Integrate CoreBTypes by composition (not inheritance), non-var fields

Make the fields of CoreBTypes non-variable. Instead, replace the
CoreBTypes instance on each compiler run. That results in fewer
variables, and the initialization code is directly where the fields
are declared, instead of an init method.

9 files changed, 253 insertions, 202 deletions

diff --git a/src/compiler/scala/tools/nsc/backend/jvm/BCodeBodyBuilder.scala b/src/compiler/scala/tools/nsc/backend/jvm/BCodeBodyBuilder.scala
index 05a2867a3a..2e629485a0 100644
--- a/src/compiler/scala/tools/nsc/backend/jvm/BCodeBodyBuilder.scala
+++ b/src/compiler/scala/tools/nsc/backend/jvm/BCodeBodyBuilder.scala
@@ -25,6 +25,7 @@ abstract class BCodeBodyBuilder extends BCodeSkelBuilder {
   import definitions._
   import bCodeICodeCommon._
   import bTypes._
+  import coreBTypes._
 
   /*
    * Functionality to build the body of ASM MethodNode, except for `synchronized` and `try` expressions.
diff --git a/src/compiler/scala/tools/nsc/backend/jvm/BCodeHelpers.scala b/src/compiler/scala/tools/nsc/backend/jvm/BCodeHelpers.scala
index c14997628f..18a9bad1b7 100644
--- a/src/compiler/scala/tools/nsc/backend/jvm/BCodeHelpers.scala
+++ b/src/compiler/scala/tools/nsc/backend/jvm/BCodeHelpers.scala
@@ -21,6 +21,7 @@ import scala.tools.nsc.io.AbstractFile
 abstract class BCodeHelpers extends BCodeIdiomatic with BytecodeWriters {
   import global._
   import bTypes._
+  import coreBTypes._
 
   /*
    * must-single-thread
diff --git a/src/compiler/scala/tools/nsc/backend/jvm/BCodeIdiomatic.scala b/src/compiler/scala/tools/nsc/backend/jvm/BCodeIdiomatic.scala
index 290e899ba4..5d187168db 100644
--- a/src/compiler/scala/tools/nsc/backend/jvm/BCodeIdiomatic.scala
+++ b/src/compiler/scala/tools/nsc/backend/jvm/BCodeIdiomatic.scala
@@ -25,6 +25,7 @@ abstract class BCodeIdiomatic extends SubComponent {
 
   import global._
   import bTypes._
+  import coreBTypes._
 
   val classfileVersion: Int = settings.target.value match {
     case "jvm-1.5"     => asm.Opcodes.V1_5
diff --git a/src/compiler/scala/tools/nsc/backend/jvm/BCodeSkelBuilder.scala b/src/compiler/scala/tools/nsc/backend/jvm/BCodeSkelBuilder.scala
index 35a9962620..3f3c0d0620 100644
--- a/src/compiler/scala/tools/nsc/backend/jvm/BCodeSkelBuilder.scala
+++ b/src/compiler/scala/tools/nsc/backend/jvm/BCodeSkelBuilder.scala
@@ -26,6 +26,7 @@ import java.io.PrintWriter
 abstract class BCodeSkelBuilder extends BCodeHelpers {
   import global._
   import bTypes._
+  import coreBTypes._
 
   /*
    * There's a dedicated PlainClassBuilder for each CompilationUnit,
diff --git a/src/compiler/scala/tools/nsc/backend/jvm/BCodeSyncAndTry.scala b/src/compiler/scala/tools/nsc/backend/jvm/BCodeSyncAndTry.scala
index c271e7b129..7c95b7fc3b 100644
--- a/src/compiler/scala/tools/nsc/backend/jvm/BCodeSyncAndTry.scala
+++ b/src/compiler/scala/tools/nsc/backend/jvm/BCodeSyncAndTry.scala
@@ -21,7 +21,7 @@ import scala.tools.asm
 abstract class BCodeSyncAndTry extends BCodeBodyBuilder {
   import global._
   import bTypes._
-
+  import coreBTypes._
 
   /*
    * Functionality to lower `synchronized` and `try` expressions.
diff --git a/src/compiler/scala/tools/nsc/backend/jvm/BTypes.scala b/src/compiler/scala/tools/nsc/backend/jvm/BTypes.scala
index 390de5fae1..389dbe43eb 100644
--- a/src/compiler/scala/tools/nsc/backend/jvm/BTypes.scala
+++ b/src/compiler/scala/tools/nsc/backend/jvm/BTypes.scala
@@ -42,6 +42,12 @@ abstract class BTypes {
    */
   def classBTypeFromInternalName(internalName: String) = classBTypeFromInternalNameMap(internalName)
 
+  // Some core BTypes are required here, in class BType, where no Global instance is available.
+  // The Global is only available in the subclass BTypesFromSymbols. We cannot depend on the actual
+  // implementation (CoreBTypesProxy) here because it has members that refer to global.Symbol.
+  val coreBTypes: CoreBTypesProxyGlobalIndependent[this.type]
+  import coreBTypes._
+
   /**
    * A BType is either a primitve type, a ClassBType, an ArrayBType of one of these, or a MethodType
    * referring to BTypes.
@@ -834,14 +840,10 @@ abstract class BTypes {
    * They are defs (not vals) because they are implemented using vars (see comment on CoreBTypes).
    */
 
