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/*
* Scala.js (https://www.scala-js.org/)
*
* Copyright EPFL.
*
* Licensed under Apache License 2.0
* (https://www.apache.org/licenses/LICENSE-2.0).
*
* See the NOTICE file distributed with this work for
* additional information regarding copyright ownership.
*/
package org.scalajs.nscplugin
import scala.language.implicitConversions
import scala.annotation.switch
import scala.collection.mutable
import scala.collection.mutable.ListBuffer
import scala.tools.nsc._
import scala.annotation.tailrec
import scala.reflect.internal.Flags
import org.scalajs.ir
import org.scalajs.ir.{Trees => js, Types => jstpe, ClassKind, Hashers, OriginalName}
import org.scalajs.ir.Names.{LocalName, SimpleFieldName, FieldName, SimpleMethodName, MethodName, ClassName}
import org.scalajs.ir.OriginalName.NoOriginalName
import org.scalajs.ir.Trees.OptimizerHints
import org.scalajs.ir.Version.Unversioned
import org.scalajs.nscplugin.util.{ScopedVar, VarBox}
import ScopedVar.withScopedVars
/** Generate JavaScript code and output it to disk
*
* @author Sébastien Doeraene
*/
abstract class GenJSCode[G <: Global with Singleton](val global: G)
extends plugins.PluginComponent with TypeConversions[G] with JSEncoding[G]
with GenJSExports[G] with GenJSFiles[G] with CompatComponent {
import GenJSCode._
/** Not for use in the constructor body: only initialized afterwards. */
val jsAddons: JSGlobalAddons {
val global: GenJSCode.this.global.type
}
/** Not for use in the constructor body: only initialized afterwards. */
val scalaJSOpts: ScalaJSOptions
import global._
import jsAddons._
import rootMirror._
import definitions._
import jsDefinitions._
import jsInterop.{jsNameOf, jsNativeLoadSpecOfOption, JSName, JSCallingConvention}
import treeInfo.{hasSynthCaseSymbol, StripCast}
import platform.isMaybeBoxed
val phaseName: String = "jscode"
override val description: String = "generate JavaScript code from ASTs"
/** testing: this will be called for each generated `ClassDef`. */
def generatedJSAST(clDef: js.ClassDef): Unit
/** Implicit conversion from nsc Position to ir.Position. */
implicit def pos2irPos(pos: Position): ir.Position = {
if (pos == NoPosition) ir.Position.NoPosition
else {
val source = pos2irPosCache.toIRSource(pos.source)
// nsc positions are 1-based but IR positions are 0-based
ir.Position(source, pos.line-1, pos.column-1)
}
}
private[this] object pos2irPosCache {
import scala.reflect.internal.util._
private[this] var lastNscSource: SourceFile = null
private[this] var lastIRSource: ir.Position.SourceFile = null
def toIRSource(nscSource: SourceFile): ir.Position.SourceFile = {
if (nscSource != lastNscSource) {
lastIRSource = convert(nscSource)
lastNscSource = nscSource
}
lastIRSource
}
private[this] def convert(nscSource: SourceFile): ir.Position.SourceFile = {
nscSource.file.file match {
case null =>
new java.net.URI(
"virtualfile", // Pseudo-Scheme
nscSource.file.path, // Scheme specific part
null // Fragment
)
case file =>
val srcURI = file.toURI
def matches(pat: java.net.URI) = pat.relativize(srcURI) != srcURI
scalaJSOpts.sourceURIMaps.collectFirst {
case ScalaJSOptions.URIMap(from, to) if matches(from) =>
val relURI = from.relativize(srcURI)
to.fold(relURI)(_.resolve(relURI))
} getOrElse srcURI
}
}
def clear(): Unit = {
lastNscSource = null
lastIRSource = null
}
}
/** Materialize implicitly an ir.Position from an implicit nsc Position. */
implicit def implicitPos2irPos(implicit pos: Position): ir.Position = pos
override def newPhase(p: Phase): StdPhase = new JSCodePhase(p)
object jsnme {
val anyHash = newTermName("anyHash")
val arg_outer = newTermName("arg$outer")
}
private sealed abstract class EnclosingLabelDefInfo {
var generatedReturns: Int = 0
}
private final class EnclosingLabelDefInfoWithResultAsReturn()
extends EnclosingLabelDefInfo
private final class EnclosingLabelDefInfoWithResultAsAssigns(
val paramSyms: List[Symbol])
extends EnclosingLabelDefInfo
class JSCodePhase(prev: Phase) extends StdPhase(prev) with JSExportsPhase {
override def name: String = phaseName
override def description: String = GenJSCode.this.description
// Scoped state ------------------------------------------------------------
// Per class body
val currentClassSym = new ScopedVar[Symbol]
private val fieldsMutatedInCurrentClass = new ScopedVar[mutable.Set[Name]]
private val generatedSAMWrapperCount = new ScopedVar[VarBox[Int]]
def currentThisTypeNullable: jstpe.Type =
encodeClassType(currentClassSym)
def currentThisType: jstpe.Type = {
currentThisTypeNullable match {
case tpe @ jstpe.ClassType(cls, _) =>
jstpe.BoxedClassToPrimType.getOrElse(cls, tpe.toNonNullable)
case tpe @ jstpe.AnyType =>
// We are in a JS class, in which even `this` is nullable
tpe
case tpe =>
throw new AssertionError(
s"Unexpected IR this type $tpe for class ${currentClassSym.get}")
}
}
// Per method body
private val currentMethodSym = new ScopedVar[Symbol]
private val thisLocalVarIdent = new ScopedVar[Option[js.LocalIdent]]
private val enclosingLabelDefInfos = new ScopedVar[Map[Symbol, EnclosingLabelDefInfo]]
private val isModuleInitialized = new ScopedVar[VarBox[Boolean]]
private val undefinedDefaultParams = new ScopedVar[mutable.Set[Symbol]]
private val mutableLocalVars = new ScopedVar[mutable.Set[Symbol]]
private val mutatedLocalVars = new ScopedVar[mutable.Set[Symbol]]
private def withPerMethodBodyState[A](methodSym: Symbol)(body: => A): A = {
withScopedVars(
currentMethodSym := methodSym,
thisLocalVarIdent := None,
enclosingLabelDefInfos := Map.empty,
isModuleInitialized := new VarBox(false),
undefinedDefaultParams := mutable.Set.empty,
mutableLocalVars := mutable.Set.empty,
mutatedLocalVars := mutable.Set.empty
) {
body
}
}
// For anonymous methods
// These have a default, since we always read them.
private val tryingToGenMethodAsJSFunction = new ScopedVar[Boolean](false)
private val paramAccessorLocals = new ScopedVar(Map.empty[Symbol, js.ParamDef])
/* Contextual JS class value for some operations of nested JS classes that
* need one.
*/
private val contextualJSClassValue =
new ScopedVar[Option[js.Tree]](None)
private def acquireContextualJSClassValue[A](f: Option[js.Tree] => A): A = {
val jsClassValue = contextualJSClassValue.get
withScopedVars(
contextualJSClassValue := None
) {
f(jsClassValue)
}
}
private class CancelGenMethodAsJSFunction(message: String)
extends scala.util.control.ControlThrowable {
override def getMessage(): String = message
}
// Rewriting of anonymous function classes ---------------------------------
/** Start nested generation of a class.
*
* Fully resets the scoped state (including local name scope).
* Allows to generate an anonymous class as needed.
*/
private def nestedGenerateClass[T](clsSym: Symbol)(body: => T): T = {
withScopedVars(
currentClassSym := clsSym,
fieldsMutatedInCurrentClass := mutable.Set.empty,
generatedSAMWrapperCount := new VarBox(0),
currentMethodSym := null,
thisLocalVarIdent := null,
enclosingLabelDefInfos := null,
isModuleInitialized := null,
undefinedDefaultParams := null,
mutableLocalVars := null,
mutatedLocalVars := null,
tryingToGenMethodAsJSFunction := false,
paramAccessorLocals := Map.empty
)(withNewLocalNameScope(body))
}
// Global class generation state -------------------------------------------
private val lazilyGeneratedAnonClasses = mutable.Map.empty[Symbol, ClassDef]
private val generatedClasses = ListBuffer.empty[(js.ClassDef, Position)]
private val generatedStaticForwarderClasses = ListBuffer.empty[(Symbol, js.ClassDef)]
private def consumeLazilyGeneratedAnonClass(sym: Symbol): ClassDef = {
/* If we are trying to generate an method as JSFunction, we cannot
* actually consume the symbol, since we might fail trying and retry.
* We will then see the same tree again and not find the symbol anymore.
*
* If we are sure this is the only generation, we remove the symbol to
* make sure we don't generate the same class twice.
*/
val optDef = {
if (tryingToGenMethodAsJSFunction)
lazilyGeneratedAnonClasses.get(sym)
else
lazilyGeneratedAnonClasses.remove(sym)
}
optDef.getOrElse {
abort("Couldn't find tree for lazily generated anonymous class " +
s"${sym.fullName} at ${sym.pos}")
}
}
// Top-level apply ---------------------------------------------------------
override def run(): Unit = {
scalaPrimitives.init()
genBCode.bTypes.initializeCoreBTypes()
jsPrimitives.init()
super.run()
}
/** Generates the Scala.js IR for a compilation unit
* This method iterates over all the class and interface definitions
* found in the compilation unit and emits their IR (.sjsir).
*
* Some classes are never actually emitted:
* - Classes representing primitive types
* - The scala.Array class
* - Implementation classes for JS traits
*
* Some classes representing anonymous functions are not actually emitted.
* Instead, a temporary representation of their `apply` method is built
* and recorded, so that it can be inlined as a JavaScript anonymous
* function in the method that instantiates it.
*
* Other ClassDefs are emitted according to their nature:
* * Non-native JS class -> `genNonNativeJSClass()`
* * Other JS type (<: js.Any) -> `genJSClassData()`
* * Interface -> `genInterface()`
* * Normal class -> `genClass()`
*/
override def apply(cunit: CompilationUnit): Unit = {
try {
def collectClassDefs(tree: Tree): List[ClassDef] = {
tree match {
case EmptyTree => Nil
case PackageDef(_, stats) => stats flatMap collectClassDefs
case cd: ClassDef => cd :: Nil
}
}
val allClassDefs = collectClassDefs(cunit.body)
/* There are three types of anonymous classes we want to generate
* only once we need them so we can inline them at construction site:
*
* - anonymous class that are JS types, which includes:
* - lambdas for js.FunctionN and js.ThisFunctionN (SAMs). (We may
* not generate actual Scala classes for these).
* - anonymous (non-lambda) JS classes. These classes may not have
* their own prototype. Therefore, their constructor *must* be
* inlined.
* - lambdas for scala.FunctionN. This is only an optimization and may
* fail. In the case of failure, we fall back to generating a
* fully-fledged Scala class.
*
* Since for all these, we don't know how they inter-depend, we just
* store them in a map at this point.
*/
val (lazyAnons, fullClassDefs) = allClassDefs.partition { cd =>
val sym = cd.symbol
isAnonymousJSClass(sym) || isJSFunctionDef(sym) || sym.isAnonymousFunction
}
lazilyGeneratedAnonClasses ++= lazyAnons.map(cd => cd.symbol -> cd)
/* Finally, we emit true code for the remaining class defs. */
for (cd <- fullClassDefs) {
val sym = cd.symbol
implicit val pos = sym.pos
/* Do not actually emit code for primitive types nor scala.Array. */
val isPrimitive =
isPrimitiveValueClass(sym) || (sym == ArrayClass)
if (!isPrimitive) {
withScopedVars(
currentClassSym := sym,
fieldsMutatedInCurrentClass := mutable.Set.empty,
generatedSAMWrapperCount := new VarBox(0)
) {
val tree = if (isJSType(sym)) {
if (!sym.isTraitOrInterface && isNonNativeJSClass(sym) &&
!isJSFunctionDef(sym)) {
genNonNativeJSClass(cd)
} else {
genJSClassData(cd)
}
} else if (sym.isTraitOrInterface) {
genInterface(cd)
} else {
genClass(cd)
}
generatedClasses += tree -> sym.pos
}
}
}
val clDefs: List[(js.ClassDef, Position)] = if (generatedStaticForwarderClasses.isEmpty) {
/* Fast path, applicable under -Xno-forwarders, as well as when all
* the `object`s of a compilation unit have a companion class.
*/
generatedClasses.toList
} else {
val regularClasses = generatedClasses.toList
/* #4148 Add generated static forwarder classes, except those that
* would collide with regular classes on case insensitive file
* systems.
*/
/* I could not find any reference anywhere about what locale is used
* by case insensitive file systems to compare case-insensitively.
* In doubt, force the English locale, which is probably going to do
* the right thing in virtually all cases (especially if users stick
* to ASCII class names), and it has the merit of being deterministic,
* as opposed to using the OS' default locale.
* The JVM backend performs a similar test to emit a warning for
* conflicting top-level classes. However, it uses `toLowerCase()`
* without argument, which is not deterministic.
*/
def caseInsensitiveNameOf(classDef: js.ClassDef): String =
classDef.name.name.nameString.toLowerCase(java.util.Locale.ENGLISH)
val generatedCaseInsensitiveNames =
regularClasses.map(pair => caseInsensitiveNameOf(pair._1)).toSet
val staticForwarderClasses = generatedStaticForwarderClasses.toList
.withFilter { case (site, classDef) =>
if (!generatedCaseInsensitiveNames.contains(caseInsensitiveNameOf(classDef))) {
true
} else {
global.runReporting.warning(
site.pos,
s"Not generating the static forwarders of ${classDef.name.name.nameString} " +
"because its name differs only in case from the name of another class or " +
"trait in this compilation unit.",
WarningCategory.Other,
site)
false
}
}
.map(pair => (pair._2, pair._1.pos))
regularClasses ::: staticForwarderClasses
}
for ((classDef, pos) <- clDefs) {
try {
val hashedClassDef = Hashers.hashClassDef(classDef)
generatedJSAST(hashedClassDef)
genIRFile(cunit, hashedClassDef)
} catch {
case e: ir.InvalidIRException =>
e.tree match {
case ir.Trees.Transient(UndefinedParam) =>
reporter.error(pos,
"Found a dangling UndefinedParam at " +
s"${e.tree.pos}. This is likely due to a bad " +
"interaction between a macro or a compiler plugin " +
"and the Scala.js compiler plugin. If you hit " +
"this, please let us know.")
case _ =>
reporter.error(pos,
"The Scala.js compiler generated invalid IR for " +
"this class. Please report this as a bug. IR: " +
e.tree)
}
}
}
} catch {
// Handle exceptions in exactly the same way as the JVM backend
case ex: InterruptedException =>
throw ex
case ex: Throwable =>
if (settings.debug.value)
ex.printStackTrace()
globalError(s"Error while emitting ${cunit.source}\n${ex.getMessage}")
} finally {
lazilyGeneratedAnonClasses.clear()
generatedStaticForwarderClasses.clear()
generatedClasses.clear()
pos2irPosCache.clear()
}
}
// Generate a class --------------------------------------------------------
/** Gen the IR ClassDef for a class definition (maybe a module class).
*/
def genClass(cd: ClassDef): js.ClassDef = {
val ClassDef(mods, name, _, impl) = cd
val sym = cd.symbol
implicit val pos = sym.pos
assert(!sym.isTraitOrInterface,
"genClass() must be called only for normal classes: "+sym)
assert(sym.superClass != NoSymbol, sym)
if (hasDefaultCtorArgsAndJSModule(sym)) {
reporter.error(pos,
"Implementation restriction: constructors of " +
"Scala classes cannot have default parameters " +
"if their companion module is JS native.")
}
val classIdent = encodeClassNameIdent(sym)
val originalName = originalNameOfClass(sym)
val isHijacked = isHijackedClass(sym)
// Optimizer hints
val isDynamicImportThunk = sym.isSubClass(DynamicImportThunkClass)
def isStdLibClassWithAdHocInlineAnnot(sym: Symbol): Boolean = {
val fullName = sym.fullName
(fullName.startsWith("scala.Tuple") && !fullName.endsWith("$")) ||
(fullName.startsWith("scala.collection.mutable.ArrayOps$of"))
}
val shouldMarkInline = (
isDynamicImportThunk ||
sym.hasAnnotation(InlineAnnotationClass) ||
(sym.isAnonymousFunction && !sym.isSubClass(PartialFunctionClass)) ||
isStdLibClassWithAdHocInlineAnnot(sym))
val optimizerHints =
OptimizerHints.empty.
withInline(shouldMarkInline).
withNoinline(sym.hasAnnotation(NoinlineAnnotationClass))
// Generate members (constructor + methods)
val methodsBuilder = List.newBuilder[js.MethodDef]
val jsNativeMembersBuilder = List.newBuilder[js.JSNativeMemberDef]
def gen(tree: Tree): Unit = {
tree match {
case EmptyTree => ()
case Template(_, _, body) => body foreach gen
case ValDef(mods, name, tpt, rhs) =>
() // fields are added via genClassFields()
case dd: DefDef =>
if (dd.symbol.hasAnnotation(JSNativeAnnotation))
jsNativeMembersBuilder += genJSNativeMemberDef(dd)
else
methodsBuilder ++= genMethod(dd)
case _ => abort("Illegal tree in gen of genClass(): " + tree)
}
}
gen(impl)
val fields = if (!isHijacked) genClassFields(cd) else Nil
val jsNativeMembers = jsNativeMembersBuilder.result()
val generatedMethods = methodsBuilder.result()
val memberExports = genMemberExports(sym)
val topLevelExportDefs = genTopLevelExports(sym)
// Static initializer
val optStaticInitializer = {
// Initialization of reflection data, if required
val reflectInit = {
val enableReflectiveInstantiation = {
(sym :: sym.ancestors).exists { ancestor =>
ancestor.hasAnnotation(EnableReflectiveInstantiationAnnotation)
}
}
if (enableReflectiveInstantiation)
genRegisterReflectiveInstantiation(sym)
else
None
}
// Initialization of the module because of field exports
val needsStaticModuleInit =
topLevelExportDefs.exists(_.isInstanceOf[js.TopLevelFieldExportDef])
val staticModuleInit =
if (!needsStaticModuleInit) None
else Some(genLoadModule(sym))
val staticInitializerStats =
reflectInit.toList ::: staticModuleInit.toList
if (staticInitializerStats.nonEmpty) {
List(genStaticConstructorWithStats(
ir.Names.StaticInitializerName,
js.Block(staticInitializerStats)))
} else {
Nil
}
}
val optDynamicImportForwarder =
if (isDynamicImportThunk) List(genDynamicImportForwarder(sym))
else Nil
val allMethodsExceptStaticForwarders: List[js.MethodDef] =
generatedMethods ::: optStaticInitializer ::: optDynamicImportForwarder
// Add static forwarders
val allMethods = if (!isCandidateForForwarders(sym)) {
allMethodsExceptStaticForwarders
} else {
if (sym.isModuleClass) {
/* If the module class has no linked class, we must create one to
* hold the static forwarders. Otherwise, this is going to be handled
* when generating the companion class.
*/
if (!sym.linkedClassOfClass.exists) {
val forwarders = genStaticForwardersFromModuleClass(Nil, sym)
if (forwarders.nonEmpty) {
val forwardersClassDef = js.ClassDef(
js.ClassIdent(ClassName(classIdent.name.nameString.stripSuffix("$"))),
originalName,
ClassKind.Class,
None,
Some(js.ClassIdent(ir.Names.ObjectClass)),
Nil,
None,
None,
fields = Nil,
methods = forwarders,
jsConstructor = None,
jsMethodProps = Nil,
jsNativeMembers = Nil,
topLevelExportDefs = Nil
)(js.OptimizerHints.empty)
generatedStaticForwarderClasses += sym -> forwardersClassDef
}
}
allMethodsExceptStaticForwarders
} else {
val forwarders = genStaticForwardersForClassOrInterface(
allMethodsExceptStaticForwarders, sym)
allMethodsExceptStaticForwarders ::: forwarders
}
}
// The complete class definition
val kind =
if (isStaticModule(sym)) ClassKind.ModuleClass
else if (isHijacked) ClassKind.HijackedClass
else ClassKind.Class
js.ClassDef(
classIdent,
originalName,
kind,
None,
Some(encodeClassNameIdent(sym.superClass)),
genClassInterfaces(sym, forJSClass = false),
None,
None,
fields,
allMethods,
jsConstructor = None,
memberExports,
jsNativeMembers,
topLevelExportDefs)(
optimizerHints)
}
/** Gen the IR ClassDef for a non-native JS class. */
def genNonNativeJSClass(cd: ClassDef): js.ClassDef = {
val sym = cd.symbol
implicit val pos = sym.pos
assert(isNonNativeJSClass(sym),
"genNonNativeJSClass() must be called only for " +
s"non-native JS classes: $sym")
assert(sym.superClass != NoSymbol, sym)
if (hasDefaultCtorArgsAndJSModule(sym)) {
reporter.error(pos,
"Implementation restriction: constructors of " +
"non-native JS classes cannot have default parameters " +
"if their companion module is JS native.")
}
val classIdent = encodeClassNameIdent(sym)
// Generate members (constructor + methods)
val constructorTrees = new ListBuffer[DefDef]
val generatedMethods = new ListBuffer[js.MethodDef]
val dispatchMethodNames = new ListBuffer[JSName]
def gen(tree: Tree): Unit = {
tree match {
case EmptyTree => ()
case Template(_, _, body) => body foreach gen
case ValDef(mods, name, tpt, rhs) =>
() // fields are added via genClassFields()
case dd: DefDef =>
val sym = dd.symbol
val exposed = isExposed(sym)
if (sym.isClassConstructor) {
constructorTrees += dd
} else if (exposed && sym.isAccessor && !sym.isLazy) {
/* Exposed accessors must not be emitted, since the field they
* access is enough.
*/
} else if (sym.hasAnnotation(JSOptionalAnnotation)) {
// Optional methods must not be emitted
} else {
generatedMethods ++= genMethod(dd)
// Collect the names of the dispatchers we have to create
if (exposed && !sym.isDeferred) {
/* We add symbols that we have to expose here. This way we also
* get inherited stuff that is implemented in this class.
*/
dispatchMethodNames += jsNameOf(sym)
}
}
case _ => abort("Illegal tree in gen of genClass(): " + tree)
}
}
gen(cd.impl)
// Static members (exported from the companion object)
val (staticFields, staticExports) = {
/* Phase travel is necessary for non-top-level classes, because flatten
* breaks their companionModule. This is tracked upstream at
* https://github.com/scala/scala-dev/issues/403
*/
val companionModuleClass =
exitingPhase(currentRun.picklerPhase)(sym.linkedClassOfClass)
if (companionModuleClass == NoSymbol) {
(Nil, Nil)
} else {
val (staticFields, staticExports) = {
withScopedVars(currentClassSym := companionModuleClass) {
genStaticExports(companionModuleClass)
}
}
if (staticFields.nonEmpty) {
generatedMethods += genStaticConstructorWithStats(
ir.Names.ClassInitializerName, genLoadModule(companionModuleClass))
}
(staticFields, staticExports)
}
}
val topLevelExports = genTopLevelExports(sym)
val (generatedCtor, jsClassCaptures) = withNewLocalNameScope {
val isNested = isNestedJSClass(sym)
if (isNested)
reserveLocalName(JSSuperClassParamName)
val (captures, ctor) =
genJSClassCapturesAndConstructor(constructorTrees.toList)
val jsClassCaptures = {
if (isNested) {
val superParam = js.ParamDef(
js.LocalIdent(JSSuperClassParamName),
NoOriginalName, jstpe.AnyType, mutable = false)
Some(superParam :: captures)
} else {
assert(captures.isEmpty,
s"found non nested JS class with captures $captures at $pos")
None
}
}
(ctor, jsClassCaptures)
}
// Generate fields (and add to methods + ctors)
val fields = genClassFields(cd)
val jsMethodProps =
genJSClassDispatchers(sym, dispatchMethodNames.result().distinct) ::: staticExports
// The complete class definition
val kind =
if (isStaticModule(sym)) ClassKind.JSModuleClass
else ClassKind.JSClass
js.ClassDef(
classIdent,
originalNameOfClass(sym),
kind,
jsClassCaptures,
Some(encodeClassNameIdent(sym.superClass)),
genClassInterfaces(sym, forJSClass = true),
jsSuperClass = jsClassCaptures.map(_.head.ref),
None,
fields ::: staticFields,
generatedMethods.toList,
Some(generatedCtor),
jsMethodProps,
jsNativeMembers = Nil,
topLevelExports)(
OptimizerHints.empty)
}
/** Generate an instance of an anonymous (non-lambda) JS class inline
*
* @param sym Class to generate the instance of
* @param jsSuperClassValue JS class value of the super class
* @param args Arguments to the Scala constructor, which map to JS class captures
* @param pos Position of the original New tree
*/
def genAnonJSClassNew(sym: Symbol, jsSuperClassValue: js.Tree,
args: List[js.Tree])(
implicit pos: Position): js.Tree = {
assert(isAnonymousJSClass(sym),
"Generating AnonJSClassNew of non anonymous JS class")
// Find the ClassDef for this anonymous class
val classDef = consumeLazilyGeneratedAnonClass(sym)
// Generate a normal, non-native JS class
val origJsClass =
nestedGenerateClass(sym)(genNonNativeJSClass(classDef))
// Partition class members.
val privateFieldDefs = ListBuffer.empty[js.FieldDef]
val jsFieldDefs = ListBuffer.empty[js.JSFieldDef]
origJsClass.fields.foreach {
case fdef: js.FieldDef =>
privateFieldDefs += fdef
case fdef: js.JSFieldDef =>
jsFieldDefs += fdef
}
assert(origJsClass.jsNativeMembers.isEmpty,
"Found JS native members in anonymous JS class at " + pos)
assert(origJsClass.topLevelExportDefs.isEmpty,
"Found top-level exports in anonymous JS class at " + pos)
// Make new class def with static members
val newClassDef = {
implicit val pos = origJsClass.pos
val parent = js.ClassIdent(ir.Names.ObjectClass)
js.ClassDef(origJsClass.name, origJsClass.originalName,
ClassKind.AbstractJSType, None, Some(parent), interfaces = Nil,
jsSuperClass = None, jsNativeLoadSpec = None, fields = Nil,
methods = origJsClass.methods, jsConstructor = None, jsMethodProps = Nil,
jsNativeMembers = Nil, topLevelExportDefs = Nil)(
origJsClass.optimizerHints)
}
generatedClasses += newClassDef -> pos
// Construct inline class definition
val jsClassCaptures = origJsClass.jsClassCaptures.getOrElse {
throw new AssertionError(
s"no class captures for anonymous JS class at $pos")
}
val js.JSConstructorDef(_, ctorParams, ctorRestParam, ctorBody) = origJsClass.jsConstructor.getOrElse {
throw new AssertionError("No ctor found")
}
assert(ctorParams.isEmpty && ctorRestParam.isEmpty,
s"non-empty constructor params for anonymous JS class at $pos")
/* The first class capture is always a reference to the super class.
* This is enforced by genJSClassCapturesAndConstructor.
*/
def jsSuperClassRef(implicit pos: ir.Position): js.VarRef =
jsClassCaptures.head.ref
/* The `this` reference.
* FIXME This could clash with a local variable of the constructor or a JS
* class capture. How do we avoid this?
*/
val selfName = freshLocalIdent("this")(pos)
def selfRef(implicit pos: ir.Position) =
js.VarRef(selfName)(jstpe.AnyType)
def memberLambda(params: List[js.ParamDef], restParam: Option[js.ParamDef],
body: js.Tree)(implicit pos: ir.Position) = {
js.Closure(arrow = false, captureParams = Nil, params, restParam, body,
captureValues = Nil)
}
val fieldDefinitions = jsFieldDefs.toList.map { fdef =>
implicit val pos = fdef.pos
js.Assign(js.JSSelect(selfRef, fdef.name), jstpe.zeroOf(fdef.ftpe))
}
val memberDefinitions0 = origJsClass.jsMethodProps.toList.map {
case mdef: js.JSMethodDef =>
implicit val pos = mdef.pos
val impl = memberLambda(mdef.args, mdef.restParam, mdef.body)
js.Assign(js.JSSelect(selfRef, mdef.name), impl)
case pdef: js.JSPropertyDef =>
implicit val pos = pdef.pos
val optGetter = pdef.getterBody.map { body =>
js.StringLiteral("get") -> memberLambda(params = Nil, restParam = None, body)
}
val optSetter = pdef.setterArgAndBody.map { case (arg, body) =>
js.StringLiteral("set") -> memberLambda(params = arg :: Nil, restParam = None, body)
}
val descriptor = js.JSObjectConstr(
optGetter.toList :::
optSetter.toList :::
List(js.StringLiteral("configurable") -> js.BooleanLiteral(true))
)
js.JSMethodApply(js.JSGlobalRef("Object"),
js.StringLiteral("defineProperty"),
List(selfRef, pdef.name, descriptor))
}
val memberDefinitions1 = fieldDefinitions ::: memberDefinitions0
val memberDefinitions = if (privateFieldDefs.isEmpty) {
memberDefinitions1
} else {
/* Private fields, declared in FieldDefs, are stored in a separate
* object, itself stored as a non-enumerable field of the `selfRef`.
* The name of that field is retrieved at
* `scala.scalajs.runtime.privateFieldsSymbol()`, and is a Symbol if
* supported, or a randomly generated string that has the same enthropy
* as a UUID (i.e., 128 random bits).
*
* This encoding solves two issues:
*
* - Hide private fields in anonymous JS classes from `JSON.stringify`
* and other cursory inspections in JS (#2748).
* - Get around the fact that abstract JS types cannot declare
* FieldDefs (#3777).
*/
val fieldsObjValue = {
js.JSObjectConstr(privateFieldDefs.toList.map { fdef =>
implicit val pos = fdef.pos
js.StringLiteral(fdef.name.name.nameString) -> jstpe.zeroOf(fdef.ftpe)
})
}
val definePrivateFieldsObj = {
/* Object.defineProperty(selfRef, privateFieldsSymbol, {
* value: fieldsObjValue
* });
*
* `writable`, `configurable` and `enumerable` are false by default.
