Merge pull request #1188 from dotty-staging/remove-newarray-magic

Fix #1167: Reduce the magic in Arrays.newRefArray. Implement multidimensional arrays

Author: DarkDimius

project/Build.scala

@@ -77,7 +77,7 @@ object DottyBuild extends Build {
       com.typesafe.sbteclipse.plugin.EclipsePlugin.EclipseKeys.withSource := true,
 
       // get libraries onboard
-      partestDeps := Seq("me.d-d" % "scala-compiler" % "2.11.5-20151022-113908-7fb0e653fd",
+      partestDeps := Seq("me.d-d" % "scala-compiler" % "2.11.5-20160322-171045-e19b30b3cd",
                          "org.scala-lang" % "scala-reflect" % scalaVersion.value,
                          "org.scala-lang" % "scala-library" % scalaVersion.value % "test"),
       libraryDependencies ++= partestDeps.value,

src/dotty/runtime/Arrays.scala

@@ -2,6 +2,8 @@ package dotty.runtime
 
 import scala.reflect.ClassTag
 
+import java.lang.{reflect => jlr}
+
 /** All but the first two operations should be short-circuited and implemented specially by
  *  the backend.
  */
@@ -22,35 +24,8 @@ object Arrays {
     arr
   }
 
-  /** Create an array of type T. T must be of form Array[E], with
-   *  E being a reference type.
+  /** Create an array of a reference type T.
    */
-  def newRefArray[T](length: Int): T = ???
-
-  /** Create a Byte[] array */
-  def newByteArray(length: Int): Array[Byte] = ???
-
-  /** Create a Short[] array */
-  def newShortArray(length: Int): Array[Short] = ???
-
-  /** Create a Char[] array */
-  def newCharArray(length: Int): Array[Char] = ???
-
-  /** Create an Int[] array */
-  def newIntArray(length: Int): Array[Int] = ???
-
-  /** Create a Long[] array */
-  def newLongArray(length: Int): Array[Long] = ???
-
-  /** Create a Float[] array */
-  def newFloatArray(length: Int): Array[Float] = ???
-
-  /** Create a Double[] array */
-  def newDoubleArray(length: Int): Array[Double] = ???
-
-  /** Create a Boolean[] array */
-  def newBooleanArray(length: Int): Array[Boolean] = ???
-
-  /** Create a scala.runtime.BoxedUnit[] array */
-  def newUnitArray(length: Int): Array[Unit] = ???
+  def newArray[Arr](componentType: Class[_], returnType: Class[Arr], dimensions: Array[Int]): Arr =
+    jlr.Array.newInstance(componentType, dimensions: _*).asInstanceOf[Arr]
 }

src/dotty/tools/backend/jvm/DottyBackendInterface.scala

@@ -153,15 +153,8 @@ class DottyBackendInterface(outputDirectory: AbstractFile)(implicit ctx: Context
   }.toMap
   def unboxMethods: Map[Symbol, Symbol] = defn.ScalaValueClasses().map(x => (x, Erasure.Boxing.unboxMethod(x.asClass))).toMap
 
-  private val mkArrayNames: Set[Name] = Set("Byte", "Float", "Char", "Double", "Boolean", "Unit", "Long", "Int", "Short", "Ref").map{ x=>
-    ("new" + x + "Array").toTermName
-  }
-
-  val dottyArraysModuleClass = toDenot(defn.DottyArraysModule).moduleClass.asClass
-
-
   override def isSyntheticArrayConstructor(s: Symbol) = {
-    (toDenot(s).maybeOwner eq dottyArraysModuleClass) && mkArrayNames.contains(s.name)
+    s eq defn.newArrayMethod
   }
 
   def isBox(sym: Symbol): Boolean = Erasure.Boxing.isBox(sym)

