scala.scalanative.nscplugin.GenReflectiveInstantisation.scala Maven / Gradle / Ivy
package scala.scalanative
package nscplugin
import scala.language.implicitConversions
import dotty.tools.dotc.ast.tpd._
import dotty.tools.dotc.core
import core.Contexts._
import core.Symbols._
import core.StdNames._
import core.Flags._
import scala.collection.mutable
import scala.scalanative.util.ScopedVar
object GenReflectiveInstantisation {
object nirSymbols {
val AbstractFunction0Name =
nir.Global.Top("scala.runtime.AbstractFunction0")
val AbstractFunction1Name =
nir.Global.Top("scala.runtime.AbstractFunction1")
val SerializableName = nir.Global.Top("java.io.Serializable")
val Tuple2Name = nir.Global.Top("scala.Tuple2")
val Tuple2Ref = nir.Type.Ref(Tuple2Name)
}
}
trait GenReflectiveInstantisation(using Context) {
self: NirCodeGen =>
import GenReflectiveInstantisation._
import positionsConversions.given
protected val reflectiveInstantiationBuffers =
mutable.UnrolledBuffer.empty[ReflectiveInstantiationBuffer]
protected class ReflectiveInstantiationBuffer(fqcn: String) {
val name = nir.Global.Top(fqcn + "$scalanative$ReflectivelyInstantiate$")
reflectiveInstantiationBuffers += this
private val buf = mutable.UnrolledBuffer.empty[nir.Defn]
def +=(defn: nir.Defn): Unit = buf += defn
def nonEmpty = buf.nonEmpty
def toSeq = buf.toSeq
}
def genReflectiveInstantiation(td: TypeDef): Unit = {
val sym = td.symbol.asClass
val enableReflectiveInstantiation =
sym.baseClasses
.exists(
_.hasAnnotation(defnNir.EnableReflectiveInstantiationAnnotationClass)
)
if (enableReflectiveInstantiation) {
ScopedVar.scoped(
curClassSym := sym,
curFresh := nir.Fresh(),
curScopeId := nir.ScopeId.TopLevel,
curUnwindHandler := None,
curMethodThis := None
) {
registerReflectiveInstantiation(td)
}
}
}
private def registerReflectiveInstantiation(td: TypeDef): Unit = {
given nir.SourcePosition = td.span
val sym: Symbol = curClassSym
val owner = genTypeName(sym)
val name = owner.member(nir.Sig.Clinit)
val staticInitBody =
if (curClassSym.get.is(flag = Module, butNot = Lifted))
Some(registerModuleClass(td))
else if (sym.is(Module))
None // see: https://github.com/scala-js/scala-js/issues/3228
else if (sym.is(Lifted) && !sym.originalOwner.isClass)
None // see: https://github.com/scala-js/scala-js/issues/3227
else Some(registerNormalClass(td))
staticInitBody
.filter(_.nonEmpty)
.foreach { body =>
generatedDefns += new nir.Defn.Define(
nir.Attrs(),
name,
nir.Type.Function(Seq.empty[nir.Type], nir.Type.Unit),
body
)
}
}
private def registerModuleClass(
td: TypeDef
): Seq[nir.Inst] = {
val fqSymId = curClassSym.get.fullName.mangledString
val fqSymName = nir.Global.Top(fqSymId)
val fqcnArg = nir.Val.String(fqSymId)
val runtimeClassArg = nir.Val.ClassOf(fqSymName)
given nir.SourcePosition = td.span
given reflInstBuffer: ReflectiveInstantiationBuffer =
ReflectiveInstantiationBuffer(fqSymId)
withFreshExprBuffer { buf ?=>
buf.label(curFresh(), Seq.empty)
val loadModuleFunArg = genModuleLoader(fqSymName)
buf.genApplyModuleMethod(
defnNir.ReflectModule,
defnNir.Reflect_registerLoadableModuleClass,
Seq(fqcnArg, runtimeClassArg, loadModuleFunArg).map(ValTree(_)(td.span))
)
buf.ret(nir.Val.Unit)
buf.toSeq
}
}
private def registerNormalClass(
td: TypeDef
): Seq[nir.Inst] = {
given nir.SourcePosition = td.span
val fqSymId = curClassSym.get.fullName.mangledString
val fqSymName = nir.Global.Top(fqSymId)
val fqcnArg = nir.Val.String(fqSymId)
val runtimeClassArg = nir.Val.ClassOf(fqSymName)
// Collect public constructors.