*/
js.JSMethodApply(
js.JSGlobalRef("Object"),
js.StringLiteral("defineProperty"),
List(
selfRef,
genPrivateFieldsSymbol(),
js.JSObjectConstr(List(
js.StringLiteral("value") -> fieldsObjValue))
)
)
}
definePrivateFieldsObj :: memberDefinitions1
}
// Transform the constructor body.
val inlinedCtorStats = {
val beforeSuper = ctorBody.beforeSuper
val superCall = {
implicit val pos = ctorBody.superCall.pos
val js.JSSuperConstructorCall(args) = ctorBody.superCall
val newTree = {
val ident =
origJsClass.superClass.getOrElse(abort("No superclass"))
if (args.isEmpty && ident.name == JSObjectClassName)
js.JSObjectConstr(Nil)
else
js.JSNew(jsSuperClassRef, args)
}
val selfVarDef = js.VarDef(selfName, thisOriginalName, jstpe.AnyType, mutable = false, newTree)
selfVarDef :: memberDefinitions
}
// After the super call, substitute `selfRef` for `This()`
val afterSuper = new ir.Transformers.Transformer {
override def transform(tree: js.Tree, isStat: Boolean): js.Tree = tree match {
case js.This() =>
selfRef(tree.pos)
// Don't traverse closure boundaries
case closure: js.Closure =>
val newCaptureValues = closure.captureValues.map(transformExpr)
closure.copy(captureValues = newCaptureValues)(closure.pos)
case tree =>
super.transform(tree, isStat)
}
}.transformStats(ctorBody.afterSuper)
beforeSuper ::: superCall ::: afterSuper
}
val closure = js.Closure(arrow = true, jsClassCaptures, Nil, None,
js.Block(inlinedCtorStats, selfRef), jsSuperClassValue :: args)
js.JSFunctionApply(closure, Nil)
}
// Generate the class data of a JS class -----------------------------------
/** Gen the IR ClassDef for a JS class or trait.
*/
def genJSClassData(cd: ClassDef): js.ClassDef = {
val sym = cd.symbol
implicit val pos = sym.pos
val classIdent = encodeClassNameIdent(sym)
val kind = {
if (sym.isTraitOrInterface) ClassKind.AbstractJSType
else if (isJSFunctionDef(sym)) ClassKind.AbstractJSType
else if (sym.isModuleClass) ClassKind.NativeJSModuleClass
else ClassKind.NativeJSClass
}
val superClass =
if (sym.isTraitOrInterface) None
else Some(encodeClassNameIdent(sym.superClass))
val jsNativeLoadSpec = jsNativeLoadSpecOfOption(sym)
js.ClassDef(classIdent, originalNameOfClass(sym), kind, None, superClass,
genClassInterfaces(sym, forJSClass = true), None, jsNativeLoadSpec,
Nil, Nil, None, Nil, Nil, Nil)(
OptimizerHints.empty)
}
// Generate an interface ---------------------------------------------------
/** Gen the IR ClassDef for an interface definition.
*/
def genInterface(cd: ClassDef): js.ClassDef = {
val sym = cd.symbol
implicit val pos = sym.pos
val classIdent = encodeClassNameIdent(sym)
// fill in class info builder
def gen(tree: Tree): List[js.MethodDef] = {
tree match {
case EmptyTree => Nil
case Template(_, _, body) => body.flatMap(gen)
case dd: DefDef =>
genMethod(dd).toList
case _ =>
abort("Illegal tree in gen of genInterface(): " + tree)
}
}
val generatedMethods = gen(cd.impl)
val interfaces = genClassInterfaces(sym, forJSClass = false)
val allMemberDefs =
if (!isCandidateForForwarders(sym)) generatedMethods
else generatedMethods ::: genStaticForwardersForClassOrInterface(generatedMethods, sym)
js.ClassDef(classIdent, originalNameOfClass(sym), ClassKind.Interface,
None, None, interfaces, None, None, fields = Nil, methods = allMemberDefs,
None, Nil, Nil, Nil)(
OptimizerHints.empty)
}
private lazy val jsTypeInterfacesBlacklist: Set[Symbol] =
Set(DynamicClass, SerializableClass) // #3118, #3252
private def genClassInterfaces(sym: Symbol, forJSClass: Boolean)(
implicit pos: Position): List[js.ClassIdent] = {
val blacklist =
if (forJSClass) jsTypeInterfacesBlacklist
else Set.empty[Symbol]
for {
parent <- sym.info.parents
typeSym = parent.typeSymbol
_ = assert(typeSym != NoSymbol, "parent needs symbol")
if typeSym.isTraitOrInterface && !blacklist.contains(typeSym)
} yield {
encodeClassNameIdent(typeSym)
}
}
// Static forwarders -------------------------------------------------------
/* This mimics the logic in BCodeHelpers.addForwarders and the code that
* calls it, except that we never have collisions with existing methods in
* the companion class. This is because in the IR, only methods with the
* same `MethodName` (including signature) and that are also
* `PublicStatic` would collide. Since we never emit any `PublicStatic`
* method otherwise, there can be no collision. If that assumption is broken,
* an error message is emitted asking the user to report a bug.
*
* It is important that we always emit forwarders, because some Java APIs
* actually have a public static method and a public instance method with
* the same name. For example the class `Integer` has a
* `def hashCode(): Int` and a `static def hashCode(Int): Int`. The JVM
* back-end considers them as colliding because they have the same name,
* but we must not.
*
* By default, we only emit forwarders for top-level objects, like scalac.
* However, if requested via a compiler option, we enable them for all
* static objects. This is important so we can implement static methods
* of nested static classes of JDK APIs (see #3950).
*/
/** Is the given Scala class, interface or module class a candidate for
* static forwarders?
*/
def isCandidateForForwarders(sym: Symbol): Boolean = {
!settings.noForwarders.value && sym.isStatic && {
// Reject non-top-level objects unless opted in via the appropriate option
scalaJSOpts.genStaticForwardersForNonTopLevelObjects ||
!sym.name.containsChar('$') // this is the same test that scalac performs
}
}
/** Gen the static forwarders to the members of a class or interface for
* methods of its companion object.
*
* This is only done if there exists a companion object and it is not a JS
* type.
*
* Precondition: `isCandidateForForwarders(sym)` is true
*/
def genStaticForwardersForClassOrInterface(
existingMethods: List[js.MethodDef], sym: Symbol)(
implicit pos: Position): List[js.MethodDef] = {
/* Phase travel is necessary for non-top-level classes, because flatten
* breaks their companionModule. This is tracked upstream at
* https://github.com/scala/scala-dev/issues/403
*/
val module = exitingPhase(currentRun.picklerPhase)(sym.companionModule)
if (module == NoSymbol) {
Nil
} else {
val moduleClass = module.moduleClass
if (!isJSType(moduleClass))
genStaticForwardersFromModuleClass(existingMethods, moduleClass)
else
Nil
}
}
/** Gen the static forwarders for the methods of a module class.
*
* Precondition: `isCandidateForForwarders(moduleClass)` is true
*/
def genStaticForwardersFromModuleClass(existingMethods: List[js.MethodDef],
moduleClass: Symbol)(
implicit pos: Position): List[js.MethodDef] = {
assert(moduleClass.isModuleClass, moduleClass)
val hasAnyExistingPublicStaticMethod =
existingMethods.exists(_.flags.namespace == js.MemberNamespace.PublicStatic)
if (hasAnyExistingPublicStaticMethod) {
reporter.error(pos,
"Unexpected situation: found existing public static methods in " +
s"the class ${moduleClass.fullName} while trying to generate " +
"static forwarders for its companion object. " +
"Please report this as a bug in Scala.js.")
}
def listMembersBasedOnFlags = {
// Copy-pasted from BCodeHelpers.
val ExcludedForwarderFlags: Long = {
import scala.tools.nsc.symtab.Flags._
SPECIALIZED | LIFTED | PROTECTED | STATIC | EXPANDEDNAME | PRIVATE | MACRO
}
moduleClass.info.membersBasedOnFlags(ExcludedForwarderFlags, symtab.Flags.METHOD)
}
// See BCodeHelprs.addForwarders in 2.12+ for why we use exitingUncurry.
val members = exitingUncurry(listMembersBasedOnFlags)
def isExcluded(m: Symbol): Boolean = {
def isOfJLObject: Boolean = {
val o = m.owner
(o eq ObjectClass) || (o eq AnyRefClass) || (o eq AnyClass)
}
def isDefaultParamOfJSNativeDef: Boolean = {
DefaultParamInfo.isApplicable(m) && {
val info = new DefaultParamInfo(m)
!info.isForConstructor && info.attachedMethod.hasAnnotation(JSNativeAnnotation)
}
}
m.isDeferred || m.isConstructor || m.hasAccessBoundary ||
isOfJLObject ||
m.hasAnnotation(JSNativeAnnotation) || isDefaultParamOfJSNativeDef // #4557
}
val forwarders = for {
m <- members
if !isExcluded(m)
} yield {
withNewLocalNameScope {
val flags = js.MemberFlags.empty.withNamespace(js.MemberNamespace.PublicStatic)
val methodIdent = encodeMethodSym(m)
val originalName = originalNameOfMethod(m)
val jsParams = m.tpe.params.map(genParamDef(_))
val resultType = toIRType(m.tpe.resultType)
js.MethodDef(flags, methodIdent, originalName, jsParams, resultType, Some {
genApplyMethod(genLoadModule(moduleClass), m, jsParams.map(_.ref))
})(OptimizerHints.empty, Unversioned)
}
}
forwarders.toList
}
// Generate the fields of a class ------------------------------------------
/** Gen definitions for the fields of a class.
* The fields are initialized with the zero of their types.
*/
def genClassFields(cd: ClassDef): List[js.AnyFieldDef] = {
val classSym = cd.symbol
assert(currentClassSym.get == classSym,
"genClassFields called with a ClassDef other than the current one")
val isJSClass = isNonNativeJSClass(classSym)
// Non-method term members are fields, except for module members.
(for {
f <- classSym.info.decls
if !f.isMethod && f.isTerm && !f.isModule
if !f.hasAnnotation(JSOptionalAnnotation) && !f.hasAnnotation(JSNativeAnnotation)
if jsInterop.staticExportsOf(f).isEmpty
} yield {
implicit val pos = f.pos
val static = jsInterop.topLevelExportsOf(f).nonEmpty
val mutable = {
static || // static fields must always be mutable
f.isMutable || // mutable fields can be mutated from anywhere
fieldsMutatedInCurrentClass.contains(f.name) // the field is mutated in the current class
}
val namespace =
if (static) js.MemberNamespace.PublicStatic
else js.MemberNamespace.Public
val flags =
js.MemberFlags.empty.withNamespace(namespace).withMutable(mutable)
val irTpe0 = {
if (isJSClass) genExposedFieldIRType(f)
else if (static) jstpe.AnyType
else toIRType(f.tpe)
}
// #4370 Fields cannot have type NothingType
val irTpe =
if (irTpe0 == jstpe.NothingType) encodeClassType(RuntimeNothingClass)
else irTpe0
if (isJSClass && isExposed(f))
js.JSFieldDef(flags, genExpr(jsNameOf(f)), irTpe)
else
js.FieldDef(flags, encodeFieldSym(f), originalNameOfField(f), irTpe)
}).toList
}
def genExposedFieldIRType(f: Symbol): jstpe.Type = {
val tpeEnteringPosterasure =
enteringPhase(currentRun.posterasurePhase)(f.tpe)
tpeEnteringPosterasure match {
case tpe: ErasedValueType =>
/* Here, we must store the field as the boxed representation of
* the value class. The default value of that field, as
* initialized at the time the instance is created, will
* therefore be null. This will not match the behavior we would
* get in a Scala class. To match the behavior, we would need to
* initialized to an instance of the boxed representation, with
* an underlying value set to the zero of its type. However we
* cannot implement that, so we live with the discrepancy.
* Anyway, scalac also has problems with uninitialized value
* class values, if they come from a generic context.
*/
jstpe.ClassType(encodeClassName(tpe.valueClazz), nullable = true)
case _ =>
/* Other types are not boxed, so we can initialize them to
* their true zero.
*/
toIRType(f.tpe)
}
}
// Static initializers -----------------------------------------------------
private def genStaticConstructorWithStats(name: MethodName, stats: js.Tree)(
implicit pos: Position): js.MethodDef = {
js.MethodDef(
js.MemberFlags.empty.withNamespace(js.MemberNamespace.StaticConstructor),
js.MethodIdent(name),
NoOriginalName,
Nil,
jstpe.NoType,
Some(stats))(
OptimizerHints.empty, Unversioned)
}
private def genRegisterReflectiveInstantiation(sym: Symbol)(
implicit pos: Position): Option[js.Tree] = {
if (isStaticModule(sym))
genRegisterReflectiveInstantiationForModuleClass(sym)
else if (sym.isModuleClass)
None // #3228
else if (sym.isLifted && !sym.originalOwner.isClass)
None // #3227
else
genRegisterReflectiveInstantiationForNormalClass(sym)
}
private def genRegisterReflectiveInstantiationForModuleClass(sym: Symbol)(
implicit pos: Position): Option[js.Tree] = {
val fqcnArg = js.StringLiteral(sym.fullName + "$")
val runtimeClassArg = js.ClassOf(toTypeRef(sym.info))
val loadModuleFunArg =
js.Closure(arrow = true, Nil, Nil, None, genLoadModule(sym), Nil)
val stat = genApplyMethod(
genLoadModule(ReflectModule),
Reflect_registerLoadableModuleClass,
List(fqcnArg, runtimeClassArg, loadModuleFunArg))
Some(stat)
}
private def genRegisterReflectiveInstantiationForNormalClass(sym: Symbol)(
implicit pos: Position): Option[js.Tree] = {
val ctors =
if (sym.isAbstractClass) Nil
else sym.info.member(nme.CONSTRUCTOR).alternatives.filter(_.isPublic)
if (ctors.isEmpty) {
None
} else {
val constructorsInfos = for {
ctor <- ctors
} yield {
withNewLocalNameScope {
val (parameterTypes, formalParams, actualParams) = (for {
param <- ctor.tpe.params
} yield {
/* Note that we do *not* use `param.tpe` entering posterasure
* (neither to compute `paramType` nor to give to `fromAny`).
* Logic would tell us that we should do so, but we intentionally
* do not to preserve the behavior on the JVM regarding value
* classes. If a constructor takes a value class as parameter, as
* in:
*
* class ValueClass(val underlying: Int) extends AnyVal
* class Foo(val vc: ValueClass)
*
* then, from a reflection point of view, on the JVM, the
* constructor of `Foo` takes an `Int`, not a `ValueClas`. It
* must therefore be identified as the constructor whose
* parameter types is `List(classOf[Int])`, and when invoked
* reflectively, it must be given an `Int` (or `Integer`).
*/
val paramType = js.ClassOf(toTypeRef(param.tpe))
val paramDef = genParamDef(param, jstpe.AnyType)
val actualParam = fromAny(paramDef.ref, param.tpe)
(paramType, paramDef, actualParam)
}).unzip3
val paramTypesArray = js.JSArrayConstr(parameterTypes)
val newInstanceFun = js.Closure(arrow = true, Nil, formalParams, None, {
genNew(sym, ctor, actualParams)
}, Nil)
js.JSArrayConstr(List(paramTypesArray, newInstanceFun))
}
}
val fqcnArg = js.StringLiteral(sym.fullName)
val runtimeClassArg = js.ClassOf(toTypeRef(sym.info))
val ctorsInfosArg = js.JSArrayConstr(constructorsInfos)
val stat = genApplyMethod(
genLoadModule(ReflectModule),
Reflect_registerInstantiatableClass,
List(fqcnArg, runtimeClassArg, ctorsInfosArg))
Some(stat)
}
}
// Constructor of a non-native JS class ------------------------------
def genJSClassCapturesAndConstructor(constructorTrees: List[DefDef])(
implicit pos: Position): (List[js.ParamDef], js.JSConstructorDef) = {
/* We need to merge all Scala constructors into a single one because
* JavaScript only allows a single one.
*
* We do this by applying:
* 1. Applying runtime type based dispatch, just like exports.
* 2. Splitting secondary ctors into parts before and after the `this` call.
* 3. Topo-sorting all constructor statements and including/excluding
* them based on the overload that was chosen.
*/
val (primaryTree :: Nil, secondaryTrees) =
constructorTrees.partition(_.symbol.isPrimaryConstructor)
val primaryCtor = genPrimaryJSClassCtor(primaryTree)
val secondaryCtors = secondaryTrees.map(genSecondaryJSClassCtor(_))
// VarDefs for the parameters of all constructors.
val paramVarDefs = for {
vparam <- constructorTrees.flatMap(_.vparamss.flatten)
} yield {
val sym = vparam.symbol
val tpe = toIRType(sym.tpe)
js.VarDef(encodeLocalSym(sym), originalNameOfLocal(sym), tpe, mutable = true,
jstpe.zeroOf(tpe))(vparam.pos)
}
/* organize constructors in a called-by tree
* (the implicit root is the primary constructor)
*/
val ctorTree = {
val ctorToChildren = secondaryCtors
.groupBy(_.targetCtor)
.withDefaultValue(Nil)
/* when constructing the call-by tree, we use pre-order traversal to
* assign overload numbers.
* this puts all descendants of a ctor in a range of overloads numbers.
*
* this property is useful, later, when we need to make statements
* conditional based on the chosen overload.
*/
var nextOverloadNum = 0
def subTree[T <: JSCtor](ctor: T): ConstructorTree[T] = {
val overloadNum = nextOverloadNum
nextOverloadNum += 1
val subtrees = ctorToChildren(ctor.sym).map(subTree(_))
new ConstructorTree(overloadNum, ctor, subtrees)
}
subTree(primaryCtor)
}
/* prepare overload dispatch for all constructors.
* as a side-product, we retrieve the capture parameters.
*/
val (exports, jsClassCaptures) = {
val exports = List.newBuilder[Exported]
val jsClassCaptures = List.newBuilder[js.ParamDef]
def add(tree: ConstructorTree[_ <: JSCtor]): Unit = {
val (e, c) = genJSClassCtorDispatch(tree.ctor.sym,
tree.ctor.paramsAndInfo, tree.overloadNum)
exports += e
jsClassCaptures ++= c
tree.subCtors.foreach(add(_))
}
add(ctorTree)
(exports.result(), jsClassCaptures.result())
}
// The name 'constructor' is used for error reporting here
val (formalArgs, restParam, overloadDispatchBody) =
genOverloadDispatch(JSName.Literal("constructor"), exports, jstpe.IntType)
val overloadVar = js.VarDef(freshLocalIdent("overload"), NoOriginalName,
jstpe.IntType, mutable = false, overloadDispatchBody)
val constructorBody = wrapJSCtorBody(
paramVarDefs :+ overloadVar,
genJSClassCtorBody(overloadVar.ref, ctorTree),
js.Undefined() :: Nil
)
val constructorDef = js.JSConstructorDef(
js.MemberFlags.empty.withNamespace(js.MemberNamespace.Constructor),
formalArgs, restParam, constructorBody)(OptimizerHints.empty, Unversioned)
(jsClassCaptures, constructorDef)
}
private def genPrimaryJSClassCtor(dd: DefDef): PrimaryJSCtor = {
val DefDef(_, _, _, vparamss, _, Block(stats, _)) = dd
val sym = dd.symbol
assert(sym.isPrimaryConstructor, s"called with non-primary ctor: $sym")
var preSuperStats = List.newBuilder[js.Tree]
var jsSuperCall: Option[js.JSSuperConstructorCall] = None
val postSuperStats = List.newBuilder[js.Tree]
/* Move param accessor initializers and early initializers after the
* super constructor call since JS cannot access `this` before the super
* constructor call.
*
* scalac inserts statements before the super constructor call for early
* initializers and param accessor initializers (including val's and var's
* declared in the params). Those statements include temporary local `val`
* definitions (for true early initializers only) and the assignments,
* whose rhs'es are always simple Idents (either constructor params or the
* temporary local `val`s).
*
* There can also be local `val`s before the super constructor call for
* default arguments to the super constructor. These must remain before.
*
* Our strategy is therefore to move only the field assignments after the
* super constructor call. They are therefore executed later than for a
* Scala class (as specified for non-native JS classes semantics).
* However, side effects and evaluation order of all the other
* computations remains unchanged.
*
* For a somewhat extreme example of the shapes we can get here, consider
* the source code:
*
* class Parent(output: Any = "output", callbackObject: Any = "callbackObject") extends js.Object {
* println(s"Parent constructor; $output; $callbackObject")
* }
*
* class Child(val foo: Int, callbackObject: Any, val bar: Int) extends {
* val xyz = foo + bar
* val yz = { println(xyz); xyz + 2 }
* } with Parent(callbackObject = { println(foo); xyz + bar }) {
* println("Child constructor")
* println(xyz)
* }
*
* At this phase, for the constructor of `Child`, we receive the following
* scalac Tree:
*
* def (foo: Int, callbackObject: Object, bar: Int): helloworld.Child = {
* Child.this.foo = foo; // param accessor assignment, moved
* Child.this.bar = bar; // param accessor assignment, moved
* val xyz: Int = foo.+(bar); // note that these still use the ctor params, not the fields
* Child.this.xyz = xyz; // early initializer, moved
* val yz: Int = {
* scala.Predef.println(scala.Int.box(xyz)); // note that this uses the local val, not the field
* xyz.+(2)
* };
* Child.this.yz = yz; // early initializer, moved
* {
* val x$1: Int = {
* scala.Predef.println(scala.Int.box(foo));
* xyz.+(bar) // here as well, we use the local vals, not the fields
* };
* val x$2: Object = helloworld.this.Parent.$default$1();
* Child.super.(x$2, scala.Int.box(x$1))
* };
* scala.Predef.println("Child constructor");
* scala.Predef.println(scala.Int.box(Child.this.xyz()));
* ()
* }
*
*/
withPerMethodBodyState(sym) {
def isThisFieldAssignment(tree: Tree): Boolean = tree match {
case Assign(Select(ths: This, _), Ident(_)) => ths.symbol == currentClassSym.get
case _ => false
}
flatStats(stats).foreach {
case tree @ Apply(fun @ Select(Super(This(_), _), _), args)
if fun.symbol.isClassConstructor =>
assert(jsSuperCall.isEmpty, s"Found 2 JS Super calls at ${dd.pos}")
implicit val pos = tree.pos
jsSuperCall = Some(js.JSSuperConstructorCall(genPrimitiveJSArgs(fun.symbol, args)))
case tree if jsSuperCall.isDefined =>
// Once we're past the super constructor call, everything goes after.
postSuperStats += genStat(tree)
case tree if isThisFieldAssignment(tree) =>
/* If that shape appears before the jsSuperCall, it is an early
* initializer or param accessor initializer. We move it.
*/
postSuperStats += genStat(tree)
case tree @ OuterPointerNullCheck(outer, assign) if isThisFieldAssignment(assign) =>
/* Variant of the above with an outer pointer null check. The actual
* null check remains before the super call, while the associated
* assignment is moved after.
*/
preSuperStats += js.UnaryOp(js.UnaryOp.CheckNotNull, genExpr(outer))(tree.pos)
postSuperStats += genStat(assign)
case stat =>
// Other statements are left before.
preSuperStats += genStat(stat)
}
}
assert(jsSuperCall.isDefined, "Did not find Super call in primary JS " +
s"construtor at ${dd.pos}")
new PrimaryJSCtor(sym, genParamsAndInfo(sym, vparamss),
js.JSConstructorBody(preSuperStats.result(), jsSuperCall.get, postSuperStats.result())(dd.pos))
}
private def genSecondaryJSClassCtor(dd: DefDef): SplitSecondaryJSCtor = {
val DefDef(_, _, _, vparamss, _, Block(stats, _)) = dd
val sym = dd.symbol
assert(!sym.isPrimaryConstructor, s"called with primary ctor $sym")
val beforeThisCall = List.newBuilder[js.Tree]
var thisCall: Option[(Symbol, List[js.Tree])] = None
val afterThisCall = List.newBuilder[js.Tree]
withPerMethodBodyState(sym) {
flatStats(stats).foreach {
case tree @ Apply(fun @ Select(This(_), _), args)
if fun.symbol.isClassConstructor =>
assert(thisCall.isEmpty,
s"duplicate this() call in secondary JS constructor at ${dd.pos}")
implicit val pos = tree.pos
val sym = fun.symbol
thisCall = Some((sym, genActualArgs(sym, args)))
case stat =>
val jsStat = genStat(stat)
if (thisCall.isEmpty)
beforeThisCall += jsStat
else
afterThisCall += jsStat
}
}
val Some((targetCtor, ctorArgs)) = thisCall
new SplitSecondaryJSCtor(sym, genParamsAndInfo(sym, vparamss),
beforeThisCall.result(), targetCtor, ctorArgs, afterThisCall.result())
}
private def genParamsAndInfo(ctorSym: Symbol,
vparamss: List[List[ValDef]]): List[(js.VarRef, JSParamInfo)] = {
implicit val pos = ctorSym.pos
val paramSyms = if (vparamss.isEmpty) Nil else vparamss.head.map(_.symbol)
for {
(paramSym, info) <- paramSyms.zip(jsParamInfos(ctorSym))
} yield {
genVarRef(paramSym) -> info
}
}
private def genJSClassCtorDispatch(ctorSym: Symbol,
allParamsAndInfos: List[(js.VarRef, JSParamInfo)],
overloadNum: Int): (Exported, List[js.ParamDef]) = {
implicit val pos = ctorSym.pos
/* `allParams` are the parameters as seen from *inside* the constructor
* body. the symbols returned in jsParamInfos are the parameters as seen
* from *outside* (i.e. from a caller).
*
* we need to use the symbols from inside to generate the right
* identifiers (the ones generated by the trees in the constructor body).
*/
val (captureParamsAndInfos, normalParamsAndInfos) =
allParamsAndInfos.partition(_._2.capture)
/* We use the *outer* param symbol to get different names than the *inner*
* symbols. This is necessary so that we can forward captures properly
* between constructor delegation calls.
*/
val jsClassCaptures =
captureParamsAndInfos.map(x => genParamDef(x._2.sym))
val normalInfos = normalParamsAndInfos.map(_._2).toIndexedSeq
val jsExport = new Exported(ctorSym, normalInfos) {
def genBody(formalArgsRegistry: FormalArgsRegistry): js.Tree = {
val captureAssigns = for {
(param, info) <- captureParamsAndInfos
} yield {
js.Assign(param, genVarRef(info.sym))
}
val paramAssigns = for {
((param, info), i) <- normalParamsAndInfos.zipWithIndex
} yield {
val rhs = genScalaArg(sym, i, formalArgsRegistry, info, static = true,
captures = captureParamsAndInfos.map(_._1))(
prevArgsCount => normalParamsAndInfos.take(prevArgsCount).map(_._1))
js.Assign(param, rhs)
}
js.Block(captureAssigns ::: paramAssigns, js.IntLiteral(overloadNum))
}
}
(jsExport, jsClassCaptures)
}
/** Generates a JS constructor body based on a constructor tree. */
private def genJSClassCtorBody(overloadVar: js.VarRef,
ctorTree: ConstructorTree[PrimaryJSCtor])(implicit pos: Position): js.JSConstructorBody = {
/* generates a statement that conditionally executes body iff the chosen
* overload is any of the descendants of `tree` (including itself).
*
* here we use the property from building the trees, that a set of
* descendants always has a range of overload numbers.
*/
def ifOverload(tree: ConstructorTree[_], body: js.Tree): js.Tree = body match {
case js.Skip() => js.Skip()
case body =>
val x = overloadVar
val cond = {
import tree.{lo, hi}
if (lo == hi) {
js.BinaryOp(js.BinaryOp.Int_==, js.IntLiteral(lo), x)
} else {
val lhs = js.BinaryOp(js.BinaryOp.Int_<=, js.IntLiteral(lo), x)
val rhs = js.BinaryOp(js.BinaryOp.Int_<=, x, js.IntLiteral(hi))
js.If(lhs, rhs, js.BooleanLiteral(false))(jstpe.BooleanType)
}
}
js.If(cond, body, js.Skip())(jstpe.NoType)
}
/* preStats / postStats use pre/post order traversal respectively to
* generate a topo-sorted sequence of statements.
*/
def preStats(tree: ConstructorTree[SplitSecondaryJSCtor],
nextParamsAndInfo: List[(js.VarRef, JSParamInfo)]): js.Tree = {
val inner = tree.subCtors.map(preStats(_, tree.ctor.paramsAndInfo))
assert(tree.ctor.ctorArgs.size == nextParamsAndInfo.size, "param count mismatch")
val paramsInfosAndArgs = nextParamsAndInfo.zip(tree.ctor.ctorArgs)
val (captureParamsInfosAndArgs, normalParamsInfosAndArgs) =
paramsInfosAndArgs.partition(_._1._2.capture)
val captureAssigns = for {
((param, _), arg) <- captureParamsInfosAndArgs
} yield {
js.Assign(param, arg)
}
val normalAssigns = for {
(((param, info), arg), i) <- normalParamsInfosAndArgs.zipWithIndex
} yield {
val newArg = arg match {
case js.Transient(UndefinedParam) =>
assert(info.hasDefault,
s"unexpected UndefinedParam for non default param: $param")
/* Go full circle: We have ignored the default param getter for
* this, we'll create it again.
*
* This seems not optimal: We could simply not ignore the calls to
* default param getters in the first place.
*
* However, this proves to be difficult: Because of translations in
* earlier phases, calls to default param getters may be assigned
* to temporary variables first (see the undefinedDefaultParams
* ScopedVar). If this happens, it becomes increasingly difficult
* to distinguish a default param getter call for a constructor
* call of *this* instance (in which case we would want to keep
* the default param getter call) from one for a *different*
* instance (in which case we would want to discard the default
* param getter call)
*
* Because of this, it ends up being easier to just re-create the
* default param getter call if necessary.
*/
genCallDefaultGetter(tree.ctor.sym, i, tree.ctor.sym.pos, static = false,
captures = captureParamsInfosAndArgs.map(_._1._1))(
prevArgsCount => normalParamsInfosAndArgs.take(prevArgsCount).map(_._1._1))
case arg => arg
}
js.Assign(param, newArg)
}
ifOverload(tree, js.Block(
inner ++ tree.ctor.beforeCall ++ captureAssigns ++ normalAssigns))
}
def postStats(tree: ConstructorTree[SplitSecondaryJSCtor]): js.Tree = {
val inner = tree.subCtors.map(postStats(_))
ifOverload(tree, js.Block(tree.ctor.afterCall ++ inner))
}
val primaryCtor = ctorTree.ctor
val secondaryCtorTrees = ctorTree.subCtors
wrapJSCtorBody(
secondaryCtorTrees.map(preStats(_, primaryCtor.paramsAndInfo)),
primaryCtor.body,
secondaryCtorTrees.map(postStats(_))
)
}
private def wrapJSCtorBody(before: List[js.Tree], body: js.JSConstructorBody,
after: List[js.Tree]): js.JSConstructorBody = {
js.JSConstructorBody(before ::: body.beforeSuper, body.superCall,
body.afterSuper ::: after)(body.pos)
}
private sealed trait JSCtor {
val sym: Symbol
val paramsAndInfo: List[(js.VarRef, JSParamInfo)]
}
private class PrimaryJSCtor(val sym: Symbol,
val paramsAndInfo: List[(js.VarRef, JSParamInfo)],
val body: js.JSConstructorBody) extends JSCtor
private class SplitSecondaryJSCtor(val sym: Symbol,
val paramsAndInfo: List[(js.VarRef, JSParamInfo)],
val beforeCall: List[js.Tree],
val targetCtor: Symbol, val ctorArgs: List[js.Tree],
val afterCall: List[js.Tree]) extends JSCtor
private class ConstructorTree[Ctor <: JSCtor](
val overloadNum: Int, val ctor: Ctor,
val subCtors: List[ConstructorTree[SplitSecondaryJSCtor]]) {
val lo: Int = overloadNum
val hi: Int = subCtors.lastOption.fold(lo)(_.hi)
assert(lo <= hi, "bad overload range")
}
// Generate a method -------------------------------------------------------
/** Maybe gen JS code for a method definition.
