dotty.tools.backend.jvm.BCodeBodyBuilder.scala Maven / Gradle / Ivy
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package dotty.tools
package backend
package jvm
import scala.annotation.switch
import scala.tools.asm
import scala.tools.asm.{Handle, Label, Opcodes}
import BCodeHelpers.InvokeStyle
/*
*
* @author Miguel Garcia, http://lamp.epfl.ch/~magarcia/ScalaCompilerCornerReloaded/
* @version 1.0
*
*/
trait BCodeBodyBuilder extends BCodeSkelBuilder {
// import global._
// import definitions._
import int._
import bTypes._
import coreBTypes._
import BCodeBodyBuilder._
/*
* Functionality to build the body of ASM MethodNode, except for `synchronized` and `try` expressions.
*/
abstract class PlainBodyBuilder(cunit: CompilationUnit) extends PlainSkelBuilder(cunit) {
import Primitives.TestOp
/* If the selector type has a member with the right name,
* it is the host class; otherwise the symbol's owner.
*/
def findHostClass(selector: Type, sym: Symbol) = selector member sym.name match {
case NoSymbol => debuglog(s"Rejecting $selector as host class for $sym") ; sym.owner
case _ => selector.typeSymbol
}
/* ---------------- helper utils for generating methods and code ---------------- */
def emit(opc: Int): Unit = { mnode.visitInsn(opc) }
def emitZeroOf(tk: BType): Unit = {
tk match {
case BOOL => bc.boolconst(false)
case BYTE |
SHORT |
CHAR |
INT => bc.iconst(0)
case LONG => bc.lconst(0)
case FLOAT => bc.fconst(0)
case DOUBLE => bc.dconst(0)
case UNIT => ()
case _ => emit(asm.Opcodes.ACONST_NULL)
}
}
/*
* Emits code that adds nothing to the operand stack.
* Two main cases: `tree` is an assignment,
* otherwise an `adapt()` to UNIT is performed if needed.
*/
def genStat(tree: Tree): Unit = {
lineNumber(tree)
tree match {
case Assign(lhs @ Select(_, _), rhs) =>
val isStatic = lhs.symbol.isStaticMember
if (!isStatic) { genLoadQualifier(lhs) }
genLoad(rhs, symInfoTK(lhs.symbol))
lineNumber(tree)
fieldStore(lhs.symbol)
case Assign(lhs, rhs) =>
val s = lhs.symbol
val Local(tk, _, idx, _) = locals.getOrMakeLocal(s)
genLoad(rhs, tk)
lineNumber(tree)
bc.store(idx, tk)
case _ =>
genLoad(tree, UNIT)
}
}
def genThrow(expr: Tree): BType = {
val thrownKind = tpeTK(expr)
// `throw null` is valid although scala.Null (as defined in src/libray-aux) isn't a subtype of Throwable.
// Similarly for scala.Nothing (again, as defined in src/libray-aux).
assert(thrownKind.isNullType || thrownKind.isNothingType || thrownKind.asClassBType.isSubtypeOf(ThrowableReference))
genLoad(expr, thrownKind)
lineNumber(expr)
emit(asm.Opcodes.ATHROW) // ICode enters here into enterIgnoreMode, we'll rely instead on DCE at ClassNode level.
RT_NOTHING // always returns the same, the invoker should know :)
}
/* Generate code for primitive arithmetic operations. */
def genArithmeticOp(tree: Tree, code: Int): BType = tree match{
case Apply(fun @ Select(larg, _), args) =>
var resKind = tpeTK(larg)
assert(resKind.isNumericType || (resKind == BOOL),
s"$resKind is not a numeric or boolean type [operation: ${fun.symbol}]")
import ScalaPrimitivesOps._
args match {
// unary operation
case Nil =>
genLoad(larg, resKind)
code match {
case POS => () // nothing
case NEG => bc.neg(resKind)
case NOT => bc.genPrimitiveArithmetic(Primitives.NOT, resKind)
case _ => abort(s"Unknown unary operation: ${fun.symbol.fullName} code: $code")
}
// binary operation
case rarg :: Nil =>
val isShift = isShiftOp(code)
resKind = tpeTK(larg).maxType(if (isShift) INT else tpeTK(rarg))
if (isShift || isBitwiseOp(code)) {
assert(resKind.isIntegralType || (resKind == BOOL),
s"$resKind incompatible with arithmetic modulo operation.")
}
genLoad(larg, resKind)
genLoad(rarg, if (isShift) INT else resKind)
(code: @switch) match {
case ADD => bc add resKind
case SUB => bc sub resKind
case MUL => bc mul resKind
case DIV => bc div resKind
case MOD => bc rem resKind
case OR | XOR | AND => bc.genPrimitiveLogical(code, resKind)
case LSL | LSR | ASR => bc.genPrimitiveShift(code, resKind)
case _ => abort(s"Unknown primitive: ${fun.symbol}[$code]")
}
case _ =>
abort(s"Too many arguments for primitive function: $tree")
}
lineNumber(tree)
resKind
}
/* Generate primitive array operations. */
def genArrayOp(tree: Tree, code: Int, expectedType: BType): BType = tree match{
case Apply(Select(arrayObj, _), args) =>
import ScalaPrimitivesOps._
val k = tpeTK(arrayObj)
genLoad(arrayObj, k)
val elementType = typeOfArrayOp.getOrElse[bTypes.BType](code, abort(s"Unknown operation on arrays: $tree code: $code"))
var generatedType = expectedType
if (isArrayGet(code)) {
// load argument on stack
assert(args.length == 1, s"Too many arguments for array get operation: $tree");
genLoad(args.head, INT)
generatedType = k.asArrayBType.componentType
bc.aload(elementType)
}
else if (isArraySet(code)) {
args match {
case a1 :: a2 :: Nil =>
genLoad(a1, INT)
genLoad(a2)
// the following line should really be here, but because of bugs in erasure
// we pretend we generate whatever type is expected from us.