-  def boxedClasses: Set[ClassBType]
-
-  def RT_NOTHING : ClassBType
-  def RT_NULL    : ClassBType
-
-  def ObjectReference          : ClassBType
-  def jlCloneableReference     : ClassBType
-  def jioSerializableReference : ClassBType
+  /**
+   * Just a named pair, used in CoreBTypes.asmBoxTo/asmUnboxTo.
+   */
+  final case class MethodNameAndType(name: String, methodType: MethodBType)
 
   /**
    * True if the current compilation unit is of a primitive class (scala.Boolean et al).
diff --git a/src/compiler/scala/tools/nsc/backend/jvm/BTypesFromSymbols.scala b/src/compiler/scala/tools/nsc/backend/jvm/BTypesFromSymbols.scala
index 3b11a484bb..da3244ba23 100644
--- a/src/compiler/scala/tools/nsc/backend/jvm/BTypesFromSymbols.scala
+++ b/src/compiler/scala/tools/nsc/backend/jvm/BTypesFromSymbols.scala
@@ -20,10 +20,18 @@ import scala.tools.asm
  * of the core btypes. They are declared in BTypes as abstract members. Note that BTypes does
  * not have access to the compiler instance.
  */
-class BTypesFromSymbols[G <: Global](val global: G) extends BTypes with CoreBTypes[G] {
+class BTypesFromSymbols[G <: Global](val global: G) extends BTypes {
   import global._
   import definitions._
 
+  // Why the proxy, see documentation of class [[CoreBTypes]].
+  val coreBTypes = new CoreBTypesProxy[this.type](this)
+  import coreBTypes._
+
+  final def intializeCoreBTypes(): Unit = {
+    coreBTypes.setBTypes(new CoreBTypes[this.type](this))
+  }
+
   def internalNameString(offset: Int, length: Int) = new String(global.chrs, offset, length)
 
   protected val classBTypeFromInternalNameMap = {
diff --git a/src/compiler/scala/tools/nsc/backend/jvm/CoreBTypes.scala b/src/compiler/scala/tools/nsc/backend/jvm/CoreBTypes.scala
index d92e775185..fac3c93be2 100644
--- a/src/compiler/scala/tools/nsc/backend/jvm/CoreBTypes.scala
+++ b/src/compiler/scala/tools/nsc/backend/jvm/CoreBTypes.scala
@@ -7,16 +7,27 @@ import scala.annotation.switch
  * Core BTypes and some other definitions. The initialization of these definitions requies access
  * to symbols / types (global).
  *
- * There is a reason for using vars instead of lazy vals. The symbols used to initialize the
- * ClassBTypes may change from one compiler run to the next. To make sure the definitions are
- * consistent with the symbols in the current run, the `intializeCoreBTypes` (which assigns the
- * vars) is executed once for every compiler run.
+ * The symbols used to initialize the ClassBTypes may change from one compiler run to the next. To
+ * make sure the definitions are consistent with the symbols in the current run, the
+ * `intializeCoreBTypes` method in BTypesFromSymbols creates a new instance of CoreBTypes in each
+ * compiler run.
  *
- * Note: if they were lazy vals, BType.classBTypeFromInternalNameMap could not be a perRunCache
- * anymore: the classes defeined here need to be in that map, they are added when the ClassBTypes
- * are created. The per run cache removes them, so they would be missing in the second run.
+ * The class BTypesFromSymbols does not directly reference CoreBTypes, but CoreBTypesProxy. The
+ * reason is that having a `var bTypes: CoreBTypes` would not allow `import bTypes._`. Instead, the
+ * proxy class holds a `CoreBTypes` in a variable field and forwards to this instance.
+ *
+ * The definitions in `CoreBTypes` need to be lazy vals to break an initialization cycle. When
+ * creating a new instance to assign to the proxy, the `classBTypeFromSymbol` invoked in the
+ * constructor will actucally go through the proxy. The lazy vals make sure the instance is assigned
+ * in the proxy before the fields are initialized.
+ *
+ * Note: if we did not re-create the core BTypes on each compiler run, BType.classBTypeFromInternalNameMap
+ * could not be a perRunCache anymore: the classes defeined here need to be in that map, they are
+ * added when the ClassBTypes are created. The per run cache removes them, so they would be missing
+ * in the second run.
  */
-trait CoreBTypes[G <: Global] { self: BTypesFromSymbols[G] =>
+class CoreBTypes[BTFS <: BTypesFromSymbols[_ <: Global]](val bTypes: BTFS) {
+  import bTypes._
   import global._
   import rootMirror.{requiredClass, getClassIfDefined}
   import definitions._
@@ -25,36 +36,62 @@ trait CoreBTypes[G <: Global] { self: BTypesFromSymbols[G] =>
    * Maps primitive types to their corresponding PrimitiveBType. The map is defined lexically above
    * the first use of `classBTypeFromSymbol` because that method looks at the map.
    */
-  var primitiveTypeMap: Map[Symbol, PrimitiveBType] = _
-
-  var BOXED_UNIT    : ClassBType = _
-  var BOXED_BOOLEAN : ClassBType = _
-  var BOXED_BYTE    : ClassBType = _
-  var BOXED_SHORT   : ClassBType = _
-  var BOXED_CHAR    : ClassBType = _
-  var BOXED_INT     : ClassBType = _
-  var BOXED_LONG    : ClassBType = _
-  var BOXED_FLOAT   : ClassBType = _
-  var BOXED_DOUBLE  : ClassBType = _
-
-  var boxedClasses: Set[ClassBType] = _
+  lazy val primitiveTypeMap: Map[Symbol, PrimitiveBType] = Map(
+    UnitClass    -> UNIT,
+    BooleanClass -> BOOL,
+    CharClass    -> CHAR,
+    ByteClass    -> BYTE,
+    ShortClass   -> SHORT,
+    IntClass     -> INT,
+    LongClass    -> LONG,
+    FloatClass   -> FLOAT,
+    DoubleClass  -> DOUBLE
+  )
+
+  lazy val BOXED_UNIT    : ClassBType = classBTypeFromSymbol(requiredClass[java.lang.Void])
+  lazy val BOXED_BOOLEAN : ClassBType = classBTypeFromSymbol(BoxedBooleanClass)
+  lazy val BOXED_BYTE    : ClassBType = classBTypeFromSymbol(BoxedByteClass)
+  lazy val BOXED_SHORT   : ClassBType = classBTypeFromSymbol(BoxedShortClass)
+  lazy val BOXED_CHAR    : ClassBType = classBTypeFromSymbol(BoxedCharacterClass)
+  lazy val BOXED_INT     : ClassBType = classBTypeFromSymbol(BoxedIntClass)
+  lazy val BOXED_LONG    : ClassBType = classBTypeFromSymbol(BoxedLongClass)
+  lazy val BOXED_FLOAT   : ClassBType = classBTypeFromSymbol(BoxedFloatClass)
+  lazy val BOXED_DOUBLE  : ClassBType = classBTypeFromSymbol(BoxedDoubleClass)
 