*
* Some methods are not emitted at all:
*
* - Primitives, since they are never actually called (with exceptions)
* - Abstract methods in non-native JS classes
* - Default accessor of a native JS constructor
* - Constructors of hijacked classes
*/
def genMethod(dd: DefDef): Option[js.MethodDef] = {
val sym = dd.symbol
val isAbstract = isAbstractMethod(dd)
/* Is this method a default accessor that should be ignored?
*
* This is the case iff one of the following applies:
* - It is a constructor default accessor and the linked class is a
* native JS class.
* - It is a default accessor for a native JS def, but with the caveat
* that its rhs must be `js.native` because of #4553.
*
* Both of those conditions can only happen if the default accessor is in
* a module class, so we use that as a fast way out. (But omitting that
* condition would not change the result.)
*
* This is different than `isJSDefaultParam` in `genApply`: we do not
* ignore default accessors of *non-native* JS types. Neither for
* constructor default accessor nor regular default accessors. We also
* do not need to worry about non-constructor members of native JS types,
* since for those, the entire member list is ignored in `genJSClassData`.
*/
def isIgnorableDefaultParam: Boolean = {
DefaultParamInfo.isApplicable(sym) && sym.owner.isModuleClass && {
val info = new DefaultParamInfo(sym)
if (info.isForConstructor) {
/* This is a default accessor for a constructor parameter. Check
* whether the attached constructor is a native JS constructor,
* which is the case iff the linked class is a native JS type.
*/
isJSNativeClass(info.constructorOwner)
} else {
/* #4553 We need to ignore default accessors for JS native defs.
* However, because Scala.js <= 1.7.0 actually emitted code calling
* those accessors, we must keep default accessors that would
* compile. The only accessors we can actually get rid of are those
* that are `= js.native`.
*/
!isJSType(sym.owner) &&
info.attachedMethod.hasAnnotation(JSNativeAnnotation) && {
dd.rhs match {
case MaybeAsInstanceOf(Apply(fun, _)) =>
fun.symbol == JSPackage_native
case _ =>
false
}
}
}
}
}
if (scalaPrimitives.isPrimitive(sym)) {
None
} else if (isAbstract && isNonNativeJSClass(currentClassSym)) {
// #4409: Do not emit abstract methods in non-native JS classes
None
} else if (isIgnorableDefaultParam) {
None
} else if (sym.isClassConstructor && isHijackedClass(sym.owner)) {
None
} else {
withNewLocalNameScope {
Some(genMethodWithCurrentLocalNameScope(dd))
}
}
}
/** Gen JS code for a method definition in a class or in an impl class.
* On the JS side, method names are mangled to encode the full signature
* of the Scala method, as described in `JSEncoding`, to support
* overloading.
*
* Constructors are emitted by generating their body as a statement.
*
* Other (normal) methods are emitted with `genMethodDef()`.
*/
def genMethodWithCurrentLocalNameScope(dd: DefDef): js.MethodDef = {
implicit val pos = dd.pos
val sym = dd.symbol
withPerMethodBodyState(sym) {
val methodName = encodeMethodSym(sym)
val originalName = originalNameOfMethod(sym)
val jsParams = {
val vparamss = dd.vparamss
assert(vparamss.isEmpty || vparamss.tail.isEmpty,
"Malformed parameter list: " + vparamss)
val params = if (vparamss.isEmpty) Nil else vparamss.head.map(_.symbol)
params.map(genParamDef(_))
}
val jsMethodDef = if (isAbstractMethod(dd)) {
js.MethodDef(js.MemberFlags.empty, methodName, originalName,
jsParams, toIRType(sym.tpe.resultType), None)(
OptimizerHints.empty, Unversioned)
} else {
val shouldMarkInline = {
sym.hasAnnotation(InlineAnnotationClass) ||
sym.name.startsWith(nme.ANON_FUN_NAME) ||
adHocInlineMethods.contains(sym.fullName)
}
val shouldMarkNoinline = {
sym.hasAnnotation(NoinlineAnnotationClass) &&
!ignoreNoinlineAnnotation(sym)
}
val optimizerHints =
OptimizerHints.empty.
withInline(shouldMarkInline).
withNoinline(shouldMarkNoinline)
val methodDef = {
if (sym.isClassConstructor) {
val namespace = js.MemberNamespace.Constructor
js.MethodDef(
js.MemberFlags.empty.withNamespace(namespace), methodName,
originalName, jsParams, jstpe.NoType, Some(genStat(dd.rhs)))(
optimizerHints, Unversioned)
} else {
val resultIRType = toIRType(sym.tpe.resultType)
val namespace = {
if (sym.isStaticMember) {
if (sym.isPrivate) js.MemberNamespace.PrivateStatic
else js.MemberNamespace.PublicStatic
} else {
if (sym.isPrivate) js.MemberNamespace.Private
else js.MemberNamespace.Public
}
}
genMethodDef(namespace, methodName, originalName, jsParams,
resultIRType, dd.rhs, optimizerHints)
}
}
val methodDefWithoutUselessVars = {
val unmutatedMutableLocalVars =
(mutableLocalVars.diff(mutatedLocalVars)).toList
val mutatedImmutableLocalVals =
(mutatedLocalVars.diff(mutableLocalVars)).toList
if (unmutatedMutableLocalVars.isEmpty &&
mutatedImmutableLocalVals.isEmpty) {
// OK, we're good (common case)
methodDef
} else {
val patches = (
unmutatedMutableLocalVars.map(encodeLocalSym(_).name -> false) :::
mutatedImmutableLocalVals.map(encodeLocalSym(_).name -> true)
).toMap
patchMutableFlagOfLocals(methodDef, patches)
}
}
methodDefWithoutUselessVars
}
/* #3953 Patch the param defs to have the type advertised by the method's type.
* This works around https://github.com/scala/bug/issues/11884, whose fix
* upstream is blocked because it is not binary compatible. The fix here
* only affects the inside of the js.MethodDef, so it is binary compat.
*/
val paramTypeRewrites = jsParams.zip(sym.tpe.paramTypes.map(toIRType(_))).collect {
case (js.ParamDef(name, _, tpe, _), sigType) if tpe != sigType => name.name -> sigType
}
if (paramTypeRewrites.isEmpty) {
// Overwhelmingly common case: all the types match, so there is nothing to do
jsMethodDef
} else {
devWarning(
"Working around https://github.com/scala/bug/issues/11884 " +
s"for ${sym.fullName} at ${sym.pos}")
patchTypeOfParamDefs(jsMethodDef, paramTypeRewrites.toMap)
}
}
}
def isAbstractMethod(dd: DefDef): Boolean =
dd.rhs == EmptyTree
private val adHocInlineMethods = Set(
"scala.collection.mutable.ArrayOps$ofRef.newBuilder$extension",
"scala.runtime.ScalaRunTime.arrayClass",
"scala.runtime.ScalaRunTime.arrayElementClass"
)
/** Patches the mutable flags of selected locals in a [[js.MethodDef]].
*
* @param patches Map from local name to new value of the mutable flags.
* For locals not in the map, the flag is untouched.
*/
private def patchMutableFlagOfLocals(methodDef: js.MethodDef,
patches: Map[LocalName, Boolean]): js.MethodDef = {
def newMutable(name: LocalName, oldMutable: Boolean): Boolean =
patches.getOrElse(name, oldMutable)
val js.MethodDef(flags, methodName, originalName, params, resultType, body) =
methodDef
val newParams = for {
p @ js.ParamDef(name, originalName, ptpe, mutable) <- params
} yield {
js.ParamDef(name, originalName, ptpe, newMutable(name.name, mutable))(p.pos)
}
val transformer = new ir.Transformers.Transformer {
override def transform(tree: js.Tree, isStat: Boolean): js.Tree = tree match {
case js.VarDef(name, originalName, vtpe, mutable, rhs) =>
assert(isStat, s"found a VarDef in expression position at ${tree.pos}")
super.transform(js.VarDef(name, originalName, vtpe,
newMutable(name.name, mutable), rhs)(tree.pos), isStat)
case js.Closure(arrow, captureParams, params, restParam, body, captureValues) =>
js.Closure(arrow, captureParams, params, restParam, body,
captureValues.map(transformExpr))(tree.pos)
case _ =>
super.transform(tree, isStat)
}
}
val newBody = body.map(
b => transformer.transform(b, isStat = resultType == jstpe.NoType))
js.MethodDef(flags, methodName, originalName, newParams, resultType,
newBody)(methodDef.optimizerHints, Unversioned)(methodDef.pos)
}
/** Patches the type of selected param defs in a [[js.MethodDef]].
*
* @param patches
* Map from local name to new type. For param defs not in the map, the
* type is untouched.
*/
private def patchTypeOfParamDefs(methodDef: js.MethodDef,
patches: Map[LocalName, jstpe.Type]): js.MethodDef = {
def newType(name: js.LocalIdent, oldType: jstpe.Type): jstpe.Type =
patches.getOrElse(name.name, oldType)
val js.MethodDef(flags, methodName, originalName, params, resultType, body) =
methodDef
val newParams = for {
p @ js.ParamDef(name, originalName, ptpe, mutable) <- params
} yield {
js.ParamDef(name, originalName, newType(name, ptpe), mutable)(p.pos)
}
val transformer = new ir.Transformers.Transformer {
override def transform(tree: js.Tree, isStat: Boolean): js.Tree = tree match {
case tree @ js.VarRef(name) =>
js.VarRef(name)(newType(name, tree.tpe))(tree.pos)
case js.Closure(arrow, captureParams, params, restParam, body, captureValues) =>
js.Closure(arrow, captureParams, params, restParam, body,
captureValues.map(transformExpr))(tree.pos)
case _ =>
super.transform(tree, isStat)
}
}
val newBody = body.map(
b => transformer.transform(b, isStat = resultType == jstpe.NoType))
js.MethodDef(flags, methodName, originalName, newParams, resultType,
newBody)(methodDef.optimizerHints, Unversioned)(methodDef.pos)
}
/** Generates the JSNativeMemberDef of a JS native method. */
def genJSNativeMemberDef(tree: DefDef): js.JSNativeMemberDef = {
implicit val pos = tree.pos
val sym = tree.symbol
val flags = js.MemberFlags.empty.withNamespace(js.MemberNamespace.PublicStatic)
val methodName = encodeMethodSym(sym)
val jsNativeLoadSpec = jsInterop.jsNativeLoadSpecOf(sym)
js.JSNativeMemberDef(flags, methodName, jsNativeLoadSpec)
}
/** Generates the MethodDef of a (non-constructor) method
*
* Most normal methods are emitted straightforwardly. If the result
* type is Unit, then the body is emitted as a statement. Otherwise, it is
* emitted as an expression.
*
* The additional complexity of this method handles the transformation of
* a peculiarity of recursive tail calls: the local ValDef that replaces
* `this`.
*/
def genMethodDef(namespace: js.MemberNamespace, methodName: js.MethodIdent,
originalName: OriginalName, jsParams: List[js.ParamDef],
resultIRType: jstpe.Type, tree: Tree,
optimizerHints: OptimizerHints): js.MethodDef = {
implicit val pos = tree.pos
val bodyIsStat = resultIRType == jstpe.NoType
def genBodyWithinReturnableScope(): js.Tree = tree match {
case Block(
(thisDef @ ValDef(_, nme.THIS, _, initialThis)) :: otherStats,
rhs) =>
// This method has tail jumps
val thisSym = thisDef.symbol
if (thisSym.isMutable)
mutableLocalVars += thisSym
/* The `thisLocalIdent` must be nullable. Even though we initially
* assign it to `this`, which is non-nullable, tail-recursive calls
* may reassign it to a different value, which in general will be
* nullable.
*/
val thisLocalIdent = encodeLocalSym(thisSym)
val thisLocalType = currentThisTypeNullable
val genRhs = {
/* #3267 In default methods, scalac will type its _$this
* pseudo-variable as the *self-type* of the enclosing class,
* instead of the enclosing class type itself. However, it then
* considers *usages* of _$this as if its type were the
* enclosing class type. The latter makes sense, since it is
* compiled as `this` in the bytecode, which necessarily needs
* to be the enclosing class type. Only the declared type of
* _$this is wrong.
*
* In our case, since we generate an actual local variable for
* _$this, we must make sure to type it correctly, as the
* enclosing class type. However, this means the rhs of the
* ValDef does not match, which is why we have to adapt it
* here.
*/
forceAdapt(genExpr(initialThis), thisLocalType)
}
val thisLocalVarDef = js.VarDef(thisLocalIdent, thisOriginalName,
thisLocalType, thisSym.isMutable, genRhs)
val innerBody = {
withScopedVars(
thisLocalVarIdent := Some(thisLocalIdent)
) {
js.Block(otherStats.map(genStat) :+ (
if (bodyIsStat) genStat(rhs)
else genExpr(rhs)))
}
}
js.Block(thisLocalVarDef, innerBody)
case _ =>
if (bodyIsStat) genStat(tree)
else genExpr(tree)
}
def genBody(): js.Tree = {
withNewReturnableScope(resultIRType) {
genBodyWithinReturnableScope()
}
}
if (!isNonNativeJSClass(currentClassSym) ||
isJSFunctionDef(currentClassSym)) {
val flags = js.MemberFlags.empty.withNamespace(namespace)
val body = {
def genAsUnaryOp(op: js.UnaryOp.Code): js.Tree =
js.UnaryOp(op, genThis())
def genAsBinaryOp(op: js.BinaryOp.Code): js.Tree =
js.BinaryOp(op, genThis(), jsParams.head.ref)
def genAsBinaryOpRhsNotNull(op: js.BinaryOp.Code): js.Tree =
js.BinaryOp(op, genThis(), js.UnaryOp(js.UnaryOp.CheckNotNull, jsParams.head.ref))
if (currentClassSym.get == HackedStringClass) {
/* Hijack the bodies of String.length and String.charAt and replace
* them with String_length and String_charAt operations, respectively.
*/
methodName.name match {
case `lengthMethodName` => genAsUnaryOp(js.UnaryOp.String_length)
case `charAtMethodName` => genAsBinaryOp(js.BinaryOp.String_charAt)
case _ => genBody()
}
} else if (currentClassSym.get == ClassClass) {
// Similar, for the Class_x operations
methodName.name match {
case `getNameMethodName` => genAsUnaryOp(js.UnaryOp.Class_name)
case `isPrimitiveMethodName` => genAsUnaryOp(js.UnaryOp.Class_isPrimitive)
case `isInterfaceMethodName` => genAsUnaryOp(js.UnaryOp.Class_isInterface)
case `isArrayMethodName` => genAsUnaryOp(js.UnaryOp.Class_isArray)
case `getComponentTypeMethodName` => genAsUnaryOp(js.UnaryOp.Class_componentType)
case `getSuperclassMethodName` => genAsUnaryOp(js.UnaryOp.Class_superClass)
case `isInstanceMethodName` => genAsBinaryOp(js.BinaryOp.Class_isInstance)
case `isAssignableFromMethodName` => genAsBinaryOpRhsNotNull(js.BinaryOp.Class_isAssignableFrom)
case `castMethodName` => genAsBinaryOp(js.BinaryOp.Class_cast)
case _ => genBody()
}
} else if (currentClassSym.get == JavaLangReflectArrayModClass) {
methodName.name match {
case `arrayNewInstanceMethodName` =>
val List(jlClassParam, lengthParam) = jsParams
js.BinaryOp(js.BinaryOp.Class_newArray,
js.UnaryOp(js.UnaryOp.CheckNotNull, jlClassParam.ref),
lengthParam.ref)
case _ =>
genBody()
}
} else {
genBody()
}
}
js.MethodDef(flags, methodName, originalName, jsParams, resultIRType,
Some(body))(
optimizerHints, Unversioned)
} else {
assert(!namespace.isStatic, tree.pos)
val thisLocalIdent = freshLocalIdent("this")
withScopedVars(
thisLocalVarIdent := Some(thisLocalIdent)
) {
val staticNamespace =
if (namespace.isPrivate) js.MemberNamespace.PrivateStatic
else js.MemberNamespace.PublicStatic
val flags =
js.MemberFlags.empty.withNamespace(staticNamespace)
val thisParamDef = js.ParamDef(thisLocalIdent, thisOriginalName,
jstpe.AnyType, mutable = false)
js.MethodDef(flags, methodName, originalName,
thisParamDef :: jsParams, resultIRType, Some(genBody()))(
optimizerHints, Unversioned)
}
}
}
/** Forces the given `tree` to a given type by adapting it.
*
* @param tree
* The tree to adapt.
* @param tpe
* The target type, which must be either `AnyType` or `ClassType`.
*/
private def forceAdapt(tree: js.Tree, tpe: jstpe.Type): js.Tree = {
if (tree.tpe == tpe || tpe == jstpe.AnyType) {
tree
} else {
/* Remove the useless cast that scalac's erasure had to introduce to
* work around their own ill-typed _$this. Note that the optimizer will
* not be able to do that, since it won't be able to prove that the
* underlying expression is indeed an instance of `tpe`.
*/
tree match {
case js.AsInstanceOf(underlying, _) if underlying.tpe == tpe =>
underlying
case _ =>
js.AsInstanceOf(tree, tpe)(tree.pos)
}
}
}
/** Gen JS code for a tree in statement position (in the IR).
*/
def genStat(tree: Tree): js.Tree = {
exprToStat(genStatOrExpr(tree, isStat = true))
}
/** Turn a JavaScript expression of type Unit into a statement */
def exprToStat(tree: js.Tree): js.Tree = {
/* Any JavaScript expression is also a statement, but at least we get rid
* of some pure expressions that come from our own codegen.
*/
implicit val pos = tree.pos
tree match {
case js.Block(stats :+ expr) =>
js.Block(stats :+ exprToStat(expr))
case _:js.Literal | _:js.This | _:js.VarRef =>
js.Skip()
case _ =>
tree
}
}
/** Gen JS code for a tree in expression position (in the IR).
*/
def genExpr(tree: Tree): js.Tree = {
val result = genStatOrExpr(tree, isStat = false)
assert(result.tpe != jstpe.NoType,
s"genExpr($tree) returned a tree with type NoType at pos ${tree.pos}")
result
}
/** Gen JS code for a tree in expression position (in the IR) or the
* global scope.
*/
def genExprOrGlobalScope(tree: Tree): MaybeGlobalScope = {
implicit def pos: Position = tree.pos
tree match {
case _: This =>
val sym = tree.symbol
if (sym != currentClassSym.get && sym.isModule)
genLoadModuleOrGlobalScope(sym)
else
MaybeGlobalScope.NotGlobalScope(genExpr(tree))
case _:Ident | _:Select =>
val sym = tree.symbol
if (sym.isModule) {
assert(!sym.isPackageClass, "Cannot use package as value: " + tree)
genLoadModuleOrGlobalScope(sym)
} else {
MaybeGlobalScope.NotGlobalScope(genExpr(tree))
}
case _ =>
MaybeGlobalScope.NotGlobalScope(genExpr(tree))
}
}
/** Gen JS code for a tree in statement or expression position (in the IR).
*
* This is the main transformation method. Each node of the Scala AST
* is transformed into an equivalent portion of the JS AST.
*/
def genStatOrExpr(tree: Tree, isStat: Boolean): js.Tree = {
implicit val pos = tree.pos
tree match {
/** LabelDefs (for while and do..while loops) */
case lblDf: LabelDef =>
genLabelDef(lblDf, isStat)
/** Local val or var declaration */
case ValDef(_, name, _, rhs) =>
/* Must have been eliminated by the tail call transform performed
* by genMethodDef().
* If you ever change/remove this assertion, you need to update
* genEnclosingLabelApply() regarding `nme.THIS`.
*/
assert(name != nme.THIS,
s"ValDef(_, nme.THIS, _, _) found at ${tree.pos}")
val sym = tree.symbol
val rhsTree =
if (rhs == EmptyTree) jstpe.zeroOf(toIRType(sym.tpe))
else genExpr(rhs)
rhsTree match {
case js.Transient(UndefinedParam) =>
// This is an intermediate assignment for default params on a
// js.Any. Add the symbol to the corresponding set to inform
// the Ident resolver how to replace it and don't emit the symbol
undefinedDefaultParams += sym
js.Skip()
case _ =>
if (sym.isMutable)
mutableLocalVars += sym
js.VarDef(encodeLocalSym(sym), originalNameOfLocal(sym),
toIRType(sym.tpe), sym.isMutable, rhsTree)
}
case tree @ If(cond, thenp, elsep) =>
def default: js.Tree = {
val tpe =
if (isStat) jstpe.NoType
else toIRType(tree.tpe)
js.If(genExpr(cond), genStatOrExpr(thenp, isStat),
genStatOrExpr(elsep, isStat))(tpe)
}
if (isStat && currentMethodSym.isClassConstructor) {
/* Nested classes that need an outer pointer have a weird shape for
* assigning it, with an explicit null check. It looks like this:
*
* if ($outer.eq(null))
* throw null
* else
* this.$outer = $outer
*
* This is a bad shape for our optimizations, notably because the
* explicit null check cannot be considered UB at the IR level if
* we compile it as is, although in the original *language*, that
* would clearly fall into UB.
*
* Therefore, we intercept that shape and rewrite it as follows
* instead:
*
* ($outer) // null check subject to UB
* this.$outer = $outer // the `else` branch in general
*/
tree match {
case OuterPointerNullCheck(outer, elsep) =>
js.Block(
js.UnaryOp(js.UnaryOp.CheckNotNull, genExpr(outer)),
genStat(elsep)
)
case _ =>
default
}
} else {
default
}
case Return(expr) =>
js.Return(toIRType(expr.tpe) match {
case jstpe.NoType => js.Block(genStat(expr), js.Undefined())
case _ => genExpr(expr)
}, getEnclosingReturnLabel())
case t: Try =>
genTry(t, isStat)
case Throw(expr) =>
val ex = genExpr(expr)
ex match {
case js.New(cls, _, _) if cls != JavaScriptExceptionClassName =>
// Common case where ex is neither null nor a js.JavaScriptException
js.Throw(ex)
case _ =>
js.Throw(js.UnwrapFromThrowable(ex))
}
/* !!! Copy-pasted from `CleanUp.scala` upstream and simplified with
* our `WrapArray` extractor.
*
* Replaces `Array(Predef.wrapArray(ArrayValue(...).$asInstanceOf[...]), )`
* with just `ArrayValue(...)`
*
* See scala/bug#6611; we must *only* do this for literal vararg arrays.
*
* This is normally done by `cleanup` but it comes later than this phase.
*/
case Apply(appMeth,
Apply(wrapRefArrayMeth, StripCast(arg @ ArrayValue(elemtpt, elems)) :: Nil) :: classTagEvidence :: Nil)
if WrapArray.isClassTagBasedWrapArrayMethod(wrapRefArrayMeth.symbol) &&
appMeth.symbol == ArrayModule_genericApply &&
!elemtpt.tpe.typeSymbol.isBottomClass &&
!elemtpt.tpe.typeSymbol.isPrimitiveValueClass /* can happen via specialization.*/ =>
classTagEvidence.attachments.get[analyzer.MacroExpansionAttachment] match {
case Some(att)
if att.expandee.symbol.name == nme.materializeClassTag && tree.isInstanceOf[ApplyToImplicitArgs] =>
genArrayValue(arg)
case _ =>
val arrValue = genApplyMethod(
genExpr(classTagEvidence),
ClassTagClass.info.decl(nme.newArray),
js.IntLiteral(elems.size) :: Nil)
val arrVarDef = js.VarDef(freshLocalIdent("arr"), NoOriginalName,
arrValue.tpe, mutable = false, arrValue)
val stats = List.newBuilder[js.Tree]
foreachWithIndex(elems) { (elem, i) =>
stats += genApplyMethod(
genLoadModule(ScalaRunTimeModule),
currentRun.runDefinitions.arrayUpdateMethod,
arrVarDef.ref :: js.IntLiteral(i) :: genExpr(elem) :: Nil)
}
js.Block(arrVarDef :: stats.result(), arrVarDef.ref)
}
case Apply(appMeth, elem0 :: WrapArray(rest @ ArrayValue(elemtpt, _)) :: Nil)
if appMeth.symbol == ArrayModule_apply(elemtpt.tpe) =>
genArrayValue(rest, elem0 :: rest.elems)
case Apply(appMeth, elem :: (nil: RefTree) :: Nil)
if nil.symbol == NilModule && appMeth.symbol == ArrayModule_apply(elem.tpe.widen) &&
treeInfo.isExprSafeToInline(nil) =>
genArrayValue(tree, elem :: Nil)
case app: Apply =>
genApply(app, isStat)
case app: ApplyDynamic =>
genApplyDynamic(app)
case This(qual) =>
if (tree.symbol == currentClassSym.get) {
genThis()
} else {
assert(tree.symbol.isModuleClass,
"Trying to access the this of another class: " +
"tree.symbol = " + tree.symbol +
", class symbol = " + currentClassSym.get +
" compilation unit:" + currentUnit)
genLoadModule(tree.symbol)
}
case Select(qualifier, selector) =>
val sym = tree.symbol
def unboxFieldValue(boxed: js.Tree): js.Tree = {
fromAny(boxed,
enteringPhase(currentRun.posterasurePhase)(sym.tpe))
}
if (sym.isModule) {
assert(!sym.isPackageClass, "Cannot use package as value: " + tree)
genLoadModule(sym)
} else if (sym.isStaticMember) {
genStaticField(sym)
} else if (paramAccessorLocals contains sym) {
paramAccessorLocals(sym).ref
} else {
val (field, boxed) = genAssignableField(sym, qualifier)
if (boxed) unboxFieldValue(field)
else field
}
case Ident(name) =>
val sym = tree.symbol
if (!sym.hasPackageFlag) {
if (sym.isModule) {
assert(!sym.isPackageClass, "Cannot use package as value: " + tree)
genLoadModule(sym)
} else if (undefinedDefaultParams contains sym) {
// This is a default parameter whose assignment was moved to
// a local variable. Put a literal undefined param again
js.Transient(UndefinedParam)
} else {
genVarRef(sym)
}
} else {
abort("Cannot use package as value: " + tree)
}
case Literal(value) =>
value.tag match {
case UnitTag =>
js.Skip()
case BooleanTag =>
js.BooleanLiteral(value.booleanValue)
case ByteTag =>
js.ByteLiteral(value.byteValue)
case ShortTag =>
js.ShortLiteral(value.shortValue)
case CharTag =>
js.CharLiteral(value.charValue)
case IntTag =>
js.IntLiteral(value.intValue)
case LongTag =>
js.LongLiteral(value.longValue)
case FloatTag =>
js.FloatLiteral(value.floatValue)
case DoubleTag =>
js.DoubleLiteral(value.doubleValue)
case StringTag =>
js.StringLiteral(value.stringValue)
case NullTag =>
js.Null()
case ClazzTag =>
js.ClassOf(toTypeRef(value.typeValue))
case EnumTag =>
genStaticField(value.symbolValue)
}
case tree: Block =>
genBlock(tree, isStat)
case Typed(Super(_, _), _) =>
genThis()
case Typed(expr, _) =>
genExpr(expr)
case Assign(lhs, rhs) =>
val sym = lhs.symbol
if (sym.isStaticMember)
abort(s"Assignment to static member ${sym.fullName} not supported")
def genRhs = genExpr(rhs)
lhs match {
case Select(qualifier, _) =>
/* Record assignments to fields of the current class.
*
* We only do that for fields of the current class sym. For other
* fields, even if we recorded it, we would forget them when
* `fieldsMutatedInCurrentClass` is reset when going out of the
* class. If we assign to an immutable field in a different
* class, it will be reported as an IR checking error.
*
* Assignments to `this.` fields in the constructor are valid
* even for immutable fields, and are therefore not recorded.
*
* #3918 We record the *names* of the fields instead of their
* symbols because, in rare cases, scalac has different fields in
* the trees than in the class' decls. Since we only record fields
* from the current class, names are non ambiguous. For the same
* reason, we record assignments to *all* fields, not only the
* immutable ones, because in 2.13 the symbol here can be mutable
* but not the one in the class' decls.
*/
if (sym.owner == currentClassSym.get) {
val ctorAssignment = (
currentMethodSym.isClassConstructor &&
currentMethodSym.owner == qualifier.symbol &&
qualifier.isInstanceOf[This]
)
if (!ctorAssignment)
fieldsMutatedInCurrentClass += sym.name
}
def genBoxedRhs: js.Tree = {
val tpeEnteringPosterasure =
enteringPhase(currentRun.posterasurePhase)(rhs.tpe)
if ((tpeEnteringPosterasure eq null) && genRhs.isInstanceOf[js.Null]) {
devWarning(
"Working around https://github.com/scala-js/scala-js/issues/3422 " +
s"for ${sym.fullName} at ${sym.pos}")
// Fortunately, a literal `null` never needs to be boxed
genRhs
} else {
ensureBoxed(genRhs, tpeEnteringPosterasure)
}
}
if (sym.hasAnnotation(JSNativeAnnotation)) {
/* This is an assignment to a @js.native field. Since we reject
* `@js.native var`s as compile errors, this can only happen in
* the constructor of the enclosing object.
* We simply ignore the assignment, since the field will not be
* emitted at all.
*/
js.Skip()
} else {
val (field, boxed) = genAssignableField(sym, qualifier)
if (boxed) js.Assign(field, genBoxedRhs)
else js.Assign(field,genRhs)
}
case _ =>
mutatedLocalVars += sym
js.Assign(
js.VarRef(encodeLocalSym(sym))(toIRType(sym.tpe)),
genRhs)
}
/** Array constructor */
case av: ArrayValue =>
genArrayValue(av)
/** A Match reaching the backend is supposed to be optimized as a switch */
case mtch: Match =>
genMatch(mtch, isStat)
/** Anonymous function */
case fun: Function =>
genAnonFunction(fun)
case EmptyTree =>
js.Skip()
case _ =>
abort("Unexpected tree in genExpr: " +
tree + "/" + tree.getClass + " at: " + tree.pos)
}
} // end of GenJSCode.genExpr()
/** Extractor for the shape of outer pointer null check.
*
* See the comment in `case If(...) =>` of `genExpr`.
*
* When successful, returns the pair `(outer, elsep)` where `outer` is the
* `Ident` of the outer constructor parameter, and `elsep` is the else
* branch of the condition.
