Scala example source code file (BCodeSkelBuilder.scala)
The BCodeSkelBuilder.scala Scala example source code
/* NSC -- new Scala compiler
* Copyright 2005-2012 LAMP/EPFL
* @author Martin Odersky
*/
package scala
package tools.nsc
package backend
package jvm
import scala.collection.{ mutable, immutable }
import scala.tools.nsc.symtab._
import scala.annotation.switch
import scala.tools.asm
import scala.tools.asm.util.{TraceMethodVisitor, ASMifier}
import java.io.PrintWriter
/*
*
* @author Miguel Garcia, http://lamp.epfl.ch/~magarcia/ScalaCompilerCornerReloaded/
* @version 1.0
*
*/
abstract class BCodeSkelBuilder extends BCodeHelpers {
import global._
/*
* There's a dedicated PlainClassBuilder for each CompilationUnit,
* which simplifies the initialization of per-class data structures in `genPlainClass()` which in turn delegates to `initJClass()`
*
* The entry-point to emitting bytecode instructions is `genDefDef()` where the per-method data structures are initialized,
* including `resetMethodBookkeeping()` and `initJMethod()`.
* Once that's been done, and assuming the method being visited isn't abstract, `emitNormalMethodBody()` populates
* the ASM MethodNode instance with ASM AbstractInsnNodes.
*
* Given that CleanUp delivers trees that produce values on the stack,
* the entry-point to all-things instruction-emit is `genLoad()`.
* There, an operation taking N arguments results in recursively emitting instructions to lead each of them,
* followed by emitting instructions to process those arguments (to be found at run-time on the operand-stack).
*
* In a few cases the above recipe deserves more details, as provided in the documentation for:
* - `genLoadTry()`
* - `genSynchronized()
* - `jumpDest` , `cleanups` , `labelDefsAtOrUnder`
*/
abstract class PlainSkelBuilder(cunit: CompilationUnit)
extends BCClassGen
with BCAnnotGen
with BCInnerClassGen
with JAndroidBuilder
with BCForwardersGen
with BCPickles
with BCJGenSigGen {
// Strangely I can't find this in the asm code 255, but reserving 1 for "this"
final val MaximumJvmParameters = 254
// current class
var cnode: asm.tree.ClassNode = null
var thisName: String = null // the internal name of the class being emitted
var claszSymbol: Symbol = null
var isCZParcelable = false
var isCZStaticModule = false
var isCZRemote = false
/* ---------------- idiomatic way to ask questions to typer ---------------- */
def paramTKs(app: Apply): List[BType] = {
val Apply(fun, _) = app
val funSym = fun.symbol
(funSym.info.paramTypes map toTypeKind) // this tracks mentioned inner classes (in innerClassBufferASM)
}
def symInfoTK(sym: Symbol): BType = {
toTypeKind(sym.info) // this tracks mentioned inner classes (in innerClassBufferASM)
}
def tpeTK(tree: Tree): BType = { toTypeKind(tree.tpe) }
def log(msg: => AnyRef) {
global synchronized { global.log(msg) }
}
override def getCurrentCUnit(): CompilationUnit = { cunit }
/* ---------------- helper utils for generating classes and fiels ---------------- */
def genPlainClass(cd: ClassDef) {
assert(cnode == null, "GenBCode detected nested methods.")
innerClassBufferASM.clear()
claszSymbol = cd.symbol
isCZParcelable = isAndroidParcelableClass(claszSymbol)
isCZStaticModule = isStaticModule(claszSymbol)
isCZRemote = isRemote(claszSymbol)
thisName = internalName(claszSymbol)
cnode = new asm.tree.ClassNode()
initJClass(cnode)
val hasStaticCtor = methodSymbols(cd) exists (_.isStaticConstructor)
if (!hasStaticCtor) {
// but needs one ...
if (isCZStaticModule || isCZParcelable) {
fabricateStaticInit()
}
}
val optSerial: Option[Long] = serialVUID(claszSymbol)
if (optSerial.isDefined) { addSerialVUID(optSerial.get, cnode)}
addClassFields()
innerClassBufferASM ++= trackMemberClasses(claszSymbol, Nil)
gen(cd.impl)
addInnerClassesASM(cnode, innerClassBufferASM.toList)
if (AsmUtils.traceClassEnabled && cnode.name.contains(AsmUtils.traceClassPattern))
AsmUtils.traceClass(cnode)
cnode.innerClasses
assert(cd.symbol == claszSymbol, "Someone messed up BCodePhase.claszSymbol during genPlainClass().")