//generatedType = UNIT
bc.astore(elementType)
case _ =>
abort(s"Too many arguments for array set operation: $tree")
}
}
else {
generatedType = INT
emit(asm.Opcodes.ARRAYLENGTH)
}
lineNumber(tree)
generatedType
}
def genLoadIf(tree: If, expectedType: BType): BType = tree match{
case If(condp, thenp, elsep) =>
val success = new asm.Label
val failure = new asm.Label
val hasElse = !elsep.isEmpty && (elsep match {
case Literal(value) if value.tag == UnitTag => false
case _ => true
})
val postIf = if (hasElse) new asm.Label else failure
genCond(condp, success, failure, targetIfNoJump = success)
markProgramPoint(success)
val thenKind = tpeTK(thenp)
val elseKind = if (!hasElse) UNIT else tpeTK(elsep)
def hasUnitBranch = (thenKind == UNIT || elseKind == UNIT) && expectedType == UNIT
val resKind = if (hasUnitBranch) UNIT else tpeTK(tree)
genLoad(thenp, resKind)
if (hasElse) { bc goTo postIf }
markProgramPoint(failure)
if (hasElse) {
genLoad(elsep, resKind)
markProgramPoint(postIf)
}
resKind
}
def genPrimitiveOp(tree: Apply, expectedType: BType): BType = tree match {
case Apply(fun @ Select(receiver, _), _) =>
val sym = tree.symbol
val code = primitives.getPrimitive(tree, receiver.tpe)
import ScalaPrimitivesOps._
if (isArithmeticOp(code)) genArithmeticOp(tree, code)
else if (code == CONCAT) genStringConcat(tree)
else if (code == HASH) genScalaHash(receiver)
else if (isArrayOp(code)) genArrayOp(tree, code, expectedType)
else if (isLogicalOp(code) || isComparisonOp(code)) {
val success, failure, after = new asm.Label
genCond(tree, success, failure, targetIfNoJump = success)
// success block
markProgramPoint(success)
bc boolconst true
bc goTo after
// failure block
markProgramPoint(failure)
bc boolconst false
// after
markProgramPoint(after)
BOOL
}
else if (isCoercion(code)) {
genLoad(receiver)
lineNumber(tree)
genCoercion(code)
coercionTo(code)
}
else abort(
s"Primitive operation not handled yet: ${sym.fullName}(${fun.symbol.simpleName}) at: ${tree.pos}"
)
}
def genLoad(tree: Tree): Unit = {
genLoad(tree, tpeTK(tree))
}
/* Generate code for trees that produce values on the stack */
def genLoad(tree: Tree, expectedType: BType): Unit = {
var generatedType = expectedType
lineNumber(tree)
tree match {
case lblDf @ LabelDef(_, _, _) => genLabelDef(lblDf, expectedType)
case ValDef(_, `nme_THIS`, _, _) =>
debuglog("skipping trivial assign to _$this: " + tree)
case ValDef(_, _, _, rhs) =>
val sym = tree.symbol
/* most of the time, !locals.contains(sym), unless the current activation of genLoad() is being called
while duplicating a finalizer that contains this ValDef. */
val loc = locals.getOrMakeLocal(sym)
val Local(tk, _, idx, isSynth) = loc
if (rhs == EmptyTree) { emitZeroOf(tk) }
else { genLoad(rhs, tk) }
val localVarStart = currProgramPoint()
bc.store(idx, tk)
if (!isSynth) { // there are case ValDef's emitted by patmat
varsInScope ::= (sym -> localVarStart)
}
generatedType = UNIT
case t @ If(_, _, _) =>
generatedType = genLoadIf(t, expectedType)
case t @ Labeled(_, _) =>
generatedType = genLabeled(t)
case r @ Return(_) =>
genReturn(r)
generatedType = expectedType
case t @ WhileDo(_, _) =>
generatedType = genWhileDo(t)
case t @ Try(_, _, _) =>
generatedType = genLoadTry(t)
case Throw(expr) =>
generatedType = genThrow(expr)
case New(tpt) =>
abort(s"Unexpected New(${tpt.summaryString}/$tpt) reached GenBCode.\n" +
" Call was genLoad" + ((tree, expectedType)))
case app @ Closure(env, call, functionalInterface) =>
val (fun, args) = call match {
case Apply(fun, args) => (fun, args)
case t @ Select(_, _) => (t, Nil)
case t @ Ident(_) => (t, Nil)
}
if (!fun.symbol.isStaticMember) {
// load receiver of non-static implementation of lambda
// darkdimius: I haven't found in spec `this` refference should go
// but I was able to derrive it by reading
// AbstractValidatingLambdaMetafactory.validateMetafactoryArgs
val Select(prefix, _) = fun
genLoad(prefix)
}
genLoadArguments(env, fun.symbol.info.paramTypes map toTypeKind)
generatedType = genInvokeDynamicLambda(NoSymbol, fun.symbol, env.size, functionalInterface)
case app @ Apply(_, _) =>
generatedType = genApply(app, expectedType)
case ApplyDynamic(qual, args) => sys.error("No invokedynamic support yet.")
case This(qual) =>
val symIsModuleClass = tree.symbol.isModuleClass
assert(tree.symbol == claszSymbol || symIsModuleClass,
s"Trying to access the this of another class: tree.symbol = ${tree.symbol}, class symbol = $claszSymbol compilation unit: $cunit")
if (symIsModuleClass && tree.symbol != claszSymbol) {
generatedType = genLoadModule(tree)
}
else {
mnode.visitVarInsn(asm.Opcodes.ALOAD, 0)
generatedType =
if (tree.symbol == ArrayClass) ObjectReference
else classBTypeFromSymbol(claszSymbol)
}
case Select(Ident(`nme_EMPTY_PACKAGE_NAME`), module) =>
assert(tree.symbol.isModule, s"Selection of non-module from empty package: $tree sym: ${tree.symbol} at: ${tree.pos}")
genLoadModule(tree)
case Select(qualifier, selector) =>
val sym = tree.symbol
generatedType = symInfoTK(sym)
val hostClass = findHostClass(qualifier.tpe, sym)
debuglog(s"Host class of $sym with qual $qualifier (${qualifier.tpe}) is $hostClass")
val qualSafeToElide = isQualifierSafeToElide(qualifier)
def genLoadQualUnlessElidable(): Unit = { if (!qualSafeToElide) { genLoadQualifier(tree) } }
if (sym.isModule) {
genLoadQualUnlessElidable()
genLoadModule(tree)
}
else if (sym.isStaticMember) {
genLoadQualUnlessElidable()
fieldLoad(sym, hostClass)
}
else {
genLoadQualifier(tree)
fieldLoad(sym, hostClass)
}
case t @ Ident(name) =>
val sym = tree.symbol
val tk = symInfoTK(sym)
generatedType = tk
val desugared = desugarIdent(t)
desugared match {
case None =>
if (!sym.hasPackageFlag) {
if (sym.isModule) genLoadModule(sym)
else locals.load(sym)
}
case Some(t) =>
genLoad(t, generatedType)
}
case Literal(value) =>
if (value.tag != UnitTag) (value.tag, expectedType) match {
case (IntTag, LONG ) => bc.lconst(value.longValue); generatedType = LONG
case (FloatTag, DOUBLE) => bc.dconst(value.doubleValue); generatedType = DOUBLE
case (NullTag, _ ) => bc.emit(asm.Opcodes.ACONST_NULL); generatedType = RT_NULL
case _ => genConstant(value); generatedType = tpeTK(tree)
}
case blck @ Block(stats, expr) =>
if(stats.isEmpty)
genLoad(expr, expectedType)
else genBlock(blck, expectedType)
case Typed(Super(_, _), _) => genLoad(This(claszSymbol), expectedType)
case Typed(expr, _) => genLoad(expr, expectedType)
case Assign(_, _) =>
generatedType = UNIT
genStat(tree)
case av @ ArrayValue(_, _) =>
generatedType = genArrayValue(av)
case mtch @ Match(_, _) =>
generatedType = genMatch(mtch)
case EmptyTree => if (expectedType != UNIT) { emitZeroOf(expectedType) }
case t: TypeApply => // dotty specific
generatedType = genTypeApply(t)
case _ => abort(s"Unexpected tree in genLoad: $tree/${tree.getClass} at: ${tree.pos}")
}
// emit conversion
if (generatedType != expectedType) {
adapt(generatedType, expectedType)
}
} // end of GenBCode.genLoad()
// ---------------- field load and store ----------------
/*
* must-single-thread
*/
def fieldLoad( field: Symbol, hostClass: Symbol = null): Unit = {
fieldOp(field, isLoad = true, hostClass)
}
/*
* must-single-thread
*/
def fieldStore(field: Symbol, hostClass: Symbol = null): Unit = {
fieldOp(field, isLoad = false, hostClass)
}
/*
* must-single-thread
*/
private def fieldOp(field: Symbol, isLoad: Boolean, hostClass: Symbol): Unit = {
// LOAD_FIELD.hostClass , CALL_METHOD.hostClass , and #4283
val owner =
if (hostClass == null) internalName(field.owner)
else internalName(hostClass)
val fieldJName = field.javaSimpleName.toString
val fieldDescr = symInfoTK(field).descriptor
val isStatic = field.isStaticMember
val opc =
if (isLoad) { if (isStatic) asm.Opcodes.GETSTATIC else asm.Opcodes.GETFIELD }
else { if (isStatic) asm.Opcodes.PUTSTATIC else asm.Opcodes.PUTFIELD }
mnode.visitFieldInsn(opc, owner, fieldJName, fieldDescr)
}
// ---------------- emitting constant values ----------------
/*
* For const.tag in {ClazzTag, EnumTag}
* must-single-thread
* Otherwise it's safe to call from multiple threads.
