package dotty.tools.backend.sjs
import scala.annotation.switch
import scala.collection.mutable
import dotty.tools.FatalError
import dotty.tools.dotc.CompilationUnit
import dotty.tools.dotc.ast.tpd
import dotty.tools.dotc.core.Phases.Phase
import dotty.tools.dotc.core._
import Periods._
import SymDenotations._
import Contexts._
import Decorators._
import Flags._
import dotty.tools.dotc.ast.Trees._
import Types._
import Symbols._
import Denotations._
import Phases._
import StdNames._
import dotty.tools.dotc.transform.Erasure
import org.scalajs.core.ir
import org.scalajs.core.ir.{ClassKind, Position, Trees => js, Types => jstpe}
import js.OptimizerHints
import JSEncoding._
import JSInterop._
import ScopedVar.withScopedVars
/** Main codegen for Scala.js IR.
*
* [[GenSJSIR]] creates one instance of `JSCodeGen` per compilation unit.
* The `run()` method processes the whole compilation unit and generates
* `.sjsir` files for it.
*
* There are 4 main levels of translation:
*
* - `genCompilationUnit()` iterates through all the type definitions in the
* compilation unit. Each generated `js.ClassDef` is serialized to an
* `.sjsir` file.
* - `genScalaClass()` and other similar methods generate the skeleton of
* classes.
* - `genMethod()` and similar methods generate the declarations of methods.
* - `genStatOrExpr()` and everything else generate the bodies of methods.
*/
class JSCodeGen()(implicit ctx: Context) {
import tpd._
private val jsdefn = JSDefinitions.jsdefn
private val primitives = new JSPrimitives(ctx)
private val positionConversions = new JSPositions()(ctx)
import positionConversions.{pos2irPos, implicitPos2irPos}
// Some state --------------------------------------------------------------
private val currentClassSym = new ScopedVar[Symbol]
private val currentMethodSym = new ScopedVar[Symbol]
private val localNames = new ScopedVar[LocalNameGenerator]
private val thisLocalVarIdent = new ScopedVar[Option[js.Ident]]
private val undefinedDefaultParams = new ScopedVar[mutable.Set[Symbol]]
/** Implicitly materializes the current local name generator. */
private implicit def implicitLocalNames: LocalNameGenerator = localNames.get
/* See genSuperCall()
* TODO Can we avoid this unscoped var?
*/
private var isModuleInitialized: Boolean = false
private def currentClassType = encodeClassType(currentClassSym)
/** Returns a new fresh local identifier. */
private def freshLocalIdent()(implicit pos: Position): js.Ident =
localNames.get.freshLocalIdent()
/** Returns a new fresh local identifier. */
private def freshLocalIdent(base: String)(implicit pos: Position): js.Ident =
localNames.get.freshLocalIdent(base)
// Compilation unit --------------------------------------------------------
def run(): Unit = {
genCompilationUnit(ctx.compilationUnit)
}
/** 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
*
* TODO 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:
* * Scala.js-defined JS class -> `genScalaJSDefinedJSClass()`
* * Other raw JS type (<: js.Any) -> `genRawJSClassData()`
* * Interface -> `genInterface()`
* * Normal class -> `genClass()`
*/
private def genCompilationUnit(cunit: CompilationUnit): Unit = {
def collectTypeDefs(tree: Tree): List[TypeDef] = {
tree match {
case EmptyTree => Nil
case PackageDef(_, stats) => stats.flatMap(collectTypeDefs)
case cd: TypeDef => cd :: Nil
case _: ValDef => Nil // module instance
}
}
val allTypeDefs = collectTypeDefs(cunit.tpdTree)
val generatedClasses = mutable.ListBuffer.empty[(Symbol, js.ClassDef)]
// TODO Record anonymous JS function classes
/* Finally, we emit true code for the remaining class defs. */
for (td <- allTypeDefs) {
val sym = td.symbol
implicit val pos: Position = sym.pos
/* Do not actually emit code for primitive types nor scala.Array. */
val isPrimitive =
sym.isPrimitiveValueClass || sym == defn.ArrayClass
if (!isPrimitive) {
withScopedVars(
currentClassSym := sym
) {
val tree = if (isJSType(sym)) {
/*assert(!isRawJSFunctionDef(sym),
s"Raw JS function def should have been recorded: $cd")*/
if (!sym.is(Trait) && isScalaJSDefinedJSClass(sym))
genScalaJSDefinedJSClass(td)
else
genRawJSClassData(td)
} else if (sym.is(Trait)) {
genInterface(td)
} else {
genScalaClass(td)
}
generatedClasses += ((sym, tree))
}
}
}
val clDefs = generatedClasses.map(_._2).toList
for ((sym, tree) <- generatedClasses) {
val writer = new java.io.PrintWriter(System.err)
try {
new ir.Printers.IRTreePrinter(writer).print(tree)
} finally {
writer.flush()
}
genIRFile(cunit, sym, tree)
}
}
private def genIRFile(cunit: CompilationUnit, sym: Symbol,
tree: ir.Trees.ClassDef): Unit = {
val outfile = getFileFor(cunit, sym, ".sjsir")
val output = outfile.bufferedOutput
try {
ir.InfoSerializers.serialize(output, ir.Infos.generateClassInfo(tree))
ir.Serializers.serialize(output, tree)
} finally {
output.close()
}
}
private def getFileFor(cunit: CompilationUnit, sym: Symbol,
suffix: String) = {
import scala.reflect.io._
val outputDirectory: AbstractFile = // TODO Support virtual files
new PlainDirectory(new Directory(new java.io.File(ctx.settings.d.value)))
val pathParts = sym.fullName.toString.split("[./]")
val dir = (outputDirectory /: pathParts.init)(_.subdirectoryNamed(_))
var filename = pathParts.last
if (sym.is(ModuleClass))
filename = filename + nme.MODULE_SUFFIX.toString
dir fileNamed (filename + suffix)
}
// Generate a class --------------------------------------------------------
/** Gen the IR ClassDef for a Scala class definition (maybe a module class).
*/
private def genScalaClass(td: TypeDef): js.ClassDef = {
val sym = td.symbol.asClass
implicit val pos: Position = sym.pos
assert(!sym.is(Trait),
"genScalaClass() must be called only for normal classes: "+sym)
assert(sym.superClass != NoSymbol, sym)
/*if (hasDefaultCtorArgsAndRawJSModule(sym)) {
reporter.error(pos,
"Implementation restriction: constructors of " +
"Scala classes cannot have default parameters " +
"if their companion module is JS native.")
}*/
val classIdent = encodeClassFullNameIdent(sym)
val isHijacked = false //isHijackedBoxedClass(sym)
// Optimizer hints
def isStdLibClassWithAdHocInlineAnnot(sym: Symbol): Boolean = {
val fullName = sym.fullName.toString
(fullName.startsWith("scala.Tuple") && !fullName.endsWith("$")) ||
(fullName.startsWith("scala.collection.mutable.ArrayOps$of"))
}
val shouldMarkInline = (
sym.hasAnnotation(jsdefn.InlineAnnot) ||
(sym.isAnonymousFunction && !sym.isSubClass(defn.PartialFunctionClass)) ||
isStdLibClassWithAdHocInlineAnnot(sym))
val optimizerHints = {
OptimizerHints.empty
.withInline(shouldMarkInline)
.withNoinline(sym.hasAnnotation(jsdefn.NoinlineAnnot))
}
// Generate members (constructor + methods)
val generatedMethods = new mutable.ListBuffer[js.MethodDef]
val exportedSymbols = new mutable.ListBuffer[Symbol]
val tpl = td.rhs.asInstanceOf[Template]
for (tree <- tpl.constr :: tpl.body) {
tree match {
case EmptyTree => ()
case _: ValDef =>
() // fields are added via genClassFields()
case dd: DefDef =>
val sym = dd.symbol
val isExport = false //jsInterop.isExport(sym)
val isNamedExport = false /*isExport && sym.annotations.exists(
_.symbol == JSExportNamedAnnotation)*/
/*if (isNamedExport)
generatedMethods += genNamedExporterDef(dd)
else*/
generatedMethods ++= genMethod(dd)
if (isExport) {
// We add symbols that we have to export here. This way we also
// get inherited stuff that is implemented in this class.
exportedSymbols += sym
}
case _ =>
throw new FatalError("Illegal tree in body of genScalaClass(): " + tree)
}
}
// Generate fields and add to methods + ctors
val generatedMembers = genClassFields(td) ++ generatedMethods.toList
// Generate the exported members, constructors and accessors
val exports = {
// Hack to export hello.world
if (sym.fullName.toString == "hello.world$") {
List(
js.ModuleExportDef("hello.world"),
js.MethodDef(static = false, js.StringLiteral("main"),
Nil, jstpe.AnyType,
js.Block(List(
js.Apply(js.This()(jstpe.ClassType(classIdent.name)), js.Ident("main__V"), Nil)(jstpe.NoType),
js.Undefined())))(
OptimizerHints.empty, None))
} else {
/*
// Generate the exported members
val memberExports = genMemberExports(sym, exportedSymbols.toList)
// Generate exported constructors or accessors
val exportedConstructorsOrAccessors =
if (isStaticModule(sym)) genModuleAccessorExports(sym)
else genConstructorExports(sym)
memberExports ++ exportedConstructorsOrAccessors
*/
Nil
}
}
// Hashed definitions of the class
val hashedDefs =
ir.Hashers.hashDefs(generatedMembers ++ exports)
// The complete class definition
val kind =
if (isStaticModule(sym)) ClassKind.ModuleClass
else if (isHijacked) ClassKind.HijackedClass
else ClassKind.Class
val classDefinition = js.ClassDef(
classIdent,
kind,
Some(encodeClassFullNameIdent(sym.superClass)),
genClassInterfaces(sym),
None,
hashedDefs)(
optimizerHints)
classDefinition
}
/** Gen the IR ClassDef for a Scala.js-defined JS class. */
private def genScalaJSDefinedJSClass(td: TypeDef): js.ClassDef = {
???