} // end of method genPlainClass()
/*
* must-single-thread
*/
private def initJClass(jclass: asm.ClassVisitor) {
val ps = claszSymbol.info.parents
val superClass: String = if (ps.isEmpty) JAVA_LANG_OBJECT.getInternalName else internalName(ps.head.typeSymbol);
val ifaces: Array[String] = {
val arrIfacesTr: Array[Tracked] = exemplar(claszSymbol).ifaces
val arrIfaces = new Array[String](arrIfacesTr.length)
var i = 0
while (i < arrIfacesTr.length) {
val ifaceTr = arrIfacesTr(i)
val bt = ifaceTr.c
if (ifaceTr.isInnerClass) { innerClassBufferASM += bt }
arrIfaces(i) = bt.getInternalName
i += 1
}
arrIfaces
}
// `internalName()` tracks inner classes.
val flags = mkFlags(
javaFlags(claszSymbol),
if (isDeprecated(claszSymbol)) asm.Opcodes.ACC_DEPRECATED else 0 // ASM pseudo access flag
)
val thisSignature = getGenericSignature(claszSymbol, claszSymbol.owner)
cnode.visit(classfileVersion, flags,
thisName, thisSignature,
superClass, ifaces)
if (emitSource) {
cnode.visitSource(cunit.source.toString, null /* SourceDebugExtension */)
}
val enclM = getEnclosingMethodAttribute(claszSymbol)
if (enclM != null) {
val EnclMethodEntry(className, methodName, methodType) = enclM
cnode.visitOuterClass(className, methodName, methodType.getDescriptor)
}
val ssa = getAnnotPickle(thisName, claszSymbol)
cnode.visitAttribute(if (ssa.isDefined) pickleMarkerLocal else pickleMarkerForeign)
emitAnnotations(cnode, claszSymbol.annotations ++ ssa)
if (isCZStaticModule || isCZParcelable) {
if (isCZStaticModule) { addModuleInstanceField() }
} else {
val skipStaticForwarders = (claszSymbol.isInterface || settings.noForwarders)
if (!skipStaticForwarders) {
val lmoc = claszSymbol.companionModule
// add static forwarders if there are no name conflicts; see bugs #363 and #1735
if (lmoc != NoSymbol) {
// it must be a top level class (name contains no $s)
val isCandidateForForwarders = {
exitingPickler { !(lmoc.name.toString contains '$') && lmoc.hasModuleFlag && !lmoc.isImplClass && !lmoc.isNestedClass }
}
if (isCandidateForForwarders) {
log(s"Adding static forwarders from '$claszSymbol' to implementations in '$lmoc'")
addForwarders(isRemote(claszSymbol), cnode, thisName, lmoc.moduleClass)
}
}
}
}
// the invoker is responsible for adding a class-static constructor.
} // end of method initJClass
/*
* can-multi-thread
*/
private def addModuleInstanceField() {
val fv =
cnode.visitField(PublicStaticFinal, // TODO confirm whether we really don't want ACC_SYNTHETIC nor ACC_DEPRECATED
strMODULE_INSTANCE_FIELD,
"L" + thisName + ";",
null, // no java-generic-signature
null // no initial value
)
fv.visitEnd()
}
/*
* must-single-thread
*/
private def fabricateStaticInit() {
val clinit: asm.MethodVisitor = cnode.visitMethod(
PublicStatic, // TODO confirm whether we really don't want ACC_SYNTHETIC nor ACC_DEPRECATED
CLASS_CONSTRUCTOR_NAME,
"()V",
null, // no java-generic-signature
null // no throwable exceptions
)
clinit.visitCode()
/* "legacy static initialization" */
if (isCZStaticModule) {
clinit.visitTypeInsn(asm.Opcodes.NEW, thisName)
clinit.visitMethodInsn(asm.Opcodes.INVOKESPECIAL,
thisName, INSTANCE_CONSTRUCTOR_NAME, "()V")
}
if (isCZParcelable) { legacyAddCreatorCode(clinit, cnode, thisName) }
clinit.visitInsn(asm.Opcodes.RETURN)
clinit.visitMaxs(0, 0) // just to follow protocol, dummy arguments
clinit.visitEnd()
}
def addClassFields() {
/* Non-method term members are fields, except for module members. Module
* members can only happen on .NET (no flatten) for inner traits. There,
* a module symbol is generated (transformInfo in mixin) which is used
* as owner for the members of the implementation class (so that the
* backend emits them as static).