*/
private object OuterPointerNullCheck {
def unapply(tree: If): Option[(Ident, Tree)] = tree match {
case If(Apply(fun @ Select(outer: Ident, nme.eq), Literal(Constant(null)) :: Nil),
Throw(Literal(Constant(null))), elsep)
if outer.symbol.isOuterParam && fun.symbol == definitions.Object_eq =>
Some((outer, elsep))
case _ =>
None
}
}
/** Gen JS this of the current class.
* Normally encoded straightforwardly as a JS this.
* But must be replaced by the tail-jump-this local variable if there
* is one.
*/
private def genThis()(implicit pos: Position): js.Tree = {
thisLocalVarIdent.fold[js.Tree] {
if (tryingToGenMethodAsJSFunction) {
throw new CancelGenMethodAsJSFunction(
"Trying to generate `this` inside the body")
}
js.This()(currentThisType)
} { thisLocalIdent =>
// .copy() to get the correct position
js.VarRef(thisLocalIdent.copy())(currentThisTypeNullable)
}
}
/** Gen JS code for LabelDef.
*
* If a LabelDef reaches this method, then the only valid jumps are from
* within it, which means it basically represents a loop. Other kinds of
* LabelDefs, notably those for matches, are caught upstream and
* transformed in ad hoc ways.
*
* The general transformation for
* {{{
* labelName(...labelParams) {
* rhs
* }: T
* }}}
* is the following:
* {{{
* block[T]: {
* while (true) {
* labelName[void]: {
* return@block transformedRhs
* }
* }
* }
* }}}
* where all jumps to the label inside the rhs of the form
* {{{
* labelName(...args)
* }}}
* are transformed into
* {{{
* ...labelParams = ...args;
* return@labelName (void 0)
* }}}
*
* This is always correct, so it can handle arbitrary labels and jumps
* such as those produced by loops, tail-recursive calls and even some
* compiler plugins (see for example #1148). However, the result is
* unnecessarily ugly for simple `while` and `do while` loops, so we have
* some post-processing to simplify those.
*/
def genLabelDef(tree: LabelDef, isStat: Boolean): js.Tree = {
implicit val pos = tree.pos
val sym = tree.symbol
val labelParamSyms = tree.params.map(_.symbol)
val info = new EnclosingLabelDefInfoWithResultAsAssigns(labelParamSyms)
val labelIdent = encodeLabelSym(sym)
val labelName = labelIdent.name
val transformedRhs = withScopedVars(
enclosingLabelDefInfos := enclosingLabelDefInfos.get + (sym -> info)
) {
genStatOrExpr(tree.rhs, isStat)
}
/** Matches a `js.Return` to the current `labelName`, and returns the
* `exprToStat()` of the returned expression.
* We only keep the `exprToStat()` because this label has a `void` type,
* so the expression is always discarded except for its side effects.
*/
object ReturnFromThisLabel {
def unapply(tree: js.Return): Option[js.Tree] = {
if (tree.label.name == labelName) Some(exprToStat(tree.expr))
else None
}
}
def genDefault(): js.Tree = {
if (transformedRhs.tpe == jstpe.NothingType) {
// In this case, we do not need the outer block label
js.While(js.BooleanLiteral(true), {
js.Labeled(labelIdent, jstpe.NoType, {
transformedRhs match {
// Eliminate a trailing return@lab
case js.Block(stats :+ ReturnFromThisLabel(exprAsStat)) =>
js.Block(stats :+ exprAsStat)
case _ =>
transformedRhs
}
})
})
} else {
// When all else has failed, we need the full machinery
val blockLabelIdent = freshLabelIdent("block")
val bodyType =
if (isStat) jstpe.NoType
else toIRType(tree.tpe)
js.Labeled(blockLabelIdent, bodyType, {
js.While(js.BooleanLiteral(true), {
js.Labeled(labelIdent, jstpe.NoType, {
if (isStat)
js.Block(transformedRhs, js.Return(js.Undefined(), blockLabelIdent))
else
js.Return(transformedRhs, blockLabelIdent)
})
})
})
}
}
info.generatedReturns match {
case 0 =>
/* There are no jumps to the loop label. Therefore we can remove
* the labeled block and and the loop altogether.
* This happens for `while (false)` and `do while (false)` loops.
*/
transformedRhs
case 1 =>
/* There is exactly one jump. Let us see if we can isolate where it
* is to try and remove unnecessary labeled blocks and keep only
* the loop.
*/
transformedRhs match {
/* { stats; return@lab expr }
* -> while (true) { stats; expr }
* This happens for `while (true)` and `do while (true)` loops.
*/
case BlockOrAlone(stats, ReturnFromThisLabel(exprAsStat)) =>
js.While(js.BooleanLiteral(true), {
js.Block(stats, exprAsStat)
})
/* if (cond) { stats; return@lab expr } else elsep [; rest]
* -> while (cond) { stats; expr }; elsep; rest
* This happens for `while (cond)` loops with a non-constant `cond`.
* There is a `rest` if the while loop is on the rhs of a case in a
* patmat.
*/
case FirstInBlockOrAlone(
js.If(cond, BlockOrAlone(stats, ReturnFromThisLabel(exprAsStat)), elsep),
rest) =>
js.Block(
js.While(cond, {
js.Block(stats, exprAsStat)
}) ::
elsep ::
rest
)
/* { stats; if (cond) { return@lab pureExpr } else { skip } }
*
* !! `cond` could refer to VarDefs declared in stats, and we have
* no way of telling (short of traversing `cond` again) so we
* generate a `while` loop anyway:
*
* -> while ({ stats; cond }) { skip }
*
* The `pureExpr` must be pure because we cannot add it after the
* `cond` above. It must be eliminated, which is only valid if it
* is pure.
*
* This happens for `do while (cond)` loops with a non-constant
* `cond`.
*
* There is no need for BlockOrAlone because the alone case would
* also be caught by the `case js.If` above.
*/
case js.Block(stats :+ js.If(cond, ReturnFromThisLabel(js.Skip()), js.Skip())) =>
js.While(js.Block(stats, cond), js.Skip())
/* { stats; if (cond) { return@lab pureExpr } else { skip }; literal }
*
* Same as above, but there is an additional `literal` at the end.
*
* This happens for `do while (cond)` loops with a non-constant
* `cond` that are in the rhs of a case in a patmat.
*/
case js.Block(stats :+ js.If(cond, ReturnFromThisLabel(js.Skip()), js.Skip()) :+ (res: js.Literal)) =>
js.Block(js.While(js.Block(stats, cond), js.Skip()), res)
case _ =>
genDefault()
}
case moreThan1 =>
genDefault()
}
}
/** Gen JS code for a try..catch or try..finally block
*
* try..finally blocks are compiled straightforwardly to try..finally
* blocks of JS.
*
* try..catch blocks are a bit more subtle, as JS does not have
* type-based selection of exceptions to catch. We thus encode explicitly
* the type tests, like in:
*
* try { ... }
* catch (e) {
* if (e.isInstanceOf[IOException]) { ... }
* else if (e.isInstanceOf[Exception]) { ... }
* else {
* throw e; // default, re-throw
* }
* }
*/
def genTry(tree: Try, isStat: Boolean): js.Tree = {
implicit val pos = tree.pos
val Try(block, catches, finalizer) = tree
val blockAST = genStatOrExpr(block, isStat)
val resultType =
if (isStat) jstpe.NoType
else toIRType(tree.tpe)
val handled =
if (catches.isEmpty) blockAST
else genTryCatch(blockAST, catches, resultType, isStat)
genStat(finalizer) match {
case js.Skip() => handled
case ast => js.TryFinally(handled, ast)
}
}
private def genTryCatch(body: js.Tree, catches: List[CaseDef],
resultType: jstpe.Type, isStat: Boolean)(
implicit pos: Position): js.Tree = {
catches match {
case CaseDef(Ident(nme.WILDCARD), _, catchAllBody) :: Nil =>
genTryCatchCatchIgnoreAll(body, catchAllBody, resultType, isStat)
case CaseDef(Typed(Ident(nme.WILDCARD), tpt), _, catchAllBody) :: Nil
if tpt.tpe.typeSymbol == ThrowableClass =>
genTryCatchCatchIgnoreAll(body, catchAllBody, resultType, isStat)
case _ =>
genTryCatchNotIgnoreAll(body, catches, resultType, isStat)
}
}
private def genTryCatchCatchIgnoreAll(body: js.Tree, catchAllBody: Tree,
resultType: jstpe.Type, isStat: Boolean)(
implicit pos: Position): js.Tree = {
js.TryCatch(body, freshLocalIdent("e"), NoOriginalName,
genStatOrExpr(catchAllBody, isStat))(
resultType)
}
private def genTryCatchNotIgnoreAll(body: js.Tree, catches: List[CaseDef],
resultType: jstpe.Type, isStat: Boolean)(
implicit pos: Position): js.Tree = {
val exceptIdent = freshLocalIdent("e")
val origExceptVar = js.VarRef(exceptIdent)(jstpe.AnyType)
val mightCatchJavaScriptException = catches.exists { caseDef =>
caseDef.pat match {
case Typed(Ident(nme.WILDCARD), tpt) =>
isMaybeJavaScriptException(tpt.tpe)
case Ident(nme.WILDCARD) =>
true
case pat @ Bind(_, _) =>
isMaybeJavaScriptException(pat.symbol.tpe)
}
}
val (exceptValDef, exceptVar) = if (mightCatchJavaScriptException) {
val valDef = js.VarDef(freshLocalIdent("e"), NoOriginalName,
encodeClassType(ThrowableClass), mutable = false, js.WrapAsThrowable(origExceptVar))
(valDef, valDef.ref)
} else {
(js.Skip(), origExceptVar)
}
val elseHandler: js.Tree = js.Throw(origExceptVar)
val handler = catches.foldRight(elseHandler) { (caseDef, elsep) =>
implicit val pos = caseDef.pos
val CaseDef(pat, _, body) = caseDef
// Extract exception type and variable
val (tpe, boundVar) = (pat match {
case Typed(Ident(nme.WILDCARD), tpt) =>
(tpt.tpe, None)
case Ident(nme.WILDCARD) =>
(ThrowableClass.tpe, None)
case Bind(_, _) =>
val ident = encodeLocalSym(pat.symbol)
val origName = originalNameOfLocal(pat.symbol)
(pat.symbol.tpe, Some((ident, origName)))
})
// Generate the body that must be executed if the exception matches
val bodyWithBoundVar = (boundVar match {
case None =>
genStatOrExpr(body, isStat)
case Some((boundVarIdent, boundVarOriginalName)) =>
val castException = genAsInstanceOf(exceptVar, tpe)
js.Block(
js.VarDef(boundVarIdent, boundVarOriginalName, toIRType(tpe),
mutable = false, castException),
genStatOrExpr(body, isStat))
})
// Generate the test
if (tpe == ThrowableClass.tpe) {
bodyWithBoundVar
} else {
val cond = genIsInstanceOf(exceptVar, tpe)
js.If(cond, bodyWithBoundVar, elsep)(resultType)
}
}
js.TryCatch(body, exceptIdent, NoOriginalName,
js.Block(exceptValDef, handler))(resultType)
}
/** Gen JS code for an Apply node (method call)
*
* There's a whole bunch of varieties of Apply nodes: regular method
* calls, super calls, constructor calls, isInstanceOf/asInstanceOf,
* primitives, JS calls, etc. They are further dispatched in here.
*/
def genApply(tree: Apply, isStat: Boolean): js.Tree = {
implicit val pos = tree.pos
val Apply(fun, args) = tree
val sym = fun.symbol
/* Is the method a JS default accessor, which should become an
* `UndefinedParam` rather than being compiled normally.
*
* This is true iff one of the following conditions apply:
* - It is a constructor default param for the constructor of a JS class.
* - It is a default param of an instance method of a native JS type.
* - It is a default param of an instance method of a non-native JS type
* and the attached method is exposed.
* - It is a default param for a native JS def.
*
* This is different than `isIgnorableDefaultParam` in `genMethod`: we
* include here the default accessors of *non-native* JS types (unless
* the corresponding methods are not exposed). We also need to handle
* non-constructor members of native JS types.
*/
def isJSDefaultParam: Boolean = {
DefaultParamInfo.isApplicable(sym) && {
val info = new DefaultParamInfo(sym)
if (info.isForConstructor) {
/* This is a default accessor for a constructor parameter. Check
* whether the attached constructor is a JS constructor, which is
* the case iff the linked class is a JS type.
*/
isJSType(info.constructorOwner)
} else {
if (isJSType(sym.owner)) {
/* The default accessor is in a JS type. It is a JS default
* param iff the enclosing class is native or the attached method
* is exposed.
*/
!isNonNativeJSClass(sym.owner) || isExposed(info.attachedMethod)
} else {
/* The default accessor is in a Scala type. It is a JS default
* param iff the attached method is a native JS def. This can
* only happen if the owner is a module class, which we test
* first as a fast way out.
*/
sym.owner.isModuleClass && info.attachedMethod.hasAnnotation(JSNativeAnnotation)
}
}
}
}
fun match {
case TypeApply(_, _) =>
genApplyTypeApply(tree, isStat)
case _ if isJSDefaultParam =>
js.Transient(UndefinedParam)
case Select(Super(_, _), _) =>
genSuperCall(tree, isStat)
case Select(New(_), nme.CONSTRUCTOR) =>
genApplyNew(tree)
case _ =>
if (sym.isLabel) {
genLabelApply(tree)
} else if (scalaPrimitives.isPrimitive(sym)) {
genPrimitiveOp(tree, isStat)
} else if (currentRun.runDefinitions.isBox(sym)) {
// Box a primitive value (cannot be Unit)
val arg = args.head
makePrimitiveBox(genExpr(arg), sym.firstParam.tpe)
} else if (currentRun.runDefinitions.isUnbox(sym)) {
// Unbox a primitive value (cannot be Unit)
val arg = args.head
makePrimitiveUnbox(genExpr(arg), tree.tpe)
} else {
genNormalApply(tree, isStat)
}
}
}
/** Gen an Apply with a TypeApply method.
*
* Until 2.12.0-M5, only `isInstanceOf` and `asInstanceOf` kept their type
* argument until the backend. Since 2.12.0-RC1, `AnyRef.synchronized`
* does so too.
*/
private def genApplyTypeApply(tree: Apply, isStat: Boolean): js.Tree = {
implicit val pos = tree.pos
val Apply(TypeApply(fun @ Select(obj, _), targs), args) = tree
val sym = fun.symbol
sym match {
case Object_isInstanceOf =>
genIsAsInstanceOf(obj, targs, cast = false)
case Object_asInstanceOf =>
genIsAsInstanceOf(obj, targs, cast = true)
case Object_synchronized =>
genSynchronized(obj, args.head, isStat)
case _ =>
abort("Unexpected type application " + fun +
"[sym: " + sym.fullName + "]" + " in: " + tree)
}
}
/** Gen `isInstanceOf` or `asInstanceOf`. */
private def genIsAsInstanceOf(obj: Tree, targs: List[Tree], cast: Boolean)(
implicit pos: Position): js.Tree = {
genIsAsInstanceOf(genExpr(obj), obj.tpe, targs.head.tpe, cast)
}
/** Gen `isInstanceOf` or `asInstanceOf`. */
private def genIsAsInstanceOf(expr: js.Tree, from: Type, to: Type,
cast: Boolean)(
implicit pos: Position): js.Tree = {
val l = toIRType(from)
val r = toIRType(to)
def isValueType(tpe: jstpe.Type): Boolean = tpe match {
case jstpe.NoType | jstpe.BooleanType | jstpe.CharType |
jstpe.ByteType | jstpe.ShortType | jstpe.IntType | jstpe.LongType |
jstpe.FloatType | jstpe.DoubleType =>
true
case _ =>
false
}
val lIsValueType = isValueType(l)
val rIsValueType = isValueType(r)
if (lIsValueType && rIsValueType) {
if (cast) {
/* It is unclear whether this case can be reached for all type
* conversions, but scalac handles all cases, so we do too.
* Three known user code patterns that become code handled by this
* case are `byte.##`, `short.##` and `char.##`, which become, e.g.,
* `char.toChar().$asInstanceOf[Int]`.
*/
genConversion(l, r, expr)
} else {
js.BooleanLiteral(l == r)
}
} else if (lIsValueType) {
val result =
if (cast) genThrowClassCastException()
else js.BooleanLiteral(false)
js.Block(expr, result) // eval and discard source
} else if (rIsValueType) {
assert(!cast, s"Unexpected asInstanceOf from ref type to value type")
genIsInstanceOf(expr, boxedClass(to.typeSymbol).tpe)
} else {
if (cast)
genAsInstanceOf(expr, to)
else
genIsInstanceOf(expr, to)
}
}
private def genThrowClassCastException()(implicit pos: Position): js.Tree = {
val ctor = ClassCastExceptionClass.info.member(
nme.CONSTRUCTOR).suchThat(_.tpe.params.isEmpty)
js.Throw(genNew(ClassCastExceptionClass, ctor, Nil))
}
/** Gen JS code for a super call, of the form Class.super[mix].fun(args).
*
* This does not include calls defined in mixin traits, as these are
* already desugared by the 'mixin' phase. Only calls to super classes
* remain.
* Since a class has exactly one direct superclass, and calling a method
* two classes above the current one is invalid, the `mix` item is
* irrelevant.
*/
private def genSuperCall(tree: Apply, isStat: Boolean): js.Tree = {
implicit val pos = tree.pos
val Apply(fun @ Select(sup @ Super(qual, _), _), args) = tree
val sym = fun.symbol
if (isJSType(qual.tpe)) {
if (sym.isMixinConstructor) {
/* Do not emit a call to the $init$ method of JS traits.
* This exception is necessary because @JSOptional fields cause the
* creation of a $init$ method, which we must not call.
*/
js.Skip()
} else {
genJSSuperCall(tree, isStat)
}
} else {
/* #3013 `qual` can be `this.$outer()` in some cases since Scala 2.12,
* so we call `genExpr(qual)`, not just `genThis()`.
*/
val superCall = genApplyMethodStatically(
genExpr(qual), sym, genActualArgs(sym, args))
// Initialize the module instance just after the super constructor call.
if (isStaticModule(currentClassSym) && !isModuleInitialized.value &&
currentMethodSym.isClassConstructor) {
isModuleInitialized.value = true
js.Block(superCall, js.StoreModule())
} else {
superCall
}
}
}
/** Gen JS code for a constructor call (new).
* Further refined into:
* * new String(...)
* * new of a hijacked boxed class
* * new of an anonymous function class that was recorded as JS function
* * new of a JS class
* * new Array
* * regular new
*/
private def genApplyNew(tree: Apply): js.Tree = {
implicit val pos = tree.pos
val Apply(fun @ Select(New(tpt), nme.CONSTRUCTOR), args) = tree
val ctor = fun.symbol
val tpe = tpt.tpe
val clsSym = tpe.typeSymbol
assert(ctor.isClassConstructor,
"'new' call to non-constructor: " + ctor.name)
if (isHijackedClass(clsSym)) {
genNewHijackedClass(clsSym, ctor, args.map(genExpr))
} else if (isJSFunctionDef(clsSym)) {
val classDef = consumeLazilyGeneratedAnonClass(clsSym)
genJSFunction(classDef, args.map(genExpr))
} else if (clsSym.isAnonymousFunction) {
val classDef = consumeLazilyGeneratedAnonClass(clsSym)
tryGenAnonFunctionClass(classDef, args.map(genExpr)).getOrElse {
// Cannot optimize anonymous function class. Generate full class.
generatedClasses += nestedGenerateClass(clsSym)(genClass(classDef)) -> clsSym.pos
genNew(clsSym, ctor, genActualArgs(ctor, args))
}
} else if (isJSType(clsSym)) {
genPrimitiveJSNew(tree)
} else {
toTypeRef(tpe) match {
case jstpe.ClassRef(className) =>
genNew(className, ctor, genActualArgs(ctor, args))
case arr: jstpe.ArrayTypeRef =>
genNewArray(arr, args.map(genExpr))
case prim: jstpe.PrimRef =>
abort(s"unexpected primitive type $prim in New at $pos")
}
}
}
/** Gen jump to a label.
*
* Some label-applys are caught upstream (jumps to next case of a pattern
* match that are in tail-pos or their own case), but most are handled
* here, notably:
*
* - Jumps to the beginning label of loops, including tail-recursive calls
* - Jumps to the next case label that are not in tail position
* - Jumps to the end of a pattern match
*/
private def genLabelApply(tree: Apply): js.Tree = {
implicit val pos = tree.pos
val Apply(fun, args) = tree
val sym = fun.symbol
val info = enclosingLabelDefInfos.getOrElse(sym, {
abort("Found unknown label apply at "+tree.pos+": "+tree)
})
val labelIdent = encodeLabelSym(sym)
info.generatedReturns += 1
def assertArgCountMatches(expected: Int): Unit = {
assert(args.size == expected,
s"argument count mismatch for label-apply at $pos: " +
s"expected $expected but got ${args.size}")
}
info match {
case info: EnclosingLabelDefInfoWithResultAsAssigns =>
val paramSyms = info.paramSyms
assertArgCountMatches(paramSyms.size)
val jump = js.Return(js.Undefined(), labelIdent)
if (args.isEmpty) {
// fast path, applicable notably to loops and case labels
jump
} else {
js.Block(genMultiAssign(paramSyms, args), jump)
}
case _: EnclosingLabelDefInfoWithResultAsReturn =>
assertArgCountMatches(1)
js.Return(genExpr(args.head), labelIdent)
}
}
/** Gen multiple "parallel" assignments.
*
* This is used when assigning the new value of multiple parameters of a
* label-def, notably for the ones generated for tail-recursive methods.
*
* Since the rhs for the new value of an argument can depend on the value
* of another argument (and since deciding if it is indeed the case is
* impossible in general), new values are computed in temporary variables
* first, then copied to the actual variables representing the argument.
*
* Trivial assignments (arg1 = arg1) are eliminated.
*
* If, after elimination of trivial assignments, only one assignment
* remains, then we do not use a temporary variable for this one.
*/
private def genMultiAssign(targetSyms: List[Symbol], values: List[Tree])(
implicit pos: Position): List[js.Tree] = {
// Prepare quadruplets of (formalArg, irType, tempVar, actualArg)
// Do not include trivial assignments (when actualArg == formalArg)
val quadruplets = {
val quadruplets =
List.newBuilder[(js.VarRef, jstpe.Type, js.LocalIdent, js.Tree)]
for ((formalArgSym, arg) <- targetSyms.zip(values)) {
val formalArg = encodeLocalSym(formalArgSym)
val actualArg = genExpr(arg)
/* #3267 The formal argument representing the special `this` of a
* tailrec method can have the wrong type in the scalac symbol table.
* We need to patch it up, along with the actual argument, to be the
* enclosing class type.
* See the longer comment in genMethodDef() for more details.
*
* Note that only testing the `name` against `nme.THIS` is safe,
* given that `genStatOrExpr()` for `ValDef` asserts that no local
* variable named `nme.THIS` can happen, other than the ones
* generated for tailrec methods.
*/
val isTailJumpThisLocalVar = formalArgSym.name == nme.THIS
val tpe =
if (isTailJumpThisLocalVar) currentThisTypeNullable
else toIRType(formalArgSym.tpe)
val fixedActualArg =
if (isTailJumpThisLocalVar) forceAdapt(actualArg, tpe)
else actualArg
actualArg match {
case js.VarRef(`formalArg`) =>
// This is trivial assignment, we don't need it
case _ =>
mutatedLocalVars += formalArgSym
quadruplets += ((js.VarRef(formalArg)(tpe), tpe,
freshLocalIdent(formalArg.name.withPrefix("temp$")),
fixedActualArg))
}
}
quadruplets.result()
}
quadruplets match {
case Nil =>
Nil
case (formalArg, _, _, actualArg) :: Nil =>
js.Assign(formalArg, actualArg) :: Nil
case _ =>
val tempAssignments =
for ((_, argType, tempArg, actualArg) <- quadruplets)
yield js.VarDef(tempArg, NoOriginalName, argType, mutable = false, actualArg)
val trueAssignments =
for ((formalArg, argType, tempArg, _) <- quadruplets)
yield js.Assign(formalArg, js.VarRef(tempArg)(argType))
tempAssignments ::: trueAssignments
}
}
/** Gen a "normal" apply (to a true method).
*
* But even these are further refined into:
*
* - Calls to methods of JS types.
* - Calls to methods in impl classes of traits.
* - Direct calls to constructors (from secondary constructor to another one).
* - Regular method calls.
*/
private def genNormalApply(tree: Apply, isStat: Boolean): js.Tree = {
implicit val pos = tree.pos
val Apply(fun @ Select(receiver, _), args) = tree
val sym = fun.symbol
val inline = {
tree.hasAttachment[InlineCallsiteAttachment.type] ||
fun.hasAttachment[InlineCallsiteAttachment.type] // nullary methods
}
val noinline = {
tree.hasAttachment[NoInlineCallsiteAttachment.type] ||
fun.hasAttachment[NoInlineCallsiteAttachment.type] // nullary methods
}
if (isJSType(receiver.tpe) && sym.owner != ObjectClass) {
if (!isNonNativeJSClass(sym.owner) || isExposed(sym))
genPrimitiveJSCall(tree, isStat)
else
genApplyJSClassMethod(genExpr(receiver), sym, genActualArgs(sym, args))
} else if (sym.hasAnnotation(JSNativeAnnotation)) {
genJSNativeMemberCall(tree, isStat)
} else if (sym.isStaticMember) {
if (sym.isMixinConstructor) {
/* Do not emit a call to the $init$ method of JS traits.
* This exception is necessary because optional JS fields cause the
* creation of a $init$ method, which we must not call.
*/
js.Skip()
} else {
genApplyStatic(sym, args.map(genExpr), inline = inline, noinline = noinline)
}
} else {
genApplyMethodMaybeStatically(genExpr(receiver), sym,
genActualArgs(sym, args), inline = inline, noinline = noinline)
}
}
def genApplyMethodMaybeStatically(receiver: js.Tree,
method: Symbol, arguments: List[js.Tree],
inline: Boolean = false, noinline: Boolean = false)(
implicit pos: Position): js.Tree = {
if (method.isPrivate || method.isClassConstructor)
genApplyMethodStatically(receiver, method, arguments, inline = inline, noinline = noinline)
else
genApplyMethod(receiver, method, arguments, inline = inline, noinline = noinline)
}
/** Gen JS code for a call to a Scala method. */
def genApplyMethod(receiver: js.Tree,
method: Symbol, arguments: List[js.Tree],
inline: Boolean = false, noinline: Boolean = false)(
implicit pos: Position): js.Tree = {
assert(!method.isPrivate,
s"Cannot generate a dynamic call to private method $method at $pos")
val flags = js.ApplyFlags.empty
.withInline(inline)
.withNoinline(noinline)
js.Apply(flags, receiver, encodeMethodSym(method), arguments)(
toIRType(method.tpe.resultType))
}
def genApplyMethodStatically(receiver: js.Tree, method: Symbol,
arguments: List[js.Tree], inline: Boolean = false, noinline: Boolean = false)(
implicit pos: Position): js.Tree = {
val flags = js.ApplyFlags.empty
.withPrivate(method.isPrivate && !method.isClassConstructor)
.withConstructor(method.isClassConstructor)
.withInline(inline)
.withNoinline(noinline)
val methodIdent = encodeMethodSym(method)
val resultType =
if (method.isClassConstructor) jstpe.NoType
else toIRType(method.tpe.resultType)
js.ApplyStatically(flags, receiver, encodeClassName(method.owner),
methodIdent, arguments)(resultType)
}
def genApplyJSClassMethod(receiver: js.Tree, method: Symbol,
arguments: List[js.Tree], inline: Boolean = false)(
implicit pos: Position): js.Tree = {
genApplyStatic(method, receiver :: arguments, inline = inline)
}
def genApplyStatic(method: Symbol, arguments: List[js.Tree],
inline: Boolean = false, noinline: Boolean = false)(
implicit pos: Position): js.Tree = {
val flags = js.ApplyFlags.empty
.withPrivate(method.isPrivate)
.withInline(inline)
.withNoinline(noinline)
js.ApplyStatic(flags, encodeClassName(method.owner),
encodeMethodSym(method), arguments)(toIRType(method.tpe.resultType))
}
private def adaptPrimitive(value: js.Tree, to: jstpe.Type)(
implicit pos: Position): js.Tree = {
genConversion(value.tpe, to, value)
}
/* This method corresponds to the method of the same name in
* BCodeBodyBuilder of the JVM back-end. It ends up calling the method
* BCodeIdiomatic.emitT2T, whose logic we replicate here.
*/
private def genConversion(from: jstpe.Type, to: jstpe.Type, value: js.Tree)(
implicit pos: Position): js.Tree = {
import js.UnaryOp._
if (from == to || from == jstpe.NothingType) {
value
} else if (from == jstpe.BooleanType || to == jstpe.BooleanType) {
throw new AssertionError(s"Invalid genConversion from $from to $to")
} else {
def intValue = (from: @unchecked) match {
case jstpe.IntType => value
case jstpe.CharType => js.UnaryOp(CharToInt, value)
case jstpe.ByteType => js.UnaryOp(ByteToInt, value)
case jstpe.ShortType => js.UnaryOp(ShortToInt, value)
case jstpe.LongType => js.UnaryOp(LongToInt, value)
case jstpe.FloatType => js.UnaryOp(DoubleToInt, js.UnaryOp(FloatToDouble, value))
case jstpe.DoubleType => js.UnaryOp(DoubleToInt, value)
}
def doubleValue = from match {
case jstpe.DoubleType => value
case jstpe.FloatType => js.UnaryOp(FloatToDouble, value)
case jstpe.LongType => js.UnaryOp(LongToDouble, value)
case _ => js.UnaryOp(IntToDouble, intValue)
}
(to: @unchecked) match {
case jstpe.CharType =>
js.UnaryOp(IntToChar, intValue)
case jstpe.ByteType =>
js.UnaryOp(IntToByte, intValue)
case jstpe.ShortType =>
js.UnaryOp(IntToShort, intValue)
case jstpe.IntType =>
intValue
case jstpe.LongType =>
from match {
case jstpe.FloatType | jstpe.DoubleType =>
js.UnaryOp(DoubleToLong, doubleValue)
case _ =>
js.UnaryOp(IntToLong, intValue)
}
case jstpe.FloatType =>
if (from == jstpe.LongType)
js.UnaryOp(js.UnaryOp.LongToFloat, value)
else
js.UnaryOp(js.UnaryOp.DoubleToFloat, doubleValue)
case jstpe.DoubleType =>
doubleValue
}
}
}
/** Gen JS code for an isInstanceOf test (for reference types only) */
def genIsInstanceOf(value: js.Tree, to: Type)(
implicit pos: Position): js.Tree = {
val sym = to.typeSymbol
if (sym == ObjectClass) {
js.BinaryOp(js.BinaryOp.!==, value, js.Null())
} else if (isJSType(sym)) {
if (sym.isTrait) {
reporter.error(pos,
s"isInstanceOf[${sym.fullName}] not supported because it is a JS trait")
js.BooleanLiteral(true)
} else {
js.AsInstanceOf(
js.JSBinaryOp(js.JSBinaryOp.instanceof, value, genPrimitiveJSClass(sym)),
jstpe.BooleanType)
}
} else {
// The Scala type system prevents x.isInstanceOf[Null] and ...[Nothing]
assert(sym != NullClass && sym != NothingClass,
s"Found a .isInstanceOf[$sym] at $pos")
js.IsInstanceOf(value, toIRType(to).toNonNullable)
}
}
/** Gen JS code for an asInstanceOf cast (for reference types only) */
def genAsInstanceOf(value: js.Tree, to: Type)(
implicit pos: Position): js.Tree = {
def default: js.Tree =
js.AsInstanceOf(value, toIRType(to))
val sym = to.typeSymbol
if (sym == ObjectClass || isJSType(sym)) {
/* asInstanceOf[Object] always succeeds, and
* asInstanceOf to a JS type is completely erased.