}
/** Gen the IR ClassDef for a raw JS class or trait.
*/
private def genRawJSClassData(td: TypeDef): js.ClassDef = {
val sym = td.symbol.asClass
implicit val pos: Position = sym.pos
val classIdent = encodeClassFullNameIdent(sym)
val superClass =
if (sym.is(Trait)) None
else Some(encodeClassFullNameIdent(sym.superClass))
val jsName =
if (sym.is(Trait) || sym.is(ModuleClass)) None
else Some(fullJSNameOf(sym))
js.ClassDef(classIdent, ClassKind.RawJSType,
superClass,
genClassInterfaces(sym),
jsName,
Nil)(
OptimizerHints.empty)
}
/** Gen the IR ClassDef for an interface definition.
*/
private def genInterface(td: TypeDef): js.ClassDef = {
val sym = td.symbol.asClass
implicit val pos: Position = sym.pos
val classIdent = encodeClassFullNameIdent(sym)
val generatedMethods = new mutable.ListBuffer[js.MethodDef]
val tpl = td.rhs.asInstanceOf[Template]
for (tree <- tpl.constr :: tpl.body) {
tree match {
case EmptyTree => ()
case dd: DefDef => generatedMethods ++= genMethod(dd)
case _ =>
throw new FatalError("Illegal tree in gen of genInterface(): " + tree)
}
}
val superInterfaces = genClassInterfaces(sym)
// Hashed definitions of the interface
val hashedDefs =
ir.Hashers.hashDefs(generatedMethods.toList)
js.ClassDef(classIdent, ClassKind.Interface, None, superInterfaces, None,
hashedDefs)(OptimizerHints.empty)
}
private def genClassInterfaces(sym: ClassSymbol)(
implicit pos: Position): List[js.Ident] = {
import dotty.tools.dotc.transform.SymUtils._
for {
intf <- sym.directlyInheritedTraits
} yield {
encodeClassFullNameIdent(intf)
}
}
// Generate the fields of a class ------------------------------------------
/** Gen definitions for the fields of a class.
*/
private def genClassFields(td: TypeDef): List[js.FieldDef] = {
val classSym = td.symbol.asClass
assert(currentClassSym.get == classSym,
"genClassFields called with a ClassDef other than the current one")
// Non-method term members are fields
(for {
f <- classSym.info.decls
if !f.is(Method) && f.isTerm
} yield {
implicit val pos: Position = f.pos
val name =
/*if (isExposed(f)) js.StringLiteral(jsNameOf(f))
else*/ encodeFieldSym(f)
val irTpe = //if (!isScalaJSDefinedJSClass(classSym)) {
toIRType(f.info)
/*} else {
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.
*
* TODO Evaluate how much of this needs to be adapted for dotc,
* which unboxes `null` to the zero of their underlying.
*/
jstpe.ClassType(encodeClassFullName(tpe.valueClazz))
case _ if f.tpe.typeSymbol == CharClass =>
/* Will be initialized to null, which will unbox to '\0' when
* read.
*/
jstpe.ClassType(ir.Definitions.BoxedCharacterClass)
case _ =>
/* Other types are not boxed, so we can initialized them to
* their true zero.
*/
toIRType(f.tpe)
}
}*/
js.FieldDef(name, irTpe, f.is(Mutable))
}).toList
}
// Generate a method -------------------------------------------------------
private def genMethod(dd: DefDef): Option[js.MethodDef] = {
withScopedVars(
localNames := new LocalNameGenerator
) {
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.
*
* Some methods are not emitted at all:
* - Primitives, since they are never actually called
* - Constructors of hijacked classes
*
* Constructors are emitted by generating their body as a statement.
*
* Other (normal) methods are emitted with `genMethodBody()`.
*/
private def genMethodWithCurrentLocalNameScope(dd: DefDef): Option[js.MethodDef] = {
implicit val pos: Position = dd.pos
val sym = dd.symbol
val vparamss = dd.vparamss
val rhs = dd.rhs
isModuleInitialized = false
withScopedVars(
currentMethodSym := sym,
undefinedDefaultParams := mutable.Set.empty,
thisLocalVarIdent := None
) {
assert(vparamss.isEmpty || vparamss.tail.isEmpty,
"Malformed parameter list: " + vparamss)
val params = if (vparamss.isEmpty) Nil else vparamss.head.map(_.symbol)
val isJSClassConstructor =
sym.isClassConstructor && isScalaJSDefinedJSClass(currentClassSym)
val methodName: js.PropertyName = encodeMethodSym(sym)
def jsParams = for (param <- params) yield {
implicit val pos: Position = param.pos
js.ParamDef(encodeLocalSym(param), toIRType(param.info),
mutable = false, rest = false)
}
/*if (primitives.isPrimitive(sym)) {
None
} else*/ if (sym.is(Deferred)) {
Some(js.MethodDef(static = false, methodName,
jsParams, toIRType(patchedResultType(sym)), js.EmptyTree)(
OptimizerHints.empty, None))
} else /*if (isJSNativeCtorDefaultParam(sym)) {
None
} else if (sym.isClassConstructor && isHijackedBoxedClass(sym.owner)) {
None
} else*/ {
/*def isTraitImplForwarder = dd.rhs match {
case app: Apply => foreignIsImplClass(app.symbol.owner)
case _ => false
}*/
val shouldMarkInline = {
sym.hasAnnotation(jsdefn.InlineAnnot) ||
sym.isAnonymousFunction
}
val shouldMarkNoinline = {
sym.hasAnnotation(jsdefn.NoinlineAnnot) /*&&
!isTraitImplForwarder*/
}
val optimizerHints = {
OptimizerHints.empty
.withInline(shouldMarkInline)
.withNoinline(shouldMarkNoinline)
}
val methodDef = {
/*if (isJSClassConstructor) {
val body0 = genStat(rhs)
val body1 =
if (!sym.isPrimaryConstructor) body0
else moveAllStatementsAfterSuperConstructorCall(body0)
js.MethodDef(static = false, methodName,
jsParams, jstpe.NoType, body1)(optimizerHints, None)
} else*/ if (sym.isConstructor) {
js.MethodDef(static = false, methodName,
jsParams, jstpe.NoType,
genStat(rhs))(optimizerHints, None)
} else {
val resultIRType = toIRType(patchedResultType(sym))
genMethodDef(static = false, methodName,
params, resultIRType, rhs, optimizerHints)
}
}
Some(methodDef)
}
}
}
/** 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.
*
* Methods Scala.js-defined JS classes are compiled as static methods taking
* an explicit parameter for their `this` value.
*/
private def genMethodDef(static: Boolean, methodName: js.PropertyName,
paramsSyms: List[Symbol], resultIRType: jstpe.Type,
tree: Tree, optimizerHints: OptimizerHints): js.MethodDef = {
implicit val pos: Position = tree.pos
ctx.debuglog("genMethod " + methodName.name)
ctx.debuglog("")
val jsParams = for (param <- paramsSyms) yield {
implicit val pos: Position = param.pos
js.ParamDef(encodeLocalSym(param), toIRType(param.info),
mutable = false, rest = false)
}
def genBody() =
if (resultIRType == jstpe.NoType) genStat(tree)
else genExpr(tree)
//if (!isScalaJSDefinedJSClass(currentClassSym)) {
js.MethodDef(static, methodName, jsParams, resultIRType, genBody())(
optimizerHints, None)
/*} else {
assert(!static, tree.pos)
withScopedVars(
thisLocalVarIdent := Some(freshLocalIdent("this"))
) {
val thisParamDef = js.ParamDef(thisLocalVarIdent.get.get,
jstpe.AnyType, mutable = false, rest = false)
js.MethodDef(static = true, methodName, thisParamDef :: jsParams,
resultIRType, genBody())(
optimizerHints, None)
}
}*/
}
// Generate statements and expressions -------------------------------------
/** Gen JS code for a tree in statement position (in the IR).
*/
private def genStat(tree: Tree): js.Tree = {
exprToStat(genStatOrExpr(tree, isStat = true))
}
/** Turn a JavaScript expression of type Unit into a statement */
private 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: Position = tree.pos
tree match {
case js.Block(stats :+ expr) => js.Block(stats :+ exprToStat(expr))
case _:js.Literal | js.This() => js.Skip()
case _ => tree
}
}
/** Gen JS code for a tree in expression position (in the IR).