* No code is needed for this module symbol.
*/
for (f <- fieldSymbols(claszSymbol)) {
val javagensig = getGenericSignature(f, claszSymbol)
val flags = mkFlags(
javaFieldFlags(f),
if (isDeprecated(f)) asm.Opcodes.ACC_DEPRECATED else 0 // ASM pseudo access flag
)
val jfield = new asm.tree.FieldNode(
flags,
f.javaSimpleName.toString,
symInfoTK(f).getDescriptor,
javagensig,
null // no initial value
)
cnode.fields.add(jfield)
emitAnnotations(jfield, f.annotations)
}
} // end of method addClassFields()
// current method
var mnode: asm.tree.MethodNode = null
var jMethodName: String = null
var isMethSymStaticCtor = false
var returnType: BType = null
var methSymbol: Symbol = null
// in GenASM this is local to genCode(), ie should get false whenever a new method is emitted (including fabricated ones eg addStaticInit())
var isModuleInitialized = false
// used by genLoadTry() and genSynchronized()
var earlyReturnVar: Symbol = null
var shouldEmitCleanup = false
var insideCleanupBlock = false
// line numbers
var lastEmittedLineNr = -1
object bc extends JCodeMethodN {
override def jmethod = PlainSkelBuilder.this.mnode
}
/* ---------------- Part 1 of program points, ie Labels in the ASM world ---------------- */
/*
* A jump is represented as an Apply node whose symbol denotes a LabelDef, the target of the jump.
* The `jumpDest` map is used to:
* (a) find the asm.Label for the target, given an Apply node's symbol;
* (b) anchor an asm.Label in the instruction stream, given a LabelDef node.
* In other words, (a) is necessary when visiting a jump-source, and (b) when visiting a jump-target.
* A related map is `labelDef`: it has the same keys as `jumpDest` but its values are LabelDef nodes not asm.Labels.
*
*/
var jumpDest: immutable.Map[ /* LabelDef */ Symbol, asm.Label ] = null
def programPoint(labelSym: Symbol): asm.Label = {
assert(labelSym.isLabel, s"trying to map a non-label symbol to an asm.Label, at: ${labelSym.pos}")
jumpDest.getOrElse(labelSym, {
val pp = new asm.Label
jumpDest += (labelSym -> pp)
pp
})
}
/*
* A program point may be lexically nested (at some depth)
* (a) in the try-clause of a try-with-finally expression
* (b) in a synchronized block.
* Each of the constructs above establishes a "cleanup block" to execute upon
* both normal-exit, early-return, and abrupt-termination of the instructions it encloses.
*
* The `cleanups` LIFO queue represents the nesting of active (for the current program point)
* pending cleanups. For each such cleanup an asm.Label indicates the start of its cleanup-block.
* At any given time during traversal of the method body,
* the head of `cleanups` denotes the cleanup-block for the closest enclosing try-with-finally or synchronized-expression.
*
* `cleanups` is used:
*
* (1) upon visiting a Return statement.
* In case of pending cleanups, we can't just emit a RETURN instruction, but must instead:
* - store the result (if any) in `earlyReturnVar`, and
* - jump to the next pending cleanup.
* See `genReturn()`
*
* (2) upon emitting a try-with-finally or a synchronized-expr,
* In these cases, the targets of the above jumps are emitted,
* provided an early exit was actually encountered somewhere in the protected clauses.
* See `genLoadTry()` and `genSynchronized()`
*
* The code thus emitted for jumps and targets covers the early-return case.
* The case of abrupt (ie exceptional) termination is covered by exception handlers
* emitted for that purpose as described in `genLoadTry()` and `genSynchronized()`.
*/
var cleanups: List[asm.Label] = Nil
def registerCleanup(finCleanup: asm.Label) {
if (finCleanup != null) { cleanups = finCleanup :: cleanups }
}
def unregisterCleanup(finCleanup: asm.Label) {
if (finCleanup != null) {
assert(cleanups.head eq finCleanup,
s"Bad nesting of cleanup operations: $cleanups trying to unregister: $finCleanup")
cleanups = cleanups.tail
}
}
/* ---------------- local variables and params ---------------- */
case class Local(tk: BType, name: String, idx: Int, isSynth: Boolean)
/*
* Bookkeeping for method-local vars and method-params.