*/
def genConstant(const: Constant): Unit = {
(const.tag/*: @switch*/) match {
case BooleanTag => bc.boolconst(const.booleanValue)
case ByteTag => bc.iconst(const.byteValue)
case ShortTag => bc.iconst(const.shortValue)
case CharTag => bc.iconst(const.charValue)
case IntTag => bc.iconst(const.intValue)
case LongTag => bc.lconst(const.longValue)
case FloatTag => bc.fconst(const.floatValue)
case DoubleTag => bc.dconst(const.doubleValue)
case UnitTag => ()
case StringTag =>
assert(const.value != null, const) // TODO this invariant isn't documented in `case class Constant`
mnode.visitLdcInsn(const.stringValue) // `stringValue` special-cases null, but not for a const with StringTag
case NullTag => emit(asm.Opcodes.ACONST_NULL)
case ClazzTag =>
val toPush: BType = {
toTypeKind(const.typeValue) match {
case kind: PrimitiveBType => boxedClassOfPrimitive(kind)
case kind => kind
}
}
mnode.visitLdcInsn(toPush.toASMType)
case EnumTag =>
val sym = const.symbolValue
val ownerName = internalName(sym.owner)
val fieldName = sym.javaSimpleName.toString
val fieldDesc = toTypeKind(sym.tpe.underlying).descriptor
mnode.visitFieldInsn(
asm.Opcodes.GETSTATIC,
ownerName,
fieldName,
fieldDesc
)
case _ => abort(s"Unknown constant value: $const")
}
}
private def genLabelDef(lblDf: LabelDef, expectedType: BType): Unit = lblDf match {
case LabelDef(_, _, rhs) =>
assert(int.hasLabelDefs) // scalac
// duplication of LabelDefs contained in `finally`-clauses is handled when emitting RETURN. No bookkeeping for that required here.
// no need to call index() over lblDf.params, on first access that magic happens (moreover, no LocalVariableTable entries needed for them).
markProgramPoint(programPoint(lblDf.symbol))
lineNumber(lblDf)
genLoad(rhs, expectedType)
}
private def genLabeled(tree: Labeled): BType = tree match {
case Labeled(bind, expr) =>
val resKind = tpeTK(tree)
genLoad(expr, resKind)
markProgramPoint(programPoint(bind.symbol))
resKind
}
private def genReturn(r: Return): Unit = r match {
case Return(expr, fromSym) =>
if (NoSymbol == fromSym) {
// return from enclosing method
val returnedKind = tpeTK(expr)
genLoad(expr, returnedKind)
adapt(returnedKind, returnType)
val saveReturnValue = (returnType != UNIT)
lineNumber(r)
cleanups match {
case Nil =>
// not an assertion: !shouldEmitCleanup (at least not yet, pendingCleanups() may still have to run, and reset `shouldEmitCleanup`.
bc emitRETURN returnType
case nextCleanup :: rest =>
if (saveReturnValue) {
// regarding return value, the protocol is: in place of a `return-stmt`, a sequence of `adapt, store, jump` are inserted.
if (earlyReturnVar == null) {
earlyReturnVar = locals.makeLocal(returnType, "earlyReturnVar", expr.tpe, expr.pos)
}
locals.store(earlyReturnVar)
}
bc goTo nextCleanup
shouldEmitCleanup = true
}
} else {
// return from labeled
assert(fromSym.isLabel, fromSym)
assert(!fromSym.isMethod, fromSym)
/* TODO At the moment, we disregard cleanups, because by construction we don't have return-from-labels
* that cross cleanup boundaries. However, in theory such crossings are valid, so we should take care
* of them.
*/
val resultKind = toTypeKind(fromSym.info)
genLoad(expr, resultKind)
lineNumber(r)
bc goTo programPoint(fromSym)
}
} // end of genReturn()
def genWhileDo(tree: WhileDo): BType = tree match{
case WhileDo(cond, body) =>
val isInfinite = cond == EmptyTree
val loop = new asm.Label
markProgramPoint(loop)
if (isInfinite) {
genLoad(body, UNIT)
bc goTo loop
RT_NOTHING
} else {
val hasBody = cond match {
case Literal(value) if value.tag == UnitTag => false
case _ => true
}
if (hasBody) {
val success = new asm.Label
val failure = new asm.Label
genCond(cond, success, failure, targetIfNoJump = success)
markProgramPoint(success)
genLoad(body, UNIT)
bc goTo loop
markProgramPoint(failure)
} else {
// this is the shape of do..while loops, so do something smart about them
val failure = new asm.Label
genCond(cond, loop, failure, targetIfNoJump = failure)
markProgramPoint(failure)
}
UNIT
}
}
def genTypeApply(t: TypeApply): BType = t match {
case TypeApply(fun@Select(obj, _), targs) =>
val sym = fun.symbol
val cast = sym match {
case Object_isInstanceOf => false
case Object_asInstanceOf => true
case _ => abort(s"Unexpected type application $fun[sym: ${sym.fullName}] in: $t")
}
val l = tpeTK(obj)
val r = tpeTK(targs.head)
genLoadQualifier(fun)
// TODO @lry make pattern match
if (l.isPrimitive && r.isPrimitive)
genConversion(l, r, cast)
else if (l.isPrimitive) {
bc drop l
if (cast) {
mnode.visitTypeInsn(asm.Opcodes.NEW, classCastExceptionReference.internalName)
bc dup ObjectReference
emit(asm.Opcodes.ATHROW)
} else {
bc boolconst false
}
}
else if (r.isPrimitive && cast) {
abort(s"Erasure should have added an unboxing operation to prevent this cast. Tree: $t")
}
else if (r.isPrimitive) {
bc isInstance boxedClassOfPrimitive(r.asPrimitiveBType)
}
else {
assert(r.isRef, r) // ensure that it's not a method
genCast(r.asRefBType, cast)
}
if (cast) r else BOOL
} // end of genTypeApply()
private def mkArrayConstructorCall(arr: ArrayBType, app: Apply, args: List[Tree]) = {
val dims = arr.dimension
var elemKind = arr.elementType
val argsSize = args.length
if (argsSize > dims) {
error(app.pos, s"too many arguments for array constructor: found ${args.length} but array has only $dims dimension(s)")
}
if (argsSize < dims) {
/* In one step:
* elemKind = new BType(BType.ARRAY, arr.off + argsSize, arr.len - argsSize)
* however the above does not enter a TypeName for each nested arrays in chrs.