*/
private 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 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.
*/
private def genStatOrExpr(tree: Tree, isStat: Boolean): js.Tree = {
implicit val pos: Position = tree.pos
ctx.debuglog(" " + tree)
ctx.debuglog("")
tree match {
/** LabelDefs (for while and do..while loops) */
/*case lblDf: LabelDef =>
genLabelDef(lblDf)*/
/** Local val or var declaration */
case tree @ ValDef(name, _, _) =>
/* Must have been eliminated by the tail call transform performed
* by genMethodBody(). */
assert(name != nme.THIS,
s"ValDef(_, nme.THIS, _, _) found at ${tree.pos}")
val sym = tree.symbol
val rhs = tree.rhs
val rhsTree = genExpr(rhs)
rhsTree match {
case js.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 _ =>
js.VarDef(encodeLocalSym(sym),
toIRType(sym.info), sym.is(Mutable), rhsTree)
}
case If(cond, thenp, elsep) =>
js.If(genExpr(cond), genStatOrExpr(thenp, isStat),
genStatOrExpr(elsep, isStat))(toIRType(tree.tpe))
case Return(expr, from) =>
// TODO Need to consider `from`?
js.Return(toIRType(expr.tpe) match {
case jstpe.NoType => js.Block(genStat(expr), js.Undefined())
case _ => genExpr(expr)
})
/*case t: Try =>
genTry(t, isStat)*/
case app: Apply =>
genApply(app, isStat)
case app: TypeApply =>
genTypeApply(app)
/*case app: ApplyDynamic =>
genApplyDynamic(app)*/
case tree: This =>
if (tree.symbol == currentClassSym.get) {
genThis()
} else {
assert(tree.symbol.is(Module),
"Trying to access the this of another class: " +
"tree.symbol = " + tree.symbol +
", class symbol = " + currentClassSym.get +
" pos:" + pos)
genLoadModule(tree.symbol)
}
case Select(qualifier, _) =>
val sym = tree.symbol
if (sym.is(Module)) {
assert(!sym.is(Package), "Cannot use package as value: " + tree)
genLoadModule(sym)
} else if (sym.is(JavaStatic)) {
genLoadStaticField(sym)
} else /*if (paramAccessorLocals contains sym) {
paramAccessorLocals(sym).ref
} else if (isScalaJSDefinedJSClass(sym.owner)) {
val genQual = genExpr(qualifier)
val boxed = if (isExposed(sym))
js.JSBracketSelect(genQual, js.StringLiteral(jsNameOf(sym)))
else
js.JSDotSelect(genQual, encodeFieldSym(sym))
fromAny(boxed,
enteringPhase(currentRun.posterasurePhase)(sym.tpe))
} else*/ {
js.Select(genExpr(qualifier),
encodeFieldSym(sym))(toIRType(sym.info))
}
case tree: Ident =>
desugarIdent(tree).fold[js.Tree] {
val sym = tree.symbol
assert(!sym.is(Package), "Cannot use package as value: " + tree)
if (sym.is(Module)) {
genLoadModule(sym)
} else if (undefinedDefaultParams.contains(sym)) {
/* This is a default parameter whose assignment was moved to
* a local variable. Put an undefined param instead.
*/
js.UndefinedParam()(toIRType(sym.info))
} else {
js.VarRef(encodeLocalSym(sym))(toIRType(sym.info))
}
} { select =>
genStatOrExpr(select, isStat)
}
case Literal(value) =>
import Constants._
value.tag match {
case UnitTag =>
js.Skip()
case BooleanTag =>
js.BooleanLiteral(value.booleanValue)
case ByteTag | ShortTag | CharTag | 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 =>
genClassConstant(value.typeValue)
/*case EnumTag =>
genStaticMember(value.symbolValue)*/
}
case Block(stats, expr) =>
js.Block(stats.map(genStat) :+ genStatOrExpr(expr, isStat))
case Typed(expr, _) =>
expr match {
case _: Super => genThis()
case _ => genExpr(expr)
}
case Assign(lhs0, rhs) =>
val sym = lhs0.symbol
if (sym.is(JavaStaticTerm))
throw new FatalError(s"Assignment to static member ${sym.fullName} not supported")
val genRhs = genExpr(rhs)
val lhs = lhs0 match {
case lhs: Ident => desugarIdent(lhs).getOrElse(lhs)
case lhs => lhs
}
lhs match {
case lhs: Select =>
val qualifier = lhs.qualifier
def ctorAssignment = (
currentMethodSym.get.name == nme.CONSTRUCTOR &&
currentMethodSym.get.owner == qualifier.symbol &&
qualifier.isInstanceOf[This]
)
if (!sym.is(Mutable) && !ctorAssignment)
throw new FatalError(s"Assigning to immutable field ${sym.fullName} at $pos")
val genQual = genExpr(qualifier)
/*if (isScalaJSDefinedJSClass(sym.owner)) {
val genLhs = if (isExposed(sym))
js.JSBracketSelect(genQual, js.StringLiteral(jsNameOf(sym)))
else
js.JSDotSelect(genQual, encodeFieldSym(sym))
val boxedRhs =
ensureBoxed(genRhs,
enteringPhase(currentRun.posterasurePhase)(rhs.tpe))
js.Assign(genLhs, boxedRhs)
} else {*/
js.Assign(
js.Select(genQual, encodeFieldSym(sym))(toIRType(sym.info)),
genRhs)
//}
case _ =>
js.Assign(
js.VarRef(encodeLocalSym(sym))(toIRType(sym.info)),
genRhs)
}
/** Array constructor */
case javaSeqLiteral: JavaSeqLiteral =>
genJavaSeqLiteral(javaSeqLiteral)
/** A Match reaching the backend is supposed to be optimized as a switch */
/*case mtch: Match =>
genMatch(mtch, isStat)*/
case tree: Closure =>
genClosure(tree)
/*case EmptyTree =>
js.Skip()*/
case _ =>
throw new FatalError("Unexpected tree in genExpr: " +
tree + "/" + tree.getClass + " at: " + (tree.pos: Position))
}
} // end of genStatOrExpr()
// !!! DUPLICATE code with DottyBackendInterface
private def desugarIdent(i: Ident): Option[Select] = {
i.tpe match {
case TermRef(prefix: TermRef, name) =>
Some(tpd.ref(prefix).select(i.symbol))
case TermRef(prefix: ThisType, name) =>
Some(tpd.This(prefix.cls).select(i.symbol))
/*case TermRef(NoPrefix, name) =>
if (i.symbol is Method) Some(This(i.symbol.topLevelClass).select(i.symbol)) // workaround #342 todo: remove after fixed
else None*/
case _ =>
None
}
}
private def qualifierOf(fun: Tree): Tree = fun match {
case fun: Ident =>
fun.tpe match {
case TermRef(prefix: TermRef, _) => tpd.ref(prefix)
case TermRef(prefix: ThisType, _) => tpd.This(prefix.cls)
}
case Select(qualifier, _) =>
qualifier
case TypeApply(fun, _) =>
qualifierOf(fun)
}
/** Gen JS this of the current class.
* Normally encoded straightforwardly as a JS this.
* But must be replaced by the `thisLocalVarIdent` local variable if there
* is one.
*/
private def genThis()(implicit pos: Position): js.Tree = {
/*if (tryingToGenMethodAsJSFunction) {
throw new CancelGenMethodAsJSFunction(
"Trying to generate `this` inside the body")
}*/
thisLocalVarIdent.fold[js.Tree] {
js.This()(currentClassType)
} { thisLocalIdent =>
js.VarRef(thisLocalIdent)(currentClassType)
}
}
/** 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.
*/
private def genApply(tree: Apply, isStat: Boolean): js.Tree = {
implicit val pos: Position = tree.pos
val args = tree.args
val sym = tree.fun.symbol
val fun = tree.fun match {
case fun: Ident => desugarIdent(fun).getOrElse(fun)
case fun => fun
}
fun match {
case _ if isJSDefaultParam(sym) =>
js.UndefinedParam()(toIRType(sym.info.finalResultType))
case Select(Super(_, _), _) =>
genSuperCall(tree, isStat)
case Select(New(_), nme.CONSTRUCTOR) =>
genApplyNew(tree)
case _ =>
/*if (sym.isLabel) {
genLabelApply(tree)
} else*/ if (primitives.isPrimitive(tree)) {
genPrimitiveOp(tree, isStat)
} else if (Erasure.Boxing.isBox(sym)) {
// Box a primitive value (cannot be Unit)
val arg = args.head
makePrimitiveBox(genExpr(arg), arg.tpe)
} else if (Erasure.Boxing.isUnbox(sym)) {
// Unbox a primitive value (cannot be Unit)
val arg = args.head
makePrimitiveUnbox(genExpr(arg), tree.tpe)
} else {
genNormalApply(tree, isStat)
}
}
}
/** 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 in Scala, the `mix` item is
* irrelevant.