   /**
    * Map from primitive types to their boxed class type. Useful when pushing class literals onto the
    * operand stack (ldc instruction taking a class literal), see genConstant.
    */
-  var boxedClassOfPrimitive: Map[PrimitiveBType, ClassBType] = _
+  lazy val boxedClassOfPrimitive: Map[PrimitiveBType, ClassBType] = Map(
+    UNIT   -> BOXED_UNIT,
+    BOOL   -> BOXED_BOOLEAN,
+    BYTE   -> BOXED_BYTE,
+    SHORT  -> BOXED_SHORT,
+    CHAR   -> BOXED_CHAR,
+    INT    -> BOXED_INT,
+    LONG   -> BOXED_LONG,
+    FLOAT  -> BOXED_FLOAT,
+    DOUBLE -> BOXED_DOUBLE
+  )
+
+  lazy val boxedClasses: Set[ClassBType] = boxedClassOfPrimitive.values.toSet
 
   /**
    * Maps the method symbol for a box method to the boxed type of the result. For example, the
    * method symbol for `Byte.box()` is mapped to the ClassBType `java/lang/Byte`.
    */
-  var boxResultType: Map[Symbol, ClassBType] = _
+  lazy val boxResultType: Map[Symbol, ClassBType] = {
+    for ((valueClassSym, boxMethodSym) <- currentRun.runDefinitions.boxMethod)
+    yield boxMethodSym -> boxedClassOfPrimitive(primitiveTypeMap(valueClassSym))
+  }
 
   /**
    * Maps the method symbol for an unbox method to the primitive type of the result.
    * For example, the method symbol for `Byte.unbox()`) is mapped to the PrimitiveBType BYTE. */
-  var unboxResultType: Map[Symbol, PrimitiveBType] = _
+  lazy val unboxResultType: Map[Symbol, PrimitiveBType] = {
+    for ((valueClassSym, unboxMethodSym) <- currentRun.runDefinitions.unboxMethod)
+    yield unboxMethodSym -> primitiveTypeMap(valueClassSym)
+  }
 
   /*
    * RT_NOTHING and RT_NULL exist at run-time only. They are the bytecode-level manifestation (in
@@ -62,196 +99,195 @@ trait CoreBTypes[G <: Global] { self: BTypesFromSymbols[G] =>
    *
    * Therefore, when RT_NOTHING or RT_NULL are to be emitted, a mapping is needed: the internal
    * names of NothingClass and NullClass can't be emitted as-is.
+   * TODO @lry Once there's a 2.11.3 starr, use the commented argument list. The current starr crashes on the type literal `scala.runtime.Nothing$`
    */
-  var RT_NOTHING : ClassBType = _
-  var RT_NULL    : ClassBType = _
+  lazy val RT_NOTHING : ClassBType = classBTypeFromSymbol(rootMirror.getRequiredClass("scala.runtime.Nothing$")) // (requiredClass[scala.runtime.Nothing$])
+  lazy val RT_NULL    : ClassBType = classBTypeFromSymbol(rootMirror.getRequiredClass("scala.runtime.Null$"))    // (requiredClass[scala.runtime.Null$])
 
