An annotation should not prevent an inferred type from being widened.

scala · Jan 17, 2018 · f895d81 · f895d81
1 parent 8b91a3b
commit f895d81
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Showing 4 changed files with 41 additions and 2 deletions.
diff --git a/src/compiler/scala/tools/nsc/typechecker/Namers.scala b/src/compiler/scala/tools/nsc/typechecker/Namers.scala
@@ -1063,7 +1063,11 @@ trait Namers extends MethodSynthesis {
       // Are we inferring the result type of a stable symbol, whose type doesn't refer to a hidden symbol?
       // If we refer to an inaccessible symbol, let's hope widening will result in an expressible type.
       // (A LiteralType should be widened because it's too precise for a definition's type.)
-      val mayKeepSingletonType = !tpe.isInstanceOf[ConstantType] && sym.isStable && !refersToSymbolLessAccessibleThan(tpe, sym)
+      val mayKeepSingletonType =
+        tpe match {
+          case ConstantType(_) | AnnotatedType(_, ConstantType(_)) => false
+          case _ => sym.isStable && !refersToSymbolLessAccessibleThan(tpe, sym)
+        }
 
       // Only final vals may be constant folded, so deconst inferred type of other members.
       @inline def keepSingleton = if (sym.isFinal) tpe else tpe.deconst

diff --git a/test/files/neg/sip23-widen.check b/test/files/neg/sip23-widen.check
@@ -48,4 +48,9 @@ sip23-widen.scala:62: error: type mismatch;
  required: 4
   f13 = 5
         ^
-10 errors found
+sip23-widen.scala:75: error: type mismatch;
+ found   : Test.annot0.type (with underlying type Int)
+ required: 1 @unchecked
+  annot0: 1 @unchecked
+  ^
+11 errors found
diff --git a/test/files/neg/sip23-widen.scala b/test/files/neg/sip23-widen.scala
@@ -60,4 +60,23 @@ object Test {
   //f13: Int
   //f13: 4
   f13 = 5
+
+  //final val one = 1
+  //final val compiles: 2 = one + 1
+
+  //final val literalOne: 1 = 1
+  //final val alsoCompiles: 2 = literalOne + 1
+
+  //final val recFive : 5 = recFive + 0
+
+  val annot0 = 1: @unchecked
+  //annot0: Int
+  //annot0: Int @unchecked
+  annot0: 1 @unchecked
+
+  //final val annot1 = 1: @unchecked
+  //annot1: Int
+  //annot1: Int @unchecked
+  //annot1: 1
+  //annot1: 1 @unchecked
 }
diff --git a/test/files/pos/sip23-widen.scala b/test/files/pos/sip23-widen.scala
@@ -68,4 +68,15 @@ object Test {
   final val alsoCompiles: 2 = literalOne + 1
 
   final val recFive : 5 = recFive + 0
+
+  val annot0 = 1: @unchecked
+  annot0: Int
+  annot0: Int @unchecked
+  //annot0: 1 @unchecked
+
+  final val annot1 = 1: @unchecked
+  annot1: Int
+  annot1: Int @unchecked
+  annot1: 1
+  annot1: 1 @unchecked
 }