*/
private def genSuperCall(tree: Apply, isStat: Boolean): js.Tree = {
implicit val pos: Position = tree.pos
val Apply(fun @ Select(sup @ Super(_, mix), _), args) = tree
val sym = fun.symbol
if (sym == defn.Any_getClass) {
// The only primitive that is also callable as super call
js.GetClass(genThis())
} else /*if (isScalaJSDefinedJSClass(currentClassSym)) {
genJSSuperCall(tree, isStat)
} else*/ {
val superCall = genApplyMethodStatically(
genThis()(sup.pos), sym, genActualArgs(sym, args))
// Initialize the module instance just after the super constructor call.
if (isStaticModule(currentClassSym) && !isModuleInitialized &&
currentMethodSym.get.isClassConstructor) {
isModuleInitialized = true
val thisType = jstpe.ClassType(encodeClassFullName(currentClassSym))
val initModule = js.StoreModule(thisType, js.This()(thisType))
js.Block(superCall, initModule)
} 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 raw JS class
* * new Array
* * regular new
*/
private def genApplyNew(tree: Apply): js.Tree = {
implicit val pos: Position = tree.pos
val Apply(fun @ Select(New(tpt), nme.CONSTRUCTOR), args) = tree
val ctor = fun.symbol
val tpe = tpt.tpe
assert(ctor.isClassConstructor,
"'new' call to non-constructor: " + ctor.name)
if (tpe.isRef(defn.StringClass)) {
genNewString(ctor, genActualArgs(ctor, args))
} else /*if (isHijackedBoxedClass(tpe.typeSymbol)) {
genNewHijackedBoxedClass(tpe.typeSymbol, ctor, args map genExpr)
} else if (translatedAnonFunctions contains tpe.typeSymbol) {
val functionMaker = translatedAnonFunctions(tpe.typeSymbol)
functionMaker(args map genExpr)
} else*/ if (isJSType(tpe.widenDealias.typeSymbol)) {
val clsSym = tpe.widenDealias.typeSymbol
if (clsSym == jsdefn.JSObjectClass && args.isEmpty) js.JSObjectConstr(Nil)
else if (clsSym == jsdefn.JSArrayClass && args.isEmpty) js.JSArrayConstr(Nil)
else js.JSNew(genLoadJSConstructor(clsSym), genActualJSArgs(ctor, args))
} else {
toIRType(tpe) match {
case cls: jstpe.ClassType =>
js.New(cls, encodeMethodSym(ctor), genActualArgs(ctor, args))
case other =>
throw new FatalError(s"Non ClassType cannot be instantiated: $other")
}
}
}
/** Gen JS code for a primitive method call. */
private def genPrimitiveOp(tree: Apply, isStat: Boolean): js.Tree = {
import scala.tools.nsc.backend.ScalaPrimitives._
implicit val pos: Position = tree.pos
val Apply(fun, args) = tree
val receiver = qualifierOf(fun)
val code = primitives.getPrimitive(tree, receiver.tpe)
if (isArithmeticOp(code) || isLogicalOp(code) || isComparisonOp(code))
genSimpleOp(tree, receiver :: args, code)
else if (code == CONCAT)
genStringConcat(tree, receiver, args)
else if (code == HASH)
genScalaHash(tree, receiver)
else if (isArrayOp(code))
genArrayOp(tree, code)
else if (code == SYNCHRONIZED)
genSynchronized(tree, isStat)
else if (isCoercion(code))
genCoercion(tree, receiver, code)
else if (code == JSPrimitives.THROW)
genThrow(tree, args)
else /*if (primitives.isJSPrimitive(code))
genJSPrimitive(tree, receiver, args, code)
else*/
throw new FatalError(s"Unknown primitive: ${tree.symbol.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 = {
args match {
case List(arg) => genSimpleUnaryOp(tree, arg, code)
case List(lhs, rhs) => genSimpleBinaryOp(tree, lhs, rhs, code)
case _ => throw new FatalError("Incorrect arity for primitive")
}
}
/** Gen JS code for a simple unary operation. */
private def genSimpleUnaryOp(tree: Apply, arg: Tree, code: Int): js.Tree = {
import scala.tools.nsc.backend.ScalaPrimitives._
implicit val pos: Position = tree.pos
val genArg = genExpr(arg)
val resultIRType = toIRType(tree.tpe)
(code: @switch) match {
case POS =>
genArg
case NEG =>
(resultIRType: @unchecked) match {
case jstpe.IntType =>
js.BinaryOp(js.BinaryOp.Int_-, js.IntLiteral(0), genArg)
case jstpe.LongType =>
js.BinaryOp(js.BinaryOp.Long_-, js.LongLiteral(0), genArg)
case jstpe.FloatType =>
js.BinaryOp(js.BinaryOp.Float_-, js.FloatLiteral(0.0f), genArg)
case jstpe.DoubleType =>
js.BinaryOp(js.BinaryOp.Double_-, js.DoubleLiteral(0), genArg)
}
case NOT =>
(resultIRType: @unchecked) match {
case jstpe.IntType =>
js.BinaryOp(js.BinaryOp.Int_^, js.IntLiteral(-1), genArg)
case jstpe.LongType =>
js.BinaryOp(js.BinaryOp.Long_^, js.LongLiteral(-1), genArg)
}
case ZNOT =>
js.UnaryOp(js.UnaryOp.Boolean_!, genArg)
case _ =>
throw new FatalError("Unknown unary operation code: " + code)
}
}
/** Gen JS code for a simple binary operation. */
private def genSimpleBinaryOp(tree: Apply, lhs: Tree, rhs: Tree, code: Int): js.Tree = {
import scala.tools.nsc.backend.ScalaPrimitives._
import js.UnaryOp._
/* Codes for operation types, in an object so that they can be 'final val'
* and be used in switch-matches.
*/
object OpTypes {
final val DoubleOp = 1
final val FloatOp = 2
final val LongOp = 3
final val IntOp = 4
final val BooleanOp = 5
final val AnyOp = 6
}
import OpTypes._
implicit val pos: Position = tree.pos
val lhsIRType = toIRType(lhs.tpe)
val rhsIRType = toIRType(rhs.tpe)
val opType = (lhsIRType, rhsIRType) match {
case (jstpe.DoubleType, _) | (_, jstpe.DoubleType) => DoubleOp
case (jstpe.FloatType, _) | (_, jstpe.FloatType) => FloatOp
case (jstpe.LongType, _) | (_, jstpe.LongType) => LongOp
case (jstpe.IntType, _) | (_, jstpe.IntType) => IntOp
case (jstpe.BooleanType, jstpe.BooleanType) => BooleanOp
case _ => AnyOp
}
if (opType == AnyOp && isUniversalEqualityOp(code)) {
genUniversalEqualityOp(lhs, rhs, code)
} else if (code == ZOR) {
js.If(genExpr(lhs), js.BooleanLiteral(true), genExpr(rhs))(jstpe.BooleanType)
} else if (code == ZAND) {
js.If(genExpr(lhs), genExpr(rhs), js.BooleanLiteral(false))(jstpe.BooleanType)
} else {
import js.BinaryOp._
def coerce(tree: js.Tree, opType: Int): js.Tree = (opType: @switch) match {
case DoubleOp =>
if (tree.tpe == jstpe.LongType) js.UnaryOp(LongToDouble, tree)
else tree
case FloatOp =>
if (tree.tpe == jstpe.FloatType || tree.tpe == jstpe.IntType) tree
else js.UnaryOp(DoubleToFloat, coerce(tree, DoubleOp))
case LongOp =>
if (tree.tpe == jstpe.LongType) tree
else {
assert(tree.tpe == jstpe.IntType)
js.UnaryOp(IntToLong, tree)
}
case IntOp =>
if (tree.tpe == jstpe.IntType) tree
else {
assert(tree.tpe == jstpe.LongType)
js.UnaryOp(LongToInt, tree)
}
case BooleanOp | AnyOp =>
tree
}
val rhsOpType = code match {
case LSL | LSR | ASR => IntOp
case _ => opType
}
val genLhs = coerce(genExpr(lhs), opType)
val genRhs = coerce(genExpr(rhs), rhsOpType)
val op = (opType: @switch) match {
case IntOp =>
(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 => Num_==
case NE => Num_!=
case LT => Num_<
case LE => Num_<=
case GT => Num_>
case GE => Num_>=
}
case FloatOp =>
(code: @switch) match {
case ADD => Float_+
case SUB => Float_-
case MUL => Float_*
case DIV => Float_/
case MOD => Float_%
case EQ => Num_==
case NE => Num_!=
case LT => Num_<
case LE => Num_<=
case GT => Num_>
case GE => Num_>=
}
case DoubleOp =>
(code: @switch) match {
case ADD => Double_+
case SUB => Double_-
case MUL => Double_*
case DIV => Double_/
case MOD => Double_%
case EQ => Num_==
case NE => Num_!=
case LT => Num_<
case LE => Num_<=
case GT => Num_>
case GE => Num_>=
}
case LongOp =>
(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_>=
}
case BooleanOp =>
(code: @switch) match {
case EQ => Boolean_==
case NE => Boolean_!=
case OR => Boolean_|
case AND => Boolean_&
case XOR => Boolean_!=
}
case AnyOp =>
/* No @switch because some 2.11 version erroneously report a warning
* for switches with less than 3 non-default cases.