*/
value
} else if (sym == NullClass) {
js.If(
js.BinaryOp(js.BinaryOp.===, value, js.Null()),
js.Null(),
genThrowClassCastException())(
jstpe.NullType)
} else if (sym == NothingClass) {
js.Block(value, genThrowClassCastException())
} else {
default
}
}
/** Gen JS code for a call to a Scala class constructor. */
def genNew(clazz: Symbol, ctor: Symbol, arguments: List[js.Tree])(
implicit pos: Position): js.Tree = {
assert(!isJSFunctionDef(clazz),
s"Trying to instantiate a JS function def $clazz")
genNew(encodeClassName(clazz), ctor, arguments)
}
/** Gen JS code for a call to a Scala class constructor. */
def genNew(className: ClassName, ctor: Symbol, arguments: List[js.Tree])(
implicit pos: Position): js.Tree = {
js.New(className, encodeMethodSym(ctor), arguments)
}
/** Gen JS code for a call to a constructor of a hijacked class.
* Reroute them to the `new` method with the same signature in the
* companion object.
*/
private def genNewHijackedClass(clazz: Symbol, ctor: Symbol,
args: List[js.Tree])(implicit pos: Position): js.Tree = {
val flags = js.ApplyFlags.empty
val className = encodeClassName(clazz)
val initName = encodeMethodSym(ctor).name
val newName = MethodName(newSimpleMethodName, initName.paramTypeRefs,
jstpe.ClassRef(className))
val newMethodIdent = js.MethodIdent(newName)
js.ApplyStatic(flags, className, newMethodIdent, args)(
jstpe.ClassType(className, nullable = true))
}
/** Gen JS code for creating a new Array: new Array[T](length)
* For multidimensional arrays (dimensions > 1), the arguments can
* specify up to `dimensions` lengths for the first dimensions of the
* array.
*/
def genNewArray(arrayTypeRef: jstpe.ArrayTypeRef, arguments: List[js.Tree])(
implicit pos: Position): js.Tree = {
assert(arguments.size == 1,
"expected exactly 1 argument for array constructor: found " +
s"${arguments.length} at $pos")
js.NewArray(arrayTypeRef, arguments.head)
}
/** Gen JS code for an array literal. */
def genArrayValue(tree: ArrayValue): js.Tree = {
val ArrayValue(tpt @ TypeTree(), elems) = tree
genArrayValue(tree, elems)
}
/** Gen JS code for an array literal, in the context of `tree` (its `tpe`
* and `pos`) but with the elements `elems`.
*/
def genArrayValue(tree: Tree, elems: List[Tree]): js.Tree = {
implicit val pos = tree.pos
val arrayTypeRef = toTypeRef(tree.tpe).asInstanceOf[jstpe.ArrayTypeRef]
js.ArrayValue(arrayTypeRef, elems.map(genExpr))
}
/** Gen JS code for a Match, i.e., a switch-able pattern match.
*
* In most cases, this straightforwardly translates to a Match in the IR,
* which will eventually become a `switch` in JavaScript.
*
* However, sometimes there is a guard in here, despite the fact that
* matches cannot have guards (in the JVM nor in the IR). The JVM backend
* emits a jump to the default clause when a guard is not fulfilled. We
* cannot do that, since we do not have arbitrary jumps. We therefore use
* a funny encoding with two nested `Labeled` blocks. For example,
* {{{
* x match {
* case 1 if y > 0 => a
* case 2 => b
* case _ => c
* }
* }}}
* arrives at the back-end as
* {{{
* x match {
* case 1 =>
* if (y > 0)
* a
* else
* default()
* case 2 =>
* b
* case _ =>
* default() {
* c
* }
* }
* }}}
* which we then translate into the following IR:
* {{{
* matchResult[I]: {
* default[V]: {
* x match {
* case 1 =>
* return(matchResult) if (y > 0)
* a
* else
* return(default) (void 0)
* case 2 =>
* return(matchResult) b
* case _ =>
* ()
* }
* }
* c
* }
* }}}
*/
def genMatch(tree: Tree, isStat: Boolean): js.Tree = {
implicit val pos = tree.pos
val Match(selector, cases) = tree
/* Although GenBCode adapts the scrutinee and the cases to `int`, only
* true `int`s can reach the back-end, as asserted by the String-switch
* transformation in `cleanup`. Therefore, we do not adapt, preserving
* the `string`s and `null`s that come out of the pattern matching in
* Scala 2.13.2+.
*/
val genSelector = genExpr(selector)
val resultType =
if (isStat) jstpe.NoType
else toIRType(tree.tpe)
val defaultLabelSym = cases.collectFirst {
case CaseDef(Ident(nme.WILDCARD), EmptyTree,
body @ LabelDef(_, Nil, rhs)) if hasSynthCaseSymbol(body) =>
body.symbol
}.getOrElse(NoSymbol)
var clauses: List[(List[js.MatchableLiteral], js.Tree)] = Nil
var optElseClause: Option[js.Tree] = None
var optElseClauseLabel: Option[js.LabelIdent] = None
def genJumpToElseClause(implicit pos: ir.Position): js.Tree = {
if (optElseClauseLabel.isEmpty)
optElseClauseLabel = Some(freshLabelIdent("default"))
js.Return(js.Undefined(), optElseClauseLabel.get)
}
for (caze @ CaseDef(pat, guard, body) <- cases) {
assert(guard == EmptyTree, s"found a case guard at ${caze.pos}")
def genBody(body: Tree): js.Tree = body match {
case app @ Apply(_, Nil) if app.symbol == defaultLabelSym =>
genJumpToElseClause
case Block(List(app @ Apply(_, Nil)), _) if app.symbol == defaultLabelSym =>
genJumpToElseClause
case If(cond, thenp, elsep) =>
js.If(genExpr(cond), genBody(thenp), genBody(elsep))(
resultType)(body.pos)
/* For #1955. If we receive a tree with the shape
* if (cond) {
* thenp
* } else {
* elsep
* }
* scala.runtime.BoxedUnit.UNIT
* we rewrite it as
* if (cond) {
* thenp
* scala.runtime.BoxedUnit.UNIT
* } else {
* elsep
* scala.runtime.BoxedUnit.UNIT
* }
* so that it fits the shape of if/elses we can deal with.
*/
case Block(List(If(cond, thenp, elsep)), s: Select)
if s.symbol == definitions.BoxedUnit_UNIT =>
val newThenp = Block(thenp, s).setType(s.tpe).setPos(thenp.pos)
val newElsep = Block(elsep, s).setType(s.tpe).setPos(elsep.pos)
js.If(genExpr(cond), genBody(newThenp), genBody(newElsep))(
resultType)(body.pos)
case _ =>
genStatOrExpr(body, isStat)
}
def invalidCase(tree: Tree): Nothing =
abort(s"Invalid case in alternative in switch-like pattern match: $tree at: ${tree.pos}")
def genMatchableLiteral(tree: Literal): js.MatchableLiteral = {
genExpr(tree) match {
case matchableLiteral: js.MatchableLiteral => matchableLiteral
case otherExpr => invalidCase(tree)
}
}
pat match {
case lit: Literal =>
clauses = (List(genMatchableLiteral(lit)), genBody(body)) :: clauses
case Ident(nme.WILDCARD) =>
optElseClause = Some(body match {
case LabelDef(_, Nil, rhs) if hasSynthCaseSymbol(body) =>
genBody(rhs)
case _ =>
genBody(body)
})
case Alternative(alts) =>
val genAlts = {
alts map {
case lit: Literal => genMatchableLiteral(lit)
case _ => invalidCase(tree)
}
}
clauses = (genAlts, genBody(body)) :: clauses
case _ =>
invalidCase(tree)
}
}
val elseClause = optElseClause.getOrElse(
throw new AssertionError("No elseClause in pattern match"))
/* Builds a `js.Match`, but simplifies it to a `js.If` if there is only
* one case with one alternative, and to a `js.Block` if there is no case
* at all. This happens in practice in the standard library. Having no
* case is a typical product of `match`es that are full of
* `case n if ... =>`, which are used instead of `if` chains for
* convenience and/or readability.
*/
def buildMatch(cases: List[(List[js.MatchableLiteral], js.Tree)],
default: js.Tree, tpe: jstpe.Type): js.Tree = {
def isInt(tree: js.Tree): Boolean = tree.tpe == jstpe.IntType
cases match {
case Nil =>
/* Completely remove the Match. Preserve the side-effects of
* `genSelector`.
*/
js.Block(exprToStat(genSelector), default)
case (uniqueAlt :: Nil, caseRhs) :: Nil =>
/* Simplify the `match` as an `if`, so that the optimizer has less
* work to do, and we emit less code at the end of the day.
* Use `Int_==` instead of `===` if possible, since it is a common
* case.
*/
val op =
if (isInt(genSelector) && isInt(uniqueAlt)) js.BinaryOp.Int_==
else js.BinaryOp.===
js.If(js.BinaryOp(op, genSelector, uniqueAlt), caseRhs, default)(tpe)
case _ =>
// We have more than one case: use a js.Match
js.Match(genSelector, cases, default)(tpe)
}
}
optElseClauseLabel.fold[js.Tree] {
buildMatch(clauses.reverse, elseClause, resultType)
} { elseClauseLabel =>
val matchResultLabel = freshLabelIdent("matchResult")
val patchedClauses = for ((alts, body) <- clauses) yield {
implicit val pos = body.pos
val newBody =
if (isStat) js.Block(body, js.Return(js.Undefined(), matchResultLabel))
else js.Return(body, matchResultLabel)
(alts, newBody)
}
js.Labeled(matchResultLabel, resultType, js.Block(List(
js.Labeled(elseClauseLabel, jstpe.NoType, {
buildMatch(patchedClauses.reverse, js.Skip(), jstpe.NoType)
}),
elseClause
)))
}
}
/** Flatten nested Blocks that can be flattened without compromising the
* identification of pattern matches.
*/
private def flatStats(stats: List[Tree]): Iterator[Tree] = {
/* #4581 Never decompose a Block with LabelDef's, as they need to
* be processed by genBlockWithCaseLabelDefs.
*/
stats.iterator.flatMap {
case Block(stats, expr) if !stats.exists(isCaseLabelDef(_)) =>
stats.iterator ++ Iterator.single(expr)
case tree =>
Iterator.single(tree)
}
}
/** Predicate satisfied by LabelDefs produced by the pattern matcher,
* except matchEnd's.
*/
private def isCaseLabelDef(tree: Tree): Boolean = {
tree.isInstanceOf[LabelDef] && hasSynthCaseSymbol(tree) &&
!tree.symbol.name.startsWith("matchEnd")
}
/** Predicate satisfied by matchEnd LabelDefs produced by the pattern
* matcher.
*/
private def isMatchEndLabelDef(tree: LabelDef): Boolean =
hasSynthCaseSymbol(tree) && tree.symbol.name.startsWith("matchEnd")
private def genBlock(tree: Block, isStat: Boolean): js.Tree = {
implicit val pos = tree.pos
val Block(stats, expr) = tree
val genStatsAndExpr = if (!stats.exists(isCaseLabelDef(_))) {
// #4684 Collapse { ; BoxedUnit } to
val genStatsAndExpr0 = stats.map(genStat(_)) :+ genStatOrExpr(expr, isStat)
genStatsAndExpr0 match {
case (undefParam @ js.Transient(UndefinedParam)) :: js.Undefined() :: Nil =>
undefParam :: Nil
case _ =>
genStatsAndExpr0
}
} else {
genBlockWithCaseLabelDefs(stats :+ expr, isStat)
}
/* A bit of dead code elimination: we drop all statements and
* expressions after the first statement of type `NothingType`.
* This helps other optimizations.
*/
val (nonNothing, rest) = genStatsAndExpr.span(_.tpe != jstpe.NothingType)
if (rest.isEmpty || rest.tail.isEmpty)
js.Block(genStatsAndExpr)
else
js.Block(nonNothing, rest.head)
}
private def genBlockWithCaseLabelDefs(trees: List[Tree], isStat: Boolean)(
implicit pos: Position): List[js.Tree] = {
val (prologue, casesAndRest) = trees.span(!isCaseLabelDef(_))
if (casesAndRest.isEmpty) {
if (prologue.isEmpty) Nil
else if (isStat) prologue.map(genStat(_))
else prologue.init.map(genStat(_)) :+ genExpr(prologue.last)
} else {
val genPrologue = prologue.map(genStat(_))
val (cases0, rest) = casesAndRest.span(isCaseLabelDef(_))
val cases = cases0.asInstanceOf[List[LabelDef]]
val genCasesAndRest = rest match {
case (matchEnd: LabelDef) :: more if isMatchEndLabelDef(matchEnd) =>
val translatedMatch = genTranslatedMatch(cases, matchEnd)
translatedMatch :: genBlockWithCaseLabelDefs(more, isStat)
// Sometimes the pattern matcher casts its final result
case Apply(TypeApply(Select(matchEnd: LabelDef, nme.asInstanceOf_Ob),
List(targ)), Nil) :: more
if isMatchEndLabelDef(matchEnd) =>
val translatedMatch = genTranslatedMatch(cases, matchEnd)
genIsAsInstanceOf(translatedMatch, matchEnd.tpe, targ.tpe,
cast = true) :: genBlockWithCaseLabelDefs(more, isStat)
// Peculiar shape generated by `return x match {...}` - #2928
case Return(matchEnd: LabelDef) :: more if isMatchEndLabelDef(matchEnd) =>
val translatedMatch = genTranslatedMatch(cases, matchEnd)
val genMore = genBlockWithCaseLabelDefs(more, isStat)
val label = getEnclosingReturnLabel()
if (translatedMatch.tpe == jstpe.NoType) {
// Could not actually reproduce this, but better be safe than sorry
translatedMatch :: js.Return(js.Undefined(), label) :: genMore
} else {
js.Return(translatedMatch, label) :: genMore
}
// Otherwise, there is no matchEnd, only consecutive cases
case Nil =>
genTranslatedCases(cases, isStat)
case _ =>
genTranslatedCases(cases, isStat = false) ::: genBlockWithCaseLabelDefs(rest, isStat)
}
genPrologue ::: genCasesAndRest
}
}
/** Gen JS code for a translated match.
*
* A translated match consists of consecutive `case` LabelDefs directly
* followed by a `matchEnd` LabelDef.
*/
private def genTranslatedMatch(cases: List[LabelDef], matchEnd: LabelDef)(
implicit pos: Position): js.Tree = {
genMatchEnd(matchEnd) {
genTranslatedCases(cases, isStat = true)
}
}
/** Gen JS code for the cases of a patmat-transformed match.
*
* This implementation relies heavily on the patterns of trees emitted
* by the pattern match phase, including its variants across versions of
* scalac that we support.
*
* The trees output by the pattern matcher are assumed to follow these
* rules:
*
* - Each case LabelDef (in `cases`) must not take any argument.
* - Jumps to case label-defs are restricted to jumping to the very next
* case.
*
* There is an optimization to avoid generating jumps that are in tail
* position of a case, if they are in positions denoted by in:
* {{{
* ::=
* If(_, , )
* | Block(_, )
* |
* | _
* }}}
* Since all but the last case (which cannot have jumps) are in statement
* position, those jumps in tail position can be replaced by `skip`.
*/
private def genTranslatedCases(cases: List[LabelDef], isStat: Boolean)(
implicit pos: Position): List[js.Tree] = {
assert(!cases.isEmpty,
s"genTranslatedCases called with no cases at $pos")
val translatedCasesInit = for {
(caseLabelDef, nextCaseSym) <- cases.zip(cases.tail.map(_.symbol))
} yield {
implicit val pos = caseLabelDef.pos
assert(caseLabelDef.params.isEmpty,
s"found case LabelDef with parameters at $pos")
val info = new EnclosingLabelDefInfoWithResultAsAssigns(Nil)
val translatedBody = withScopedVars(
enclosingLabelDefInfos :=
enclosingLabelDefInfos.get + (nextCaseSym -> info)
) {
/* Eager optimization of jumps in tail position, following the shapes
* produced by scala until 2.12.8. 2.12.9 introduced flat patmat
* translation, which does not trigger those optimizations.
* These shapes are also often produced by the async transformation.
*/
def genCaseBody(tree: Tree): js.Tree = {
implicit val pos = tree.pos
tree match {
case If(cond, thenp, elsep) =>
js.If(genExpr(cond), genCaseBody(thenp), genCaseBody(elsep))(
jstpe.NoType)
case Block(stats, Literal(Constant(()))) =>
// Generated a lot by the async transform
if (stats.isEmpty) js.Skip()
else js.Block(stats.init.map(genStat(_)), genCaseBody(stats.last))
case Block(stats, expr) =>
js.Block((stats map genStat) :+ genCaseBody(expr))
case Apply(_, Nil) if tree.symbol == nextCaseSym =>
js.Skip()
case _ =>
genStat(tree)
}
}
genCaseBody(caseLabelDef.rhs)
}
genOptimizedCaseLabeled(encodeLabelSym(nextCaseSym), translatedBody,
info.generatedReturns)
}
val translatedLastCase = genStatOrExpr(cases.last.rhs, isStat)
translatedCasesInit :+ translatedLastCase
}
/** Gen JS code for a match-end label def following match-cases.
*
* The preceding cases, which are allowed to jump to this match-end, must
* be generated in the `genTranslatedCases` callback. During the execution
* of this callback, the enclosing label infos contain appropriate info
* for this match-end.
*
* The translation of the match-end itself is straightforward, but is
* augmented with several optimizations to remove as many labeled blocks
* as possible.
*
* Most of the time, a match-end label has exactly one parameter. However,
* with the async transform, it can sometimes have no parameter instead.
* We handle those cases very differently.
*/
private def genMatchEnd(matchEnd: LabelDef)(
genTranslatedCases: => List[js.Tree])(
implicit pos: Position): js.Tree = {
val sym = matchEnd.symbol
val labelIdent = encodeLabelSym(sym)
val matchEndBody = matchEnd.rhs
def genMatchEndBody(): js.Tree = {
genStatOrExpr(matchEndBody,
isStat = toIRType(matchEndBody.tpe) == jstpe.NoType)
}
matchEnd.params match {
// Optimizable common case produced by the regular pattern matcher
case List(matchEndParam) =>
val info = new EnclosingLabelDefInfoWithResultAsReturn()
val translatedCases = withScopedVars(
enclosingLabelDefInfos := enclosingLabelDefInfos.get + (sym -> info)
) {
genTranslatedCases
}
val innerResultType = toIRType(matchEndParam.tpe)
val optimized = genOptimizedMatchEndLabeled(encodeLabelSym(sym),
innerResultType, translatedCases, info.generatedReturns)
matchEndBody match {
case Ident(_) if matchEndParam.symbol == matchEndBody.symbol =>
// matchEnd is identity.
optimized
case Literal(Constant(())) =>
// Unit return type.
optimized
case _ =>
// matchEnd does something.
js.Block(
js.VarDef(encodeLocalSym(matchEndParam.symbol),
originalNameOfLocal(matchEndParam.symbol),
innerResultType, mutable = false, optimized),
genMatchEndBody())
}
/* Other cases, notably the matchEnd's produced by the async transform,
* which have no parameters. The case of more than one parameter is
* hypothetical, but it costs virtually nothing to handle it here.
*/
case params =>
val paramSyms = params.map(_.symbol)
val varDefs = for (s <- paramSyms) yield {
implicit val pos = s.pos
val irType = toIRType(s.tpe)
js.VarDef(encodeLocalSym(s), originalNameOfLocal(s), irType,
mutable = true, jstpe.zeroOf(irType))
}
val info = new EnclosingLabelDefInfoWithResultAsAssigns(paramSyms)
val translatedCases = withScopedVars(
enclosingLabelDefInfos := enclosingLabelDefInfos.get + (sym -> info)
) {
genTranslatedCases
}
val optimized = genOptimizedMatchEndLabeled(labelIdent, jstpe.NoType,
translatedCases, info.generatedReturns)
js.Block(varDefs ::: optimized :: genMatchEndBody() :: Nil)
}
}
/** Gen JS code for a Labeled block from a pattern match'es case, while
* trying to optimize it away as a reversed If.
*
* If there was no `return` to the label at all, simply avoid generating
* the `Labeled` block altogether.
*
* If there was more than one `return`, do not optimize anything, as
* nothing could be good enough for `genOptimizedMatchEndLabeled` to do
* anything useful down the line.
*
* If however there was a single `return`, we try and get rid of it by
* identifying the following shape:
*
* {{{
* {
* ...stats1
* if (test)
* return(nextCaseSym)
* ...stats2
* }
* }}}
*
* which we then rewrite as
*
* {{{
* {
* ...stats1
* if (!test) {
* ...stats2
* }
* }
* }}}
*
* The above rewrite is important for `genOptimizedMatchEndLabeled` below
* to be able to do its job, which in turn is important for the IR
* optimizer to perform a better analysis.
*
* This whole thing is only necessary in Scala 2.12.9+, with the new flat
* patmat ASTs. In previous versions, `returnCount` is always 0 because
* all jumps to case labels are already caught upstream by `genCaseBody()`
* inside `genTranslatedMatch()`.
*/
private def genOptimizedCaseLabeled(label: js.LabelIdent,
translatedBody: js.Tree, returnCount: Int)(
implicit pos: Position): js.Tree = {
def default: js.Tree =
js.Labeled(label, jstpe.NoType, translatedBody)
if (returnCount == 0) {
translatedBody
} else if (returnCount > 1) {
default
} else {
translatedBody match {
case js.Block(stats) =>
val (stats1, testAndStats2) = stats.span {
case js.If(_, js.Return(js.Undefined(), `label`), js.Skip()) =>
false
case _ =>
true
}
testAndStats2 match {
case js.If(cond, _, _) :: stats2 =>
val notCond = cond match {
case js.UnaryOp(js.UnaryOp.Boolean_!, notCond) =>
notCond
case _ =>
js.UnaryOp(js.UnaryOp.Boolean_!, cond)
}
js.Block(stats1 :+ js.If(notCond, js.Block(stats2), js.Skip())(jstpe.NoType))
case _ :: _ =>
throw new AssertionError("unreachable code")
case Nil =>
default
}
case _ =>
default
}
}
}
/** Gen JS code for a Labeled block from a pattern match'es match-end,
* while trying to optimize it away as an If chain.
*
* It is important to do so at compile-time because, when successful, the
* resulting IR can be much better optimized by the optimizer.
*
* The optimizer also does something similar, but *after* it has processed
* the body of the Labeled block, at which point it has already lost any
* information about stack-allocated values.
*
* !!! There is quite of bit of code duplication with
* OptimizerCore.tryOptimizePatternMatch.
*/
def genOptimizedMatchEndLabeled(label: js.LabelIdent, tpe: jstpe.Type,
translatedCases: List[js.Tree], returnCount: Int)(
implicit pos: Position): js.Tree = {
def default: js.Tree =
js.Labeled(label, tpe, js.Block(translatedCases))
@tailrec
def createRevAlts(xs: List[js.Tree],
acc: List[(js.Tree, js.Tree)]): (List[(js.Tree, js.Tree)], js.Tree) = xs match {
case js.If(cond, body, js.Skip()) :: xr =>
createRevAlts(xr, (cond, body) :: acc)
case remaining =>
(acc, js.Block(remaining)(remaining.head.pos))
}
val (revAlts, elsep) = createRevAlts(translatedCases, Nil)
if (revAlts.size == returnCount - 1) {
def tryDropReturn(body: js.Tree): Option[js.Tree] = body match {
case js.Return(result, `label`) =>
Some(result)
case js.Block(prep :+ js.Return(result, `label`)) =>
Some(js.Block(prep :+ result)(body.pos))
case _ =>
None
}
@tailrec
def constructOptimized(revAlts: List[(js.Tree, js.Tree)],
elsep: js.Tree): js.Tree = {
revAlts match {
case (cond, body) :: revAltsRest =>
// cannot use flatMap due to tailrec
tryDropReturn(body) match {
case Some(newBody) =>
constructOptimized(revAltsRest,
js.If(cond, newBody, elsep)(tpe)(cond.pos))
case None =>
default
}
case Nil =>
elsep
}
}
tryDropReturn(elsep).fold(default)(constructOptimized(revAlts, _))
} else {
default
}
}
/** Gen JS code for a primitive method call */
private def genPrimitiveOp(tree: Apply, isStat: Boolean): js.Tree = {
import scalaPrimitives._
implicit val pos = tree.pos
val sym = tree.symbol
val Apply(fun @ Select(receiver, _), args) = tree
val code = scalaPrimitives.getPrimitive(sym, receiver.tpe)
if (isArithmeticOp(code) || isLogicalOp(code) || isComparisonOp(code))
genSimpleOp(tree, receiver :: args, code)
else if (code == scalaPrimitives.CONCAT)
genStringConcat(tree, receiver, args)
else if (code == HASH)
genScalaHash(tree, receiver)
else if (isArrayOp(code))
genArrayOp(tree, code)
else if (code == SYNCHRONIZED)
genSynchronized(receiver, args.head, isStat)
else if (isCoercion(code))
genCoercion(tree, receiver, code)
else if (jsPrimitives.isJavaScriptPrimitive(code))
genJSPrimitive(tree, args, code, isStat)
else
abort("Unknown primitive operation: " + sym.fullName + "(" +
fun.symbol.simpleName + ") " + " at: " + (tree.pos))
}
private def genPrimitiveOpForReflectiveCall(sym: Symbol, receiver: js.Tree,
args: List[js.Tree])(
implicit pos: Position): js.Tree = {
import scalaPrimitives._
if (!isPrimitive(sym)) {
abort(
"Trying to reflectively call a method of a primitive type that " +
"is not itself a primitive method: " + sym.fullName + " at " + pos)
}
val code = getPrimitive(sym)
if (isArithmeticOp(code) || isLogicalOp(code) || isComparisonOp(code)) {
genSimpleOp(sym.owner.tpe :: sym.tpe.paramTypes, sym.tpe.resultType,
receiver :: args, code)
} else if (code == CONCAT) {
js.BinaryOp(js.BinaryOp.String_+, receiver, args.head)
} else if (isCoercion(code)) {
adaptPrimitive(receiver, toIRType(sym.tpe.resultType))
} else {
abort(
"Unknown primitive operation for reflective call: " + sym.fullName +
" at " + pos)
}
}
/** Gen JS code for a simple operation (arithmetic, logical, or comparison) */
private def genSimpleOp(tree: Apply, args: List[Tree], code: Int): js.Tree = {
implicit val pos = tree.pos
genSimpleOp(args.map(_.tpe), tree.tpe, args.map(genExpr), code)
}
/** Gen JS code for a simple operation (arithmetic, logical, or comparison) */
private def genSimpleOp(argTpes: List[Type], resultTpe: Type,
sources: List[js.Tree], code: Int)(
implicit pos: Position): js.Tree = {
import scalaPrimitives._
sources match {
// Unary operation
case List(src_in) =>
val opType = toIRType(resultTpe)
val src = adaptPrimitive(src_in, opType)
(code match {
case POS =>
src
case NEG =>
(opType: @unchecked) match {
case jstpe.IntType =>
js.BinaryOp(js.BinaryOp.Int_-, js.IntLiteral(0), src)
case jstpe.LongType =>
js.BinaryOp(js.BinaryOp.Long_-, js.LongLiteral(0), src)
case jstpe.FloatType =>
js.BinaryOp(js.BinaryOp.Float_*, js.FloatLiteral(-1.0f), src)
case jstpe.DoubleType =>
js.BinaryOp(js.BinaryOp.Double_*, js.DoubleLiteral(-1.0), src)
}
case NOT =>
(opType: @unchecked) match {
case jstpe.IntType =>
js.BinaryOp(js.BinaryOp.Int_^, js.IntLiteral(-1), src)
case jstpe.LongType =>
js.BinaryOp(js.BinaryOp.Long_^, js.LongLiteral(-1), src)
}
case ZNOT =>
js.UnaryOp(js.UnaryOp.Boolean_!, src)
case _ =>
abort("Unknown unary operation code: " + code)
})
// Binary operation
case List(lsrc_in, rsrc_in) =>
import js.BinaryOp._
val isShift = isShiftOp(code)
val leftIRType = toIRType(argTpes(0))
val rightIRType = toIRType(argTpes(1))
val opType = {
if (isShift) {
if (leftIRType == jstpe.LongType) jstpe.LongType
else jstpe.IntType
} else {
(leftIRType, rightIRType) match {
case (jstpe.DoubleType, _) | (_, jstpe.DoubleType) =>
jstpe.DoubleType
case (jstpe.FloatType, _) | (_, jstpe.FloatType) =>
jstpe.FloatType
case (jstpe.LongType, _) | (_, jstpe.LongType) =>
jstpe.LongType
case (jstpe.IntType | jstpe.CharType | jstpe.ByteType | jstpe.ShortType, _) |
(_, jstpe.IntType | jstpe.CharType | jstpe.ByteType | jstpe.ShortType) =>
jstpe.IntType
case (jstpe.BooleanType, _) | (_, jstpe.BooleanType) =>
jstpe.BooleanType
case _ =>
jstpe.AnyType
}
}
}
val lsrc =
if (opType == jstpe.AnyType) lsrc_in
else adaptPrimitive(lsrc_in, opType)
val rsrc =
if (opType == jstpe.AnyType) rsrc_in
else adaptPrimitive(rsrc_in, if (isShift) jstpe.IntType else opType)
(opType: @unchecked) match {
case jstpe.IntType =>
val op = (code: @switch) match {
case ADD => Int_+
case SUB => Int_-
case MUL => Int_*
case DIV => Int_/
case MOD => Int_%
case OR => Int_|
case AND => Int_&
case XOR => Int_^
case LSL => Int_<<
case LSR => Int_>>>
case ASR => Int_>>
case EQ => Int_==
case NE => Int_!=
case LT => Int_<
case LE => Int_<=
case GT => Int_>
case GE => Int_>=
}
js.BinaryOp(op, lsrc, rsrc)
case jstpe.LongType =>
val op = (code: @switch) match {
case ADD => Long_+
case SUB => Long_-
case MUL => Long_*
case DIV => Long_/
case MOD => Long_%
case OR => Long_|
case XOR => Long_^
case AND => Long_&
case LSL => Long_<<
case LSR => Long_>>>
case ASR => Long_>>
case EQ => Long_==
case NE => Long_!=
case LT => Long_<
case LE => Long_<=
case GT => Long_>
case GE => Long_>=
}
js.BinaryOp(op, lsrc, rsrc)
case jstpe.FloatType =>
def withFloats(op: Int): js.Tree =
js.BinaryOp(op, lsrc, rsrc)
def toDouble(value: js.Tree): js.Tree =
js.UnaryOp(js.UnaryOp.FloatToDouble, value)
def withDoubles(op: Int): js.Tree =
js.BinaryOp(op, toDouble(lsrc), toDouble(rsrc))
(code: @switch) match {
case ADD => withFloats(Float_+)
case SUB => withFloats(Float_-)
case MUL => withFloats(Float_*)
case DIV => withFloats(Float_/)
case MOD => withFloats(Float_%)
case EQ => withDoubles(Double_==)
case NE => withDoubles(Double_!=)
case LT => withDoubles(Double_<)
case LE => withDoubles(Double_<=)
case GT => withDoubles(Double_>)
case GE => withDoubles(Double_>=)
}
case jstpe.DoubleType =>
val op = (code: @switch) match {
case ADD => Double_+
case SUB => Double_-
case MUL => Double_*
case DIV => Double_/
case MOD => Double_%
case EQ => Double_==
case NE => Double_!=
case LT => Double_<
case LE => Double_<=
case GT => Double_>
case GE => Double_>=
}
js.BinaryOp(op, lsrc, rsrc)
case jstpe.BooleanType =>
(code: @switch) match {
case OR =>
js.BinaryOp(Boolean_|, lsrc, rsrc)
case AND =>
js.BinaryOp(Boolean_&, lsrc, rsrc)
case EQ =>
js.BinaryOp(Boolean_==, lsrc, rsrc)
case XOR | NE =>
js.BinaryOp(Boolean_!=, lsrc, rsrc)
case ZOR =>
js.If(lsrc, js.BooleanLiteral(true), rsrc)(jstpe.BooleanType)
case ZAND =>
js.If(lsrc, rsrc, js.BooleanLiteral(false))(jstpe.BooleanType)
}
case jstpe.AnyType =>
def genAnyEquality(eqeq: Boolean, not: Boolean): js.Tree = {
// Arrays, Null, Nothing never have a custom equals() method
def canHaveCustomEquals(tpe: jstpe.Type): Boolean = tpe match {
case jstpe.AnyType | _:jstpe.ClassType => true
case _ => false
}
if (eqeq &&
// don't call equals if we have a literal null at either side
!lsrc.isInstanceOf[js.Null] &&
!rsrc.isInstanceOf[js.Null] &&
canHaveCustomEquals(leftIRType)) {
val body = genEqEqPrimitive(argTpes(0), argTpes(1), lsrc, rsrc)
if (not) js.UnaryOp(js.UnaryOp.Boolean_!, body) else body
} else {
js.BinaryOp(
if (not) js.BinaryOp.!== else js.BinaryOp.===,
lsrc, rsrc)
}
}
(code: @switch) match {
case EQ => genAnyEquality(eqeq = true, not = false)
case NE => genAnyEquality(eqeq = true, not = true)
case ID => genAnyEquality(eqeq = false, not = false)
case NI => genAnyEquality(eqeq = false, not = true)
}
}
case _ =>
abort("Too many arguments for primitive function at " + pos)
}
}
/** Gen JS code for a call to Any.== */
def genEqEqPrimitive(ltpe: Type, rtpe: Type, lsrc: js.Tree, rsrc: js.Tree)(
implicit pos: Position): js.Tree = {
/* True if the equality comparison is between values that require the
* use of the rich equality comparator
* (scala.runtime.BoxesRunTime.equals).