-  var ObjectReference   : ClassBType = _
-  var objArrayReference : ArrayBType = _
+  lazy val ObjectReference   : ClassBType = classBTypeFromSymbol(ObjectClass)
+  lazy val objArrayReference : ArrayBType = ArrayBType(ObjectReference)
 
-  var StringReference             : ClassBType = _
-  var StringBuilderReference      : ClassBType = _
-  var ThrowableReference          : ClassBType = _
-  var jlCloneableReference        : ClassBType = _
-  var jlNPEReference              : ClassBType = _
-  var jioSerializableReference    : ClassBType = _
-  var scalaSerializableReference  : ClassBType = _
-  var classCastExceptionReference : ClassBType = _
+  lazy val StringReference             : ClassBType = classBTypeFromSymbol(StringClass)
+  lazy val StringBuilderReference      : ClassBType = classBTypeFromSymbol(StringBuilderClass)
+  lazy val ThrowableReference          : ClassBType = classBTypeFromSymbol(ThrowableClass)
+  lazy val jlCloneableReference        : ClassBType = classBTypeFromSymbol(JavaCloneableClass)        // java/lang/Cloneable
+  lazy val jlNPEReference              : ClassBType = classBTypeFromSymbol(NullPointerExceptionClass) // java/lang/NullPointerException
+  lazy val jioSerializableReference    : ClassBType = classBTypeFromSymbol(JavaSerializableClass)     // java/io/Serializable
+  lazy val scalaSerializableReference  : ClassBType = classBTypeFromSymbol(SerializableClass)         // scala/Serializable
+  lazy val classCastExceptionReference : ClassBType = classBTypeFromSymbol(ClassCastExceptionClass)   // java/lang/ClassCastException
 
-  var srBooleanRef : ClassBType = _
-  var srByteRef    : ClassBType = _
-  var srCharRef    : ClassBType = _
-  var srIntRef     : ClassBType = _
-  var srLongRef    : ClassBType = _
-  var srFloatRef   : ClassBType = _
-  var srDoubleRef  : ClassBType = _
+  lazy val srBooleanRef : ClassBType = classBTypeFromSymbol(requiredClass[scala.runtime.BooleanRef])
+  lazy val srByteRef    : ClassBType = classBTypeFromSymbol(requiredClass[scala.runtime.ByteRef])
+  lazy val srCharRef    : ClassBType = classBTypeFromSymbol(requiredClass[scala.runtime.CharRef])
+  lazy val srIntRef     : ClassBType = classBTypeFromSymbol(requiredClass[scala.runtime.IntRef])
+  lazy val srLongRef    : ClassBType = classBTypeFromSymbol(requiredClass[scala.runtime.LongRef])
+  lazy val srFloatRef   : ClassBType = classBTypeFromSymbol(requiredClass[scala.runtime.FloatRef])
+  lazy val srDoubleRef  : ClassBType = classBTypeFromSymbol(requiredClass[scala.runtime.DoubleRef])
 
-  var hashMethodSym: Symbol = _
+  lazy val hashMethodSym: Symbol = getMember(ScalaRunTimeModule, nme.hash_)
 
-  var AndroidParcelableInterface : Symbol = _
-  var AndroidCreatorClass        : Symbol = _
+  // TODO @lry avoiding going through through missingHook for every line in the REPL: https://github.com/scala/scala/commit/8d962ed4ddd310cc784121c426a2e3f56a112540
+  lazy val AndroidParcelableInterface : Symbol = getClassIfDefined("android.os.Parcelable")
+  lazy val AndroidCreatorClass        : Symbol = getClassIfDefined("android.os.Parcelable$Creator")
 
-  var BeanInfoAttr: Symbol = _
+  lazy val BeanInfoAttr: Symbol = requiredClass[scala.beans.BeanInfo]
 
   /* The Object => String overload. */
-  var String_valueOf: Symbol = _
+  lazy val String_valueOf: Symbol = {
+    getMember(StringModule, nme.valueOf) filter (sym => sym.info.paramTypes match {
+      case List(pt) => pt.typeSymbol == ObjectClass
+      case _        => false
+    })
+  }
 
   // scala.FunctionX and scala.runtim.AbstractFunctionX
-  var FunctionReference         : Vector[ClassBType]   = _
-  var AbstractFunctionReference : Vector[ClassBType]   = _
-  var AbstractFunctionArityMap  : Map[ClassBType, Int] = _
-
-  var PartialFunctionReference         : ClassBType = _
-  var AbstractPartialFunctionReference : ClassBType = _
+  lazy val FunctionReference         : Vector[ClassBType]   = (0 to MaxFunctionArity).map(i => classBTypeFromSymbol(FunctionClass(i)))(collection.breakOut)
+  lazy val AbstractFunctionReference : Vector[ClassBType]   = (0 to MaxFunctionArity).map(i => classBTypeFromSymbol(AbstractFunctionClass(i)))(collection.breakOut)
+  lazy val AbstractFunctionArityMap  : Map[ClassBType, Int] = AbstractFunctionReference.zipWithIndex.toMap
 