*/
code match {
case ID => ===
case NI => !==
}
}
js.BinaryOp(op, genLhs, genRhs)
}
}
/** Gen JS code for a universal equality test. */
private def genUniversalEqualityOp(lhs: Tree, rhs: Tree, code: Int)(
implicit pos: Position): js.Tree = {
import scala.tools.nsc.backend.ScalaPrimitives._
val genLhs = genExpr(lhs)
val genRhs = genExpr(rhs)
val bypassEqEq = {
// Do not call equals if we have a literal null at either side.
genLhs.isInstanceOf[js.Null] ||
genRhs.isInstanceOf[js.Null]
}
if (bypassEqEq) {
js.BinaryOp(
if (code == EQ) js.BinaryOp.=== else js.BinaryOp.!==,
genLhs, genRhs)
} else {
val body = genEqEqPrimitive(lhs.tpe, rhs.tpe, genLhs, genRhs)
if (code == EQ) body
else js.UnaryOp(js.UnaryOp.Boolean_!, body)
}
}
private lazy val externalEqualsNumNum: Symbol =
defn.BoxesRunTimeModule.requiredMethod(nme.equalsNumNum)
private lazy val externalEqualsNumChar: Symbol =
NoSymbol // ctx.requiredMethod(BoxesRunTimeTypeRef, nme.equalsNumChar) // this method is private
private lazy val externalEqualsNumObject: Symbol =
defn.BoxesRunTimeModule.requiredMethod(nme.equalsNumObject)
private lazy val externalEquals: Symbol =
defn.BoxesRunTimeClass.info.decl(nme.equals_).suchThat(toDenot(_).info.firstParamTypes.size == 2).symbol
/** Gen JS code for a call to Any.== */
private def genEqEqPrimitive(ltpe: Type, rtpe: Type, lsrc: js.Tree, rsrc: js.Tree)(
implicit pos: Position): js.Tree = {
ctx.debuglog(s"$ltpe == $rtpe")
val lsym = ltpe.widenDealias.typeSymbol.asClass
val rsym = rtpe.widenDealias.typeSymbol.asClass
/* 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.)
*/
val mustUseAnyComparator: Boolean = {
isJSType(lsym) || isJSType(rsym) || {
val p = ctx.platform
val areSameFinals = lsym.is(Final) && rsym.is(Final) && (ltpe =:= rtpe)
!areSameFinals && p.isMaybeBoxed(lsym) && p.isMaybeBoxed(rsym)
}
}
if (mustUseAnyComparator) {
val equalsMethod: Symbol = {
// scalastyle:off line.size.limit
val ptfm = ctx.platform
if (lsym.derivesFrom(defn.BoxedNumberClass)) {
if (rsym.derivesFrom(defn.BoxedNumberClass)) externalEqualsNumNum
else if (rsym.derivesFrom(defn.BoxedCharClass)) externalEqualsNumObject // will be externalEqualsNumChar in 2.12, SI-9030
else externalEqualsNumObject
} else externalEquals
// scalastyle:on line.size.limit
}
genModuleApplyMethod(equalsMethod, List(lsrc, rsrc))
} else {
// if (lsrc eq null) rsrc eq null else lsrc.equals(rsrc)
if (lsym == defn.StringClass) {
// 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(), lsrc.tpe, mutable = false, lsrc)
val rtemp = js.VarDef(freshLocalIdent(), 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, defn.Any_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: Position = tree.pos
val arg = args.head
/* 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 or String)
* so boxing is not necessary (in particular, rhs is never a primitive).
*/
assert(!isPrimitiveValueType(receiver.tpe) || arg.tpe.isRef(defn.StringClass))
assert(!isPrimitiveValueType(arg.tpe))
val genLhs = {
val genLhs0 = genExpr(receiver)
// Box the receiver if it is a primitive value
if (!isPrimitiveValueType(receiver.tpe)) genLhs0
else makePrimitiveBox(genLhs0, receiver.tpe)
}
val genRhs = genExpr(arg)
js.BinaryOp(js.BinaryOp.String_+, genLhs, genRhs)
}
/** Gen JS code for a call to Any.## */
private def genScalaHash(tree: Apply, receiver: Tree): js.Tree = {
implicit val pos: Position = tree.pos
genModuleApplyMethod(defn.ScalaRuntimeModule.requiredMethod(nme.hash_),
List(genExpr(receiver)))
}
/** Gen JS code for an array operation (get, set or length) */
private def genArrayOp(tree: Tree, code: Int): js.Tree = {
import scala.tools.nsc.backend.ScalaPrimitives._
implicit val pos: Position = tree.pos
val Apply(fun, args) = tree
val arrayObj = qualifierOf(fun)
val genArray = genExpr(arrayObj)
val genArgs = args.map(genExpr)
def elementType: Type = arrayObj.tpe.widenDealias match {
case defn.ArrayOf(el) => el
case JavaArrayType(el) => el
case tpe =>
ctx.error(s"expected Array $tpe")
ErrorType
}
def genSelect(): js.Tree =
js.ArraySelect(genArray, genArgs(0))(toIRType(elementType))
if (isArrayGet(code)) {
// get an item of the array
assert(args.length == 1,
s"Array get requires 1 argument, found ${args.length} in $tree")
genSelect()
} else if (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(), genArgs(1))
} else {
// length of the array
js.ArrayLength(genArray)
}
}
/** Gen JS code for a call to AnyRef.synchronized */
private def genSynchronized(tree: Apply, isStat: Boolean): js.Tree = {
/* JavaScript is single-threaded, so we can drop the
* synchronization altogether.
*/
val Apply(fun, List(arg)) = tree
val receiver = qualifierOf(fun)
val genReceiver = genExpr(receiver)
val genArg = genStatOrExpr(arg, isStat)
genReceiver match {
case js.This() =>
// common case for which there is no side-effect nor NPE
genArg
case _ =>
implicit val pos: Position = tree.pos
/* TODO Check for a null receiver?
* In theory, it's UB, but that decision should be left for link time.
*/
js.Block(genReceiver, genArg)
}
}
/** Gen JS code for a coercion */
private def genCoercion(tree: Apply, receiver: Tree, code: Int): js.Tree = {
import scala.tools.nsc.backend.ScalaPrimitives._
implicit val pos: Position = tree.pos
val source = genExpr(receiver)
def source2int = (code: @switch) match {
case F2C | D2C | F2B | D2B | F2S | D2S | F2I | D2I =>
js.UnaryOp(js.UnaryOp.DoubleToInt, source)
case L2C | L2B | L2S | L2I =>
js.UnaryOp(js.UnaryOp.LongToInt, source)
case _ =>
source
}
(code: @switch) match {
// To Char, need to crop at unsigned 16-bit
case B2C | S2C | I2C | L2C | F2C | D2C =>
js.BinaryOp(js.BinaryOp.Int_&, source2int, js.IntLiteral(0xffff))
// To Byte, need to crop at signed 8-bit
case C2B | S2B | I2B | L2B | F2B | D2B =>
// note: & 0xff would not work because of negative values
js.BinaryOp(js.BinaryOp.Int_>>,
js.BinaryOp(js.BinaryOp.Int_<<, source2int, js.IntLiteral(24)),
js.IntLiteral(24))
// To Short, need to crop at signed 16-bit
case C2S | I2S | L2S | F2S | D2S =>
// note: & 0xffff would not work because of negative values
js.BinaryOp(js.BinaryOp.Int_>>,
js.BinaryOp(js.BinaryOp.Int_<<, source2int, js.IntLiteral(16)),
js.IntLiteral(16))
// To Int, need to crop at signed 32-bit
case L2I | F2I | D2I =>
source2int
// Any int to Long
case C2L | B2L | S2L | I2L =>
js.UnaryOp(js.UnaryOp.IntToLong, source)
// Any double to Long
case F2L | D2L =>
js.UnaryOp(js.UnaryOp.DoubleToLong, source)
// Long to Double
case L2D =>
js.UnaryOp(js.UnaryOp.LongToDouble, source)
// Any int, or Double, to Float
case C2F | B2F | S2F | I2F | D2F =>
js.UnaryOp(js.UnaryOp.DoubleToFloat, source)
// Long to Float === Long to Double to Float
case L2F =>
js.UnaryOp(js.UnaryOp.DoubleToFloat,
js.UnaryOp(js.UnaryOp.LongToDouble, source))
// Identities and IR upcasts
case C2C | B2B | S2S | I2I | L2L | F2F | D2D |
C2I | C2D |
B2S | B2I | B2D |
S2I | S2D |
I2D |
F2D =>
source
}
}
/** Gen a call to the special `throw` method. */
private def genThrow(tree: Apply, args: List[Tree]): js.Tree = {
implicit val pos: Position = tree.pos
val exception = args.head
val genException = genExpr(exception)
js.Throw {
if (exception.tpe.widenDealias.typeSymbol.derivesFrom(jsdefn.JavaScriptExceptionClass)) {
genModuleApplyMethod(
jsdefn.RuntimePackage_unwrapJavaScriptException,
List(genException))
} else {
genException
}
}
}
/** Gen a "normal" apply (to a true method).