* This is the case when either side of the comparison might have a
* run-time type subtype of java.lang.Number or java.lang.Character,
* **which includes when either is a JS type**.
*
* When it is statically known that both sides are equal and subtypes of
* Number or Character, not using the rich equality is possible (their
* own equals method will do ok), except for java.lang.Float and
* java.lang.Double: their `equals` have different behavior around `NaN`
* and `-0.0`, see Javadoc (scala-dev#329, #2799).
*/
val mustUseAnyComparator: Boolean = {
val lsym = ltpe.typeSymbol
val rsym = rtpe.typeSymbol
isJSType(lsym) || isJSType(rsym) || {
isMaybeBoxed(lsym) && isMaybeBoxed(rsym) && {
val areSameFinals =
ltpe.isFinalType && rtpe.isFinalType && lsym == rsym
!areSameFinals || (lsym == BoxedFloatClass || lsym == BoxedDoubleClass)
}
}
}
if (mustUseAnyComparator) {
val equalsMethod: Symbol = {
// scalastyle:off line.size.limit
if (ltpe <:< BoxedNumberClass.tpe) {
if (rtpe <:< BoxedNumberClass.tpe) platform.externalEqualsNumNum
else if (rtpe <:< BoxedCharacterClass.tpe) platform.externalEqualsNumObject // will be externalEqualsNumChar in 2.12, SI-9030
else platform.externalEqualsNumObject
} else platform.externalEquals
// scalastyle:on line.size.limit
}
if (BoxesRunTimeClass.isJavaDefined)
genApplyStatic(equalsMethod, List(lsrc, rsrc))
else // this happens when in the same compilation run as BoxesRunTime
genApplyMethod(genLoadModule(BoxesRunTimeClass), equalsMethod, List(lsrc, rsrc))
} else {
// if (lsrc eq null) rsrc eq null else lsrc.equals(rsrc)
if (isStringType(ltpe)) {
// String.equals(that) === (this eq that)
js.BinaryOp(js.BinaryOp.===, lsrc, rsrc)
} else {
/* This requires to evaluate both operands in local values first.
* The optimizer will eliminate them if possible.
*/
val ltemp = js.VarDef(freshLocalIdent(), NoOriginalName, lsrc.tpe,
mutable = false, lsrc)
val rtemp = js.VarDef(freshLocalIdent(), NoOriginalName, rsrc.tpe,
mutable = false, rsrc)
js.Block(
ltemp,
rtemp,
js.If(js.BinaryOp(js.BinaryOp.===, ltemp.ref, js.Null()),
js.BinaryOp(js.BinaryOp.===, rtemp.ref, js.Null()),
genApplyMethod(ltemp.ref, Object_equals, List(rtemp.ref)))(
jstpe.BooleanType))
}
}
}
/** Gen JS code for string concatenation.
*/
private def genStringConcat(tree: Apply, receiver: Tree,
args: List[Tree]): js.Tree = {
implicit val pos = tree.pos
/* Primitive number types such as scala.Int have a
* def +(s: String): String
* method, which is why we have to box the lhs sometimes.
* Otherwise, both lhs and rhs are already reference types (Any of String)
* so boxing is not necessary (in particular, rhs is never a primitive).
*/
assert(!isPrimitiveValueType(receiver.tpe) || isStringType(args.head.tpe),
s"unexpected signature for string-concat call at $pos")
assert(!isPrimitiveValueType(args.head.tpe),
s"unexpected signature for string-concat call at $pos")
val rhs = genExpr(args.head)
val lhs = {
val lhs0 = genExpr(receiver)
// Box the receiver if it is a primitive value
if (!isPrimitiveValueType(receiver.tpe)) lhs0
else makePrimitiveBox(lhs0, receiver.tpe)
}
js.BinaryOp(js.BinaryOp.String_+, lhs, rhs)
}
/** Gen JS code for a call to `Any.##`.
*
* This method unconditionally generates a call to `Statics.anyHash`.
* On the JVM, `anyHash` is only called as of 2.12.0-M5. Previous versions
* emitted a call to `ScalaRunTime.hash`. However, since our `anyHash`
* is always consistent with `ScalaRunTime.hash`, we always use it.
*/
private def genScalaHash(tree: Apply, receiver: Tree): js.Tree = {
implicit val pos = tree.pos
val instance = genLoadModule(RuntimeStaticsModule)
val arguments = List(genExpr(receiver))
val sym = getMember(RuntimeStaticsModule, jsnme.anyHash)
genApplyMethod(instance, sym, arguments)
}
/** Gen JS code for an array operation (get, set or length) */
private def genArrayOp(tree: Tree, code: Int): js.Tree = {
import scalaPrimitives._
implicit val pos = tree.pos
val Apply(fun @ Select(arrayObj, _), args) = tree
val arrayValue = genExpr(arrayObj)
val arguments = args map genExpr
def genSelect(elemType: Type) =
js.ArraySelect(arrayValue, arguments(0))(toIRType(elemType))
if (scalaPrimitives.isArrayGet(code)) {
// get an item of the array
assert(args.length == 1,
s"Array get requires 1 argument, found ${args.length} in $tree")
genSelect(fun.tpe.resultType)
} else if (scalaPrimitives.isArraySet(code)) {
// set an item of the array
assert(args.length == 2,
s"Array set requires 2 arguments, found ${args.length} in $tree")
js.Assign(genSelect(fun.tpe.paramTypes(1)), arguments(1))
} else {
// length of the array
js.ArrayLength(arrayValue)
}
}
/** Gen JS code for a call to AnyRef.synchronized */
private def genSynchronized(receiver: Tree, arg: Tree, isStat: Boolean)(
implicit pos: Position): js.Tree = {
/* JavaScript is single-threaded, so we can drop the
* synchronization altogether.
*/
val newReceiver = genExpr(receiver)
val newArg = genStatOrExpr(arg, isStat)
newReceiver match {
case js.This() =>
// common case for which there is no side-effect nor NPE
newArg
case _ =>
js.Block(
js.UnaryOp(js.UnaryOp.CheckNotNull, newReceiver),
newArg)
}
}
/** Gen JS code for a coercion */
private def genCoercion(tree: Apply, receiver: Tree, code: Int): js.Tree = {
implicit val pos = tree.pos
val source = genExpr(receiver)
val resultType = toIRType(tree.tpe)
adaptPrimitive(source, resultType)
}
/** Gen JS code for an ApplyDynamic
* ApplyDynamic nodes appear as the result of calls to methods of a
* structural type.
*
* Most unfortunately, earlier phases of the compiler assume too much
* about the backend, namely, they believe arguments and the result must
* be boxed, and do the boxing themselves. This decision should be left
* to the backend, but it's not, so we have to undo these boxes.
* Note that this applies to parameter types only. The return type is boxed
* anyway since we do not know it's exact type.
*
* This then generates a call to the reflective call proxy for the given
* arguments.
*/
private def genApplyDynamic(tree: ApplyDynamic): js.Tree = {
implicit val pos = tree.pos
val sym = tree.symbol
val name = sym.name
val params = sym.tpe.params
/* Is this a primitive method introduced in AnyRef?
* The concerned methods are `eq`, `ne` and `synchronized`.
*
* If it is, it can be defined in a custom value class. Calling it
* reflectively works on the JVM in that case. However, it does not work
* if the reflective call should in fact resolve to the method in
* `AnyRef` (it causes a `NoSuchMethodError`). We maintain bug
* compatibility for these methods: they work if redefined in a custom
* AnyVal, and fail at run-time (with a `TypeError`) otherwise.
*/
val isAnyRefPrimitive = {
(name == nme.eq || name == nme.ne || name == nme.synchronized_) &&
params.size == 1 && params.head.tpe.typeSymbol == ObjectClass
}
/** check if the method we are invoking conforms to a method on
* scala.Array. If this is the case, we check that case specially at
* runtime to avoid having reflective call proxies on scala.Array.
* (Also, note that the element type of Array#update is not erased and
* therefore the method name mangling would turn out wrong)
*
* Note that we cannot check if the expected return type is correct,
* since this type information is already erased.
*/
def isArrayLikeOp = name match {
case nme.update =>
params.size == 2 && params.head.tpe.typeSymbol == IntClass
case nme.apply =>
params.size == 1 && params.head.tpe.typeSymbol == IntClass
case nme.length =>
params.size == 0
case nme.clone_ =>
params.size == 0
case _ =>
false
}
/**
* Tests whether one of our reflective "boxes" for primitive types
* implements the particular method. If this is the case
* (result != NoSymbol), we generate a runtime instance check if we are
* dealing with the appropriate primitive type.
*/
def matchingSymIn(clazz: Symbol) = clazz.tpe.member(name).suchThat { s =>
val sParams = s.tpe.params
!s.isBridge &&
params.size == sParams.size &&
(params zip sParams).forall { case (s1,s2) =>
s1.tpe =:= s2.tpe
}
}
val ApplyDynamic(receiver, args) = tree
val receiverType = toIRType(receiver.tpe)
val callTrgIdent = freshLocalIdent()
val callTrgVarDef = js.VarDef(callTrgIdent, NoOriginalName, receiverType,
mutable = false, genExpr(receiver))
val callTrg = js.VarRef(callTrgIdent)(receiverType)
val arguments = args zip sym.tpe.params map { case (arg, param) =>
/* No need for enteringPosterasure, because value classes are not
* supported as parameters of methods in structural types.
* We could do it for safety and future-proofing anyway, except that
* I am weary of calling enteringPosterasure for a reflective method
* symbol.
*
* Note also that this will typically unbox a primitive value that
* has just been boxed, or will .asInstanceOf[T] an expression which
* is already of type T. But the optimizer will get rid of that, and
* reflective calls are not numerous, so we don't complicate the
* compiler to eliminate them early.
*/
fromAny(genExpr(arg), param.tpe)
}
var callStatement: js.Tree = js.Apply(js.ApplyFlags.empty, callTrg,
encodeMethodSym(sym, reflProxy = true), arguments)(jstpe.AnyType)
if (!isAnyRefPrimitive) {
def boxIfNeeded(call: js.Tree, returnType: Type): js.Tree = {
if (isPrimitiveValueType(returnType))
makePrimitiveBox(call, returnType)
else
call
}
if (isArrayLikeOp) {
def genRTCall(method: Symbol, args: js.Tree*) =
genApplyMethod(genLoadModule(ScalaRunTimeModule),
method, args.toList)
val isArrayTree =
genRTCall(ScalaRunTime_isArray, callTrg, js.IntLiteral(1))
callStatement = js.If(isArrayTree, {
name match {
case nme.update =>
js.Block(
genRTCall(currentRun.runDefinitions.arrayUpdateMethod,
callTrg, arguments(0), arguments(1)),
js.Undefined()) // Boxed Unit
case nme.apply =>
genRTCall(currentRun.runDefinitions.arrayApplyMethod, callTrg,
arguments(0))
case nme.length =>
genRTCall(currentRun.runDefinitions.arrayLengthMethod, callTrg)
case nme.clone_ =>
genApplyMethod(callTrg, Object_clone, arguments)
}
}, {
callStatement
})(jstpe.AnyType)
}
/* Add an explicit type test for a hijacked class with a call to a
* hijacked method, if applicable (i.e., if there is a matching method
* in the given hijacked class). This is necessary because hijacked
* classes of the IR do not support reflective proxy calls.
*
* Returns true if this treatment was applicable.
*/
def addCallToHijackedMethodIfApplicable(hijackedClass: Symbol): Boolean = {
val hijackedMethod = matchingSymIn(hijackedClass)
val isApplicable =
hijackedMethod != NoSymbol && hijackedMethod.isPublic
if (isApplicable) {
val hijackedClassTpe = hijackedClass.tpe
callStatement = js.If(genIsInstanceOf(callTrg, hijackedClassTpe), {
boxIfNeeded(
genApplyMethod(genAsInstanceOf(callTrg, hijackedClassTpe),
hijackedMethod, arguments),
hijackedMethod.tpe.resultType)
}, { // else
callStatement
})(jstpe.AnyType)
}
isApplicable
}
// String is a hijacked class
addCallToHijackedMethodIfApplicable(StringClass)
/* For primitive types, we need to handle two cases. The method could
* either be defined in the boxed class of the primitive type (which is
* hijacked), or it could be defined in the primitive class itself.
* If the hijacked class treatment is not applicable, we also try the
* primitive treatment, in which case we directly generate the
* primitive operation.
*/
def addCallForPrimitive(primitiveClass: Symbol): Boolean = {
val boxedClass = definitions.boxedClass(primitiveClass)
if (addCallToHijackedMethodIfApplicable(boxedClass)) {
true
} else {
val methodInPrimClass = matchingSymIn(primitiveClass)
if (methodInPrimClass != NoSymbol && methodInPrimClass.isPublic) {
def isIntOrLong(tpe: jstpe.Type): Boolean = tpe match {
case jstpe.ByteType | jstpe.ShortType | jstpe.IntType | jstpe.LongType =>
true
case _ =>
false
}
val ignoreBecauseItMustBeAnInt = {
primitiveClass == DoubleClass &&
toIRType(methodInPrimClass.tpe.resultType) == jstpe.DoubleType &&
isIntOrLong(toIRType(sym.tpe.resultType))
}
if (ignoreBecauseItMustBeAnInt) {
// Fall through to the Int case that will come next
false
} else {
val boxedTpe = boxedClass.tpe
callStatement = js.If(genIsInstanceOf(callTrg, boxedTpe), {
val castCallTrg =
makePrimitiveUnbox(callTrg, primitiveClass.tpe)
val call = genPrimitiveOpForReflectiveCall(methodInPrimClass,
castCallTrg, arguments)
boxIfNeeded(call, methodInPrimClass.tpe.resultType)
}, { // else
callStatement
})(jstpe.AnyType)
true
}
} else {
false
}
}
}
addCallForPrimitive(BooleanClass)
addCallForPrimitive(LongClass)
addCallForPrimitive(CharClass)
/* For primitive numeric types that box as JS numbers, find the first
* one that matches. It will be able to handle the subsequent cases.
*/
Seq(DoubleClass, IntClass, FloatClass, ShortClass, ByteClass).find(
addCallForPrimitive)
}
js.Block(callTrgVarDef, callStatement)
}
/** Ensures that the value of the given tree is boxed when used as a method result value.
* @param expr Tree to be boxed if needed.
* @param sym Method symbol this is the result of.
*/
def ensureResultBoxed(expr: js.Tree, methodSym: Symbol)(
implicit pos: Position): js.Tree = {
val tpeEnteringPosterasure =
enteringPhase(currentRun.posterasurePhase)(methodSym.tpe.resultType)
ensureBoxed(expr, tpeEnteringPosterasure)
}
/** Ensures that the value of the given tree is boxed.
* @param expr Tree to be boxed if needed.
* @param tpeEnteringPosterasure The type of `expr` as it was entering
* the posterasure phase.
*/
def ensureBoxed(expr: js.Tree, tpeEnteringPosterasure: Type)(
implicit pos: Position): js.Tree = {
tpeEnteringPosterasure match {
case tpe if isPrimitiveValueType(tpe) =>
makePrimitiveBox(expr, tpe)
case tpe: ErasedValueType =>
val boxedClass = tpe.valueClazz
val ctor = boxedClass.primaryConstructor
genNew(boxedClass, ctor, List(expr))
case _ =>
expr
}
}
/** Extracts a value typed as Any to the given type after posterasure.
* @param expr Tree to be extracted.
* @param tpeEnteringPosterasure The type of `expr` as it was entering
* the posterasure phase.
*/
def fromAny(expr: js.Tree, tpeEnteringPosterasure: Type)(
implicit pos: Position): js.Tree = {
tpeEnteringPosterasure match {
case tpe if isPrimitiveValueType(tpe) =>
makePrimitiveUnbox(expr, tpe)
case tpe: ErasedValueType =>
val boxedClass = tpe.valueClazz
val unboxMethod = boxedClass.derivedValueClassUnbox
val content = genApplyMethod(
genAsInstanceOf(expr, tpe), unboxMethod, Nil)
if (unboxMethod.tpe.resultType <:< tpe.erasedUnderlying)
content
else
fromAny(content, tpe.erasedUnderlying)
case tpe =>
genAsInstanceOf(expr, tpe)
}
}
/** Gen a boxing operation (tpe is the primitive type) */
def makePrimitiveBox(expr: js.Tree, tpe: Type)(
implicit pos: Position): js.Tree = {
toIRType(tpe) match {
case jstpe.NoType => // for JS interop cases
js.Block(expr, js.Undefined())
case jstpe.BooleanType | jstpe.CharType | jstpe.ByteType |
jstpe.ShortType | jstpe.IntType | jstpe.LongType | jstpe.FloatType |
jstpe.DoubleType =>
expr // box is identity for all those primitive types
case _ =>
abort(s"makePrimitiveBox requires a primitive type, found $tpe at $pos")
}
}
/** Gen an unboxing operation (tpe is the primitive type) */
def makePrimitiveUnbox(expr: js.Tree, tpe: Type)(
implicit pos: Position): js.Tree = {
toIRType(tpe) match {
case jstpe.NoType => expr // for JS interop cases
case irTpe => js.AsInstanceOf(expr, irTpe)
}
}
/** Gen JS code for a Scala.js-specific primitive method */
private def genJSPrimitive(tree: Apply, args: List[Tree], code: Int,
isStat: Boolean): js.Tree = {
import jsPrimitives._
implicit val pos = tree.pos
def genArgs1: js.Tree = {
assert(args.size == 1,
s"Expected exactly 1 argument for JS primitive $code but got " +
s"${args.size} at $pos")
genExpr(args.head)
}
def genArgs2: (js.Tree, js.Tree) = {
assert(args.size == 2,
s"Expected exactly 2 arguments for JS primitive $code but got " +
s"${args.size} at $pos")
(genExpr(args.head), genExpr(args.tail.head))
}
def genArgsVarLength: List[js.TreeOrJSSpread] =
genPrimitiveJSArgs(tree.symbol, args)
def resolveReifiedJSClassSym(arg: Tree): Symbol = {
def fail(): Symbol = {
reporter.error(pos,
tree.symbol.nameString + " must be called with a constant " +
"classOf[T] representing a class extending js.Any " +
"(not a trait nor an object)")
NoSymbol
}
arg match {
case Literal(value) if value.tag == ClazzTag =>
val classSym = value.typeValue.typeSymbol
if (isJSType(classSym) && !classSym.isTrait && !classSym.isModuleClass)
classSym
else
fail()
case _ =>
fail()
}
}
(code: @switch) match {
case DYNNEW =>
// js.Dynamic.newInstance(clazz)(actualArgs: _*)
val (jsClass, actualArgs) = extractFirstArg(genArgsVarLength)
js.JSNew(jsClass, actualArgs)
case ARR_CREATE =>
// js.Array(elements: _*)
js.JSArrayConstr(genArgsVarLength)
case CONSTRUCTOROF =>
// runtime.constructorOf(clazz)
val classSym = resolveReifiedJSClassSym(args.head)
if (classSym == NoSymbol)
js.Undefined() // compile error emitted by resolveReifiedJSClassSym
else
genPrimitiveJSClass(classSym)
case CREATE_INNER_JS_CLASS | CREATE_LOCAL_JS_CLASS =>
// runtime.createInnerJSClass(clazz, superClass)
// runtime.createLocalJSClass(clazz, superClass, fakeNewInstances)
val classSym = resolveReifiedJSClassSym(args(0))
val superClassValue = genExpr(args(1))
if (classSym == NoSymbol) {
js.Undefined() // compile error emitted by resolveReifiedJSClassSym
} else {
val captureValues = {
if (code == CREATE_INNER_JS_CLASS) {
val outer = genThis()
List.fill(classSym.info.decls.count(_.isClassConstructor))(outer)
} else {
val ArrayValue(_, fakeNewInstances) = args(2)
fakeNewInstances.flatMap(genCaptureValuesFromFakeNewInstance(_))
}
}
js.CreateJSClass(encodeClassName(classSym),
superClassValue :: captureValues)
}
case WITH_CONTEXTUAL_JS_CLASS_VALUE =>
// withContextualJSClassValue(jsclass, inner)
val jsClassValue = genExpr(args(0))
withScopedVars(
contextualJSClassValue := Some(jsClassValue)
) {
genStatOrExpr(args(1), isStat)
}
case LINKING_INFO =>
// runtime.linkingInfo
js.JSLinkingInfo()
case IDENTITY_HASH_CODE =>
// runtime.identityHashCode(arg)
val arg = genArgs1
js.IdentityHashCode(arg)
case DEBUGGER =>
// js.special.debugger()
js.Debugger()
case UNITVAL =>
// BoxedUnit.UNIT, which is the boxed version of ()
js.Undefined()
case JS_NATIVE =>
// js.native
reporter.error(pos,
"js.native may only be used as stub implementation in facade types")
js.Undefined()
case TYPEOF =>
// js.typeOf(arg)
val arg = genArgs1
val typeofExpr = arg match {
case arg: js.JSGlobalRef => js.JSTypeOfGlobalRef(arg)
case _ => js.JSUnaryOp(js.JSUnaryOp.typeof, arg)
}
genAsInstanceOf(typeofExpr, StringClass.tpe)
case JS_NEW_TARGET =>
// js.new.target
val valid = currentMethodSym.isClassConstructor && isNonNativeJSClass(currentClassSym)
if (!valid) {
reporter.error(pos,
"Illegal use of js.`new`.target.\n" +
"It can only be used in the constructor of a JS class, " +
"as a statement or in the rhs of a val or var.\n" +
"It cannot be used inside a lambda or by-name parameter, nor in any other location.")
}
js.JSNewTarget()
case JS_IMPORT =>
// js.import(arg)
val arg = genArgs1
js.JSImportCall(arg)
case JS_IMPORT_META =>
// js.import.meta
js.JSImportMeta()
case DYNAMIC_IMPORT =>
assert(args.size == 1,
s"Expected exactly 1 argument for JS primitive $code but got " +
s"${args.size} at $pos")
args.head match {
case Block(stats, expr @ Apply(fun @ Select(New(tpt), _), args)) =>
/* stats is always empty if no other compiler plugin is present.
* However, code instrumentation (notably scoverage) might add
* statements here. If this is the case, the thunk anonymous class
* has already been created when the other plugin runs (i.e. the
* plugin ran after jsinterop).
*
* Therefore, it is OK to leave the statements on our side of the
* dynamic loading boundary.
*/
val clsSym = tpt.symbol
val ctor = fun.symbol
assert(clsSym.isSubClass(DynamicImportThunkClass),
s"expected subclass of DynamicImportThunk, got: $clsSym at: ${expr.pos}")
assert(ctor.isPrimaryConstructor,
s"expected primary constructor, got: $ctor at: ${expr.pos}")
js.Block(
stats.map(genStat(_)),
js.ApplyDynamicImport(
js.ApplyFlags.empty,
encodeClassName(clsSym),
encodeDynamicImportForwarderIdent(ctor.tpe.params),
genActualArgs(ctor, args))
)
case tree =>
abort("Unexpected argument tree in dynamicImport: " +
tree + "/" + tree.getClass + " at: " + tree.pos)
}
case STRICT_EQ =>
// js.special.strictEquals(arg1, arg2)
val (arg1, arg2) = genArgs2
js.JSBinaryOp(js.JSBinaryOp.===, arg1, arg2)
case IN =>
// js.special.in(arg1, arg2)
val (arg1, arg2) = genArgs2
js.AsInstanceOf(js.JSBinaryOp(js.JSBinaryOp.in, arg1, arg2),
jstpe.BooleanType)
case INSTANCEOF =>
// js.special.instanceof(arg1, arg2)
val (arg1, arg2) = genArgs2
js.AsInstanceOf(js.JSBinaryOp(js.JSBinaryOp.instanceof, arg1, arg2),
jstpe.BooleanType)
case DELETE =>
// js.special.delete(arg1, arg2)
val (arg1, arg2) = genArgs2
js.JSDelete(arg1, arg2)
case FORIN =>
/* js.special.forin(arg1, arg2)
*
* We must generate:
*
* val obj = arg1
* val f = arg2
* for (val key in obj) {
* f(key)
* }
*
* with temporary vals, because `arg2` must be evaluated only
* once, and after `arg1`.
*/
val (arg1, arg2) = genArgs2
val objVarDef = js.VarDef(freshLocalIdent("obj"), NoOriginalName,
jstpe.AnyType, mutable = false, arg1)
val fVarDef = js.VarDef(freshLocalIdent("f"), NoOriginalName,
jstpe.AnyType, mutable = false, arg2)
val keyVarIdent = freshLocalIdent("key")
val keyVarRef = js.VarRef(keyVarIdent)(jstpe.AnyType)
js.Block(
objVarDef,
fVarDef,
js.ForIn(objVarDef.ref, keyVarIdent, NoOriginalName, {
js.JSFunctionApply(fVarDef.ref, List(keyVarRef))
}))
case JS_THROW =>
// js.special.throw(arg)
js.Throw(genArgs1)
case JS_TRY_CATCH =>
/* js.special.tryCatch(arg1, arg2)
*
* We must generate:
*
* val body = arg1
* val handler = arg2
* try {
* body()
* } catch (e) {
* handler(e)
* }
*
* with temporary vals, because `arg2` must be evaluated before
* `body` executes. Moreover, exceptions thrown while evaluating
* the function values `arg1` and `arg2` must not be caught.
*/
val (arg1, arg2) = genArgs2
val bodyVarDef = js.VarDef(freshLocalIdent("body"), NoOriginalName,
jstpe.AnyType, mutable = false, arg1)
val handlerVarDef = js.VarDef(freshLocalIdent("handler"), NoOriginalName,
jstpe.AnyType, mutable = false, arg2)
val exceptionVarIdent = freshLocalIdent("e")
val exceptionVarRef = js.VarRef(exceptionVarIdent)(jstpe.AnyType)
js.Block(
bodyVarDef,
handlerVarDef,
js.TryCatch(
js.JSFunctionApply(bodyVarDef.ref, Nil),
exceptionVarIdent,
NoOriginalName,
js.JSFunctionApply(handlerVarDef.ref, List(exceptionVarRef))
)(jstpe.AnyType)
)
case WRAP_AS_THROWABLE =>
// js.special.wrapAsThrowable(arg)
js.WrapAsThrowable(genArgs1)
case UNWRAP_FROM_THROWABLE =>
// js.special.unwrapFromThrowable(arg)
js.UnwrapFromThrowable(genArgs1)
}
}
/** Gen JS code for a primitive JS call (to a method of a subclass of js.Any)
* This is the typed Scala.js to JS bridge feature. Basically it boils
* down to calling the method without name mangling. But other aspects
* come into play:
* * Operator methods are translated to JS operators (not method calls)
* * apply is translated as a function call, i.e. o() instead of o.apply()
* * Scala varargs are turned into JS varargs (see genPrimitiveJSArgs())
* * Getters and parameterless methods are translated as Selects
* * Setters are translated to Assigns of Selects
*/
private def genPrimitiveJSCall(tree: Apply, isStat: Boolean): js.Tree = {
val sym = tree.symbol
val Apply(fun @ Select(receiver0, _), args0) = tree
implicit val pos = tree.pos
val receiver = genExprOrGlobalScope(receiver0)
val args = genPrimitiveJSArgs(sym, args0)
genJSCallGeneric(sym, receiver, args, isStat)
}
/** Gen JS code for a call to a native JS def or val. */
private def genJSNativeMemberCall(tree: Apply, isStat: Boolean): js.Tree = {
val sym = tree.symbol
val Apply(_, args0) = tree
implicit val pos = tree.pos
val jsNativeMemberValue =
js.SelectJSNativeMember(encodeClassName(sym.owner), encodeMethodSym(sym))
val boxedResult =
if (jsInterop.isJSGetter(sym)) jsNativeMemberValue
else js.JSFunctionApply(jsNativeMemberValue, genPrimitiveJSArgs(sym, args0))
fromAny(boxedResult, enteringPhase(currentRun.posterasurePhase) {
sym.tpe.resultType
})
}
private def genJSSuperCall(tree: Apply, isStat: Boolean): js.Tree = {
acquireContextualJSClassValue { explicitJSSuperClassValue =>
implicit val pos = tree.pos
val Apply(fun @ Select(sup @ Super(qual, _), _), args) = tree
val sym = fun.symbol
/* #3013 `qual` can be `this.$outer()` in some cases since Scala 2.12,
* so we call `genExpr(qual)`, not just `genThis()`.