src/dotty/tools/backend/sjs/JSCodeGen.scala

@@ -718,9 +718,9 @@ class JSCodeGen()(implicit ctx: Context) {
         if (sym.is(Module)) {
           assert(!sym.is(Package), "Cannot use package as value: " + tree)
           genLoadModule(sym)
-        } else /*if (sym.isStaticMember) {
-          genStaticMember(sym)
-        } else if (paramAccessorLocals contains sym) {
+        } else if (sym.is(JavaStatic)) {
+          genLoadStaticField(sym)
+        } else /*if (paramAccessorLocals contains sym) {
           paramAccessorLocals(sym).ref
         } else if (isScalaJSDefinedJSClass(sym.owner)) {
           val genQual = genExpr(qualifier)
@@ -1036,8 +1036,6 @@ class JSCodeGen()(implicit ctx: Context) {
       genStringConcat(tree, receiver, args)
     else if (code == HASH)
       genScalaHash(tree, receiver)
-    else if (isArrayNew(code))
-      genArrayNew(tree, code)
     else if (isArrayOp(code))
       genArrayOp(tree, code)
     else if (code == SYNCHRONIZED)
@@ -1409,24 +1407,6 @@ class JSCodeGen()(implicit ctx: Context) {
         List(genExpr(receiver)))
   }
 
-  /** Gen JS code for a new array operation. */
-  private def genArrayNew(tree: Tree, code: Int): js.Tree = {
-    import scala.tools.nsc.backend.ScalaPrimitives._
-
-    implicit val pos: Position = tree.pos
-
-    val Apply(fun, args) = tree
-    val genLength = genExpr(args.head)
-
-    toIRType(tree.tpe) match {
-      case arrayType: jstpe.ArrayType =>
-        js.NewArray(arrayType, List(genLength))
-
-      case irTpe =>
-        throw new FatalError(s"ArrayNew $tree must have an array type but was $irTpe")
-    }
-  }
-
   /** Gen JS code for an array operation (get, set or length) */
   private def genArrayOp(tree: Tree, code: Int): js.Tree = {
     import scala.tools.nsc.backend.ScalaPrimitives._
@@ -2328,6 +2308,24 @@ class JSCodeGen()(implicit ctx: Context) {
     }
   }
 
+  /** Gen JS code for loading a Java static field.
+   */
+  private def genLoadStaticField(sym: Symbol)(implicit pos: Position): js.Tree = {
+    /* Actually, there is no static member in Scala.js. If we come here, that
+     * is because we found the symbol in a Java-emitted .class in the
+     * classpath. But the corresponding implementation in Scala.js will
+     * actually be a val in the companion module.
+     */
+
+    if (sym == defn.BoxedUnit_UNIT) {
+      js.Undefined()
+    } else {
+      val instance = genLoadModule(sym.owner)
+      val method = encodeStaticMemberSym(sym)
+      js.Apply(instance, method, Nil)(toIRType(sym.info))
+    }
+  }
+
   /** Gen JS code for loading a module.
    *
    *  Can be given either the module symbol, or its module class symbol.

src/dotty/tools/backend/sjs/JSPrimitives.scala

@@ -80,18 +80,6 @@ class JSPrimitives(ctx: Context) extends DottyPrimitives(ctx) {
 
     val jsdefn = JSDefinitions.jsdefn
 
-    // For some reason, the JVM primitive set does not register those
-    addPrimitive(defn.DottyArraysModule.requiredMethod(Names.termName("newBooleanArray")), NEW_ZARRAY)
-    addPrimitive(defn.DottyArraysModule.requiredMethod(Names.termName("newByteArray")), NEW_BARRAY)
-    addPrimitive(defn.DottyArraysModule.requiredMethod(Names.termName("newShortArray")), NEW_SARRAY)
-    addPrimitive(defn.DottyArraysModule.requiredMethod(Names.termName("newCharArray")), NEW_CARRAY)
-    addPrimitive(defn.DottyArraysModule.requiredMethod(Names.termName("newIntArray")), NEW_IARRAY)
-    addPrimitive(defn.DottyArraysModule.requiredMethod(Names.termName("newLongArray")), NEW_LARRAY)
-    addPrimitive(defn.DottyArraysModule.requiredMethod(Names.termName("newFloatArray")), NEW_FARRAY)
-    addPrimitive(defn.DottyArraysModule.requiredMethod(Names.termName("newDoubleArray")), NEW_DARRAY)
-    addPrimitive(defn.DottyArraysModule.requiredMethod(Names.termName("newRefArray")), NEW_OARRAY)
-    addPrimitive(defn.DottyArraysModule.requiredMethod(Names.termName("newUnitArray")), NEW_OARRAY)
-
     addPrimitive(defn.Any_getClass, GETCLASS)
 