*
* But even these are further refined into:
* * Methods of java.lang.String, which are redirected to the
* RuntimeString trait implementation.
* * Calls to methods of raw JS types (Scala.js -> JS interop)
* * Calls to methods in impl classes of Scala2 traits.
* * Regular method call
*/
private def genNormalApply(tree: Apply, isStat: Boolean): js.Tree = {
implicit val pos: Position = tree.pos
val fun = tree.fun match {
case fun: Ident => desugarIdent(fun).get
case fun: Select => fun
}
val receiver = fun.qualifier
val args = tree.args
val sym = fun.symbol
def isStringMethodFromObject: Boolean = sym.name match {
case nme.toString_ | nme.equals_ | nme.hashCode_ => true
case _ => false
}
if (sym.owner == defn.StringClass && !isStringMethodFromObject) {
genApplyMethodOfString(genExpr(receiver), sym, genActualArgs(sym, args))
} else if (isJSType(sym.owner)) {
//if (!isScalaJSDefinedJSClass(sym.owner) || isExposed(sym))
genApplyJSMethodGeneric(tree, sym, genExpr(receiver), genActualJSArgs(sym, args), isStat)
/*else
genApplyJSClassMethod(genExpr(receiver), sym, genActualArgs(sym, args))*/
} else if (foreignIsImplClass(sym.owner)) {
genTraitImplApply(sym, args.map(genExpr))
} else if (sym.isClassConstructor) {
// Calls to constructors are always statically linked
genApplyMethodStatically(genExpr(receiver), sym, genActualArgs(sym, args))
} else {
genApplyMethod(genExpr(receiver), sym, genActualArgs(sym, args))
}
}
/** Gen JS code for a call to a JS method (of a subclass of `js.Any`).
*
* Basically it boils down to calling the method as a `JSBracketSelect`,
* 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 `JSBracketSelect`
* - Setters are translated to `Assign` to `JSBracketSelect`
*/
private def genApplyJSMethodGeneric(tree: Tree, sym: Symbol,
receiver: js.Tree, args: List[js.Tree], isStat: Boolean,
superIn: Option[Symbol] = None)(
implicit pos: Position): js.Tree = {
implicit val pos: Position = tree.pos
def noSpread = !args.exists(_.isInstanceOf[js.JSSpread])
val argc = args.size // meaningful only for methods that don't have varargs
def requireNotSuper(): Unit = {
if (superIn.isDefined)
ctx.error("Illegal super call in Scala.js-defined JS class", tree.pos)
}
def hasExplicitJSEncoding = {
sym.hasAnnotation(jsdefn.JSNameAnnot) ||
sym.hasAnnotation(jsdefn.JSBracketAccessAnnot) ||
sym.hasAnnotation(jsdefn.JSBracketCallAnnot)
}
val boxedResult = sym.name match {
case JSUnaryOpMethodName(code) if argc == 0 =>
requireNotSuper()
js.JSUnaryOp(code, receiver)
case JSBinaryOpMethodName(code) if argc == 1 =>
requireNotSuper()
js.JSBinaryOp(code, receiver, args.head)
case nme.apply if !hasExplicitJSEncoding =>
requireNotSuper()
if (jsdefn.isJSThisFunctionClass(sym.owner))
js.JSBracketMethodApply(receiver, js.StringLiteral("call"), args)
else
js.JSFunctionApply(receiver, args)
case _ =>
def jsFunName = js.StringLiteral(jsNameOf(sym))
def genSuperReference(propName: js.Tree): js.Tree = {
superIn.fold[js.Tree] {
js.JSBracketSelect(receiver, propName)
} { superInSym =>
js.JSSuperBracketSelect(
jstpe.ClassType(encodeClassFullName(superInSym)),
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.Tree]): js.Tree = {
superIn.fold[js.Tree] {
js.JSBracketMethodApply(
receiver, methodName, args)
} { superInSym =>
js.JSSuperBracketCall(
jstpe.ClassType(encodeClassFullName(superInSym)),
receiver, methodName, args)
}
}
if (isJSGetter(sym)) {
assert(noSpread && argc == 0)
genSelectGet(jsFunName)
} else if (isJSSetter(sym)) {
assert(noSpread && argc == 1)
genSelectSet(jsFunName, args.head)
} else if (isJSBracketAccess(sym)) {
assert(noSpread && (argc == 1 || argc == 2),
s"@JSBracketAccess methods should have 1 or 2 non-varargs arguments")
args match {
case List(keyArg) =>
genSelectGet(keyArg)
case List(keyArg, valueArg) =>
genSelectSet(keyArg, valueArg)
}
} else if (isJSBracketCall(sym)) {
val (methodName, actualArgs) = extractFirstArg(args)
genCall(methodName, actualArgs)
} else {
genCall(jsFunName, args)
}
}
if (isStat) {
boxedResult
} else {
val tpe = ctx.atPhase(ctx.elimErasedValueTypePhase) { implicit ctx =>
sym.info.finalResultType
}
unbox(boxedResult, tpe)
}
}
private object JSUnaryOpMethodName {
private val map = Map(
nme.UNARY_+ -> js.JSUnaryOp.+,
nme.UNARY_- -> js.JSUnaryOp.-,
nme.UNARY_~ -> js.JSUnaryOp.~,
nme.UNARY_! -> js.JSUnaryOp.!
)
def unapply(name: Names.TermName): Option[js.JSUnaryOp.Code] =
map.get(name)
}
private object JSBinaryOpMethodName {
private val map = Map(
nme.ADD -> js.JSBinaryOp.+,
nme.SUB -> js.JSBinaryOp.-,
nme.MUL -> js.JSBinaryOp.*,
nme.DIV -> js.JSBinaryOp./,
nme.MOD -> js.JSBinaryOp.%,
nme.LSL -> js.JSBinaryOp.<<,
nme.ASR -> js.JSBinaryOp.>>,
nme.LSR -> js.JSBinaryOp.>>>,
nme.OR -> js.JSBinaryOp.|,
nme.AND -> js.JSBinaryOp.&,
nme.XOR -> js.JSBinaryOp.^,
nme.LT -> js.JSBinaryOp.<,
nme.LE -> js.JSBinaryOp.<=,
nme.GT -> js.JSBinaryOp.>,
nme.GE -> js.JSBinaryOp.>=,
nme.ZAND -> js.JSBinaryOp.&&,
nme.ZOR -> js.JSBinaryOp.||
)
def unapply(name: Names.TermName): Option[js.JSBinaryOp.Code] =
map.get(name)
}
/** Extract the first argument in a list of actual arguments.
*
* 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.Tree]): (js.Tree, List[js.Tree]) = {
assert(args.nonEmpty,
"Trying to extract the first argument of an empty argument list")
val firstArg = args.head
assert(!firstArg.isInstanceOf[js.JSSpread],
"Trying to extract the first argument of an argument list starting " +
"with a Spread argument: " + firstArg)
(firstArg, args.tail)
}
/** Gen JS code for a call to a polymorphic method.
*
* The only methods that reach the back-end as polymorphic are
* `isInstanceOf` and `asInstanceOf`.
*
* (Well, in fact `DottyRunTime.newRefArray` too, but it is handled as a
* primitive instead.)
*/
private def genTypeApply(tree: TypeApply): js.Tree = {
implicit val pos: Position = tree.pos
val TypeApply(fun, targs) = tree
val sym = fun.symbol
val receiver = qualifierOf(fun)
val to = targs.head.tpe
assert(!isPrimitiveValueType(receiver.tpe),
s"Found receiver of type test with primitive type ${receiver.tpe} at $pos")
assert(!isPrimitiveValueType(to),
s"Found target type of type test with primitive type ${receiver.tpe} at $pos")
val genReceiver = genExpr(receiver)
if (sym == defn.Any_asInstanceOf) {
genAsInstanceOf(genReceiver, to)
} else if (sym == defn.Any_isInstanceOf) {
genIsInstanceOf(tree, genReceiver, to)
} else {
throw new FatalError(
s"Unexpected type application $fun with symbol ${sym.fullName}")
}
}
/** Gen JS code for a Java Seq literal. */
private def genJavaSeqLiteral(tree: JavaSeqLiteral): js.Tree = {
implicit val pos: Position = tree.pos
val genElems = tree.elems.map(genExpr)
val arrayType = toReferenceType(tree.tpe).asInstanceOf[jstpe.ArrayType]
js.ArrayValue(arrayType, genElems)
}
/** Gen JS code for a closure.
*
* Input: a `Closure` tree of the form
* {{{
* Closure(env, call, functionalInterface)
* }}}
* representing the pseudo-syntax
* {{{
* { (p1, ..., pm) => call(env1, ..., envn, p1, ..., pm) }: functionInterface
* }}}
* where `envi` are identifiers in the local scope. The qualifier of `call`
* is also implicitly captured.