*/
val genReceiver = genExpr(qual)
lazy val genScalaArgs = genActualArgs(sym, args)
lazy val genJSArgs = genPrimitiveJSArgs(sym, args)
if (sym.owner == ObjectClass) {
// Normal call anyway
assert(!sym.isClassConstructor,
"Trying to call the super constructor of Object in a " +
s"non-native JS class at $pos")
genApplyMethod(genReceiver, sym, genScalaArgs)
} else if (sym.isClassConstructor) {
throw new AssertionError("calling a JS super constructor should " +
s"have happened in genPrimaryJSClassCtor at $pos")
} else if (isNonNativeJSClass(sym.owner) && !isExposed(sym)) {
// Reroute to the static method
genApplyJSClassMethod(genReceiver, sym, genScalaArgs)
} else {
val jsSuperClassValue = explicitJSSuperClassValue.orElse {
Some(genPrimitiveJSClass(currentClassSym.superClass))
}
genJSCallGeneric(sym, MaybeGlobalScope.NotGlobalScope(genReceiver),
genJSArgs, isStat, jsSuperClassValue)
}
}
}
private def genJSCallGeneric(sym: Symbol, receiver: MaybeGlobalScope,
args: List[js.TreeOrJSSpread], isStat: Boolean,
jsSuperClassValue: Option[js.Tree] = None)(
implicit pos: Position): js.Tree = {
def argsNoSpread: List[js.Tree] = {
assert(!args.exists(_.isInstanceOf[js.JSSpread]),
s"Unexpected spread at $pos")
args.asInstanceOf[List[js.Tree]]
}
val argc = args.size // meaningful only for methods that don't have varargs
def requireNotSuper(): Unit = {
if (jsSuperClassValue.isDefined) {
reporter.error(pos,
"Illegal super call in non-native JS class")
}
}
def genSuperReference(propName: js.Tree): js.AssignLhs = {
jsSuperClassValue.fold[js.AssignLhs] {
genJSBracketSelectOrGlobalRef(receiver, propName)
} { superClassValue =>
js.JSSuperSelect(superClassValue,
ruleOutGlobalScope(receiver), propName)
}
}
def genSelectGet(propName: js.Tree): js.Tree =
genSuperReference(propName)
def genSelectSet(propName: js.Tree, value: js.Tree): js.Tree =
js.Assign(genSuperReference(propName), value)
def genCall(methodName: js.Tree,
args: List[js.TreeOrJSSpread]): js.Tree = {
jsSuperClassValue.fold[js.Tree] {
genJSBracketMethodApplyOrGlobalRefApply(
receiver, methodName, args)
} { superClassValue =>
js.JSSuperMethodCall(superClassValue,
ruleOutGlobalScope(receiver), methodName, args)
}
}
val boxedResult = JSCallingConvention.of(sym) match {
case JSCallingConvention.UnaryOp(code) =>
requireNotSuper()
assert(argc == 0, s"bad argument count ($argc) for unary op at $pos")
js.JSUnaryOp(code, ruleOutGlobalScope(receiver))
case JSCallingConvention.BinaryOp(code) =>
requireNotSuper()
assert(argc == 1, s"bad argument count ($argc) for binary op at $pos")
js.JSBinaryOp(code, ruleOutGlobalScope(receiver), argsNoSpread.head)
case JSCallingConvention.Call =>
requireNotSuper()
if (sym.owner.isSubClass(JSThisFunctionClass)) {
genJSBracketMethodApplyOrGlobalRefApply(receiver,
js.StringLiteral("call"), args)
} else {
js.JSFunctionApply(ruleOutGlobalScope(receiver), args)
}
case JSCallingConvention.Property(jsName) =>
argsNoSpread match {
case Nil => genSelectGet(genExpr(jsName))
case value :: Nil => genSelectSet(genExpr(jsName), value)
case _ =>
throw new AssertionError(
s"property methods should have 0 or 1 non-varargs arguments at $pos")
}
case JSCallingConvention.BracketAccess =>
argsNoSpread match {
case keyArg :: Nil =>
genSelectGet(keyArg)
case keyArg :: valueArg :: Nil =>
genSelectSet(keyArg, valueArg)
case _ =>
throw new AssertionError(
s"@JSBracketAccess methods should have 1 or 2 non-varargs arguments at $pos")
}
case JSCallingConvention.BracketCall =>
val (methodName, actualArgs) = extractFirstArg(args)
genCall(methodName, actualArgs)
case JSCallingConvention.Method(jsName) =>
genCall(genExpr(jsName), args)
}
boxedResult match {
case js.Assign(_, _) =>
boxedResult
case _ if isStat =>
boxedResult
case _ =>
fromAny(boxedResult,
enteringPhase(currentRun.posterasurePhase)(sym.tpe.resultType))
}
}
/** Extract the first argument to a primitive JS call.
* This is nothing else than decomposing into head and tail, except that
* we assert that the first element is not a JSSpread.
*/
private def extractFirstArg(
args: List[js.TreeOrJSSpread]): (js.Tree, List[js.TreeOrJSSpread]) = {
assert(args.nonEmpty,
"Trying to extract the first argument of an empty argument list")
val firstArg = args.head match {
case firstArg: js.Tree =>
firstArg
case firstArg: js.JSSpread =>
throw new AssertionError(
"Trying to extract the first argument of an argument list starting " +
"with a Spread argument: " + firstArg)
}
(firstArg, args.tail)
}
/** Gen JS code for a new of a JS class (subclass of js.Any) */
private def genPrimitiveJSNew(tree: Apply): js.Tree = {
acquireContextualJSClassValue { jsClassValue =>
implicit val pos = tree.pos
val Apply(fun @ Select(New(tpt), _), args0) = tree
val cls = tpt.tpe.typeSymbol
val ctor = fun.symbol
val nestedJSClass = isNestedJSClass(cls)
assert(jsClassValue.isDefined == nestedJSClass,
s"$cls at $pos: jsClassValue.isDefined = ${jsClassValue.isDefined} " +
s"but isInnerNonNativeJSClass = $nestedJSClass")
def args = genPrimitiveJSArgs(ctor, args0)
if (cls == JSObjectClass && args0.isEmpty)
js.JSObjectConstr(Nil)
else if (cls == JSArrayClass && args0.isEmpty)
js.JSArrayConstr(Nil)
else if (isAnonymousJSClass(cls))
genAnonJSClassNew(cls, jsClassValue.get, args0.map(genExpr))(fun.pos)
else if (!nestedJSClass)
js.JSNew(genPrimitiveJSClass(cls), args)
else if (!cls.isModuleClass)
js.JSNew(jsClassValue.get, args)
else
genCreateInnerJSModule(cls, jsClassValue.get, args0.map(genExpr))
}
}
/** Gen JS code representing a JS class (subclass of js.Any) */
private def genPrimitiveJSClass(sym: Symbol)(
implicit pos: Position): js.Tree = {
assert(!isStaticModule(sym) && !sym.isTraitOrInterface,
s"genPrimitiveJSClass called with non-class $sym")
js.LoadJSConstructor(encodeClassName(sym))
}
/** Gen JS code to create the JS class of an inner JS module class. */
private def genCreateInnerJSModule(sym: Symbol,
jsSuperClassValue: js.Tree, args: List[js.Tree])(
implicit pos: Position): js.Tree = {
js.JSNew(js.CreateJSClass(encodeClassName(sym),
jsSuperClassValue :: args), Nil)
}
/** Gen actual actual arguments to Scala method call.
*
* Returns a list of the transformed arguments.
*
* This tries to optimize repeated arguments (varargs) by turning them
* into JS arrays wrapped in the appropriate Seq, rather than Scala
* arrays.
*/
private def genActualArgs(sym: Symbol, args: List[Tree])(
implicit pos: Position): List[js.Tree] = {
val wereRepeated = exitingPhase(currentRun.typerPhase) {
/* Do NOT use `params` instead of `paramss.flatten` here! Exiting
* typer, `params` only contains the *first* parameter list.
* This was causing #2265 and #2741.
*/
sym.tpe.paramss.flatten.map(p => isScalaRepeatedParamType(p.tpe))
}
if (wereRepeated.size > args.size) {
// Should not happen, but let's not crash
args.map(genExpr)
} else {
/* Arguments that are in excess compared to the type signature after
* typer are lambda-lifted arguments. They cannot be repeated, hence
* the extension to `false`.
*/
for ((arg, wasRepeated) <- args.zipAll(wereRepeated, EmptyTree, false)) yield {
if (wasRepeated) {
tryGenRepeatedParamAsJSArray(arg, handleNil = false).fold {
genExpr(arg)
} { genArgs =>
genJSArrayToVarArgs(js.JSArrayConstr(genArgs))
}
} else {
genExpr(arg)
}
}
}
}
/** Info about a Scala method param when called as JS method.
*
* @param sym Parameter symbol as seen now.
* @param tpe Parameter type (type of a single element if repeated)
* @param repeated Whether the parameter is repeated.
* @param capture Whether the parameter is a capture.
*/
final class JSParamInfo(val sym: Symbol, val tpe: Type,
val repeated: Boolean = false, val capture: Boolean = false) {
assert(!repeated || !capture, "capture cannot be repeated")
def hasDefault: Boolean = sym.hasFlag(Flags.DEFAULTPARAM)
}
def jsParamInfos(sym: Symbol): List[JSParamInfo] = {
assert(sym.isMethod, s"trying to take JS param info of non-method: $sym")
/* For constructors of nested JS classes (*), explicitouter and
* lambdalift have introduced some parameters for the outer parameter and
* captures. We must ignore those, as captures and outer pointers are
* taken care of by `explicitinerjs` for such classes.
*
* Unfortunately, for some reason lambdalift creates new symbol *even for
* parameters originally in the signature* when doing so! That is why we
* use the *names* of the parameters as a link through time, rather than
* the symbols, to identify which ones already existed at the time of
* explicitinerjs.
*
* This is pretty fragile, but fortunately we have a huge test suite to
* back us up should scalac alter its behavior.
*
* In addition, for actual parameters that we keep, we have to look back
* in time to see whether they were repeated and what was their type.
*
* (*) Note that we are not supposed to receive in genPrimitiveJSArgs a
* method symbol that would have such captures *and* would not be a
* class constructors. Indeed, such methods would have started their
* life as local defs, which are not exposed.
*/
val uncurryParams = enteringPhase(currentRun.uncurryPhase) {
for {
paramUncurry <- sym.tpe.paramss.flatten
} yield {
val v = {
if (isRepeated(paramUncurry))
Some(repeatedToSingle(paramUncurry.tpe))
else
None
}
paramUncurry.name -> v
}
}.toMap
val paramTpes = enteringPhase(currentRun.posterasurePhase) {
for (param <- sym.tpe.params)
yield param.name -> param.tpe
}.toMap
for {
paramSym <- sym.tpe.params
} yield {
uncurryParams.get(paramSym.name) match {
case None =>
// This is a capture parameter introduced by explicitouter or lambdalift
new JSParamInfo(paramSym, paramSym.tpe, capture = true)
case Some(Some(tpe)) =>
new JSParamInfo(paramSym, tpe, repeated = true)
case Some(None) =>
val tpe = paramTpes.getOrElse(paramSym.name, paramSym.tpe)
new JSParamInfo(paramSym, tpe)
}
}
}
/** Gen actual actual arguments to a primitive JS call.
*
* * Repeated arguments (varargs) are expanded
* * Default arguments are omitted or replaced by undefined
* * All arguments are boxed
*
* Repeated arguments that cannot be expanded at compile time (i.e., if a
* Seq is passed to a varargs parameter with the syntax `seq: _*`) will be
* wrapped in a [[js.JSSpread]] node to be expanded at runtime.
*/
private def genPrimitiveJSArgs(sym: Symbol, args: List[Tree])(
implicit pos: Position): List[js.TreeOrJSSpread] = {
var reversedArgs: List[js.TreeOrJSSpread] = Nil
for ((arg, info) <- args.zip(jsParamInfos(sym))) {
if (info.repeated) {
reversedArgs =
genPrimitiveJSRepeatedParam(arg) reverse_::: reversedArgs
} else if (info.capture) {
// Ignore captures
assert(sym.isClassConstructor,
s"Found an unknown param ${info.sym.name} in method " +
s"${sym.fullName}, which is not a class constructor, at $pos")
} else {
val unboxedArg = genExpr(arg)
val boxedArg = unboxedArg match {
case js.Transient(UndefinedParam) =>
unboxedArg
case _ =>
ensureBoxed(unboxedArg, info.tpe)
}
reversedArgs ::= boxedArg
}
}
/* Remove all consecutive UndefinedParam's at the end of the argument
* list. No check is performed whether they may be there, since they will
* only be placed where default arguments can be anyway.
*/
reversedArgs = reversedArgs.dropWhile {
case js.Transient(UndefinedParam) => true
case _ => false
}
// Find remaining UndefinedParam's and replace by js.Undefined. This can
// happen with named arguments or when multiple argument lists are present
reversedArgs = reversedArgs map {
case js.Transient(UndefinedParam) => js.Undefined()
case arg => arg
}
reversedArgs.reverse
}
/** Gen JS code for a repeated param of a primitive JS method
* In this case `arg` has type Seq[T] for some T, but the result should
* be an expanded list of the elements in the sequence. So this method
* takes care of the conversion.
* It is specialized for the shapes of tree generated by the desugaring
* of repeated params in Scala, so that these are actually expanded at
* compile-time.
* Otherwise, it returns a JSSpread with the Seq converted to a js.Array.
*/
private def genPrimitiveJSRepeatedParam(arg: Tree): List[js.TreeOrJSSpread] = {
tryGenRepeatedParamAsJSArray(arg, handleNil = true) getOrElse {
/* Fall back to calling runtime.toJSVarArgs to perform the conversion
* to js.Array, then wrap in a Spread operator.
*/
implicit val pos = arg.pos
val jsArrayArg = genApplyMethod(
genLoadModule(RuntimePackageModule),
Runtime_toJSVarArgs,
List(genExpr(arg)))
List(js.JSSpread(jsArrayArg))
}
}
/** Try and expand a repeated param (xs: T*) at compile-time.
* This method recognizes the shapes of tree generated by the desugaring
* of repeated params in Scala, and expands them.
* If `arg` does not have the shape of a generated repeated param, this
* method returns `None`.
*/
private def tryGenRepeatedParamAsJSArray(arg: Tree,
handleNil: Boolean): Option[List[js.Tree]] = {
implicit val pos = arg.pos
// Given a method `def foo(args: T*)`
arg match {
// foo(arg1, arg2, ..., argN) where N > 0
case MaybeAsInstanceOf(WrapArray(
MaybeAsInstanceOf(ArrayValue(tpt, elems)))) =>
/* Value classes in arrays are already boxed, so no need to use
* the type before erasure.
*/
val elemTpe = tpt.tpe
Some(elems.map(e => ensureBoxed(genExpr(e), elemTpe)))
// foo()
case Select(_, _) if handleNil && arg.symbol == NilModule =>
Some(Nil)
// foo(argSeq:_*) - cannot be optimized
case _ =>
None
}
}
object MaybeAsInstanceOf {
def unapply(tree: Tree): Some[Tree] = tree match {
case Apply(TypeApply(asInstanceOf_? @ Select(base, _), _), _)
if asInstanceOf_?.symbol == Object_asInstanceOf =>
Some(base)
case _ =>
Some(tree)
}
}
object WrapArray {
private val wrapArrayModule =
if (hasNewCollections) ScalaRunTimeModule
else PredefModule
val wrapRefArrayMethod: Symbol =
getMemberMethod(wrapArrayModule, nme.wrapRefArray)
val genericWrapArrayMethod: Symbol =
getMemberMethod(wrapArrayModule, nme.genericWrapArray)
def isClassTagBasedWrapArrayMethod(sym: Symbol): Boolean =
sym == wrapRefArrayMethod || sym == genericWrapArrayMethod
private val isWrapArray: Set[Symbol] = {
Seq(
nme.wrapRefArray,
nme.wrapByteArray,
nme.wrapShortArray,
nme.wrapCharArray,
nme.wrapIntArray,
nme.wrapLongArray,
nme.wrapFloatArray,
nme.wrapDoubleArray,
nme.wrapBooleanArray,
nme.wrapUnitArray,
nme.genericWrapArray
).map(getMemberMethod(wrapArrayModule, _)).toSet
}
def unapply(tree: Apply): Option[Tree] = tree match {
case Apply(wrapArray_?, List(wrapped))
if isWrapArray(wrapArray_?.symbol) =>
Some(wrapped)
case _ =>
None
}
}
/** Wraps a `js.Array` to use as varargs. */
def genJSArrayToVarArgs(arrayRef: js.Tree)(
implicit pos: Position): js.Tree = {
genApplyMethod(genLoadModule(RuntimePackageModule),
Runtime_toScalaVarArgs, List(arrayRef))
}
/** Gen the actual capture values for a JS constructor based on its fake
* `new` invocation.
*/
private def genCaptureValuesFromFakeNewInstance(
tree: Tree): List[js.Tree] = {
implicit val pos = tree.pos
val Apply(fun @ Select(New(_), _), args) = tree
val sym = fun.symbol
/* We use the same strategy as genPrimitiveJSArgs to detect which
* parameters were introduced by explicitouter or lambdalift (but
* reversed, of course).
*/
val existedBeforeUncurry = enteringPhase(currentRun.uncurryPhase) {
for {
params <- sym.tpe.paramss
param <- params
} yield {
param.name
}
}.toSet
for {
(arg, paramSym) <- args.zip(sym.tpe.params)
if !existedBeforeUncurry(paramSym.name)
} yield {
genExpr(arg)
}
}
// Synthesizers for JS functions -------------------------------------------
/** Try and generate JS code for an anonymous function class.
*
* Returns Some() if the class could be rewritten that way, None
* otherwise.
*
* We make the following assumptions on the form of such classes:
* - It is an anonymous function
* - Includes being anonymous, final, and having exactly one constructor
* - It is not a PartialFunction
* - It has no field other than param accessors
* - It has exactly one constructor
* - It has exactly one non-bridge method apply if it is not specialized,
* or a method apply$...$sp and a forwarder apply if it is specialized.
* - As a precaution: it is synthetic
*
* From a class looking like this:
*
* final class (outer, capture1, ..., captureM) extends AbstractionFunctionN[...] {
* def apply(param1, ..., paramN) = {
*
* }
* }
* new (o, c1, ..., cM)
*
* we generate a function:
*
* lambda[notype](
* outer, capture1, ..., captureM, param1, ..., paramN) {
*
* }
*
* so that, at instantiation point, we can write:
*
* new AnonFunctionN(function)
*
* the latter tree is returned in case of success.
*
* Trickier things apply when the function is specialized.
*/
private def tryGenAnonFunctionClass(cd: ClassDef,
capturedArgs: List[js.Tree]): Option[js.Tree] = {
// scalastyle:off return
implicit val pos = cd.pos
val sym = cd.symbol
assert(sym.isAnonymousFunction,
s"tryGenAndRecordAnonFunctionClass called with non-anonymous function $cd")
if (!sym.superClass.fullName.startsWith("scala.runtime.AbstractFunction")) {
/* This is an anonymous class for a non-LMF capable SAM in 2.12.
* We must not rewrite it, as it would then not inherit from the
* appropriate parent class and/or interface.
*/
None
} else {
nestedGenerateClass(sym) {
val (functionBase, arity) =
tryGenAnonFunctionClassGeneric(cd, capturedArgs)(_ => return None)
Some(genJSFunctionToScala(functionBase, arity))
}
}
// scalastyle:on return
}
/** Gen a conversion from a JavaScript function into a Scala function. */
private def genJSFunctionToScala(jsFunction: js.Tree, arity: Int)(
implicit pos: Position): js.Tree = {
val clsSym = getRequiredClass("scala.scalajs.runtime.AnonFunction" + arity)
val ctor = clsSym.primaryConstructor
genNew(clsSym, ctor, List(jsFunction))
}
/** Gen JS code for a JS function class.
*
* This is called when emitting a ClassDef that represents an anonymous
* class extending `js.FunctionN`. These are generated by the SAM
* synthesizer when the target type is a `js.FunctionN`. Since JS
* functions are not classes, we deconstruct the ClassDef, then
* reconstruct it to be a genuine Closure.
*
* Compared to `tryGenAnonFunctionClass()`, this function must
* always succeed, because we really cannot afford keeping them as
* anonymous classes. The good news is that it can do so, because the
* body of SAM lambdas is hoisted in the enclosing class. Hence, the
* apply() method is just a forwarder to calling that hoisted method.
*
* From a class looking like this:
*
* final class (outer, capture1, ..., captureM) extends js.FunctionN[...] {
* def apply(param1, ..., paramN) = {
* outer.lambdaImpl(param1, ..., paramN, capture1, ..., captureM)
* }
* }
* new (o, c1, ..., cM)
*
* we generate a function:
*
* lambda[notype](
* outer, capture1, ..., captureM, param1, ..., paramN) {
* outer.lambdaImpl(param1, ..., paramN, capture1, ..., captureM)
* }
*/
def genJSFunction(cd: ClassDef, captures: List[js.Tree]): js.Tree = {
val sym = cd.symbol
assert(isJSFunctionDef(sym),
s"genAndRecordJSFunctionClass called with non-JS function $cd")
nestedGenerateClass(sym) {
val (function, _) = tryGenAnonFunctionClassGeneric(cd, captures)(msg =>
abort(s"Could not generate function for JS function: $msg"))
function
}
}
/** Code common to tryGenAndRecordAnonFunctionClass and
* genAndRecordJSFunctionClass.
*/
private def tryGenAnonFunctionClassGeneric(cd: ClassDef,
initialCapturedArgs: List[js.Tree])(
fail: (=> String) => Nothing): (js.Tree, Int) = {
implicit val pos = cd.pos
val sym = cd.symbol
// First checks
if (sym.isSubClass(PartialFunctionClass))
fail(s"Cannot rewrite PartialFunction $cd")
// First step: find the apply method def, and collect param accessors
var paramAccessors: List[Symbol] = Nil
var applyDef: DefDef = null
def gen(tree: Tree): Unit = {
tree match {
case EmptyTree => ()
case Template(_, _, body) => body foreach gen
case vd @ ValDef(mods, name, tpt, rhs) =>
val fsym = vd.symbol
if (!fsym.isParamAccessor)
fail(s"Found field $fsym which is not a param accessor in anon function $cd")
if (fsym.isPrivate) {
paramAccessors ::= fsym
} else {
// Uh oh ... an inner something will try to access my fields
fail(s"Found a non-private field $fsym in $cd")
}
case dd: DefDef =>
val ddsym = dd.symbol
if (ddsym.isClassConstructor) {
if (!ddsym.isPrimaryConstructor)
fail(s"Non-primary constructor $ddsym in anon function $cd")
} else {
val name = dd.name.toString
if (name == "apply" || (ddsym.isSpecialized && name.startsWith("apply$"))) {
if ((applyDef eq null) || ddsym.isSpecialized)
applyDef = dd
} else if (ddsym.hasAnnotation(JSOptionalAnnotation)) {
// Ignore (this is useful for default parameters in custom JS function types)
} else {
// Found a method we cannot encode in the rewriting
fail(s"Found a non-apply method $ddsym in $cd")
}
}
case _ =>
fail("Illegal tree in gen of genAndRecordAnonFunctionClass(): " + tree)
}
}
gen(cd.impl)
paramAccessors = paramAccessors.reverse // preserve definition order
if (applyDef eq null)
fail(s"Did not find any apply method in anon function $cd")
withNewLocalNameScope {
// Second step: build the list of useful constructor parameters
val ctorParams = sym.primaryConstructor.tpe.params
if (paramAccessors.size != ctorParams.size &&
!(paramAccessors.size == ctorParams.size-1 &&
ctorParams.head.unexpandedName == jsnme.arg_outer)) {
fail(
s"Have param accessors $paramAccessors but "+
s"ctor params $ctorParams in anon function $cd")
}
val hasUnusedOuterCtorParam = paramAccessors.size != ctorParams.size
val usedCtorParams =
if (hasUnusedOuterCtorParam) ctorParams.tail
else ctorParams
val ctorParamDefs = usedCtorParams.map(genParamDef(_))
// Third step: emit the body of the apply method def
val applyMethod = withScopedVars(
paramAccessorLocals := (paramAccessors zip ctorParamDefs).toMap,
tryingToGenMethodAsJSFunction := true
) {
try {
genMethodWithCurrentLocalNameScope(applyDef)
} catch {
case e: CancelGenMethodAsJSFunction =>
fail(e.getMessage)
}
}
// Fourth step: patch the body to unbox parameters and box result
val hasRepeatedParam = {
sym.superClass == JSFunctionClass && // Scala functions are known not to have repeated params
enteringUncurry {
applyDef.symbol.paramss.flatten.lastOption.exists(isRepeated(_))
}
}
val js.MethodDef(_, _, _, params, _, body) = applyMethod
val (patchedParams, paramsLocals) = {
val nonRepeatedParams =
if (hasRepeatedParam) params.init
else params
patchFunParamsWithBoxes(applyDef.symbol, nonRepeatedParams,
useParamsBeforeLambdaLift = false)
}
val (patchedRepeatedParam, repeatedParamLocal) = {
/* Instead of this circus, simply `unzip` would be nice.
* But that lowers the type to iterable.
*/
if (hasRepeatedParam) {
val (p, l) = genPatchedParam(params.last, genJSArrayToVarArgs(_))
(Some(p), Some(l))
} else {
(None, None)
}
}
val patchedBody =
js.Block(paramsLocals ++ repeatedParamLocal :+ ensureResultBoxed(body.get, applyDef.symbol))
// Fifth step: build the js.Closure
val isThisFunction = sym.isSubClass(JSThisFunctionClass) && {
val ok = patchedParams.nonEmpty
if (!ok) {
reporter.error(pos,
"The SAM or apply method for a js.ThisFunction must have a " +
"leading non-varargs parameter")
}
ok
}
val capturedArgs =
if (hasUnusedOuterCtorParam) initialCapturedArgs.tail
else initialCapturedArgs
assert(capturedArgs.size == ctorParamDefs.size,
s"$capturedArgs does not match $ctorParamDefs")
val closure = {
if (isThisFunction) {
val thisParam :: actualParams = patchedParams
js.Closure(
arrow = false,
ctorParamDefs,
actualParams,
patchedRepeatedParam,
js.Block(
js.VarDef(thisParam.name, thisParam.originalName,
thisParam.ptpe, mutable = false,
js.This()(thisParam.ptpe)(thisParam.pos))(thisParam.pos),
patchedBody),
capturedArgs)
} else {
js.Closure(arrow = true, ctorParamDefs, patchedParams,
patchedRepeatedParam, patchedBody, capturedArgs)
}
}
val arity = params.size
(closure, arity)
}
}
/** Generate JS code for an anonymous function
*
* Anonymous functions survive until the backend for any
* LambdaMetaFactory-capable type.
*
* When they do, their body is always of the form
* {{{
* EnclosingClass.this.someMethod(args)
* }}}
* where the args are either formal parameters of the lambda, or local
* variables or the enclosing def. The latter must be captured.
*
* We identify the captures using the same method as the `delambdafy`
* phase. We have an additional hack for `this`.
*
* To translate them, we first construct a JS closure for the body:
* {{{
* lambda(
* _this, capture1, ..., captureM, arg1, ..., argN) {
* _this.someMethod(arg1, ..., argN, capture1, ..., captureM)
* }
* }}}
* In the closure, input params are unboxed before use, and the result of
* `someMethod()` is boxed back.
*
* Then, we wrap that closure in a class satisfying the expected type.
* For Scala function types, we use the existing
* `scala.scalajs.runtime.AnonFunctionN` from the library. For other
* LMF-capable types, we generate a class on the fly, which looks like
* this:
* {{{
* class AnonFun extends Object with FunctionalInterface {
* val f: any
* def (f: any) {
* super();
* this.f = f
* }
* def theSAMMethod(params: Types...): Type =
* unbox((this.f)(boxParams...))
* }
* }}}
*/
private def genAnonFunction(originalFunction: Function): js.Tree = {
implicit val pos = originalFunction.pos
val Function(paramTrees, Apply(
targetTree @ Select(receiver, _), allArgs0)) = originalFunction
val captureSyms =
global.delambdafy.FreeVarTraverser.freeVarsOf(originalFunction)
val target = targetTree.symbol
val params = paramTrees.map(_.symbol)
val allArgs = allArgs0 map genExpr
val formalCaptures = captureSyms.toList.map(genParamDef(_, pos))
val actualCaptures = formalCaptures.map(_.ref)
val formalArgs = params.map(genParamDef(_))
val (allFormalCaptures, body, allActualCaptures) = if (!target.isStaticMember) {
val thisActualCapture = genExpr(receiver)
val thisFormalCapture = js.ParamDef(
freshLocalIdent("this")(receiver.pos), thisOriginalName,
thisActualCapture.tpe, mutable = false)(receiver.pos)
val thisCaptureArg = thisFormalCapture.ref
val body = if (isJSType(receiver.tpe) && target.owner != ObjectClass) {
assert(isNonNativeJSClass(target.owner) && !isExposed(target),
s"A Function lambda is trying to call an exposed JS method ${target.fullName}")
genApplyJSClassMethod(thisCaptureArg, target, allArgs)
} else {
genApplyMethodMaybeStatically(thisCaptureArg, target, allArgs)
}
(thisFormalCapture :: formalCaptures,
body, thisActualCapture :: actualCaptures)
} else {
val body = genApplyStatic(target, allArgs)
(formalCaptures, body, actualCaptures)
}
val (patchedFormalArgs, paramsLocals) =
patchFunParamsWithBoxes(target, formalArgs, useParamsBeforeLambdaLift = true)
val patchedBody =
js.Block(paramsLocals :+ ensureResultBoxed(body, target))
val closure = js.Closure(
arrow = true,
allFormalCaptures,
patchedFormalArgs,
restParam = None,
patchedBody,
allActualCaptures)
// Wrap the closure in the appropriate box for the SAM type
val funSym = originalFunction.tpe.typeSymbolDirect
if (isFunctionSymbol(funSym)) {
/* This is a scala.FunctionN. We use the existing AnonFunctionN
* wrapper.
