefDef(tree)(super.transform(tree).asInstanceOf[DefDef])
+        case tree: MemberDef =>
+          transformAnnots(tree)
+          super.transform(tree)
+        case tree: New if !inJavaAnnot && !parentNews.contains(tree) =>
+          checkInstantiable(tree.tpe, tree.pos)
+          super.transform(tree)
+        case Annotated(annot, annotated) =>
+          cpy.Annotated(tree)(transformAnnot(annot), transform(annotated))
+        case tree: TypeTree =>
+          tree.withType(
+            tree.tpe match {
+              case AnnotatedType(annot, tpe) => AnnotatedType(transformAnnot(annot), tpe)
+              case tpe => tpe
+            }
+          )
         case _ =>
           super.transform(tree)
       }