*
* Output: a `js.Closure` tree of the form
* {{{
* js.Closure(formalCaptures, formalParams, body, actualCaptures)
* }}}
* representing the pseudo-syntax
* {{{
* lambda<formalCapture1 = actualCapture1, ..., formalCaptureN = actualCaptureN>(
* formalParam1, ..., formalParamM) = body
* }}}
* where the `actualCaptures` and `body` are, in general, arbitrary
* expressions. But in this case, `actualCaptures` will be identifiers from
* `env`, and the `body` will be of the form
* {{{
* call(formalCapture1.ref, ..., formalCaptureN.ref,
* formalParam1.ref, ...formalParamM.ref)
* }}}
*
* When the `js.Closure` node is evaluated, i.e., when the closure value is
* created, the expressions of the `actualCaptures` are evaluated, and the
* results of those evaluations is "stored" in the environment of the
* closure as the corresponding `formalCapture`.
*
* When we later *call* the closure, the `formalCaptures` already have their
* values from the environment, and they are available in the `body`. The
* `formalParams` of the created closure receive their values from the
* actual arguments at the call-site of the closure, and they are also
* available in the `body`.
*/
private def genClosure(tree: Closure): js.Tree = {
implicit val pos: Position = tree.pos
val Closure(env, call, functionalInterface) = tree
val envSize = env.size
val (fun, args) = call match {
// case Apply(fun, args) => (fun, args) // Conjectured not to happen
case t @ Select(_, _) => (t, Nil)
case t @ Ident(_) => (t, Nil)
}
val sym = fun.symbol
val qualifier = qualifierOf(fun)
val allCaptureValues = qualifier :: env
val (formalCaptures, actualCaptures) = allCaptureValues.map { value =>
implicit val pos: Position = value.pos
val formalIdent = value match {
case Ident(name) => freshLocalIdent(name.toString)
case This(_) => freshLocalIdent("this")
case _ => freshLocalIdent()
}
val formalCapture =
js.ParamDef(formalIdent, toIRType(value.tpe), mutable = false, rest = false)
val actualCapture = genExpr(value)
(formalCapture, actualCapture)
}.unzip
val formalParamNames = sym.info.paramNamess.flatten.drop(envSize)
val formalParamTypes = sym.info.paramTypess.flatten.drop(envSize)
val (formalParams, actualParams) = formalParamNames.zip(formalParamTypes).map {
case (name, tpe) =>
val formalParam = js.ParamDef(freshLocalIdent(name.toString),
jstpe.AnyType, mutable = false, rest = false)
val actualParam = unbox(formalParam.ref, tpe)
(formalParam, actualParam)
}.unzip
val genBody = {
val thisCaptureRef :: argCaptureRefs = formalCaptures.map(_.ref)
val call = genApplyMethod(thisCaptureRef, sym, argCaptureRefs ::: actualParams)
box(call, sym.info.finalResultType)
}
val closure = js.Closure(formalCaptures, formalParams, genBody, actualCaptures)
ctx.debuglog(closure.toString)
val funInterfaceSym = functionalInterface.tpe.widenDealias.typeSymbol
if (jsdefn.isJSFunctionClass(funInterfaceSym)) {
closure
} else {
assert(!funInterfaceSym.exists || defn.isFunctionClass(funInterfaceSym),
s"Invalid functional interface $funInterfaceSym reached the back-end")
val cls = "sjsr_AnonFunction" + formalParams.size
val ctor = js.Ident("init___sjs_js_Function" + formalParams.size)
js.New(jstpe.ClassType(cls), ctor, List(closure))
}
}
/** Boxes a value of the given type before `elimErasedValueType`.
*
* This should be used when sending values to a JavaScript context, which
* is erased/boxed at the IR level, although it is not erased at the
* dotty/JVM level.
*
* @param expr Tree to be boxed if needed.
* @param tpeEnteringElimErasedValueType The type of `expr` as it was
* entering the `elimErasedValueType` phase.
*/
private def box(expr: js.Tree, tpeEnteringElimErasedValueType: Type)(
implicit pos: Position): js.Tree = {
tpeEnteringElimErasedValueType 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
}
}
/** Unboxes a value typed as Any to the given type before `elimErasedValueType`.
*
* This should be used when receiving values from a JavaScript context,
* which is erased/boxed at the IR level, although it is not erased at the
* dotty/JVM level.
*
* @param expr Tree to be extracted.
* @param tpeEnteringElimErasedValueType The type of `expr` as it was
* entering the `elimErasedValueType` phase.
*/
private def unbox(expr: js.Tree, tpeEnteringElimErasedValueType: Type)(
implicit pos: Position): js.Tree = {
tpeEnteringElimErasedValueType 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 JS code for an asInstanceOf cast (for reference types only) */
private def genAsInstanceOf(value: js.Tree, to: Type)(
implicit pos: Position): js.Tree = {
val sym = to.widenDealias.typeSymbol
if (sym == defn.ObjectClass || isJSType(sym)) {
/* asInstanceOf[Object] always succeeds, and
* asInstanceOf to a raw JS type is completely erased.
*/
value
} else {
js.AsInstanceOf(value, toReferenceType(to))
}
}
/** Gen JS code for an isInstanceOf test (for reference types only) */
private def genIsInstanceOf(tree: Tree, value: js.Tree, to: Type): js.Tree = {
implicit val pos: Position = tree.pos
val sym = to.widenDealias.typeSymbol
if (sym == defn.ObjectClass) {
js.BinaryOp(js.BinaryOp.!==, value, js.Null())
} else if (isJSType(sym)) {
if (sym.is(Trait)) {
ctx.error(
s"isInstanceOf[${sym.fullName}] not supported because it is a JS trait",
tree.pos)
js.BooleanLiteral(true)
} else {
js.Unbox(js.JSBinaryOp(
js.JSBinaryOp.instanceof, value, genLoadJSConstructor(sym)), 'Z')
}
} else {
js.IsInstanceOf(value, toReferenceType(to))
}
}
/** Gen a dynamically linked call to a Scala method. */
private def genApplyMethod(receiver: js.Tree,
methodSym: Symbol, arguments: List[js.Tree])(
implicit pos: Position): js.Tree = {
js.Apply(receiver, encodeMethodSym(methodSym), arguments)(
toIRType(patchedResultType(methodSym)))
}
/** Gen a statically linked call to an instance method. */
private def genApplyMethodStatically(receiver: js.Tree, method: Symbol,
arguments: List[js.Tree])(implicit pos: Position): js.Tree = {
val className = encodeClassFullName(method.owner)
val methodIdent = encodeMethodSym(method)
val resultType = toIRType(patchedResultType(method))
js.ApplyStatically(receiver, jstpe.ClassType(className),
methodIdent, arguments)(resultType)
}
/** Gen a call to a static method. */
private def genApplyStatic(method: Symbol, arguments: List[js.Tree])(
implicit pos: Position): js.Tree = {
val cls = jstpe.ClassType(encodeClassFullName(method.owner))
val methodIdent = encodeMethodSym(method)
js.ApplyStatic(cls, methodIdent, arguments)(
toIRType(patchedResultType(method)))
}
/** Gen a call to a Scala2 impl class method. */
private def genTraitImplApply(method: Symbol, arguments: List[js.Tree])(
implicit pos: Position): js.Tree = {
genApplyStatic(method, arguments)
}
/** Gen a call to a non-exposed method of a non-native JS class. */
private def genApplyJSClassMethod(receiver: js.Tree, method: Symbol,
arguments: List[js.Tree])(implicit pos: Position): js.Tree = {
genApplyStatic(method, receiver :: arguments)
}
/** Gen a call to a method of a Scala top-level module. */
private def genModuleApplyMethod(methodSym: Symbol, arguments: List[js.Tree])(
implicit pos: Position): js.Tree = {
genApplyMethod(genLoadModule(methodSym.owner), methodSym, arguments)
}
/** Gen JS code for `new java.lang.String(...)`.
*
* Rewires the instantiation to calling the appropriate overload of
* `newString` in the object `scala.scalajs.runtime.RuntimeString`.
*/
private def genNewString(ctor: Symbol, arguments: List[js.Tree])(
implicit pos: Position): js.Tree = {
js.Apply(
genLoadModule(jsdefn.RuntimeStringModuleClass),
encodeRTStringCtorSym(ctor), arguments)(
jstpe.ClassType(ir.Definitions.StringClass))
}
/** Gen a dynamically linked call to a method of java.lang.String.
*
* Forwards the call to the module scala.scalajs.runtime.RuntimeString.