*/
for (i <- args.length until dims) elemKind = ArrayBType(elemKind)
}
genLoadArguments(args, List.fill(args.size)(INT))
(argsSize /*: @switch*/) match {
case 1 => bc newarray elemKind
case _ =>
val descr = ("[" * argsSize) + elemKind.descriptor // denotes the same as: arrayN(elemKind, argsSize).descriptor
mnode.visitMultiANewArrayInsn(descr, argsSize)
}
}
private def genApply(app: Apply, expectedType: BType): BType = {
var generatedType = expectedType
lineNumber(app)
app match {
case Apply(_, args) if isSyntheticArrayConstructor(app.symbol) =>
val List(elemClaz, Literal(c: Constant), ArrayValue(_, dims)) = args
generatedType = toTypeKind(c.typeValue)
mkArrayConstructorCall(generatedType.asArrayBType, app, dims)
case Apply(t :TypeApply, _) =>
generatedType =
if (t.symbol ne Object_synchronized) genTypeApply(t)
else genSynchronized(app, expectedType)
// 'super' call: Note: since constructors are supposed to
// return an instance of what they construct, we have to take
// special care. On JVM they are 'void', and Scala forbids (syntactically)
// to call super constructors explicitly and/or use their 'returned' value.
// therefore, we can ignore this fact, and generate code that leaves nothing
// on the stack (contrary to what the type in the AST says).
case Apply(fun @ Select(Super(_, mix), _), args) =>
val invokeStyle = InvokeStyle.Super
// if (fun.symbol.isConstructor) Static(true) else SuperCall(mix);
mnode.visitVarInsn(asm.Opcodes.ALOAD, 0)
genLoadArguments(args, paramTKs(app))
genCallMethod(fun.symbol, invokeStyle, pos = app.pos)
generatedType = asmMethodType(fun.symbol).returnType
// 'new' constructor call: Note: since constructors are
// thought to return an instance of what they construct,
// we have to 'simulate' it by DUPlicating the freshly created
// instance (on JVM, methods return VOID).
case Apply(fun @ Select(New(tpt), `nme_CONSTRUCTOR`), args) =>
val ctor = fun.symbol
assert(ctor.isClassConstructor, s"'new' call to non-constructor: ${ctor.name}")
generatedType = toTypeKind(tpt)
assert(generatedType.isRef, s"Non reference type cannot be instantiated: $generatedType")
generatedType match {
case arr: ArrayBType =>
mkArrayConstructorCall(arr, app, args)
case rt: ClassBType =>
assert(classBTypeFromSymbol(ctor.owner) == rt, s"Symbol ${ctor.owner.fullName} is different from $rt")
mnode.visitTypeInsn(asm.Opcodes.NEW, rt.internalName)
bc dup generatedType
genLoadArguments(args, paramTKs(app))
genCallMethod(ctor, InvokeStyle.Special)
case _ =>
abort(s"Cannot instantiate $tpt of kind: $generatedType")
}
case Apply(fun, List(expr)) if isBox(fun.symbol) =>
val nativeKind = tpeTK(expr)
genLoad(expr, nativeKind)
val MethodNameAndType(mname, methodType) = asmBoxTo(nativeKind)
bc.invokestatic(BoxesRunTime.internalName, mname, methodType.descriptor, itf = false)
generatedType = boxResultType(fun.symbol) // was toTypeKind(fun.symbol.tpe.resultType)
case Apply(fun, List(expr)) if isUnbox(fun.symbol) =>
genLoad(expr)
val boxType = unboxResultType(fun.symbol) // was toTypeKind(fun.symbol.owner.linkedClassOfClass.tpe)
generatedType = boxType
val MethodNameAndType(mname, methodType) = asmUnboxTo(boxType)
bc.invokestatic(BoxesRunTime.internalName, mname, methodType.descriptor, itf = false)
case app @ Apply(fun, args) =>
val sym = fun.symbol
if (sym.isLabel) { // jump to a label
assert(int.hasLabelDefs)
genLoadLabelArguments(args, labelDef(sym), app.pos)
bc goTo programPoint(sym)
} else if (isPrimitive(fun)) { // primitive method call
generatedType = genPrimitiveOp(app, expectedType)
} else { // normal method call
def genNormalMethodCall(): Unit = {
val invokeStyle =
if (sym.isStaticMember) InvokeStyle.Static
else if (sym.isPrivate || sym.isClassConstructor) InvokeStyle.Special
else InvokeStyle.Virtual
if (invokeStyle.hasInstance) {
genLoadQualifier(fun)
}
genLoadArguments(args, paramTKs(app))
// In "a couple cases", squirrel away a extra information (hostClass, targetTypeKind). TODO Document what "in a couple cases" refers to.
var hostClass: Symbol = null
fun match {
case Select(qual, _) if isArrayClone(fun) && invokeStyle.isVirtual =>
val targetTypeKind = tpeTK(qual)
val target: String = targetTypeKind.asRefBType.classOrArrayType
bc.invokevirtual(target, "clone", "()Ljava/lang/Object;")
generatedType = targetTypeKind
case Select(qual, _) =>
val qualSym = findHostClass(qual.tpe, sym)
hostClass = qualSym
if (qual.tpe.typeSymbol != qualSym) {
log(s"Precisified host class for $sym from ${qual.tpe.typeSymbol.fullName} to ${qualSym.fullName}")
}
genCallMethod(sym, invokeStyle, hostClass, app.pos)
generatedType = asmMethodType(sym).returnType
case _ =>
genCallMethod(sym, invokeStyle, hostClass, app.pos)
generatedType = asmMethodType(sym).returnType
}
} // end of genNormalMethodCall()
genNormalMethodCall()
}
}
generatedType
} // end of genApply()
private def genArrayValue(av: ArrayValue): BType = av match {
case ArrayValue(tpt, elems) =>
val ArrayValue(tpt, elems) = av
lineNumber(av)
genArray(elems, tpt)
}
private def genArray(elems: List[Tree], elemType: Type): BType = {
val elmKind = toTypeKind(elemType)
val generatedType = ArrayBType(elmKind)
bc iconst elems.length
bc newarray elmKind
var i = 0
var rest = elems
while (!rest.isEmpty) {
bc dup generatedType
bc iconst i
genLoad(rest.head, elmKind)
bc astore elmKind
rest = rest.tail
i = i + 1
}
generatedType
}
/*
* A Match node contains one or more case clauses,
* each case clause lists one or more Int values to use as keys, and a code block.