val ctors =
if (curClassSym.get.isOneOf(AbstractOrTrait)) Nil
else
curClassSym.get.info
.member(nme.CONSTRUCTOR)
.alternatives
.collect {
case denot if denot.asSymDenotation.isPublic =>
denot.asSymDenotation.underlyingSymbol
}
if (ctors.isEmpty) Nil
else
withFreshExprBuffer { buf ?=>
buf.label(curFresh(), Seq.empty)
val instantiateClassFunArg = genClassConstructorsInfo(fqSymName, ctors)
buf.genApplyModuleMethod(
defnNir.ReflectModule,
defnNir.Reflect_registerInstantiatableClass,
Seq(fqcnArg, runtimeClassArg, instantiateClassFunArg)
.map(ValTree(_)(td.span))
)
buf.ret(nir.Val.Unit)
buf.toSeq
}
}
// Generate the constructor for the class instantiator class,
// which is expected to extend one of scala.runtime.AbstractFunctionX.
private def genConstructor(
superClass: nir.Global.Top
)(using
nir.SourcePosition
)(using reflInstBuffer: ReflectiveInstantiationBuffer): Unit = {
withFreshExprBuffer { buf ?=>
val body = {
// first argument is this
val thisArg =
nir.Val.Local(curFresh(), nir.Type.Ref(reflInstBuffer.name))
buf.label(curFresh(), Seq(thisArg))
// call to super constructor
buf.call(
nir.Type.Function(Seq(nir.Type.Ref(superClass)), nir.Type.Unit),
nir.Val
.Global(superClass.member(nir.Sig.Ctor(Seq.empty)), nir.Type.Ptr),
Seq(thisArg),
unwind(curFresh)
)
buf.ret(nir.Val.Unit)
buf.toSeq
}
reflInstBuffer += new nir.Defn.Define(
nir.Attrs(),
reflInstBuffer.name.member(nir.Sig.Ctor(Seq.empty)),
nir.Type
.Function(Seq(nir.Type.Ref(reflInstBuffer.name)), nir.Type.Unit),
body
)
}
}
// Allocate and construct an object, using the provided ExprBuffer.
private def allocAndConstruct(
name: nir.Global.Top,
argTypes: Seq[nir.Type],
args: Seq[nir.Val]
)(using pos: nir.SourcePosition, buf: ExprBuffer): nir.Val = {
val alloc = buf.classalloc(name, unwind(curFresh))
buf.call(
nir.Type.Function(nir.Type.Ref(name) +: argTypes, nir.Type.Unit),
nir.Val.Global(name.member(nir.Sig.Ctor(argTypes)), nir.Type.Ptr),
alloc +: args,
unwind(curFresh)
)
alloc
}
private def genModuleLoader(
fqSymName: nir.Global.Top
)(using
pos: nir.SourcePosition,
buf: ExprBuffer,
reflInstBuffer: ReflectiveInstantiationBuffer
): nir.Val = {
val applyMethodSig = nir.Sig.Method("apply", Seq(nir.Rt.Object))
val enclosingClass = curClassSym.get.originalOwner
// Generate the module loader class. The generated class extends
// AbstractFunction0[Any], i.e. has an apply method, which loads the module.
// We need a fresh ExprBuffer for this, since it is different scope.
withFreshExprBuffer { buf ?=>
val body = {
// first argument is this
val thisArg =
nir.Val.Local(curFresh(), nir.Type.Ref(reflInstBuffer.name))
buf.label(curFresh(), Seq(thisArg))
val module =
if (enclosingClass.exists && !enclosingClass.is(ModuleClass))
nir.Val.Null
else buf.module(fqSymName, unwind(curFresh))
buf.ret(module)
buf.toSeq
}
reflInstBuffer += new nir.Defn.Define(
nir.Attrs(),
reflInstBuffer.name.member(applyMethodSig),
nir.Type
.Function(Seq(nir.Type.Ref(reflInstBuffer.name)), nir.Rt.Object),
body
)
}
// Generate the module loader class constructor.
genConstructor(nirSymbols.AbstractFunction0Name)
reflInstBuffer += nir.Defn.Class(
nir.Attrs(),
reflInstBuffer.name,
Some(nirSymbols.AbstractFunction0Name),
Seq(nirSymbols.SerializableName)
)
// Allocate and return an instance of the generated class.
allocAndConstruct(reflInstBuffer.name, Seq.empty, Seq.empty)(using pos, buf)
}
// Create a new Tuple2 and initialise it with the provided values.
private def createTuple(arg1: nir.Val, arg2: nir.Val)(using
nir.SourcePosition,
ExprBuffer
): nir.Val = {
allocAndConstruct(
nirSymbols.Tuple2Name,
Seq(nir.Rt.Object, nir.Rt.Object),
Seq(arg1, arg2)
)
}
private def genClassConstructorsInfo(
fqSymName: nir.Global.Top,
ctors: Seq[Symbol]
)(using pos: nir.SourcePosition, buf: ExprBuffer): nir.Val = {
val applyMethodSig =
nir.Sig.Method("apply", Seq(nir.Rt.Object, nir.Rt.Object))
// Constructors info is an array of Tuple2 (tpes, inst), where:
// - tpes is an array with the runtime classes of the constructor arguments.
