Elide prefixes in printed types uniformly in runtime reflection

retronym · retronym · commit 9c7362b70957 · 2017-12-05T15:38:06.000+10:00
The logic that decides to print `Function`, rather than `scala.Function`
did not account for the multiplicity of symbols for a given package
in the JavaMirrors universe.
diff --git a/src/reflect/scala/reflect/internal/Symbols.scala b/src/reflect/scala/reflect/internal/Symbols.scala
@@ -869,10 +869,13 @@ trait Symbols extends api.Symbols { self: SymbolTable =>
     /** Conditions where we omit the prefix when printing a symbol, to avoid
      *  unpleasantries like Predef.String, $iw.$iw.Foo and <empty>.Bippy.
      */
-    final def isOmittablePrefix = /*!settings.debug.value &&*/ (
-         UnqualifiedOwners(skipPackageObject)
-      || isEmptyPrefix
-    )
+    final def isOmittablePrefix = /*!settings.debug.value &&*/ {
+      // scala/bug#5941 runtime reflection can have distinct symbols representing `package scala` (from different mirrors)
+      // We check equality by FQN here to make sure we omit prefixes uniformly for all of them.
+      def matches(sym1: Symbol, sym2: Symbol) = (sym1 eq sym2) || (sym1.hasPackageFlag && sym2.hasPackageFlag && sym1.name == sym2.name && sym1.fullNameString == sym2.fullNameString)
+      val skipped = skipPackageObject
+      UnqualifiedOwners.exists((sym: Symbol) => matches(sym, skipped)) || isEmptyPrefix
+    }
     def isEmptyPrefix = (
          isEffectiveRoot                      // has no prefix for real, <empty> or <root>
       || isAnonOrRefinementClass              // has uninteresting <anon> or <refinement> prefix
diff --git a/test/files/jvm/manifests-new.check b/test/files/jvm/manifests-new.check
@@ -2,25 +2,25 @@ x=(), t=TypeTag[Unit], k=TypeRef, s=class Unit
 x=true, t=TypeTag[Boolean], k=TypeRef, s=class Boolean
 x=a, t=TypeTag[Char], k=TypeRef, s=class Char
 x=1, t=TypeTag[Int], k=TypeRef, s=class Int
-x=abc, t=TypeTag[java.lang.String], k=TypeRef, s=class String
+x=abc, t=TypeTag[String], k=TypeRef, s=class String
 x='abc, t=TypeTag[Symbol], k=TypeRef, s=class Symbol
 
 x=List(()), t=TypeTag[List[Unit]], k=TypeRef, s=class List
 x=List(true), t=TypeTag[List[Boolean]], k=TypeRef, s=class List
 x=List(1), t=TypeTag[List[Int]], k=TypeRef, s=class List
-x=List(abc), t=TypeTag[List[java.lang.String]], k=TypeRef, s=class List
+x=List(abc), t=TypeTag[List[String]], k=TypeRef, s=class List
 x=List('abc), t=TypeTag[List[Symbol]], k=TypeRef, s=class List
 
 x=[Z, t=TypeTag[Array[Boolean]], k=TypeRef, s=class Array
 x=[C, t=TypeTag[Array[Char]], k=TypeRef, s=class Array
 x=[I, t=TypeTag[Array[Int]], k=TypeRef, s=class Array
-x=[Ljava.lang.String;, t=TypeTag[Array[java.lang.String]], k=TypeRef, s=class Array
+x=[Ljava.lang.String;, t=TypeTag[Array[String]], k=TypeRef, s=class Array
 x=[Lscala.Symbol;, t=TypeTag[Array[Symbol]], k=TypeRef, s=class Array
 
 x=((),()), t=TypeTag[(Unit, Unit)], k=TypeRef, s=class Tuple2
 x=(true,false), t=TypeTag[(Boolean, Boolean)], k=TypeRef, s=class Tuple2
 x=(1,2), t=TypeTag[(Int, Int)], k=TypeRef, s=class Tuple2
-x=(abc,xyz), t=TypeTag[(java.lang.String, java.lang.String)], k=TypeRef, s=class Tuple2
+x=(abc,xyz), t=TypeTag[(String, String)], k=TypeRef, s=class Tuple2
 x=('abc,'xyz), t=TypeTag[(Symbol, Symbol)], k=TypeRef, s=class Tuple2
 