* Except the "default" case clause which (if it exists) doesn't list any Int key.
*
* On a first pass over the case clauses, we flatten the keys and their targets (the latter represented with asm.Labels).
* That representation allows JCodeMethodV to emit a lookupswitch or a tableswitch.
*
* On a second pass, we emit the switch blocks, one for each different target.
*/
private def genMatch(tree: Match): BType = tree match {
case Match(selector, cases) =>
lineNumber(tree)
genLoad(selector, INT)
val generatedType = tpeTK(tree)
var flatKeys: List[Int] = Nil
var targets: List[asm.Label] = Nil
var default: asm.Label = null
var switchBlocks: List[(asm.Label, Tree)] = Nil
// collect switch blocks and their keys, but don't emit yet any switch-block.
for (caze @ CaseDef(pat, guard, body) <- cases) {
assert(guard == EmptyTree, guard)
val switchBlockPoint = new asm.Label
switchBlocks ::= (switchBlockPoint, body)
pat match {
case Literal(value) =>
flatKeys ::= value.intValue
targets ::= switchBlockPoint
case Ident(`nme_WILDCARD`) =>
assert(default == null, s"multiple default targets in a Match node, at ${tree.pos}")
default = switchBlockPoint
case Alternative(alts) =>
alts foreach {
case Literal(value) =>
flatKeys ::= value.intValue
targets ::= switchBlockPoint
case _ =>
abort(s"Invalid alternative in alternative pattern in Match node: $tree at: ${tree.pos}")
}
case _ =>
abort(s"Invalid pattern in Match node: $tree at: ${tree.pos}")
}
}
bc.emitSWITCH(mkArrayReverse(flatKeys), mkArrayL(targets.reverse), default, MIN_SWITCH_DENSITY)
// emit switch-blocks.
val postMatch = new asm.Label
for (sb <- switchBlocks.reverse) {
val (caseLabel, caseBody) = sb
markProgramPoint(caseLabel)
genLoad(caseBody, generatedType)
bc goTo postMatch
}
markProgramPoint(postMatch)
generatedType
}
def genBlock(tree: Block, expectedType: BType) = tree match {
case Block(stats, expr) =>
val savedScope = varsInScope
varsInScope = Nil
stats foreach genStat
genLoad(expr, expectedType)
val end = currProgramPoint()
if (emitVars) {
// add entries to LocalVariableTable JVM attribute
for ((sym, start) <- varsInScope.reverse) {
emitLocalVarScope(sym, start, end)
}
}
varsInScope = savedScope
}
def adapt(from: BType, to: BType): Unit = {
if (!from.conformsTo(to)) {
to match {
case UNIT => bc drop from
case _ => bc.emitT2T(from, to)
}
} else if (from.isNothingType) {
/* There are two possibilities for from.isNothingType: emitting a "throw e" expressions and
* loading a (phantom) value of type Nothing.
*
* The Nothing type in Scala's type system does not exist in the JVM. In bytecode, Nothing
* is mapped to scala.runtime.Nothing$. To the JVM, a call to Predef.??? looks like it would
* return an object of type Nothing$. We need to do something with that phantom object on
* the stack. "Phantom" because it never exists: such methods always throw, but the JVM does
* not know that.
*
* Note: The two verifiers (old: type inference, new: type checking) have different
* requirements. Very briefly:
*
* Old (http://docs.oracle.com/javase/specs/jvms/se8/html/jvms-4.html#jvms-4.10.2.1): at
* each program point, no matter what branches were taken to get there
* - Stack is same size and has same typed values
* - Local and stack values need to have consistent types
* - In practice, the old verifier seems to ignore unreachable code and accept any
* instructions after an ATHROW. For example, there can be another ATHROW (without
* loading another throwable first).
*
* New (http://docs.oracle.com/javase/specs/jvms/se8/html/jvms-4.html#jvms-4.10.1)
* - Requires consistent stack map frames. GenBCode generates stack frames if -target:jvm-1.6
* or higher.
* - In practice: the ASM library computes stack map frames for us (ClassWriter). Emitting
* correct frames after an ATHROW is probably complex, so ASM uses the following strategy:
* - Every time when generating an ATHROW, a new basic block is started.
* - During classfile writing, such basic blocks are found to be dead: no branches go there
* - Eliminating dead code would probably require complex shifts in the output byte buffer
* - But there's an easy solution: replace all code in the dead block with with
* `nop; nop; ... nop; athrow`, making sure the bytecode size stays the same
* - The corresponding stack frame can be easily generated: on entering a dead the block,
* the frame requires a single Throwable on the stack.
* - Since there are no branches to the dead block, the frame requirements are never violated.
*
* To summarize the above: it does matter what we emit after an ATHROW.
*
* NOW: if we end up here because we emitted a load of a (phantom) value of type Nothing$,
* there was no ATHROW emitted. So, we have to make the verifier happy and do something
* with that value. Since Nothing$ extends Throwable, the easiest is to just emit an ATHROW.
*
* If we ended up here because we generated a "throw e" expression, we know the last
* emitted instruction was an ATHROW. As explained above, it is OK to emit a second ATHROW,
* the verifiers will be happy.
*/
if (lastInsn.getOpcode != asm.Opcodes.ATHROW)
emit(asm.Opcodes.ATHROW)
} else if (from.isNullType) {
/* After loading an expression of type `scala.runtime.Null$`, introduce POP; ACONST_NULL.
* This is required to pass the verifier: in Scala's type system, Null conforms to any
* reference type. In bytecode, the type Null is represented by scala.runtime.Null$, which
* is not a subtype of all reference types. Example:
*
* def nl: Null = null // in bytecode, nl has return type scala.runtime.Null$
* val a: String = nl // OK for Scala but not for the JVM, scala.runtime.Null$ does not conform to String
*
* In order to fix the above problem, the value returned by nl is dropped and ACONST_NULL is
* inserted instead - after all, an expression of type scala.runtime.Null$ can only be null.