*/
object locals {
private val slots = mutable.Map.empty[Symbol, Local] // (local-or-param-sym -> Local(BType, name, idx, isSynth))
private var nxtIdx = -1 // next available index for local-var
def reset(isStaticMethod: Boolean) {
slots.clear()
nxtIdx = if (isStaticMethod) 0 else 1
}
def contains(locSym: Symbol): Boolean = { slots.contains(locSym) }
def apply(locSym: Symbol): Local = { slots.apply(locSym) }
/* Make a fresh local variable, ensuring a unique name.
* The invoker must make sure inner classes are tracked for the sym's tpe.
*/
def makeLocal(tk: BType, name: String): Symbol = {
val locSym = methSymbol.newVariable(cunit.freshTermName(name), NoPosition, Flags.SYNTHETIC) // setInfo tpe
makeLocal(locSym, tk)
locSym
}
def makeLocal(locSym: Symbol): Local = {
makeLocal(locSym, symInfoTK(locSym))
}
def getOrMakeLocal(locSym: Symbol): Local = {
// `getOrElse` below has the same effect as `getOrElseUpdate` because `makeLocal()` adds an entry to the `locals` map.
slots.getOrElse(locSym, makeLocal(locSym))
}
private def makeLocal(sym: Symbol, tk: BType): Local = {
assert(!slots.contains(sym), "attempt to create duplicate local var.")
assert(nxtIdx != -1, "not a valid start index")
val loc = Local(tk, sym.javaSimpleName.toString, nxtIdx, sym.isSynthetic)
slots += (sym -> loc)
assert(tk.getSize > 0, "makeLocal called for a symbol whose type is Unit.")
nxtIdx += tk.getSize
loc
}
// not to be confused with `fieldStore` and `fieldLoad` which also take a symbol but a field-symbol.
def store(locSym: Symbol) {
val Local(tk, _, idx, _) = slots(locSym)
bc.store(idx, tk)
}
def load(locSym: Symbol) {
val Local(tk, _, idx, _) = slots(locSym)
bc.load(idx, tk)
}
}
/* ---------------- Part 2 of program points, ie Labels in the ASM world ---------------- */
/*
* The semantics of try-with-finally and synchronized-expr require their cleanup code
* to be present in three forms in the emitted bytecode:
* (a) as normal-exit code, reached via fall-through from the last program point being protected,
* (b) as code reached upon early-return from an enclosed return statement.
* The only difference between (a) and (b) is their next program-point:
* the former must continue with fall-through while
* the latter must continue to the next early-return cleanup (if any, otherwise return from the method).
* Otherwise they are identical.
* (c) as exception-handler, reached via exceptional control flow,
* which rethrows the caught exception once it's done with the cleanup code.
*
* A particular cleanup may in general contain LabelDefs. Care is needed when duplicating such jump-targets,
* so as to preserve agreement wit the (also duplicated) jump-sources.
* This is achieved based on the bookkeeping provided by two maps:
* - `labelDefsAtOrUnder` lists all LabelDefs enclosed by a given Tree node (the key)
* - `labelDef` provides the LabelDef node whose symbol is used as key.
* As a sidenote, a related map is `jumpDest`: it has the same keys as `labelDef` but its values are asm.Labels not LabelDef nodes.
*
* Details in `emitFinalizer()`, which is invoked from `genLoadTry()` and `genSynchronized()`.
*/
var labelDefsAtOrUnder: scala.collection.Map[Tree, List[LabelDef]] = null
var labelDef: scala.collection.Map[Symbol, LabelDef] = null// (LabelDef-sym -> LabelDef)
// bookkeeping the scopes of non-synthetic local vars, to emit debug info (`emitVars`).
var varsInScope: List[Tuple2[Symbol, asm.Label]] = null // (local-var-sym -> start-of-scope)
// helpers around program-points.
def lastInsn: asm.tree.AbstractInsnNode = {
mnode.instructions.getLast
}
def currProgramPoint(): asm.Label = {
lastInsn match {
case labnode: asm.tree.LabelNode => labnode.getLabel
case _ =>
val pp = new asm.Label
mnode visitLabel pp
pp
}
}
def markProgramPoint(lbl: asm.Label) {
val skip = (lbl == null) || isAtProgramPoint(lbl)
if (!skip) { mnode visitLabel lbl }
}
def isAtProgramPoint(lbl: asm.Label): Boolean = {
(lastInsn match { case labnode: asm.tree.LabelNode => (labnode.getLabel == lbl); case _ => false } )
}
def lineNumber(tree: Tree) {
if (!emitLines || !tree.pos.isDefined) return;
val nr = tree.pos.finalPosition.line
if (nr != lastEmittedLineNr) {
lastEmittedLineNr = nr
lastInsn match {
case lnn: asm.tree.LineNumberNode =>
// overwrite previous landmark as no instructions have been emitted for it
lnn.line = nr
case _ =>
mnode.visitLineNumber(nr, currProgramPoint())
}
}
}
// on entering a method
def resetMethodBookkeeping(dd: DefDef) {
locals.reset(isStaticMethod = methSymbol.isStaticMember)
jumpDest = immutable.Map.empty[ /* LabelDef */ Symbol, asm.Label ]
// populate labelDefsAtOrUnder
val ldf = new LabelDefsFinder
ldf.traverse(dd.rhs)
labelDefsAtOrUnder = ldf.result.withDefaultValue(Nil)
labelDef = labelDefsAtOrUnder(dd.rhs).map(ld => (ld.symbol -> ld)).toMap
// check previous invocation of genDefDef exited as many varsInScope as it entered.