// - inst is a function, which accepts an array with tpes and returns a new
// instance of the class.
val ctorsInfo = buf.arrayalloc(
nir.Type.Array(nirSymbols.Tuple2Ref),
nir.Val.Int(ctors.length),
unwind(curFresh)
)
// For each (public) constructor C, generate a lambda responsible for
// initialising and returning an instance of the class, using C.
for ((ctor, ctorIdx) <- ctors.zipWithIndex) {
val ctorSig = genMethodSig(ctor)
given nir.SourcePosition = ctor.span
val ctorSuffix = if (ctorIdx == 0) "" else s"$$$ctorIdx"
given reflInstBuffer: ReflectiveInstantiationBuffer =
ReflectiveInstantiationBuffer(fqSymName.id + ctorSuffix)
// Lambda generation consists of generating a class which extends
// scala.runtime.AbstractFunction1, with an apply method that accepts
// the list of arguments, instantiates an instance of the class by
// forwarding the arguments to C, and returns the instance.
withFreshExprBuffer { buf ?=>
val body = {
// first argument is this
val thisArg =
nir.Val.Local(curFresh(), nir.Type.Ref(reflInstBuffer.name))
// second argument is parameters sequence
val argsArg = nir.Val.Local(curFresh(), nir.Type.Array(nir.Rt.Object))
buf.label(curFresh(), Seq(thisArg, argsArg))
// Extract and cast arguments to proper types.
val argsVals =
for (arg, argIdx) <- ctorSig.args.tail.zipWithIndex
yield {
val elem =
buf.arrayload(
nir.Rt.Object,
argsArg,
nir.Val.Int(argIdx),
unwind(curFresh)
)
// If the expected argument type can be boxed (i.e. is a primitive
// type), then we need to unbox it before passing it to C.
nir.Type.box.get(arg) match {
case Some(bt) => buf.unbox(bt, elem, unwind(curFresh))
case None => buf.as(arg, elem, unwind(curFresh))
}
}
// Allocate a new instance and call constructor
val alloc = allocAndConstruct(
fqSymName,
ctorSig.args.tail,
argsVals
)
buf.ret(alloc)
buf.toSeq
}
reflInstBuffer += new nir.Defn.Define(
nir.Attrs.None,
reflInstBuffer.name.member(applyMethodSig),
nir.Type.Function(
Seq(
nir.Type.Ref(reflInstBuffer.name),
nir.Type.Array(nir.Rt.Object)
),
nir.Rt.Object
),
body
)
}
// Generate the class instantiator constructor.
genConstructor(nirSymbols.AbstractFunction1Name)
reflInstBuffer += nir.Defn.Class(
nir.Attrs(),
reflInstBuffer.name,
Some(nirSymbols.AbstractFunction1Name),
Seq(nirSymbols.SerializableName)
)
// Allocate an instance of the generated class.
val instantiator =
allocAndConstruct(reflInstBuffer.name, Seq.empty, Seq.empty)
// Create the current constructor's info. We need:
// - an array with the runtime classes of the ctor parameters.
// - the instantiator function created above (instantiator).
val rtClasses = buf.arrayalloc(
nir.Rt.Class,
nir.Val.Int(ctorSig.args.tail.length),
unwind(curFresh)
)
for ((arg, argIdx) <- ctorSig.args.tail.zipWithIndex) {
// Store the runtime class in the array.
buf.arraystore(
nir.Rt.Class,
rtClasses,
nir.Val.Int(argIdx),
nir.Val.ClassOf(nir.Type.typeToName(arg)),
unwind(curFresh)
)
}
// Allocate a tuple to store the current constructor's info
val to = createTuple(rtClasses, instantiator)
buf.arraystore(
nirSymbols.Tuple2Ref,
ctorsInfo,
nir.Val.Int(ctorIdx),
to,
unwind(curFresh)
)
}
ctorsInfo
}
}
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