 x=Test$, t=TypeTag[Test.type], k=SingleType, s=object Test
diff --git a/test/files/run/abstypetags_core.check b/test/files/run/abstypetags_core.check
@@ -23,7 +23,7 @@ TypeTag[AnyVal]
 true
 TypeTag[AnyRef]
 true
-TypeTag[java.lang.Object]
+TypeTag[Object]
 true
 TypeTag[Null]
 true
diff --git a/test/files/run/exprs_serialize.check b/test/files/run/exprs_serialize.check
@@ -1,5 +1,5 @@
 Expr[Int(2)](2)
-Expr[java.lang.String]({
+Expr[String]({
   def foo = "hello";
   foo.$plus("world!")
 })
diff --git a/test/files/run/freetypes_false_alarm1.check b/test/files/run/freetypes_false_alarm1.check
@@ -1 +1 @@
-scala.List[Int]
+List[Int]
diff --git a/test/files/run/inferred-type-constructors-hou.check b/test/files/run/inferred-type-constructors-hou.check
@@ -51,6 +51,6 @@ warning: there were two feature warnings; re-run with -feature for details
                 Seq[Int]
                 Array[Int]
                 scala.collection.AbstractSet[Int]
-                Comparable[java.lang.String]
+                Comparable[String]
                 scala.collection.immutable.LinearSeq[Int]
                 Iterable[Int]
diff --git a/test/files/run/inferred-type-constructors.check b/test/files/run/inferred-type-constructors.check
@@ -51,6 +51,6 @@ warning: there were two feature warnings; re-run with -feature for details
                 Seq[Int]
                 Array[Int]
                 scala.collection.AbstractSet[Int]
-                Comparable[java.lang.String]
+                Comparable[String]
                 scala.collection.immutable.LinearSeq[Int]
                 Iterable[Int]
diff --git a/test/files/run/interop_manifests_are_abstypetags.check b/test/files/run/interop_manifests_are_abstypetags.check
@@ -1,3 +1,3 @@
 Int
-java.lang.String
+String
 Array[Int]
diff --git a/test/files/run/interop_manifests_are_typetags.check b/test/files/run/interop_manifests_are_typetags.check
@@ -1,3 +1,3 @@
 Int
-java.lang.String
+String
 Array[Int]
diff --git a/test/files/run/macro-reify-unreify.check b/test/files/run/macro-reify-unreify.check
@@ -1 +1 @@
-hello world = Expr[java.lang.String("hello world")]("hello world")
+hello world = Expr[String("hello world")]("hello world")
diff --git a/test/files/run/reflection-equality.check b/test/files/run/reflection-equality.check
@@ -20,16 +20,16 @@ cs: reflect.runtime.universe.ClassSymbol = class X
 
 scala> val ts: Type = cs.info
 ts: reflect.runtime.universe.Type =
-scala.AnyRef {
+AnyRef {
   def <init>(): X
-  def methodIntIntInt(x: scala.Int,y: scala.Int): scala.Int
+  def methodIntIntInt(x: Int,y: Int): Int
 }
 
 scala> val ms: MethodSymbol = ts.decl(TermName("methodIntIntInt")).asMethod
 ms: reflect.runtime.universe.MethodSymbol = method methodIntIntInt
 
 scala> val MethodType( _, t1 ) = ms.info
-t1: reflect.runtime.universe.Type = scala.Int
+t1: reflect.runtime.universe.Type = Int
 