-  var BoxesRunTime: ClassBType = _
+  lazy val PartialFunctionReference         : ClassBType = classBTypeFromSymbol(PartialFunctionClass)
+  lazy val AbstractPartialFunctionReference : ClassBType = classBTypeFromSymbol(AbstractPartialFunctionClass)
 
-  case class MethodNameAndType(name: String, methodType: MethodBType)
+  lazy val BoxesRunTime: ClassBType = classBTypeFromSymbol(requiredClass[scala.runtime.BoxesRunTime])
 
   /**
    * Methods in scala.runtime.BoxesRuntime
    */
-  var asmBoxTo  : Map[BType, MethodNameAndType] = _
-  var asmUnboxTo: Map[BType, MethodNameAndType] = _
+  lazy val asmBoxTo  : Map[BType, MethodNameAndType] = Map(
+    BOOL   -> MethodNameAndType("boxToBoolean",   MethodBType(List(BOOL),   BOXED_BOOLEAN)),
+    BYTE   -> MethodNameAndType("boxToByte",      MethodBType(List(BYTE),   BOXED_BYTE)),
+    CHAR   -> MethodNameAndType("boxToCharacter", MethodBType(List(CHAR),   BOXED_CHAR)),
+    SHORT  -> MethodNameAndType("boxToShort",     MethodBType(List(SHORT),  BOXED_SHORT)),
+    INT    -> MethodNameAndType("boxToInteger",   MethodBType(List(INT),    BOXED_INT)),
+    LONG   -> MethodNameAndType("boxToLong",      MethodBType(List(LONG),   BOXED_LONG)),
+    FLOAT  -> MethodNameAndType("boxToFloat",     MethodBType(List(FLOAT),  BOXED_FLOAT)),
+    DOUBLE -> MethodNameAndType("boxToDouble",    MethodBType(List(DOUBLE), BOXED_DOUBLE))
+  )
+
+  lazy val asmUnboxTo: Map[BType, MethodNameAndType] = Map(
+    BOOL   -> MethodNameAndType("unboxToBoolean", MethodBType(List(ObjectReference), BOOL)),
+    BYTE   -> MethodNameAndType("unboxToByte",    MethodBType(List(ObjectReference), BYTE)),
+    CHAR   -> MethodNameAndType("unboxToChar",    MethodBType(List(ObjectReference), CHAR)),
+    SHORT  -> MethodNameAndType("unboxToShort",   MethodBType(List(ObjectReference), SHORT)),
+    INT    -> MethodNameAndType("unboxToInt",     MethodBType(List(ObjectReference), INT)),
+    LONG   -> MethodNameAndType("unboxToLong",    MethodBType(List(ObjectReference), LONG)),
+    FLOAT  -> MethodNameAndType("unboxToFloat",   MethodBType(List(ObjectReference), FLOAT)),
+    DOUBLE -> MethodNameAndType("unboxToDouble",  MethodBType(List(ObjectReference), DOUBLE))
+  )
+
+  lazy val typeOfArrayOp: Map[Int, BType] = {
+    import scalaPrimitives._
+    Map(
+        (List(ZARRAY_LENGTH, ZARRAY_GET, ZARRAY_SET) map (_ -> BOOL))   ++
+        (List(BARRAY_LENGTH, BARRAY_GET, BARRAY_SET) map (_ -> BYTE))   ++
+        (List(SARRAY_LENGTH, SARRAY_GET, SARRAY_SET) map (_ -> SHORT))  ++
+        (List(CARRAY_LENGTH, CARRAY_GET, CARRAY_SET) map (_ -> CHAR))   ++
+        (List(IARRAY_LENGTH, IARRAY_GET, IARRAY_SET) map (_ -> INT))    ++
+        (List(LARRAY_LENGTH, LARRAY_GET, LARRAY_SET) map (_ -> LONG))   ++
+        (List(FARRAY_LENGTH, FARRAY_GET, FARRAY_SET) map (_ -> FLOAT))  ++
+        (List(DARRAY_LENGTH, DARRAY_GET, DARRAY_SET) map (_ -> DOUBLE)) ++
+        (List(OARRAY_LENGTH, OARRAY_GET, OARRAY_SET) map (_ -> ObjectReference)) : _*
+    )
+  }
+}
 
-  var typeOfArrayOp: Map[Int, BType] = _
+/**
+ * This trait make some core BTypes availalbe that don't depend on a Global instance. Some core
+ * BTypes are required to be accessible in the BTypes trait, which does not have access to Global.
+ *
+ * BTypes cannot refer to CoreBTypesProxy because some of its members depend on global, for example
+ * the type Symbol in
+ *   def primitiveTypeMap: Map[Symbol, PrimitiveBType]
+ */
+trait CoreBTypesProxyGlobalIndependent[BTS <: BTypes] {
+  val bTypes: BTS
+  import bTypes._
 