     for (i <- 0 to 22)

src/dotty/tools/dotc/Compiler.scala

@@ -66,7 +66,8 @@ class Compiler {
            new Getters,             // Replace non-private vals and vars with getter defs (fields are added later)
            new ElimByName,          // Expand by-name parameters and arguments
            new AugmentScala2Traits, // Expand traits defined in Scala 2.11 to simulate old-style rewritings
-           new ResolveSuper),       // Implement super accessors and add forwarders to trait methods
+           new ResolveSuper,        // Implement super accessors and add forwarders to trait methods
+           new ArrayConstructors),  // Intercept creation of (non-generic) arrays and intrinsify.
       List(new Erasure),            // Rewrite types to JVM model, erasing all type parameters, abstract types and refinements.
       List(new ElimErasedValueType, // Expand erased value types to their underlying implmementation types
            new VCElideAllocations,  // Peep-hole optimization to eliminate unnecessary value class allocations

src/dotty/tools/dotc/ast/tpd.scala

@@ -125,8 +125,8 @@ object tpd extends Trees.Instance[Type] with TypedTreeInfo {
   def SeqLiteral(elems: List[Tree], elemtpt: Tree)(implicit ctx: Context): SeqLiteral =
     ta.assignType(untpd.SeqLiteral(elems, elemtpt), elems, elemtpt)
 
-  def JavaSeqLiteral(elems: List[Tree], elemtpt: Tree)(implicit ctx: Context): SeqLiteral =
-    ta.assignType(new untpd.JavaSeqLiteral(elems, elemtpt), elems, elemtpt)
+  def JavaSeqLiteral(elems: List[Tree], elemtpt: Tree)(implicit ctx: Context): JavaSeqLiteral =
+    ta.assignType(new untpd.JavaSeqLiteral(elems, elemtpt), elems, elemtpt).asInstanceOf[JavaSeqLiteral]
 
   def TypeTree(original: Tree)(implicit ctx: Context): TypeTree =
     TypeTree(original.tpe, original)
@@ -362,18 +362,16 @@ object tpd extends Trees.Instance[Type] with TypedTreeInfo {
    *  kind for the given element type in `typeArg`. No type arguments or
    *  `length` arguments are given.
    */
-  def newArray(typeArg: Tree, pos: Position)(implicit ctx: Context): Tree = {
-    val elemType = typeArg.tpe
-    val elemClass = elemType.classSymbol
-    def newArr(kind: String) =
-      ref(defn.DottyArraysModule).select(s"new${kind}Array".toTermName).withPos(pos)
-    if (TypeErasure.isUnboundedGeneric(elemType))
-      newArr("Generic").appliedToTypeTrees(typeArg :: Nil)
-    else if (elemClass.isPrimitiveValueClass)
-      newArr(elemClass.name.toString)
-    else
-      newArr("Ref").appliedToTypeTrees(
-        TypeTree(defn.ArrayOf(elemType)).withPos(typeArg.pos) :: Nil)
+  def newArray(elemTpe: Type, returnTpe: Type, pos: Position, dims: JavaSeqLiteral)(implicit ctx: Context): Tree = {
+    val elemClass = elemTpe.classSymbol
+    def newArr =
+      ref(defn.DottyArraysModule).select(defn.newArrayMethod).withPos(pos)
+
+    if (!ctx.erasedTypes) {
+      assert(!TypeErasure.isUnboundedGeneric(elemTpe)) //needs to be done during typer. See Applications.convertNewGenericArray
+      newArr.appliedToTypeTrees(TypeTree(returnTpe) :: Nil).appliedToArgs(clsOf(elemTpe) :: clsOf(returnTpe) :: dims :: Nil).withPos(pos)
+    } else  // after erasure
+      newArr.appliedToArgs(clsOf(elemTpe) :: clsOf(returnTpe) :: dims :: Nil).withPos(pos)
   }
 
   // ------ Creating typed equivalents of trees that exist only in untyped form -------
@@ -835,7 +833,10 @@ object tpd extends Trees.Instance[Type] with TypedTreeInfo {
       case tpnme.Float => TYPE(defn.BoxedFloatModule)
       case tpnme.Double => TYPE(defn.BoxedDoubleModule)
       case tpnme.Unit => TYPE(defn.BoxedUnitModule)
-      case _ => Literal(Constant(TypeErasure.erasure(tp)))
+      case _ =>
+        if(ctx.erasedTypes || !tp.derivesFrom(defn.ArrayClass))
+          Literal(Constant(TypeErasure.erasure(tp)))
+        else Literal(Constant(tp))
     }
   }
 

