initial works

Author: liufengyun

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

@@ -50,8 +50,17 @@ class PatternMatcher extends MiniPhaseTransform with DenotTransformer {thisTrans
   private var _id = 0 // left for debuging
 
   override def transformMatch(tree: Match)(implicit ctx: Context, info: TransformerInfo): Tree = {
+    val Match(sel, cases) = tree
+
     val translated = new Translator()(ctx).translator.translateMatch(tree)
 
+    // check exhaustivity and unreachability
+    val engine = new SpaceEngine
+    if (!engine.skipCheck(sel.tpe)) {
+      engine.exhaustivity(tree)
+      engine.redundancy(tree)
+    }
+
     translated.ensureConforms(tree.tpe)
   }
 
@@ -1275,6 +1284,7 @@ class PatternMatcher extends MiniPhaseTransform with DenotTransformer {thisTrans
         case _                                                    => (cases, None)
       }
 
+
       // checkMatchVariablePatterns(nonSyntheticCases) // only used for warnings
 
       // we don't transform after uncurry

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

@@ -38,6 +38,8 @@ import Symbols._, TypeUtils._
  *
  *  (9) Adds SourceFile annotations to all top-level classes and objects
  *
+ *  (10) Adds Child annotations to all sealed classes
+ *
  *  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
  *  don't lend themselves to the bottom-up approach of a mini phase. The other two functions
@@ -231,6 +233,13 @@ class PostTyper extends MacroTransform with IdentityDenotTransformer  { thisTran
                   ctx.compilationUnit.source.exists &&
                   sym != defn.SourceFileAnnot)
                 sym.addAnnotation(Annotation.makeSourceFile(ctx.compilationUnit.source.file.path))
+
+              if (!sym.isAnonymousClass) // ignore anonymous class
+                for (parent <- sym.asClass.classInfo.classParents) {
+                  val pclazz = parent.classSymbol
+                  if (pclazz.is(Sealed)) pclazz.addAnnotation(Annotation.makeChild(sym))
+                }
+
               tree
             }
             else {