-  /**
-   * Initialize core ClassBTypes computed from symbols. Invoked once for each compiler run.
-   */
-  def intializeCoreBTypes(): Unit = {
-    primitiveTypeMap = Map(
-      UnitClass    -> UNIT,
-      BooleanClass -> BOOL,
-      CharClass    -> CHAR,
-      ByteClass    -> BYTE,
-      ShortClass   -> SHORT,
-      IntClass     -> INT,
-      LongClass    -> LONG,
-      FloatClass   -> FLOAT,
-      DoubleClass  -> DOUBLE
-    )
+  def boxedClasses: Set[ClassBType]
 
-    BOXED_UNIT    = classBTypeFromSymbol(requiredClass[java.lang.Void])
-    BOXED_BOOLEAN = classBTypeFromSymbol(BoxedBooleanClass)
-    BOXED_BYTE    = classBTypeFromSymbol(BoxedByteClass)
-    BOXED_SHORT   = classBTypeFromSymbol(BoxedShortClass)
-    BOXED_CHAR    = classBTypeFromSymbol(BoxedCharacterClass)
-    BOXED_INT     = classBTypeFromSymbol(BoxedIntClass)
-    BOXED_LONG    = classBTypeFromSymbol(BoxedLongClass)
-    BOXED_FLOAT   = classBTypeFromSymbol(BoxedFloatClass)
-    BOXED_DOUBLE  = classBTypeFromSymbol(BoxedDoubleClass)
-
-    boxedClassOfPrimitive = Map(
-      UNIT   -> BOXED_UNIT,
-      BOOL   -> BOXED_BOOLEAN,
-      BYTE   -> BOXED_BYTE,
-      SHORT  -> BOXED_SHORT,
-      CHAR   -> BOXED_CHAR,
-      INT    -> BOXED_INT,
-      LONG   -> BOXED_LONG,
-      FLOAT  -> BOXED_FLOAT,
-      DOUBLE -> BOXED_DOUBLE
-    )
+  def RT_NOTHING : ClassBType
+  def RT_NULL    : ClassBType
 
-    boxedClasses = boxedClassOfPrimitive.values.toSet
-
-    boxResultType = {
-      for ((valueClassSym, boxMethodSym) <- currentRun.runDefinitions.boxMethod)
-      yield boxMethodSym -> boxedClassOfPrimitive(primitiveTypeMap(valueClassSym))
-    }
-
-    unboxResultType = {
-      for ((valueClassSym, unboxMethodSym) <- currentRun.runDefinitions.unboxMethod)
-      yield unboxMethodSym -> primitiveTypeMap(valueClassSym)
-    }
-
-    // TODO @lry Once there's a 2.11.2 starr, use the commented argument list. The current starr crashes on the type literal `scala.runtime.Nothing$`
-    RT_NOTHING = classBTypeFromSymbol(rootMirror.getRequiredClass("scala.runtime.Nothing$")) // (requiredClass[scala.runtime.Nothing$])
-    RT_NULL    = classBTypeFromSymbol(rootMirror.getRequiredClass("scala.runtime.Null$"))    // (requiredClass[scala.runtime.Null$])
-
-    ObjectReference   = classBTypeFromSymbol(ObjectClass)
-    objArrayReference = ArrayBType(ObjectReference)
-
-    StringReference             = classBTypeFromSymbol(StringClass)
-    StringBuilderReference      = classBTypeFromSymbol(StringBuilderClass)
-    ThrowableReference          = classBTypeFromSymbol(ThrowableClass)
-    jlCloneableReference        = classBTypeFromSymbol(JavaCloneableClass)        // java/lang/Cloneable
-    jlNPEReference              = classBTypeFromSymbol(NullPointerExceptionClass) // java/lang/NullPointerException
-    jioSerializableReference    = classBTypeFromSymbol(JavaSerializableClass)     // java/io/Serializable
-    scalaSerializableReference  = classBTypeFromSymbol(SerializableClass)         // scala/Serializable
-    classCastExceptionReference = classBTypeFromSymbol(ClassCastExceptionClass)   // java/lang/ClassCastException
-
-    srBooleanRef = classBTypeFromSymbol(requiredClass[scala.runtime.BooleanRef])
-    srByteRef    = classBTypeFromSymbol(requiredClass[scala.runtime.ByteRef])
-    srCharRef    = classBTypeFromSymbol(requiredClass[scala.runtime.CharRef])
-    srIntRef     = classBTypeFromSymbol(requiredClass[scala.runtime.IntRef])
-    srLongRef    = classBTypeFromSymbol(requiredClass[scala.runtime.LongRef])
-    srFloatRef   = classBTypeFromSymbol(requiredClass[scala.runtime.FloatRef])
-    srDoubleRef  = classBTypeFromSymbol(requiredClass[scala.runtime.DoubleRef])
-
-    hashMethodSym = getMember(ScalaRunTimeModule, nme.hash_)
-
-    // TODO @lry avoiding going through through missingHook for every line in the REPL: https://github.com/scala/scala/commit/8d962ed4ddd310cc784121c426a2e3f56a112540
-    AndroidParcelableInterface = getClassIfDefined("android.os.Parcelable")
-    AndroidCreatorClass = getClassIfDefined("android.os.Parcelable$Creator")
-
-    BeanInfoAttr = requiredClass[scala.beans.BeanInfo]
-
-    String_valueOf = {
-      getMember(StringModule, nme.valueOf) filter (sym => sym.info.paramTypes match {
-        case List(pt) => pt.typeSymbol == ObjectClass
-        case _        => false
-      })
-    }
-
-    // scala.FunctionX and scala.runtim.AbstractFunctionX
-    FunctionReference = (0 to MaxFunctionArity).map(i => classBTypeFromSymbol(FunctionClass(i)))(collection.breakOut)
-
-    AbstractFunctionReference = (0 to MaxFunctionArity).map(i => classBTypeFromSymbol(AbstractFunctionClass(i)))(collection.breakOut)
-
-    AbstractFunctionArityMap = AbstractFunctionReference.zipWithIndex.toMap
-
-    PartialFunctionReference         = classBTypeFromSymbol(PartialFunctionClass)
-    AbstractPartialFunctionReference = classBTypeFromSymbol(AbstractPartialFunctionClass)
-
-    BoxesRunTime = classBTypeFromSymbol(requiredClass[scala.runtime.BoxesRunTime])
-
-    asmBoxTo = Map(
-      BOOL   -> MethodNameAndType("boxToBoolean",   MethodBType(List(BOOL),   BOXED_BOOLEAN)),
-      BYTE   -> MethodNameAndType("boxToByte",      MethodBType(List(BYTE),   BOXED_BYTE)),
-      CHAR   -> MethodNameAndType("boxToCharacter", MethodBType(List(CHAR),   BOXED_CHAR)),
-      SHORT  -> MethodNameAndType("boxToShort",     MethodBType(List(SHORT),  BOXED_SHORT)),
-      INT    -> MethodNameAndType("boxToInteger",   MethodBType(List(INT),    BOXED_INT)),
-      LONG   -> MethodNameAndType("boxToLong",      MethodBType(List(LONG),   BOXED_LONG)),
-      FLOAT  -> MethodNameAndType("boxToFloat",     MethodBType(List(FLOAT),  BOXED_FLOAT)),
-      DOUBLE -> MethodNameAndType("boxToDouble",    MethodBType(List(DOUBLE), BOXED_DOUBLE))
-    )
+  def ObjectReference          : ClassBType
+  def jlCloneableReference     : ClassBType
+  def jioSerializableReference : ClassBType
+}
 