*/
if (lastInsn.getOpcode != asm.Opcodes.ACONST_NULL) {
bc drop from
emit(asm.Opcodes.ACONST_NULL)
}
}
else (from, to) match {
case (BYTE, LONG) | (SHORT, LONG) | (CHAR, LONG) | (INT, LONG) => bc.emitT2T(INT, LONG)
case _ => ()
}
}
/* Emit code to Load the qualifier of `tree` on top of the stack. */
def genLoadQualifier(tree: Tree): Unit = {
lineNumber(tree)
tree match {
case Select(qualifier, _) => genLoad(qualifier)
case t: Ident => // dotty specific
desugarIdent(t) match {
case Some(sel) => genLoadQualifier(sel)
case None =>
assert(t.symbol.owner == this.claszSymbol)
}
case _ => abort(s"Unknown qualifier $tree")
}
}
/* Generate code that loads args into label parameters. */
def genLoadLabelArguments(args: List[Tree], lblDef: LabelDef, gotoPos: Position) = lblDef match {
case LabelDef(_, param, _) =>
val aps = {
val params: List[Symbol] = param
assert(args.length == params.length, s"Wrong number of arguments in call to label at: $gotoPos")
def isTrivial(kv: (Tree, Symbol)) = kv match {
case (This(_), p) if p.name == nme_THIS => true
case (arg @ Ident(_), p) if arg.symbol == p => true
case _ => false
}
(args zip params) filterNot isTrivial
}
// first push *all* arguments. This makes sure muliple uses of the same labelDef-var will all denote the (previous) value.
aps foreach { case (arg, param) => genLoad(arg, locals(param).tk) } // `locals` is known to contain `param` because `genDefDef()` visited `labelDefsAtOrUnder`
// second assign one by one to the LabelDef's variables.
aps.reverse foreach {
case (_, param) =>
// TODO FIXME a "this" param results from tail-call xform. If so, the `else` branch seems perfectly fine. And the `then` branch must be wrong.
if (param.name == nme_THIS) mnode.visitVarInsn(asm.Opcodes.ASTORE, 0)
else locals.store(param)
}
}
def genLoadArguments(args: List[Tree], btpes: List[BType]): Unit = {
(args zip btpes) foreach { case (arg, btpe) => genLoad(arg, btpe) }
}
def genLoadModule(tree: Tree): BType = {
val module = (
if (!tree.symbol.isPackageClass) tree.symbol
else tree.symbol.info.member(nme_PACKAGE) match {
case NoSymbol => abort(s"SI-5604: Cannot use package as value: $tree")
case s => abort(s"SI-5604: found package class where package object expected: $tree")
}
)
lineNumber(tree)
genLoadModule(module)
symInfoTK(module)
}
def genLoadModule(module: Symbol): Unit = {
def inStaticMethod = methSymbol != null && methSymbol.isStaticMember
if (claszSymbol == module.moduleClass && jMethodName != "readResolve" && !inStaticMethod) {
mnode.visitVarInsn(asm.Opcodes.ALOAD, 0)
} else {
val mbt = symInfoTK(module).asClassBType
mnode.visitFieldInsn(
asm.Opcodes.GETSTATIC,
mbt.internalName /* + "$" */ ,
MODULE_INSTANCE_FIELD,
mbt.descriptor // for nostalgics: toTypeKind(module.tpe).descriptor
)
}
}
def genConversion(from: BType, to: BType, cast: Boolean): Unit = {
if (cast) { bc.emitT2T(from, to) }
else {
bc drop from
bc boolconst (from == to)
}
}
def genCast(to: RefBType, cast: Boolean): Unit = {
if (cast) { bc checkCast to }
else { bc isInstance to }
}
/* Is the given symbol a primitive operation? */
def isPrimitive(fun: Tree): Boolean = {
primitives.isPrimitive(fun)
}
/* Generate coercion denoted by "code" */
def genCoercion(code: Int): Unit = {
import ScalaPrimitivesOps._
(code: @switch) match {
case B2B | S2S | C2C | I2I | L2L | F2F | D2D => ()
case _ =>
val from = coercionFrom(code)
val to = coercionTo(code)
bc.emitT2T(from, to)
}
}
def genStringConcat(tree: Tree): BType = {
lineNumber(tree)
liftStringConcat(tree) match {
// Optimization for expressions of the form "" + x. We can avoid the StringBuilder.
case List(Literal(Constant("")), arg) =>
genLoad(arg, ObjectReference)
genCallMethod(String_valueOf, InvokeStyle.Static)
case concatenations =>
bc.genStartConcat
for (elem <- concatenations) {
val loadedElem = elem match {
case Apply(boxOp, value :: Nil) if isBox(boxOp.symbol) =>
// Eliminate boxing of primitive values. Boxing is introduced by erasure because
// there's only a single synthetic `+` method "added" to the string class.
value
case _ => elem
}
val elemType = tpeTK(loadedElem)
genLoad(loadedElem, elemType)
bc.genConcat(elemType)
}
bc.genEndConcat
}
StringRef
}
def genCallMethod(method: Symbol, style: InvokeStyle, hostClass0: Symbol = null, pos: Position = NoPosition): Unit = {
val siteSymbol = claszSymbol
val hostSymbol = if (hostClass0 == null) method.owner else hostClass0
val methodOwner = method.owner
// info calls so that types are up to date; erasure may add lateINTERFACE to traits
hostSymbol.info ; methodOwner.info
def needsInterfaceCall(sym: Symbol) = (
sym.isInterface
|| sym.isJavaDefined && sym.isNonBottomSubClass(ClassfileAnnotationClass)
)
// whether to reference the type of the receiver or
// the type of the method owner
val useMethodOwner = (
!style.isVirtual
|| hostSymbol.isBottomClass
|| methodOwner == ObjectClass
)
val receiver = if (useMethodOwner) methodOwner else hostSymbol
val jowner = internalName(receiver)
val jname = method.javaSimpleName.toString
val bmType = asmMethodType(method)
val mdescr = bmType.descriptor
def initModule(): Unit = {
// we initialize the MODULE$ field immediately after the super ctor
if (!isModuleInitialized &&
jMethodName == INSTANCE_CONSTRUCTOR_NAME &&
jname == INSTANCE_CONSTRUCTOR_NAME &&
siteSymbol.isStaticModuleClass) {
isModuleInitialized = true
mnode.visitVarInsn(asm.Opcodes.ALOAD, 0)
mnode.visitFieldInsn(
asm.Opcodes.PUTSTATIC,
thisName,
MODULE_INSTANCE_FIELD,
"L" + thisName + ";"
)
}
}
val isInterface = receiver.isEmittedInterface
if (style.isStatic) { bc.invokestatic (jowner, jname, mdescr, itf = isInterface) }
else if (style.isSpecial) { bc.invokespecial (jowner, jname, mdescr, itf = isInterface) }
else if (style.isVirtual) {
if (needsInterfaceCall(receiver)) { bc.invokeinterface(jowner, jname, mdescr) }
else { bc.invokevirtual (jowner, jname, mdescr) }
}
else {
assert(style.isSuper, s"An unknown InvokeStyle: $style")
bc.invokespecial(jowner, jname, mdescr, itf = isInterface)
initModule()
}
} // end of genCallMethod()
/* Generate the scala ## method. */
def genScalaHash(tree: Tree): BType = {
genLoadModule(ScalaRunTimeModule) // TODO why load ScalaRunTimeModule if ## has InvokeStyle of Static(false) ?
genLoad(tree, ObjectReference)
genCallMethod(hashMethodSym, InvokeStyle.Static)
INT
}
/*
* Returns a list of trees that each should be concatenated, from left to right.
* It turns a chained call like "a".+("b").+("c") into a list of arguments.