*/
private def genApplyMethodOfString(receiver: js.Tree,
methodSym: Symbol, arguments: List[js.Tree])(
implicit pos: Position): js.Tree = {
js.Apply(
genLoadModule(jsdefn.RuntimeStringModuleClass),
encodeRTStringMethodSym(methodSym),
receiver :: arguments)(
toIRType(patchedResultType(methodSym)))
}
/** Gen a boxing operation (tpe is the primitive type) */
private def makePrimitiveBox(expr: js.Tree, tpe: Type)(
implicit pos: Position): js.Tree = {
toReferenceType(tpe) match {
case jstpe.ClassType(cls) if ir.Definitions.isPrimitiveClass(cls) =>
assert(cls.length == 1)
(cls.charAt(0): @switch) match {
case 'V' =>
// must be handled at least for JS interop
js.Block(expr, js.Undefined())
case 'C' =>
genModuleApplyMethod(jsdefn.BoxesRunTime_boxToCharacter, List(expr))
case _ =>
expr // box is identity for all non-Char types
}
case _ =>
throw new FatalError(
s"makePrimitiveBox requires a primitive type, found $tpe at $pos")
}
}
/** Gen an unboxing operation (tpe is the primitive type) */
private def makePrimitiveUnbox(expr: js.Tree, tpe: Type)(
implicit pos: Position): js.Tree = {
toReferenceType(tpe) match {
case jstpe.ClassType(cls) if ir.Definitions.isPrimitiveClass(cls) =>
assert(cls.length == 1)
(cls.charAt(0): @switch) match {
case 'V' =>
// must be handled at least for JS interop
expr
case 'C' =>
genModuleApplyMethod(jsdefn.BoxesRunTime_unboxToChar, List(expr))
case primitiveCharCode =>
js.Unbox(expr, primitiveCharCode)
}
case _ =>
throw new FatalError(
s"makePrimitiveUnbox requires a primitive type, found $tpe at $pos")
}
}
/** 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.WrappedArray instead of Scala wrapped arrays.
*/
private def genActualArgs(sym: Symbol, args: List[Tree])(
implicit pos: Position): List[js.Tree] = {
args.map(genExpr)
/*val wereRepeated = exitingPhase(currentRun.typerPhase) {
sym.tpe.params.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
* erasure 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 =>
genNew(WrappedArrayClass, WrappedArray_ctor,
List(js.JSArrayConstr(genArgs)))
}
} else {
genExpr(arg)
}
}
}*/
}
/** Gen actual actual arguments to a JS method call.
* Returns a list of the transformed arguments.
*
* - TODO 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 genActualJSArgs(sym: Symbol, args: List[Tree])(
implicit pos: Position): List[js.Tree] = {
def paramNamesAndTypes(implicit ctx: Context): List[(Names.TermName, Type)] =
sym.info.paramNamess.flatten.zip(sym.info.paramTypess.flatten)
val wereRepeated = ctx.atPhase(ctx.elimRepeatedPhase) { implicit ctx =>
for ((name, tpe) <- paramNamesAndTypes)
yield (name -> tpe.isRepeatedParam)
}.toMap
val paramTypes = ctx.atPhase(ctx.elimErasedValueTypePhase) { implicit ctx =>
paramNamesAndTypes
}.toMap
var reversedArgs: List[js.Tree] = Nil
for ((arg, (paramName, paramType)) <- args.zip(paramNamesAndTypes)) {
val wasRepeated = wereRepeated.getOrElse(paramName, false)
if (wasRepeated) {
reversedArgs =
genJSRepeatedParam(arg) reverse_::: reversedArgs
} else {
val unboxedArg = genExpr(arg)
val boxedArg = unboxedArg match {
case js.UndefinedParam() =>
unboxedArg
case _ =>
val tpe = paramTypes.getOrElse(paramName, paramType)
box(unboxedArg, tpe)
}
reversedArgs ::= boxedArg
}
}
/* Remove all consecutive js.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(_.isInstanceOf[js.UndefinedParam])
/* Find remaining js.UndefinedParam and replace by js.Undefined. This can
* happen with named arguments or with multiple argument lists.
*/
reversedArgs = reversedArgs map {
case js.UndefinedParam() => js.Undefined()
case arg => arg
}
reversedArgs.reverse
}
/** Gen JS code for a repeated param of a 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 genJSRepeatedParam(arg: Tree): List[js.Tree] = {
tryGenRepeatedParamAsJSArray(arg, handleNil = true).getOrElse {
/* Fall back to calling runtime.genTraversableOnce2jsArray
* to perform the conversion to js.Array, then wrap in a Spread
* operator.
*/
implicit val pos: Position = arg.pos
val jsArrayArg = genModuleApplyMethod(
jsdefn.RuntimePackage_genTraversableOnce2jsArray,
List(genExpr(arg)))
List(js.JSSpread(jsArrayArg))
}
}
/** Try and expand an actual argument to a repeated param `(xs: T*)`.
*
* 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: Position = arg.pos
// Given a method `def foo(args: T*)`
arg match {
// foo(arg1, arg2, ..., argN) where N > 0
case MaybeAsInstanceOf(WrapArray(MaybeAsInstanceOf(array: JavaSeqLiteral))) =>
/* Value classes in arrays are already boxed, so no need to use
* the type before erasure.
* TODO Is this true in dotty?
*/
Some(array.elems.map(e => box(genExpr(e), e.tpe)))
// foo()
case Ident(_) if handleNil && arg.symbol == defn.NilModule =>
Some(Nil)
// foo(argSeq: _*) - cannot be optimized
case _ =>
None
}
}
private object MaybeAsInstanceOf {
def unapply(tree: Tree): Some[Tree] = tree match {
case TypeApply(asInstanceOf_? @ Select(base, _), _)
if asInstanceOf_?.symbol == defn.Any_asInstanceOf =>
Some(base)
case _ =>
Some(tree)
}
}
private object WrapArray {
lazy val isWrapArray: Set[Symbol] = {
val names = {
defn.ScalaValueClasses().map(sym => nme.wrapXArray(sym.name)) ++
Set(nme.wrapRefArray, nme.genericWrapArray)
}
names.map(defn.ScalaPredefModule.requiredMethod(_)).toSet
}
def unapply(tree: Apply): Option[Tree] = tree match {
case Apply(wrapArray_?, List(wrapped)) if isWrapArray(wrapArray_?.symbol) =>
Some(wrapped)
case _ =>
None
}
}
/** Gen JS code for loading a Java static field.
*/
private def genLoadStaticField(sym: Symbol)(implicit pos: Position): js.Tree = {
/* Actually, there is no static member in Scala.js. If we come here, that
* is because we found the symbol in a Java-emitted .class in the
* classpath. But the corresponding implementation in Scala.js will
* actually be a val in the companion module.
*/
if (sym == defn.BoxedUnit_UNIT) {
js.Undefined()
} else {
val instance = genLoadModule(sym.owner)
val method = encodeStaticMemberSym(sym)
js.Apply(instance, method, Nil)(toIRType(sym.info))
}
}
/** Gen JS code for loading a module.
*
* Can be given either the module symbol, or its module class symbol.
*/
private def genLoadModule(sym0: Symbol)(implicit pos: Position): js.Tree = {
require(sym0.is(Module),
"genLoadModule called with non-module symbol: " + sym0)
val sym1 = if (sym0.isTerm) sym0.moduleClass else sym0
val sym = // redirect all static methods of String to RuntimeString
if (sym1 == defn.StringModule) jsdefn.RuntimeStringModule.moduleClass
else sym1
if (isJSType(sym)) {
if (isScalaJSDefinedJSClass(sym))
js.LoadJSModule(jstpe.ClassType(encodeClassFullName(sym)))
else if (sym.derivesFrom(jsdefn.JSGlobalScopeClass))
genLoadJSGlobal()
else
genLoadNativeJSModule(sym)
} else {
js.LoadModule(jstpe.ClassType(encodeClassFullName(sym)))
}
}
/** Gen JS code representing the constructor of a JS class. */
private def genLoadJSConstructor(sym: Symbol)(
implicit pos: Position): js.Tree = {
assert(!isStaticModule(sym) && !sym.is(Trait),
s"genPrimitiveJSClass called with non-class $sym")
js.LoadJSConstructor(jstpe.ClassType(encodeClassFullName(sym)))
}
/** Gen JS code representing a native JS module. */
private def genLoadNativeJSModule(sym: Symbol)(
implicit pos: Position): js.Tree = {
require(sym.is(ModuleClass),
s"genLoadNativeJSModule called with non-module $sym")
fullJSNameOf(sym).split('.').foldLeft(genLoadJSGlobal()) { (memo, chunk) =>
js.JSBracketSelect(memo, js.StringLiteral(chunk))
}
}
/** Gen JS code to load the JavaScript global scope. */
private def genLoadJSGlobal()(implicit pos: Position): js.Tree = {
js.JSBracketSelect(
js.JSBracketSelect(js.JSLinkingInfo(), js.StringLiteral("envInfo")),
js.StringLiteral("global"))
}
/** Generate a Class[_] value (e.g. coming from classOf[T]) */
private def genClassConstant(tpe: Type)(implicit pos: Position): js.Tree =
js.ClassOf(toReferenceType(tpe))
private def isStaticModule(sym: Symbol): Boolean =
sym.is(Module) && sym.isStatic
private def isPrimitiveValueType(tpe: Type): Boolean = {
tpe.widenDealias match {
case JavaArrayType(_) => false
case t => t.typeSymbol.asClass.isPrimitiveValueClass
}
}
}