 scala> val t2 = typeOf[scala.Int]
 t2: reflect.runtime.universe.Type = Int
diff --git a/test/files/run/reflection-magicsymbols-invoke.check b/test/files/run/reflection-magicsymbols-invoke.check
@@ -7,10 +7,10 @@ method ##: ()Int
 method ==: (x$1: Any)Boolean
 method asInstanceOf: [T0]=> T0
 method equals: (x$1: Any)Boolean
-method getClass: ()java.lang.Class[_]
+method getClass: ()Class[_]
 method hashCode: ()Int
 method isInstanceOf: [T0]=> Boolean
-method toString: ()java.lang.String
+method toString: ()String
 testing Any.!=: false
 testing Any.##: 50
 testing Any.==: true
@@ -34,25 +34,25 @@ testing AnyVal.getClass: class scala.ScalaReflectionException: expected a member
 AnyRef
 it's important to print the list of AnyRef's members
 if some of them change (possibly, adding and/or removing magic symbols), we must update this test
-constructor Object: ()java.lang.Object
+constructor Object: ()Object
 method !=: (x$1: Any)Boolean
 method ##: ()Int
 method $asInstanceOf: [T0]()T0
 method $isInstanceOf: [T0]()Boolean
 method ==: (x$1: Any)Boolean
 method asInstanceOf: [T0]=> T0
-method clone: ()java.lang.Object
+method clone: ()Object
 method eq: (x$1: AnyRef)Boolean
 method equals: (x$1: Any)Boolean
 method finalize: ()Unit
-method getClass: ()java.lang.Class[_]
+method getClass: ()Class[_]
 method hashCode: ()Int
 method isInstanceOf: [T0]=> Boolean
 method ne: (x$1: AnyRef)Boolean
 method notify: ()Unit
 method notifyAll: ()Unit
 method synchronized: [T0](x$1: T0)T0
-method toString: ()java.lang.String
+method toString: ()String
 method wait: ()Unit
 method wait: (x$1: Long)Unit
 method wait: (x$1: Long, x$2: Int)Unit
@@ -91,15 +91,15 @@ method clone: ()Array[T]
 method eq: (x$1: AnyRef)Boolean
 method equals: (x$1: Any)Boolean
 method finalize: ()Unit
-method getClass: ()java.lang.Class[_]
+method getClass: ()Class[_]
 method hashCode: ()Int
 method isInstanceOf: [T0]=> Boolean
 method length: => Int
 method ne: (x$1: AnyRef)Boolean
 method notify: ()Unit
 method notifyAll: ()Unit
 method synchronized: [T0](x$1: T0)T0
-method toString: ()java.lang.String
+method toString: ()String
 method update: (i: Int, x: T)Unit
 method wait: ()Unit
 method wait: (x$1: Long)Unit
diff --git a/test/files/run/reflection-magicsymbols-repl.check b/test/files/run/reflection-magicsymbols-repl.check
@@ -23,13 +23,13 @@ warning: there was one feature warning; for details, enable `:setting -feature'
 test: (n: Int)Unit
 
 scala> for (i <- 1 to 8) test(i)
-scala.Int*
-=> scala.Int
-scala.Any
-scala.AnyRef
-scala.AnyVal
-scala.Null
-scala.Nothing
-scala.Singleton
+Int*
+=> Int
+Any
+AnyRef
+AnyVal
+Null
+Nothing
+Singleton
 
 scala> :quit
diff --git a/test/files/run/reflection-repl-elementary.check b/test/files/run/reflection-repl-elementary.check
@@ -1,5 +1,5 @@
 
 scala> scala.reflect.runtime.universe.typeOf[List[Nothing]]
-res0: reflect.runtime.universe.Type = scala.List[Nothing]
+res0: reflect.runtime.universe.Type = List[Nothing]
 
 scala> :quit
diff --git a/test/files/run/reflection-valueclasses-magic.check b/test/files/run/reflection-valueclasses-magic.check
@@ -112,7 +112,7 @@ method toFloat: => Float
 method toInt: => Int
 method toLong: => Long
 method toShort: => Short
-method toString: ()java.lang.String
+method toString: ()String
 method unary_+: => Int
 method unary_-: => Int
 method unary_~: => Int
@@ -320,7 +320,7 @@ method toFloat: => Float
 method toInt: => Int
 method toLong: => Long
 method toShort: => Short
-method toString: ()java.lang.String
+method toString: ()String
 method unary_+: => Int
 method unary_-: => Int
 method unary_~: => Int
@@ -528,7 +528,7 @@ method toFloat: => Float
 method toInt: => Int
 method toLong: => Long
 method toShort: => Short
-method toString: ()java.lang.String
+method toString: ()String
 method unary_+: => Int
 method unary_-: => Int
 method unary_~: => Int
@@ -736,7 +736,7 @@ method toFloat: => Float
 method toInt: => Int
 method toLong: => Long
 method toShort: => Short
-method toString: ()java.lang.String
+method toString: ()String
 method unary_+: => Int
 method unary_-: => Int
 method unary_~: => Int
@@ -944,7 +944,7 @@ method toFloat: => Float
 method toInt: => Int
 method toLong: => Long
 method toShort: => Short
-method toString: ()java.lang.String
+method toString: ()String
 method unary_+: => Long
 method unary_-: => Long
 method unary_~: => Long
@@ -1136,7 +1136,7 @@ method toFloat: => Float
 method toInt: => Int
 method toLong: => Long
 method toShort: => Short
-method toString: ()java.lang.String
+method toString: ()String
 method unary_+: => Float
 method unary_-: => Float
 testing Float.toByte() with receiver = 2.0 and args = List(): [class java.lang.Byte] =======> 2
@@ -1322,7 +1322,7 @@ method toFloat: => Float
 method toInt: => Int
 method toLong: => Long
 method toShort: => Short
-method toString: ()java.lang.String
+method toString: ()String
 method unary_+: => Double
 method unary_-: => Double
 testing Double.toByte() with receiver = 2.0 and args = List(): [class java.lang.Byte] =======> 2
@@ -1428,7 +1428,7 @@ method equals: (x$1: Any)Boolean
 method getClass: ()Class[Boolean]
 method hashCode: ()Int
 method isInstanceOf: [T0]=> Boolean
-method toString: ()java.lang.String
+method toString: ()String
 method unary_!: => Boolean
 method |: (x: Boolean)Boolean
 method ||: (x: Boolean)Boolean
@@ -1453,4 +1453,4 @@ method equals: (x$1: Any)Boolean
 method getClass: ()Class[Unit]
 method hashCode: ()Int
 method isInstanceOf: [T0]=> Boolean
-method toString: ()java.lang.String
+method toString: ()String
diff --git a/test/files/run/reify_newimpl_26.check b/test/files/run/reify_newimpl_26.check
@@ -10,6 +10,6 @@ On line 3: free type: Ident(TypeName("T")) defined by foo in <console>:1:9
 foo: [T]=> Unit
 