assert(varsInScope == null, "Unbalanced entering/exiting of GenBCode's genBlock().")
// check previous invocation of genDefDef unregistered as many cleanups as it registered.
assert(cleanups == Nil, "Previous invocation of genDefDef didn't unregister as many cleanups as it registered.")
isModuleInitialized = false
earlyReturnVar = null
shouldEmitCleanup = false
lastEmittedLineNr = -1
}
/* ---------------- top-down traversal invoking ASM Tree API along the way ---------------- */
def gen(tree: Tree) {
tree match {
case EmptyTree => ()
case _: ModuleDef => abort(s"Modules should have been eliminated by refchecks: $tree")
case ValDef(mods, name, tpt, rhs) => () // fields are added in `genPlainClass()`, via `addClassFields()`
case dd : DefDef => genDefDef(dd)
case Template(_, _, body) => body foreach gen
case _ => abort(s"Illegal tree in gen: $tree")
}
}
/*
* must-single-thread
*/
def initJMethod(flags: Int, paramAnnotations: List[List[AnnotationInfo]]) {
val jgensig = getGenericSignature(methSymbol, claszSymbol)
addRemoteExceptionAnnot(isCZRemote, hasPublicBitSet(flags), methSymbol)
val (excs, others) = methSymbol.annotations partition (_.symbol == definitions.ThrowsClass)
val thrownExceptions: List[String] = getExceptions(excs)
val bytecodeName =
if (isMethSymStaticCtor) CLASS_CONSTRUCTOR_NAME
else jMethodName
val mdesc = asmMethodType(methSymbol).getDescriptor
mnode = cnode.visitMethod(
flags,
bytecodeName,
mdesc,
jgensig,
mkArray(thrownExceptions)
).asInstanceOf[asm.tree.MethodNode]
// TODO param names: (m.params map (p => javaName(p.sym)))
emitAnnotations(mnode, others)
emitParamAnnotations(mnode, paramAnnotations)
} // end of method initJMethod
def genDefDef(dd: DefDef) {
// the only method whose implementation is not emitted: getClass()
if (definitions.isGetClass(dd.symbol)) { return }
assert(mnode == null, "GenBCode detected nested method.")
methSymbol = dd.symbol
jMethodName = methSymbol.javaSimpleName.toString
returnType = asmMethodType(dd.symbol).getReturnType
isMethSymStaticCtor = methSymbol.isStaticConstructor
resetMethodBookkeeping(dd)
// add method-local vars for params
val DefDef(_, _, _, vparamss, _, rhs) = dd
assert(vparamss.isEmpty || vparamss.tail.isEmpty, s"Malformed parameter list: $vparamss")
val params = if (vparamss.isEmpty) Nil else vparamss.head
for (p <- params) { locals.makeLocal(p.symbol) }
// debug assert((params.map(p => locals(p.symbol).tk)) == asmMethodType(methSymbol).getArgumentTypes.toList, "debug")
if (params.size > MaximumJvmParameters) {
// SI-7324
cunit.error(methSymbol.pos, s"Platform restriction: a parameter list's length cannot exceed $MaximumJvmParameters.")
return
}
val isNative = methSymbol.hasAnnotation(definitions.NativeAttr)
val isAbstractMethod = (methSymbol.isDeferred || methSymbol.owner.isInterface)
val flags = mkFlags(
javaFlags(methSymbol),
if (claszSymbol.isInterface) asm.Opcodes.ACC_ABSTRACT else 0,
if (methSymbol.isStrictFP) asm.Opcodes.ACC_STRICT else 0,
if (isNative) asm.Opcodes.ACC_NATIVE else 0, // native methods of objects are generated in mirror classes
if (isDeprecated(methSymbol)) asm.Opcodes.ACC_DEPRECATED else 0 // ASM pseudo access flag
)
// TODO needed? for(ann <- m.symbol.annotations) { ann.symbol.initialize }
initJMethod(flags, params.map(p => p.symbol.annotations))
/* Add method-local vars for LabelDef-params.