*/
def liftStringConcat(tree: Tree): List[Tree] = tree match {
case tree @ Apply(fun @ Select(larg, method), rarg) =>
if (isPrimitive(fun) &&
primitives.getPrimitive(tree, larg.tpe) == ScalaPrimitivesOps.CONCAT)
liftStringConcat(larg) ::: rarg
else
tree :: Nil
case _ =>
tree :: Nil
}
/* Emit code to compare the two top-most stack values using the 'op' operator. */
private def genCJUMP(success: asm.Label, failure: asm.Label, op: TestOp, tk: BType, targetIfNoJump: asm.Label): Unit = {
if (targetIfNoJump == success) genCJUMP(failure, success, op.negate(), tk, targetIfNoJump)
else {
if (tk.isIntSizedType) { // BOOL, BYTE, CHAR, SHORT, or INT
bc.emitIF_ICMP(op, success)
} else if (tk.isRef) { // REFERENCE(_) | ARRAY(_)
bc.emitIF_ACMP(op, success)
} else {
import Primitives._
(tk: @unchecked) match {
case LONG => emit(asm.Opcodes.LCMP)
case FLOAT =>
if (op == LT || op == LE) emit(asm.Opcodes.FCMPL)
else emit(asm.Opcodes.FCMPG)
case DOUBLE =>
if (op == LT || op == LE) emit(asm.Opcodes.DCMPL)
else emit(asm.Opcodes.DCMPG)
}
bc.emitIF(op, success)
}
if (targetIfNoJump != failure) bc goTo failure
}
}
/* Emits code to compare (and consume) stack-top and zero using the 'op' operator */
private def genCZJUMP(success: asm.Label, failure: asm.Label, op: TestOp, tk: BType, targetIfNoJump: asm.Label): Unit = {
import Primitives._
if (targetIfNoJump == success) genCZJUMP(failure, success, op.negate(), tk, targetIfNoJump)
else {
if (tk.isIntSizedType) { // BOOL, BYTE, CHAR, SHORT, or INT
bc.emitIF(op, success)
} else if (tk.isRef) { // REFERENCE(_) | ARRAY(_)
(op: @unchecked) match { // references are only compared with EQ and NE
case EQ => bc emitIFNULL success
case NE => bc emitIFNONNULL success
}
} else {
(tk: @unchecked) match {
case LONG =>
emit(asm.Opcodes.LCONST_0)
emit(asm.Opcodes.LCMP)
case FLOAT =>
emit(asm.Opcodes.FCONST_0)
if (op == LT || op == LE) emit(asm.Opcodes.FCMPL)
else emit(asm.Opcodes.FCMPG)
case DOUBLE =>
emit(asm.Opcodes.DCONST_0)
if (op == LT || op == LE) emit(asm.Opcodes.DCMPL)
else emit(asm.Opcodes.DCMPG)
}
bc.emitIF(op, success)
}
if (targetIfNoJump != failure) bc goTo failure
}
}
def testOpForPrimitive(primitiveCode: Int) = (primitiveCode: @switch) match {
case ScalaPrimitivesOps.ID => Primitives.EQ
case ScalaPrimitivesOps.NI => Primitives.NE
case ScalaPrimitivesOps.EQ => Primitives.EQ
case ScalaPrimitivesOps.NE => Primitives.NE
case ScalaPrimitivesOps.LT => Primitives.LT
case ScalaPrimitivesOps.LE => Primitives.LE
case ScalaPrimitivesOps.GE => Primitives.GE
case ScalaPrimitivesOps.GT => Primitives.GT
}
/*
* Generate code for conditional expressions.
* The jump targets success/failure of the test are `then-target` and `else-target` resp.
*/
private def genCond(tree: Tree, success: asm.Label, failure: asm.Label, targetIfNoJump: asm.Label): Unit = {
def genComparisonOp(l: Tree, r: Tree, code: Int): Unit = {
val op = testOpForPrimitive(code)
val nonNullSide = if (ScalaPrimitivesOps.isReferenceEqualityOp(code)) ifOneIsNull(l, r) else null
if (nonNullSide != null) {
// special-case reference (in)equality test for null (null eq x, x eq null)
genLoad(nonNullSide, ObjectReference)
genCZJUMP(success, failure, op, ObjectReference, targetIfNoJump)
} else {
val tk = tpeTK(l).maxType(tpeTK(r))
genLoad(l, tk)
genLoad(r, tk)
genCJUMP(success, failure, op, tk, targetIfNoJump)
}
}
def loadAndTestBoolean() = {
genLoad(tree, BOOL)
genCZJUMP(success, failure, Primitives.NE, BOOL, targetIfNoJump)
}
lineNumber(tree)
tree match {
case tree @ Apply(fun, args) if isPrimitive(fun) =>
import ScalaPrimitivesOps.{ ZNOT, ZAND, ZOR, EQ }
// lhs and rhs of test
lazy val Select(lhs, _) = fun
val rhs = if (args.isEmpty) EmptyTree else args.head // args.isEmpty only for ZNOT
def genZandOrZor(and: Boolean): Unit = {
// reaching "keepGoing" indicates the rhs should be evaluated too (ie not short-circuited).
val keepGoing = new asm.Label
if (and) genCond(lhs, keepGoing, failure, targetIfNoJump = keepGoing)
else genCond(lhs, success, keepGoing, targetIfNoJump = keepGoing)
markProgramPoint(keepGoing)
genCond(rhs, success, failure, targetIfNoJump)
}
primitives.getPrimitive(tree, lhs.tpe) match {
case ZNOT => genCond(lhs, failure, success, targetIfNoJump)
case ZAND => genZandOrZor(and = true)
case ZOR => genZandOrZor(and = false)
case code =>
if (ScalaPrimitivesOps.isUniversalEqualityOp(code) && tpeTK(lhs).isClass) {
// rewrite `==` to null tests and `equals`. not needed for arrays (`equals` is reference equality).
if (code == EQ) genEqEqPrimitive(lhs, rhs, success, failure, targetIfNoJump)
else genEqEqPrimitive(lhs, rhs, failure, success, targetIfNoJump)
} else if (ScalaPrimitivesOps.isComparisonOp(code)) {
genComparisonOp(lhs, rhs, code)
} else
loadAndTestBoolean()
}
case _ => loadAndTestBoolean()
}
} // end of genCond()
/*
* Generate the "==" code for object references. It is equivalent of
* if (l eq null) r eq null else l.equals(r);
*
* @param l left-hand-side of the '=='
* @param r right-hand-side of the '=='
*/
def genEqEqPrimitive(l: Tree, r: Tree, success: asm.Label, failure: asm.Label, targetIfNoJump: asm.Label): Unit = {
/* True if the equality comparison is between values that require the use of the rich equality
* comparator (scala.runtime.Comparator.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.
* When it is statically known that both sides are equal and subtypes of Number of Character,
* not using the rich equality is possible (their own equals method will do ok.)