-    asmUnboxTo = Map(
-      BOOL   -> MethodNameAndType("unboxToBoolean", MethodBType(List(ObjectReference), BOOL)),
-      BYTE   -> MethodNameAndType("unboxToByte",    MethodBType(List(ObjectReference), BYTE)),
-      CHAR   -> MethodNameAndType("unboxToChar",    MethodBType(List(ObjectReference), CHAR)),
-      SHORT  -> MethodNameAndType("unboxToShort",   MethodBType(List(ObjectReference), SHORT)),
-      INT    -> MethodNameAndType("unboxToInt",     MethodBType(List(ObjectReference), INT)),
-      LONG   -> MethodNameAndType("unboxToLong",    MethodBType(List(ObjectReference), LONG)),
-      FLOAT  -> MethodNameAndType("unboxToFloat",   MethodBType(List(ObjectReference), FLOAT)),
-      DOUBLE -> MethodNameAndType("unboxToDouble",  MethodBType(List(ObjectReference), DOUBLE))
-    )
+/**
+ * See comment in class [[CoreBTypes]].
+ */
+final class CoreBTypesProxy[BTFS <: BTypesFromSymbols[_ <: Global]](val bTypes: BTFS) extends CoreBTypesProxyGlobalIndependent[BTFS] {
+  import bTypes._
+  import global._
 