*/
genJSFunctionToScala(closure, params.size)
} else {
/* This is an arbitrary SAM type (can only happen in 2.12).
* We have to synthesize a class like LambdaMetaFactory would do on
* the JVM.
*/
val sam = originalFunction.attachments.get[SAMFunction].getOrElse {
abort(s"Cannot find the SAMFunction attachment on $originalFunction at $pos")
}
val samWrapperClassName = synthesizeSAMWrapper(funSym, sam)
js.New(samWrapperClassName, js.MethodIdent(ObjectArgConstructorName),
List(closure))
}
}
private def synthesizeSAMWrapper(funSym: Symbol, samInfo: SAMFunction)(
implicit pos: Position): ClassName = {
val intfName = encodeClassName(funSym)
val suffix = {
generatedSAMWrapperCount.value += 1
// LambdaMetaFactory names classes like this
"$$Lambda$" + generatedSAMWrapperCount.value
}
val className = encodeClassName(currentClassSym).withSuffix(suffix)
val thisType = jstpe.ClassType(className, nullable = false)
// val f: Any
val fFieldIdent = js.FieldIdent(FieldName(className, SimpleFieldName("f")))
val fFieldDef = js.FieldDef(js.MemberFlags.empty, fFieldIdent,
NoOriginalName, jstpe.AnyType)
// def this(f: Any) = { this.f = f; super() }
val ctorDef = {
val fParamDef = js.ParamDef(js.LocalIdent(LocalName("f")),
NoOriginalName, jstpe.AnyType, mutable = false)
js.MethodDef(
js.MemberFlags.empty.withNamespace(js.MemberNamespace.Constructor),
js.MethodIdent(ObjectArgConstructorName),
NoOriginalName,
List(fParamDef),
jstpe.NoType,
Some(js.Block(List(
js.Assign(
js.Select(js.This()(thisType), fFieldIdent)(jstpe.AnyType),
fParamDef.ref),
js.ApplyStatically(js.ApplyFlags.empty.withConstructor(true),
js.This()(thisType),
ir.Names.ObjectClass,
js.MethodIdent(ir.Names.NoArgConstructorName),
Nil)(jstpe.NoType)))))(
js.OptimizerHints.empty, Unversioned)
}
// Compute the set of method symbols that we need to implement
val sams = {
val samsBuilder = List.newBuilder[Symbol]
val seenMethodNames = mutable.Set.empty[MethodName]
/* scala/bug#10512: any methods which `samInfo.sam` overrides need
* bridges made for them.
* On Scala < 2.12.5, `synthCls` is polyfilled to `NoSymbol` and hence
* `samBridges` will always be empty. This causes our compiler to be
* bug-compatible on these versions.
*/
val synthCls = samInfo.synthCls
val samBridges = if (synthCls == NoSymbol) {
Nil
} else {
import scala.reflect.internal.Flags.BRIDGE
synthCls.info.findMembers(excludedFlags = 0L, requiredFlags = BRIDGE).toList
}
for (sam <- samInfo.sam :: samBridges) {
/* Remove duplicates, e.g., if we override the same method declared
* in two super traits.
*/
if (seenMethodNames.add(encodeMethodSym(sam).name))
samsBuilder += sam
}
samsBuilder.result()
}
// def samMethod(...params): resultType = this.f(...params)
val samMethodDefs = for (sam <- sams) yield {
val jsParams = sam.tpe.params.map(genParamDef(_, pos))
val resultType = toIRType(sam.tpe.finalResultType)
val actualParams = enteringPhase(currentRun.posterasurePhase) {
for ((formal, param) <- jsParams.zip(sam.tpe.params))
yield (formal.ref, param.tpe)
}.map((ensureBoxed _).tupled)
val call = js.JSFunctionApply(
js.Select(js.This()(thisType), fFieldIdent)(jstpe.AnyType),
actualParams)
val body = fromAny(call, enteringPhase(currentRun.posterasurePhase) {
sam.tpe.finalResultType
})
js.MethodDef(js.MemberFlags.empty, encodeMethodSym(sam),
originalNameOfMethod(sam), jsParams, resultType,
Some(body))(
js.OptimizerHints.empty, Unversioned)
}
// The class definition
val classDef = js.ClassDef(
js.ClassIdent(className),
NoOriginalName,
ClassKind.Class,
None,
Some(js.ClassIdent(ir.Names.ObjectClass)),
List(js.ClassIdent(intfName)),
None,
None,
fields = fFieldDef :: Nil,
methods = ctorDef :: samMethodDefs,
jsConstructor = None,
Nil,
Nil,
Nil)(
js.OptimizerHints.empty.withInline(true))
generatedClasses += classDef -> pos
className
}
private def patchFunParamsWithBoxes(methodSym: Symbol,
params: List[js.ParamDef], useParamsBeforeLambdaLift: Boolean)(
implicit pos: Position): (List[js.ParamDef], List[js.VarDef]) = {
// See the comment in genPrimitiveJSArgs for a rationale about this
val paramTpes = enteringPhase(currentRun.posterasurePhase) {
for (param <- methodSym.tpe.params)
yield param.name -> param.tpe
}.toMap
/* Normally, we should work with the list of parameters as seen right
* now. But when generating an anonymous function from a Function node,
* the `methodSym` we use is the *target* of the inner call, not the
* enclosing method for which we're patching the params and body. This
* is a hack which we have to do because there is no such enclosing
* method in that case. When we use the target, the list of symbols for
* formal parameters that we want to see is that before lambdalift, not
* the one we see right now.
*/
val paramSyms = {
if (useParamsBeforeLambdaLift)
enteringPhase(currentRun.phaseNamed("lambdalift"))(methodSym.tpe.params)
else
methodSym.tpe.params
}
(for {
(param, paramSym) <- params zip paramSyms
} yield {
val paramTpe = paramTpes.getOrElse(paramSym.name, paramSym.tpe)
genPatchedParam(param, fromAny(_, paramTpe))
}).unzip
}
private def genPatchedParam(param: js.ParamDef, rhs: js.VarRef => js.Tree)(
implicit pos: Position): (js.ParamDef, js.VarDef) = {
val paramNameIdent = param.name
val origName = param.originalName
val newNameIdent = freshLocalIdent(paramNameIdent.name)(paramNameIdent.pos)
val newOrigName = origName.orElse(paramNameIdent.name)
val patchedParam = js.ParamDef(newNameIdent, newOrigName, jstpe.AnyType,
mutable = false)(param.pos)
val paramLocal = js.VarDef(paramNameIdent, origName, param.ptpe,
mutable = false, rhs(patchedParam.ref))
(patchedParam, paramLocal)
}
/** Generates a static method instantiating and calling this
* DynamicImportThunk's `apply`:
*
* {{{
* static def dynamicImport$;;Ljava.lang.Object(): any = {
* new .;:V().apply;Ljava.lang.Object()
* }
* }}}
*/
private def genDynamicImportForwarder(clsSym: Symbol)(
implicit pos: Position): js.MethodDef = {
withNewLocalNameScope {
val ctor = clsSym.primaryConstructor
val paramSyms = ctor.tpe.params
val paramDefs = paramSyms.map(genParamDef(_))
val body = {
val inst = genNew(clsSym, ctor, paramDefs.map(_.ref))
genApplyMethod(inst, DynamicImportThunkClass_apply, Nil)
}
js.MethodDef(
js.MemberFlags.empty.withNamespace(js.MemberNamespace.PublicStatic),
encodeDynamicImportForwarderIdent(paramSyms),
NoOriginalName,
paramDefs,
jstpe.AnyType,
Some(body))(OptimizerHints.empty, Unversioned)
}
}
// Methods to deal with JSName ---------------------------------------------
def genExpr(name: JSName)(implicit pos: Position): js.Tree = name match {
case JSName.Literal(name) => js.StringLiteral(name)
case JSName.Computed(sym) => genComputedJSName(sym)
}
private def genComputedJSName(sym: Symbol)(implicit pos: Position): js.Tree = {
/* By construction (i.e. restriction in PrepJSInterop), we know that sym
* must be a static method.
* Therefore, at this point, we can invoke it by loading its owner and
* calling it.
*/
def moduleOrGlobalScope = genLoadModuleOrGlobalScope(sym.owner)
def module = genLoadModule(sym.owner)
if (isJSType(sym.owner)) {
if (!isNonNativeJSClass(sym.owner) || isExposed(sym))
genJSCallGeneric(sym, moduleOrGlobalScope, args = Nil, isStat = false)
else
genApplyJSClassMethod(module, sym, arguments = Nil)
} else {
genApplyMethod(module, sym, arguments = Nil)
}
}
// Utilities ---------------------------------------------------------------
def genVarRef(sym: Symbol)(implicit pos: Position): js.VarRef =
js.VarRef(encodeLocalSym(sym))(toIRType(sym.tpe))
def genParamDef(sym: Symbol): js.ParamDef =
genParamDef(sym, toIRType(sym.tpe))
private def genParamDef(sym: Symbol, ptpe: jstpe.Type): js.ParamDef =
genParamDef(sym, ptpe, sym.pos)
private def genParamDef(sym: Symbol, pos: Position): js.ParamDef =
genParamDef(sym, toIRType(sym.tpe), pos)
private def genParamDef(sym: Symbol, ptpe: jstpe.Type,
pos: Position): js.ParamDef = {
js.ParamDef(encodeLocalSym(sym)(pos), originalNameOfLocal(sym), ptpe,
mutable = false)(pos)
}
/** Generates a call to `runtime.privateFieldsSymbol()` */
private def genPrivateFieldsSymbol()(implicit pos: Position): js.Tree = {
genApplyMethod(genLoadModule(RuntimePackageModule),
Runtime_privateFieldsSymbol, Nil)
}
/** Generate loading of a module value.
*
* Can be given either the module symbol or its module class symbol.
*
* If the module we load refers to the global scope (i.e., it is
* annotated with `@JSGlobalScope`), report a compile error specifying
* that a global scope object should only be used as the qualifier of a
* `.`-selection.
*/
def genLoadModule(sym0: Symbol)(implicit pos: Position): js.Tree =
ruleOutGlobalScope(genLoadModuleOrGlobalScope(sym0))
/** Generate loading of a module value or the global scope.
*
* Can be given either the module symbol of its module class symbol.
*
* Unlike `genLoadModule`, this method does not fail if the module we load
* refers to the global scope.
*/
def genLoadModuleOrGlobalScope(sym0: Symbol)(
implicit pos: Position): MaybeGlobalScope = {
require(sym0.isModuleOrModuleClass,
"genLoadModule called with non-module symbol: " + sym0)
if (sym0.isModule && sym0.isScala3Defined && sym0.hasAttachment[DottyEnumSingletonCompat.type]) {
/* #4739 This is a reference to a singleton `case` from a Scala 3 `enum`.
* It is not a module. Instead, it is a static field (accessed through
* a static getter) in the `enum` class.
* We use `originalOwner` and `rawname` because that's what the JVM back-end uses.
*/
val className = encodeClassName(sym0.originalOwner)
val getterSimpleName = sym0.rawname.toString()
val getterMethodName = MethodName(getterSimpleName, Nil, toTypeRef(sym0.tpe))
val tree = js.ApplyStatic(js.ApplyFlags.empty, className, js.MethodIdent(getterMethodName), Nil)(
toIRType(sym0.tpe))
MaybeGlobalScope.NotGlobalScope(tree)
} else {
val sym = if (sym0.isModule) sym0.moduleClass else sym0
// Does that module refer to the global scope?
if (sym.hasAnnotation(JSGlobalScopeAnnotation)) {
MaybeGlobalScope.GlobalScope(pos)
} else {
if (sym == currentClassSym.get && isModuleInitialized.get != null && isModuleInitialized.value) {
/* This is a LoadModule(myClass) after the StoreModule(). It is
* guaranteed to always return the `this` value. We eagerly replace
* it by a `This()` node to help the elidable constructors analysis
* of the linker. If we don't do this, then the analysis must
* tolerate `LoadModule(myClass)` after `StoreModule()` to be
* side-effect-free, but that would weaken the guarantees resulting
* from the analysis. In particular, it cannot guarantee that the
* result of a `LoadModule()` of a module with elidable constructors
* is always fully initialized.
*/
MaybeGlobalScope.NotGlobalScope(genThis())
} else {
val className = encodeClassName(sym)
val tree =
if (isJSType(sym)) js.LoadJSModule(className)
else js.LoadModule(className)
MaybeGlobalScope.NotGlobalScope(tree)
}
}
}
}
private final val GenericGlobalObjectInformationMsg = {
"\n " +
"See https://www.scala-js.org/doc/interoperability/global-scope.html " +
"for further information."
}
/** Rule out the `GlobalScope` case of a `MaybeGlobalScope` and extract the
* value tree.
*
* If `tree` represents the global scope, report a compile error.
*/
private def ruleOutGlobalScope(tree: MaybeGlobalScope): js.Tree = {
tree match {
case MaybeGlobalScope.NotGlobalScope(t) =>
t
case MaybeGlobalScope.GlobalScope(pos) =>
reportErrorLoadGlobalScope()(pos)
}
}
/** Report a compile error specifying that the global scope cannot be
* loaded as a value.
*/
private def reportErrorLoadGlobalScope()(implicit pos: Position): js.Tree = {
reporter.error(pos,
"Loading the global scope as a value (anywhere but as the " +
"left-hand-side of a `.`-selection) is not allowed." +
GenericGlobalObjectInformationMsg)
js.Undefined()(pos)
}
/** Gen a JS bracket select or a `JSGlobalRef`.
*
* If the receiver is a normal value, i.e., not the global scope, then
* emit a `JSBracketSelect`.
*
* Otherwise, if the `item` is a constant string that is a valid
* JavaScript identifier, emit a `JSGlobalRef`.
*
* Otherwise, report a compile error.
*/
private def genJSBracketSelectOrGlobalRef(qual: MaybeGlobalScope,
item: js.Tree)(implicit pos: Position): js.AssignLhs = {
qual match {
case MaybeGlobalScope.NotGlobalScope(qualTree) =>
js.JSSelect(qualTree, item)
case MaybeGlobalScope.GlobalScope(_) =>
genJSGlobalRef(item, "Selecting a field", "selection")
}
}
/** Gen a JS bracket method apply or an apply of a `GlobalRef`.
*
* If the receiver is a normal value, i.e., not the global scope, then
* emit a `JSBracketMethodApply`.
*
* Otherwise, if the `method` is a constant string that is a valid
* JavaScript identifier, emit a `JSFunctionApply(JSGlobalRef(...), ...)`.
*
* Otherwise, report a compile error.
*/
private def genJSBracketMethodApplyOrGlobalRefApply(
receiver: MaybeGlobalScope, method: js.Tree,
args: List[js.TreeOrJSSpread])(
implicit pos: Position): js.Tree = {
receiver match {
case MaybeGlobalScope.NotGlobalScope(receiverTree) =>
js.JSMethodApply(receiverTree, method, args)
case MaybeGlobalScope.GlobalScope(_) =>
val globalRef = genJSGlobalRef(method, "Calling a method", "call")
js.JSFunctionApply(globalRef, args)
}
}
private def genJSGlobalRef(propName: js.Tree,
actionFull: String, actionSimpleNoun: String)(
implicit pos: Position): js.JSGlobalRef = {
propName match {
case js.StringLiteral(value) =>
if (js.JSGlobalRef.isValidJSGlobalRefName(value)) {
if (value == "await") {
global.runReporting.warning(pos,
s"$actionFull of the global scope with the name '$value' is deprecated.\n" +
" It may produce invalid JavaScript code causing a SyntaxError in some environments." +
GenericGlobalObjectInformationMsg,
WarningCategory.Deprecation,
currentMethodSym.get)
}
js.JSGlobalRef(value)
} else if (js.JSGlobalRef.ReservedJSIdentifierNames.contains(value)) {
reporter.error(pos,
s"Invalid $actionSimpleNoun in the global scope of the reserved identifier name `$value`." +
GenericGlobalObjectInformationMsg)
js.JSGlobalRef("erroneous")
} else {
reporter.error(pos,
s"$actionFull of the global scope whose name is not a valid JavaScript identifier is not allowed." +
GenericGlobalObjectInformationMsg)
js.JSGlobalRef("erroneous")
}
case _ =>
reporter.error(pos,
s"$actionFull of the global scope with a dynamic name is not allowed." +
GenericGlobalObjectInformationMsg)
js.JSGlobalRef("erroneous")
}
}
private def genAssignableField(sym: Symbol, qualifier: Tree)(
implicit pos: Position): (js.AssignLhs, Boolean) = {
def qual = genExpr(qualifier)
if (isNonNativeJSClass(sym.owner)) {
val f = if (isExposed(sym)) {
js.JSSelect(qual, genExpr(jsNameOf(sym)))
} else if (isAnonymousJSClass(sym.owner)) {
js.JSSelect(
js.JSSelect(qual, genPrivateFieldsSymbol()),
encodeFieldSymAsStringLiteral(sym))
} else {
js.JSPrivateSelect(qual, encodeFieldSym(sym))
}
(f, true)
} else if (jsInterop.topLevelExportsOf(sym).nonEmpty) {
val f = js.SelectStatic(encodeFieldSym(sym))(jstpe.AnyType)
(f, true)
} else if (jsInterop.staticExportsOf(sym).nonEmpty) {
val exportInfo = jsInterop.staticExportsOf(sym).head
val companionClass = patchedLinkedClassOfClass(sym.owner)
val f = js.JSSelect(
genPrimitiveJSClass(companionClass),
js.StringLiteral(exportInfo.jsName))
(f, true)
} else {
val fieldIdent = encodeFieldSym(sym)
/* #4370 Fields cannot have type NothingType, so we box them as
* scala.runtime.Nothing$ instead. They will be initialized with
* `null`, and any attempt to access them will throw a
* `ClassCastException` (generated in the unboxing code).
*/
toIRType(sym.tpe) match {
case jstpe.NothingType =>
val f = js.Select(qual, fieldIdent)(
encodeClassType(RuntimeNothingClass))
(f, true)
case ftpe =>
val f = js.Select(qual, fieldIdent)(ftpe)
(f, false)
}
}
}
/** Generate access to a static field. */
private def genStaticField(sym: Symbol)(implicit pos: Position): js.Tree = {
/* Static fields are not accessed directly at the IR level, because there
* is no lazily-executed static initializer to make sure they are
* initialized. Instead, reading a static field must always go through a
* static getter with the same name as the field, 0 argument, and with
* the field's type as result type. The static getter is responsible for
* proper initialization, if required.
*/
import scalaPrimitives._
import jsPrimitives._
if (isPrimitive(sym)) {
getPrimitive(sym) match {
case UNITVAL => js.Undefined()
}
} else {
val className = encodeClassName(sym.owner)
val method = encodeStaticFieldGetterSym(sym)
js.ApplyStatic(js.ApplyFlags.empty, className, method, Nil)(toIRType(sym.tpe))
}
}
}
private lazy val hasNewCollections =
!scala.util.Properties.versionNumberString.startsWith("2.12.")
/** Tests whether the given type represents a JavaScript type,
* i.e., whether it extends scala.scalajs.js.Any.
*/
def isJSType(tpe: Type): Boolean =
isJSType(tpe.typeSymbol)
/** Tests whether the given type symbol represents a JavaScript type,
* i.e., whether it extends scala.scalajs.js.Any.
*/
def isJSType(sym: Symbol): Boolean =
sym.hasAnnotation(JSTypeAnnot)
/** Tests whether the given class is a non-native JS class. */
def isNonNativeJSClass(sym: Symbol): Boolean =
!sym.isTrait && isJSType(sym) && !sym.hasAnnotation(JSNativeAnnotation)
def isNestedJSClass(sym: Symbol): Boolean =
sym.isLifted && !isStaticModule(sym.originalOwner) && isJSType(sym)
/** Tests whether the given class is a JS native class. */
private def isJSNativeClass(sym: Symbol): Boolean =
sym.hasAnnotation(JSNativeAnnotation)
/** Tests whether the given member is exposed, i.e., whether it was
* originally a public or protected member of a non-native JS class.
*/
private def isExposed(sym: Symbol): Boolean = {
!sym.isBridge && {
if (sym.isLazy)
sym.isAccessor && sym.accessed.hasAnnotation(ExposedJSMemberAnnot)
else
sym.hasAnnotation(ExposedJSMemberAnnot)
}
}
/** Test whether `sym` is the symbol of a JS function definition */
private def isJSFunctionDef(sym: Symbol): Boolean = {
/* A JS function may only reach the backend if it originally was a lambda.
* This is difficult to check in the backend, so we use the fact that a
* non-lambda, concrete, non-native JS type, cannot implement a method named
* `apply`.
*
* Therefore, a class is a JS lambda iff it is anonymous, its direct
* super class is `js.Function`, and it contains an implementation of an
* `apply` method.
*
* Note that being anonymous implies being concrete and non-native, so we
* do not have to test that.
*/
sym.isAnonymousClass &&
sym.superClass == JSFunctionClass &&
sym.info.decl(nme.apply).filter(JSCallingConvention.isCall(_)).exists
}
private def hasDefaultCtorArgsAndJSModule(classSym: Symbol): Boolean = {
/* Get the companion module class.
* For inner classes the sym.owner.companionModule can be broken,
* therefore companionModule is fetched at uncurryPhase.
*/
val companionClass = enteringPhase(currentRun.uncurryPhase) {
classSym.companionModule
}.moduleClass
def hasDefaultParameters = {
val syms = classSym.info.members.filter(_.isClassConstructor)
enteringPhase(currentRun.uncurryPhase) {
syms.exists(_.paramss.iterator.flatten.exists(_.hasDefault))
}
}
isJSNativeClass(companionClass) && hasDefaultParameters
}
private def patchedLinkedClassOfClass(sym: Symbol): Symbol = {
/* Work around a bug of scalac with linkedClassOfClass where package
* objects are involved (the companion class would somehow exist twice
* in the scope, making an assertion fail in Symbol.suchThat).
* Basically this inlines linkedClassOfClass up to companionClass,
* then replaces the `suchThat` by a `filter` and `head`.
*/
val flatOwnerInfo = {
// inline Symbol.flatOwnerInfo because it is protected
if (sym.needsFlatClasses)
sym.info
sym.owner.rawInfo
}
val result = flatOwnerInfo.decl(sym.name).filter(_ isCoDefinedWith sym)
if (!result.isOverloaded) result
else result.alternatives.head
}
private object DefaultParamInfo {
/** Is the symbol applicable to `DefaultParamInfo`?
*
* This is true iff it is a default accessor and it is not an value class
* `$extension` method. The latter condition is for #4583.
*
* Excluding all `$extension` methods is fine because `DefaultParamInfo`
* is used for JS default accessors, i.e., default accessors of
* `@js.native def`s or of `def`s in JS types. Those can never appear in
* an `AnyVal` class (as a class, it cannot contain `@js.native def`s, and
* as `AnyVal` it cannot also extend `js.Any`).
*/
def isApplicable(sym: Symbol): Boolean =
sym.hasFlag(Flags.DEFAULTPARAM) && !sym.name.endsWith("$extension")
}
/** Info about a default param accessor.
*
* `DefaultParamInfo.isApplicable(sym)` must be true for this class to make
* sense.
*/
private class DefaultParamInfo(sym: Symbol) {
private val methodName = nme.defaultGetterToMethod(sym.name)
def isForConstructor: Boolean = methodName == nme.CONSTRUCTOR
/** When `isForConstructor` is true, returns the owner of the attached
* constructor.
*/
def constructorOwner: Symbol = patchedLinkedClassOfClass(sym.owner)
/** When `isForConstructor` is false, returns the method attached to the
* specified default accessor.
*/
def attachedMethod: Symbol = {
// If there are overloads, we need to find the one that has default params.
val overloads = sym.owner.info.decl(methodName)
if (!overloads.isOverloaded) {
overloads
} else {
/* We should use `suchThat` here instead of `filter`+`head`. Normally,
* it can never happen that two overloads of a method both have default
* params. However, there is a loophole until Scala 2.12, with the
* `-Xsource:2.10` flag, which disables a check and allows that to
* happen in some circumstances. This is still tested as part of the
* partest test `pos/t8157-2.10.scala`. The use of `filter` instead of
* `suchThat` allows those situations not to crash, although that is
* mostly for (intense) backward compatibility purposes.
*
* This loophole can be use to construct a case of miscompilation where
* one of the overloads would be `@js.native` but the other not. We
* don't really care, though, as it needs some deep hackery to produce
* it.
*/
overloads
.filter(_.paramss.exists(_.exists(_.hasFlag(Flags.DEFAULTPARAM))))
.alternatives
.head
}
}
}
private def isStringType(tpe: Type): Boolean =
tpe.typeSymbol == StringClass
protected lazy val isHijackedClass: Set[Symbol] = {
/* This list is a duplicate of ir.Definitions.HijackedClasses, but
* with global.Symbol's instead of IR encoded names as Strings.
* We also add java.lang.Void, which BoxedUnit "erases" to, and
* HackedStringClass if it is defined.
*/
val s = Set[Symbol](
JavaLangVoidClass, BoxedUnitClass, BoxedBooleanClass,
BoxedCharacterClass, BoxedByteClass, BoxedShortClass, BoxedIntClass,
BoxedLongClass, BoxedFloatClass, BoxedDoubleClass, StringClass
)
if (HackedStringClass == NoSymbol) s
else s + HackedStringClass
}
private lazy val InlineAnnotationClass = requiredClass[scala.inline]
private lazy val NoinlineAnnotationClass = requiredClass[scala.noinline]
private lazy val ignoreNoinlineAnnotation: Set[Symbol] = {
val ccClass = getClassIfDefined("scala.util.continuations.ControlContext")
Set(
getMemberIfDefined(ListClass, nme.map),
getMemberIfDefined(ListClass, nme.flatMap),
getMemberIfDefined(ListClass, newTermName("collect")),
getMemberIfDefined(ccClass, nme.map),
getMemberIfDefined(ccClass, nme.flatMap)
) - NoSymbol
}
private def isMaybeJavaScriptException(tpe: Type) =
JavaScriptExceptionClass isSubClass tpe.typeSymbol
def isStaticModule(sym: Symbol): Boolean =
sym.isModuleClass && !sym.isLifted
def isAnonymousJSClass(sym: Symbol): Boolean = {
/* sym.isAnonymousClass simply checks if
* `name containsName tpnme.ANON_CLASS_NAME`
* so after flatten (which we are) it identifies classes nested inside
* anonymous classes as anonymous (notably local classes, see #4278).
*
* Instead we recognize names generated for anonymous classes:
* tpnme.ANON_CLASS_NAME followed by $ where `n` is an integer.
*/
isJSType(sym) && {
val name = sym.name
val i = name.lastIndexOf('$')
i > 0 &&
name.endsWith(tpnme.ANON_CLASS_NAME, i) &&
(i + 1 until name.length).forall(j => name.charAt(j).isDigit)
}
}
sealed abstract class MaybeGlobalScope
object MaybeGlobalScope {
case class NotGlobalScope(tree: js.Tree) extends MaybeGlobalScope
case class GlobalScope(pos: Position) extends MaybeGlobalScope
}
/** Marker object for undefined parameters in JavaScript semantic calls.
*
* To be used inside a `js.Transient` node.
*/
case object UndefinedParam extends js.Transient.Value {
val tpe: jstpe.Type = jstpe.UndefType
def traverse(traverser: ir.Traversers.Traverser): Unit = ()
def transform(transformer: ir.Transformers.Transformer, isStat: Boolean)(
implicit pos: ir.Position): js.Tree = {
js.Transient(this)
}
def printIR(out: ir.Printers.IRTreePrinter): Unit =
out.print("")
}
}
private object GenJSCode {
private val JSObjectClassName = ClassName("scala.scalajs.js.Object")
private val JavaScriptExceptionClassName = ClassName("scala.scalajs.js.JavaScriptException")
private val newSimpleMethodName = SimpleMethodName("new")
private val ObjectArgConstructorName =
MethodName.constructor(List(jstpe.ClassRef(ir.Names.ObjectClass)))
private val lengthMethodName =
MethodName("length", Nil, jstpe.IntRef)
private val charAtMethodName =
MethodName("charAt", List(jstpe.IntRef), jstpe.CharRef)
private val getNameMethodName =
MethodName("getName", Nil, jstpe.ClassRef(ir.Names.BoxedStringClass))
private val isPrimitiveMethodName =
MethodName("isPrimitive", Nil, jstpe.BooleanRef)
private val isInterfaceMethodName =
MethodName("isInterface", Nil, jstpe.BooleanRef)
private val isArrayMethodName =
MethodName("isArray", Nil, jstpe.BooleanRef)
private val getComponentTypeMethodName =
MethodName("getComponentType", Nil, jstpe.ClassRef(ir.Names.ClassClass))
private val getSuperclassMethodName =
MethodName("getSuperclass", Nil, jstpe.ClassRef(ir.Names.ClassClass))
private val isInstanceMethodName =
MethodName("isInstance", List(jstpe.ClassRef(ir.Names.ObjectClass)), jstpe.BooleanRef)
private val isAssignableFromMethodName =
MethodName("isAssignableFrom", List(jstpe.ClassRef(ir.Names.ClassClass)), jstpe.BooleanRef)
private val castMethodName =
MethodName("cast", List(jstpe.ClassRef(ir.Names.ObjectClass)), jstpe.ClassRef(ir.Names.ObjectClass))
private val arrayNewInstanceMethodName = {
MethodName("newInstance",
List(jstpe.ClassRef(ir.Names.ClassClass), jstpe.IntRef),
jstpe.ClassRef(ir.Names.ObjectClass))
}
private val thisOriginalName = OriginalName("this")
private object BlockOrAlone {
def unapply(tree: js.Tree): Some[(List[js.Tree], js.Tree)] = tree match {
case js.Block(trees) => Some((trees.init, trees.last))
case _ => Some((Nil, tree))
}
}
private object FirstInBlockOrAlone {
def unapply(tree: js.Tree): Some[(js.Tree, List[js.Tree])] = tree match {
case js.Block(trees) => Some((trees.head, trees.tail))
case _ => Some((tree, Nil))
}
}
}