*/
val mustUseAnyComparator: Boolean = {
val areSameFinals = l.tpe.isFinalType && r.tpe.isFinalType && (l.tpe =:= r.tpe)
!areSameFinals && isMaybeBoxed(l.tpe.typeSymbol) && isMaybeBoxed(r.tpe.typeSymbol)
}
if (mustUseAnyComparator) {
val equalsMethod: Symbol = {
if (l.tpe <:< BoxedNumberClass.tpe) {
if (r.tpe <:< BoxedNumberClass.tpe) externalEqualsNumNum
else if (r.tpe <:< BoxedCharacterClass.tpe) externalEqualsNumChar
else externalEqualsNumObject
} else externalEquals
}
genLoad(l, ObjectReference)
genLoad(r, ObjectReference)
genCallMethod(equalsMethod, InvokeStyle.Static)
genCZJUMP(success, failure, Primitives.NE, BOOL, targetIfNoJump)
}
else {
if (isNull(l)) {
// null == expr -> expr eq null
genLoad(r, ObjectReference)
genCZJUMP(success, failure, Primitives.EQ, ObjectReference, targetIfNoJump)
} else if (isNull(r)) {
// expr == null -> expr eq null
genLoad(l, ObjectReference)
genCZJUMP(success, failure, Primitives.EQ, ObjectReference, targetIfNoJump)
} else if (isNonNullExpr(l)) {
// SI-7852 Avoid null check if L is statically non-null.
genLoad(l, ObjectReference)
genLoad(r, ObjectReference)
genCallMethod(Object_equals, InvokeStyle.Virtual)
genCZJUMP(success, failure, Primitives.NE, BOOL, targetIfNoJump)
} else {
// l == r -> if (l eq null) r eq null else l.equals(r)
val eqEqTempLocal = locals.makeLocal(ObjectReference, nme_EQEQ_LOCAL_VAR.mangledString, Object_Type, r.pos)
val lNull = new asm.Label
val lNonNull = new asm.Label
genLoad(l, ObjectReference)
genLoad(r, ObjectReference)
locals.store(eqEqTempLocal)
bc dup ObjectReference
genCZJUMP(lNull, lNonNull, Primitives.EQ, ObjectReference, targetIfNoJump = lNull)
markProgramPoint(lNull)
bc drop ObjectReference
locals.load(eqEqTempLocal)
genCZJUMP(success, failure, Primitives.EQ, ObjectReference, targetIfNoJump = lNonNull)
markProgramPoint(lNonNull)
locals.load(eqEqTempLocal)
genCallMethod(Object_equals, InvokeStyle.Virtual)
genCZJUMP(success, failure, Primitives.NE, BOOL, targetIfNoJump)
}
}
}
def genSynchronized(tree: Apply, expectedType: BType): BType
def genLoadTry(tree: Try): BType
def genInvokeDynamicLambda(ctor: Symbol, lambdaTarget: Symbol, environmentSize: Int, functionalInterface: Symbol): BType = {
import java.lang.invoke.LambdaMetafactory.FLAG_SERIALIZABLE
debuglog(s"Using invokedynamic rather than `new ${ctor.owner}`")
val generatedType = classBTypeFromSymbol(functionalInterface)
// Lambdas should be serializable if they implement a SAM that extends Serializable or if they
// implement a scala.Function* class.
val isSerializable = functionalInterface.isSerializable || functionalInterface.isFunctionClass
val isInterface = lambdaTarget.owner.isEmittedInterface
val invokeStyle =
if (lambdaTarget.isStaticMember) asm.Opcodes.H_INVOKESTATIC
else if (lambdaTarget.isPrivate || lambdaTarget.isClassConstructor) asm.Opcodes.H_INVOKESPECIAL
else if (isInterface) asm.Opcodes.H_INVOKEINTERFACE
else asm.Opcodes.H_INVOKEVIRTUAL
val targetHandle =
new asm.Handle(invokeStyle,
classBTypeFromSymbol(lambdaTarget.owner).internalName,
lambdaTarget.name.mangledString,
asmMethodType(lambdaTarget).descriptor,
/* itf = */ isInterface)
val (a,b) = lambdaTarget.info.paramTypes.splitAt(environmentSize)
var (capturedParamsTypes, lambdaParamTypes) = if(int.doLabmdasFollowJVMMetafactoryOrder) (a,b) else (b,a)
if (invokeStyle != asm.Opcodes.H_INVOKESTATIC) capturedParamsTypes = lambdaTarget.owner.info :: capturedParamsTypes
// Requires https://github.com/scala/scala-java8-compat on the runtime classpath
val returnUnit = lambdaTarget.info.resultType.typeSymbol == UnitClass
val functionalInterfaceDesc: String = generatedType.descriptor
val desc = capturedParamsTypes.map(tpe => toTypeKind(tpe)).mkString(("("), "", ")") + functionalInterfaceDesc
// TODO specialization
val constrainedType = new MethodBType(lambdaParamTypes.map(p => toTypeKind(p)), toTypeKind(lambdaTarget.tpe.resultType)).toASMType
val abstractMethod = functionalInterface.samMethod()
val methodName = abstractMethod.name.mangledString
val applyN = {
val mt = asmMethodType(abstractMethod)
mt.toASMType
}
val bsmArgs0 = Seq(applyN, targetHandle, constrainedType)
val bsmArgs =
if (isSerializable)
bsmArgs0 :+ Int.box(FLAG_SERIALIZABLE)
else
bsmArgs0
val metafactory =
if (isSerializable)
lambdaMetaFactoryAltMetafactoryHandle // altMetafactory needed to be able to pass the SERIALIZABLE flag
else
lambdaMetaFactoryMetafactoryHandle
bc.jmethod.visitInvokeDynamicInsn(methodName, desc, metafactory, bsmArgs: _*)
generatedType
}
}
}
object BCodeBodyBuilder {
val lambdaMetaFactoryMetafactoryHandle = new Handle(
Opcodes.H_INVOKESTATIC,
"java/lang/invoke/LambdaMetafactory",
"metafactory",
"(Ljava/lang/invoke/MethodHandles$Lookup;Ljava/lang/String;Ljava/lang/invoke/MethodType;Ljava/lang/invoke/MethodType;Ljava/lang/invoke/MethodHandle;Ljava/lang/invoke/MethodType;)Ljava/lang/invoke/CallSite;",
/* itf = */ false)
val lambdaMetaFactoryAltMetafactoryHandle = new Handle(
Opcodes.H_INVOKESTATIC,
"java/lang/invoke/LambdaMetafactory",
"altMetafactory",
"(Ljava/lang/invoke/MethodHandles$Lookup;Ljava/lang/String;Ljava/lang/invoke/MethodType;[Ljava/lang/Object;)Ljava/lang/invoke/CallSite;",
/* itf = */ false)
val lambdaDeserializeBootstrapHandle = new Handle(
Opcodes.H_INVOKESTATIC,
"scala/runtime/LambdaDeserialize",
"bootstrap",
"(Ljava/lang/invoke/MethodHandles$Lookup;Ljava/lang/String;Ljava/lang/invoke/MethodType;[Ljava/lang/invoke/MethodHandle;)Ljava/lang/invoke/CallSite;",
/* itf = */ false)
}
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