-    typeOfArrayOp = {
-      import scalaPrimitives._
-      Map(
-          (List(ZARRAY_LENGTH, ZARRAY_GET, ZARRAY_SET) map (_ -> BOOL))   ++
-          (List(BARRAY_LENGTH, BARRAY_GET, BARRAY_SET) map (_ -> BYTE))   ++
-          (List(SARRAY_LENGTH, SARRAY_GET, SARRAY_SET) map (_ -> SHORT))  ++
-          (List(CARRAY_LENGTH, CARRAY_GET, CARRAY_SET) map (_ -> CHAR))   ++
-          (List(IARRAY_LENGTH, IARRAY_GET, IARRAY_SET) map (_ -> INT))    ++
-          (List(LARRAY_LENGTH, LARRAY_GET, LARRAY_SET) map (_ -> LONG))   ++
-          (List(FARRAY_LENGTH, FARRAY_GET, FARRAY_SET) map (_ -> FLOAT))  ++
-          (List(DARRAY_LENGTH, DARRAY_GET, DARRAY_SET) map (_ -> DOUBLE)) ++
-          (List(OARRAY_LENGTH, OARRAY_GET, OARRAY_SET) map (_ -> ObjectReference)) : _*
-      )
-    }
+  private[this] var _coreBTypes: CoreBTypes[bTypes.type] = _
+  def setBTypes(coreBTypes: CoreBTypes[BTFS]): Unit = {
+    _coreBTypes = coreBTypes.asInstanceOf[CoreBTypes[bTypes.type]]
   }
+
+  def primitiveTypeMap: Map[Symbol, PrimitiveBType] = _coreBTypes.primitiveTypeMap
+
+  def BOXED_UNIT    : ClassBType = _coreBTypes.BOXED_UNIT
+  def BOXED_BOOLEAN : ClassBType = _coreBTypes.BOXED_BOOLEAN
+  def BOXED_BYTE    : ClassBType = _coreBTypes.BOXED_BYTE
+  def BOXED_SHORT   : ClassBType = _coreBTypes.BOXED_SHORT
+  def BOXED_CHAR    : ClassBType = _coreBTypes.BOXED_CHAR
+  def BOXED_INT     : ClassBType = _coreBTypes.BOXED_INT
+  def BOXED_LONG    : ClassBType = _coreBTypes.BOXED_LONG
+  def BOXED_FLOAT   : ClassBType = _coreBTypes.BOXED_FLOAT
+  def BOXED_DOUBLE  : ClassBType = _coreBTypes.BOXED_DOUBLE
+
+  def boxedClasses: Set[ClassBType] = _coreBTypes.boxedClasses
+
+  def boxedClassOfPrimitive: Map[PrimitiveBType, ClassBType] = _coreBTypes.boxedClassOfPrimitive
+
+  def boxResultType: Map[Symbol, ClassBType] = _coreBTypes.boxResultType
+
+  def unboxResultType: Map[Symbol, PrimitiveBType] = _coreBTypes.unboxResultType
+
+  def RT_NOTHING : ClassBType = _coreBTypes.RT_NOTHING
+  def RT_NULL    : ClassBType = _coreBTypes.RT_NULL
+
+  def ObjectReference   : ClassBType = _coreBTypes.ObjectReference
+  def objArrayReference : ArrayBType = _coreBTypes.objArrayReference
+
+  def StringReference             : ClassBType = _coreBTypes.StringReference
+  def StringBuilderReference      : ClassBType = _coreBTypes.StringBuilderReference
+  def ThrowableReference          : ClassBType = _coreBTypes.ThrowableReference
+  def jlCloneableReference        : ClassBType = _coreBTypes.jlCloneableReference
+  def jlNPEReference              : ClassBType = _coreBTypes.jlNPEReference
+  def jioSerializableReference    : ClassBType = _coreBTypes.jioSerializableReference
+  def scalaSerializableReference  : ClassBType = _coreBTypes.scalaSerializableReference
+  def classCastExceptionReference : ClassBType = _coreBTypes.classCastExceptionReference
+
+  def srBooleanRef : ClassBType = _coreBTypes.srBooleanRef
+  def srByteRef    : ClassBType = _coreBTypes.srByteRef
+  def srCharRef    : ClassBType = _coreBTypes.srCharRef
+  def srIntRef     : ClassBType = _coreBTypes.srIntRef
+  def srLongRef    : ClassBType = _coreBTypes.srLongRef
+  def srFloatRef   : ClassBType = _coreBTypes.srFloatRef
+  def srDoubleRef  : ClassBType = _coreBTypes.srDoubleRef
+
+  def hashMethodSym: Symbol = _coreBTypes.hashMethodSym
+
+  def AndroidParcelableInterface : Symbol = _coreBTypes.AndroidParcelableInterface
+  def AndroidCreatorClass        : Symbol = _coreBTypes.AndroidCreatorClass
+
+  def BeanInfoAttr: Symbol = _coreBTypes.BeanInfoAttr
+
+  def String_valueOf: Symbol = _coreBTypes.String_valueOf
+
+  def FunctionReference         : Vector[ClassBType]   = _coreBTypes.FunctionReference
+  def AbstractFunctionReference : Vector[ClassBType]   = _coreBTypes.AbstractFunctionReference
+  def AbstractFunctionArityMap  : Map[ClassBType, Int] = _coreBTypes.AbstractFunctionArityMap
+
+  def PartialFunctionReference         : ClassBType = _coreBTypes.PartialFunctionReference
+  def AbstractPartialFunctionReference : ClassBType = _coreBTypes.AbstractPartialFunctionReference
+
+  def BoxesRunTime: ClassBType = _coreBTypes.BoxesRunTime
+
+  def asmBoxTo  : Map[BType, MethodNameAndType] = _coreBTypes.asmBoxTo
+  def asmUnboxTo: Map[BType, MethodNameAndType] = _coreBTypes.asmUnboxTo
+
+  def typeOfArrayOp: Map[Int, BType] = _coreBTypes.typeOfArrayOp
 }
diff --git a/src/compiler/scala/tools/nsc/backend/jvm/GenBCode.scala b/src/compiler/scala/tools/nsc/backend/jvm/GenBCode.scala
index 480767f407..0a7c894a69 100644
--- a/src/compiler/scala/tools/nsc/backend/jvm/GenBCode.scala
+++ b/src/compiler/scala/tools/nsc/backend/jvm/GenBCode.scala
@@ -47,6 +47,7 @@ abstract class GenBCode extends BCodeSyncAndTry {
   import global._
 
   import bTypes._
+  import coreBTypes._
 
   val phaseName = "jvm"