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

@@ -246,8 +246,8 @@ class Definitions {
   def DottyPredefModule(implicit ctx: Context) = DottyPredefModuleRef.symbol
   lazy val DottyArraysModuleRef = ctx.requiredModuleRef("dotty.runtime.Arrays")
   def DottyArraysModule(implicit ctx: Context) = DottyArraysModuleRef.symbol
-
-    def newRefArrayMethod(implicit ctx: Context) = DottyArraysModule.requiredMethod("newRefArray")
+    def newGenericArrayMethod(implicit ctx: Context) = DottyArraysModule.requiredMethod("newGenericArray")
+    def newArrayMethod(implicit ctx: Context) = DottyArraysModule.requiredMethod("newArray")
 
   lazy val NilModuleRef = ctx.requiredModuleRef("scala.collection.immutable.Nil")
   def NilModule(implicit ctx: Context) = NilModuleRef.symbol
@@ -279,6 +279,9 @@ class Definitions {
     def Array_clone(implicit ctx: Context) = Array_cloneR.symbol
     lazy val ArrayConstructorR            = ArrayClass.requiredMethodRef(nme.CONSTRUCTOR)
     def ArrayConstructor(implicit ctx: Context) = ArrayConstructorR.symbol
+  lazy val ArrayModuleType = ctx.requiredModuleRef("scala.Array")
+  def ArrayModule(implicit ctx: Context) = ArrayModuleType.symbol.moduleClass.asClass
+
 
   lazy val UnitType: TypeRef = valueTypeRef("scala.Unit", BoxedUnitType, java.lang.Void.TYPE, UnitEnc)
   def UnitClass(implicit ctx: Context) = UnitType.symbol.asClass
@@ -622,7 +625,7 @@ class Definitions {
   lazy val PhantomClasses = Set[Symbol](AnyClass, AnyValClass, NullClass, NothingClass)
 
   def isPolymorphicAfterErasure(sym: Symbol) =
-     (sym eq Any_isInstanceOf) || (sym eq Any_asInstanceOf) || (sym eq newRefArrayMethod)
+     (sym eq Any_isInstanceOf) || (sym eq Any_asInstanceOf)
 
   def isTupleType(tp: Type)(implicit ctx: Context) = {
     val arity = tp.dealias.argInfos.length

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

@@ -0,0 +1,57 @@
+package dotty.tools.dotc
+package transform
+
+import core._
+import TreeTransforms._
+import Contexts.Context
+import Flags._
+import SymUtils._
+import Symbols._
+import SymDenotations._
+import Types._
+import Decorators._
+import DenotTransformers._
+import StdNames._
+import NameOps._
+import ast.Trees._
+import dotty.tools.dotc.ast.tpd
+import util.Positions._
+import Names._
+
+import collection.mutable
+import ResolveSuper._
+
+import scala.collection.immutable.::
+
+
+/** This phase rewrites calls to array constructors to newArray method in Dotty.runtime.Arrays module.
+ *
+ * It assummes that generic arrays have already been handled by typer(see Applications.convertNewGenericArray).
+ * Additionally it optimizes calls to scala.Array.ofDim functions by replacing them with calls to newArray with specific dimensions
+ */
+class ArrayConstructors extends MiniPhaseTransform { thisTransform =>
+  import ast.tpd._
+
+  override def phaseName: String = "arrayConstructors"
+
+  override def transformApply(tree: tpd.Apply)(implicit ctx: Context, info: TransformerInfo): tpd.Tree = {
+    def rewrite(elemType: Type, dims: List[Tree]) =
+      tpd.newArray(elemType, tree.tpe, tree.pos, JavaSeqLiteral(dims, TypeTree(defn.IntClass.typeRef)))
+
+    if (tree.fun.symbol eq defn.ArrayConstructor) {
+      val TypeApply(tycon, targ :: Nil) = tree.fun
+      rewrite(targ.tpe, tree.args)
+    } else if ((tree.fun.symbol.maybeOwner eq defn.ArrayModule) && (tree.fun.symbol.name eq nme.ofDim) && !tree.tpe.isInstanceOf[MethodicType]) {
+
+      tree.fun match {
+        case Apply(TypeApply(t: Ident, targ), dims)  if !TypeErasure.isUnboundedGeneric(targ.head.tpe) =>
+          rewrite(targ.head.tpe, dims)
+        case Apply(TypeApply(t: Select, targ), dims) if !TypeErasure.isUnboundedGeneric(targ.head.tpe) =>
+          Block(t.qualifier :: Nil, rewrite(targ.head.tpe, dims))
+        case _ => tree
+      }
+
+    } else tree
+  }
+}
+