 scala> foo[Int]
-WeakTypeTag[scala.List[T]]
+WeakTypeTag[List[T]]
 
 scala> :quit
diff --git a/test/files/run/t5256c.check b/test/files/run/t5256c.check
@@ -1,6 +1,6 @@
 class A$1
 Test.A$1
-java.lang.Object {
+Object {
   def foo(): Nothing
   def <init>(): Test.A$1
 }
diff --git a/test/files/run/t5256d.check b/test/files/run/t5256d.check
@@ -18,9 +18,9 @@ scala> println(c.fullName)
 $line8.$read.$iw.$iw.$iw.$iw.A
 
 scala> println(c.info)
-scala.AnyRef {
+AnyRef {
   def <init>(): A
-  def foo: scala.Nothing
+  def foo: Nothing
 }
 
 scala> :quit
diff --git a/test/files/run/t5256h.check b/test/files/run/t5256h.check
@@ -1,6 +1,6 @@
 $anon
 Test.$anon$1
-java.lang.Object {
+Object {
   final private val x: Int
   def x(): Int
   def <init>(): $anon$1
diff --git a/test/files/run/t5418a.check b/test/files/run/t5418a.check
@@ -1 +1 @@
-Expr[Class[_ <: java.lang.Object]](new Object().getClass())
+Expr[Class[_ <: Object]](new Object().getClass())
diff --git a/test/files/run/t7008.check b/test/files/run/t7008.check
@@ -3,7 +3,7 @@ bar: List(throws[Exception](classOf[java.lang.Exception]))
 baz: List(throws[IllegalStateException](classOf[java.lang.IllegalStateException]))
 foo: List(throws[Exception](classOf[java.lang.Exception]))
 =============
-<init>: List(throws[java.lang.NullPointerException](classOf[java.lang.NullPointerException]))
-bar: List(throws[java.lang.Exception](classOf[java.lang.Exception]))
-baz: List(throws[java.lang.IllegalStateException](classOf[java.lang.IllegalStateException]))
-foo: List(throws[java.lang.Exception](classOf[java.lang.Exception]))
+<init>: List(throws[NullPointerException](classOf[java.lang.NullPointerException]))
+bar: List(throws[Exception](classOf[java.lang.Exception]))
+baz: List(throws[IllegalStateException](classOf[java.lang.IllegalStateException]))
+foo: List(throws[Exception](classOf[java.lang.Exception]))
diff --git a/test/files/run/typetags_core.check b/test/files/run/typetags_core.check
@@ -23,7 +23,7 @@ TypeTag[AnyVal]
 true
 TypeTag[AnyRef]
 true
-TypeTag[java.lang.Object]
+TypeTag[Object]
 true
 TypeTag[Null]
 true

-Original file line number
+Diff line change
@@ @@ -1,3 +1,3 @@ @@
 Int
 -java.lang.String
 +String
 Array[Int]
Original file line number	Diff line number	Diff line change
`@@ -1 +1 @@`
`1`		`-hello world = Expr[java.lang.String("hello world")]("hello world")`
	`1`	`+hello world = Expr[String("hello world")]("hello world")`