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

@@ -21,7 +21,7 @@ import core.Decorators._
 import dotty.tools.dotc.ast.{Trees, tpd, untpd}
 import ast.Trees._
 import scala.collection.mutable.ListBuffer
-import dotty.tools.dotc.core.Flags
+import dotty.tools.dotc.core.{Constants, Flags}
 import ValueClasses._
 import TypeUtils._
 import ExplicitOuter._
@@ -299,8 +299,9 @@ object Erasure extends TypeTestsCasts{
       assignType(untpd.cpy.Typed(tree)(expr1, tpt1), tpt1)
     }
 
-    override def typedLiteral(tree: untpd.Literal)(implicit ctc: Context): Literal =
+    override def typedLiteral(tree: untpd.Literal)(implicit ctx: Context): Literal =
       if (tree.typeOpt.isRef(defn.UnitClass)) tree.withType(tree.typeOpt)
+      else if (tree.const.tag == Constants.ClazzTag) Literal(Constant(erasure(tree.const.typeValue)))
       else super.typedLiteral(tree)
 
     /** Type check select nodes, applying the following rewritings exhaustively
@@ -467,28 +468,18 @@ object Erasure extends TypeTestsCasts{
         tpt = untpd.TypedSplice(TypeTree(sym.info).withPos(vdef.tpt.pos))), sym)
 
     override def typedDefDef(ddef: untpd.DefDef, sym: Symbol)(implicit ctx: Context) = {
-      var effectiveSym = sym
-      if (sym == defn.newRefArrayMethod) {
-        // newRefArray is treated specially: It's the only source-defined method
-        // that has a polymorphic type after erasure. But treating its (dummy) definition
-        // with a polymorphic type at and after erasure is an awkward special case.
-        // We therefore rewrite the method definition with a new Symbol of type
-        // (length: Int)Object
-        val MethodType(pnames, ptypes) = sym.info.resultType
-        effectiveSym = sym.copy(info = MethodType(pnames, ptypes, defn.ObjectType))
-      }
       val restpe =
-        if (effectiveSym.isConstructor) defn.UnitType
-        else effectiveSym.info.resultType
+        if (sym.isConstructor) defn.UnitType
+        else sym.info.resultType
       val ddef1 = untpd.cpy.DefDef(ddef)(
         tparams = Nil,
-        vparamss = (outer.paramDefs(effectiveSym) ::: ddef.vparamss.flatten) :: Nil,
+        vparamss = (outer.paramDefs(sym) ::: ddef.vparamss.flatten) :: Nil,
         tpt = untpd.TypedSplice(TypeTree(restpe).withPos(ddef.tpt.pos)),
         rhs = ddef.rhs match {
           case id @ Ident(nme.WILDCARD) => untpd.TypedSplice(id.withType(restpe))
           case _ => ddef.rhs
         })
-      super.typedDefDef(ddef1, effectiveSym)
+      super.typedDefDef(ddef1, sym)
     }
 
     /** After erasure, we may have to replace the closure method by a bridge.

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

@@ -359,8 +359,7 @@ class TreeChecker extends Phase with SymTransformer {
       def isNonMagicalMethod(x: Symbol) =
         x.is(Method) &&
           !x.isCompanionMethod &&
-          !x.isValueClassConvertMethod &&
-          x != defn.newRefArrayMethod
+          !x.isValueClassConvertMethod
 
       val symbolsNotDefined = cls.classInfo.decls.toSet.filter(isNonMagicalMethod) -- impl.body.map(_.symbol) - constr.symbol