*
* This makes sure that:
* (1) upon visiting any "forward-jumping" Apply (ie visited before its target LabelDef), and after
* (2) grabbing the corresponding param symbols,
* those param-symbols can be used to access method-local vars.
*
* When duplicating a finally-contained LabelDef, another program-point is needed for the copy (each such copy has its own asm.Label),
* but the same vars (given by the LabelDef's params) can be reused,
* because no LabelDef ends up nested within itself after such duplication.
*/
for(ld <- labelDefsAtOrUnder(dd.rhs); ldp <- ld.params; if !locals.contains(ldp.symbol)) {
// the tail-calls xform results in symbols shared btw method-params and labelDef-params, thus the guard above.
locals.makeLocal(ldp.symbol)
}
if (!isAbstractMethod && !isNative) {
def emitNormalMethodBody() {
val veryFirstProgramPoint = currProgramPoint()
genLoad(rhs, returnType)
rhs match {
case Block(_, Return(_)) => ()
case Return(_) => ()
case EmptyTree =>
globalError("Concrete method has no definition: " + dd + (
if (settings.debug) "(found: " + methSymbol.owner.info.decls.toList.mkString(", ") + ")"
else "")
)
case _ =>
bc emitRETURN returnType
}
if (emitVars) {
// add entries to LocalVariableTable JVM attribute
val onePastLastProgramPoint = currProgramPoint()
val hasStaticBitSet = ((flags & asm.Opcodes.ACC_STATIC) != 0)
if (!hasStaticBitSet) {
mnode.visitLocalVariable(
"this",
"L" + thisName + ";",
null,
veryFirstProgramPoint,
onePastLastProgramPoint,
0
)
}
for (p <- params) { emitLocalVarScope(p.symbol, veryFirstProgramPoint, onePastLastProgramPoint, force = true) }
}
if (isMethSymStaticCtor) { appendToStaticCtor(dd) }
} // end of emitNormalMethodBody()
lineNumber(rhs)
emitNormalMethodBody()
// Note we don't invoke visitMax, thus there are no FrameNode among mnode.instructions.
// The only non-instruction nodes to be found are LabelNode and LineNumberNode.
}
if (AsmUtils.traceMethodEnabled && mnode.name.contains(AsmUtils.traceMethodPattern))
AsmUtils.traceMethod(mnode)
mnode = null
} // end of method genDefDef()
/*
* must-single-thread
*
* TODO document, explain interplay with `fabricateStaticInit()`
*/
private def appendToStaticCtor(dd: DefDef) {
def insertBefore(
location: asm.tree.AbstractInsnNode,
i0: asm.tree.AbstractInsnNode,
i1: asm.tree.AbstractInsnNode) {
if (i0 != null) {
mnode.instructions.insertBefore(location, i0.clone(null))
mnode.instructions.insertBefore(location, i1.clone(null))
}
}
// collect all return instructions
var rets: List[asm.tree.AbstractInsnNode] = Nil
mnode foreachInsn { i => if (i.getOpcode() == asm.Opcodes.RETURN) { rets ::= i } }
if (rets.isEmpty) { return }
var insnModA: asm.tree.AbstractInsnNode = null
var insnModB: asm.tree.AbstractInsnNode = null
// call object's private ctor from static ctor
if (isCZStaticModule) {
// NEW `moduleName`
val className = internalName(methSymbol.enclClass)
insnModA = new asm.tree.TypeInsnNode(asm.Opcodes.NEW, className)
// INVOKESPECIAL <init>
val callee = methSymbol.enclClass.primaryConstructor
val jname = callee.javaSimpleName.toString
val jowner = internalName(callee.owner)
val jtype = asmMethodType(callee).getDescriptor
insnModB = new asm.tree.MethodInsnNode(asm.Opcodes.INVOKESPECIAL, jowner, jname, jtype)
}
var insnParcA: asm.tree.AbstractInsnNode = null
var insnParcB: asm.tree.AbstractInsnNode = null
// android creator code
if (isCZParcelable) {
// add a static field ("CREATOR") to this class to cache android.os.Parcelable$Creator
val andrFieldDescr = asmClassType(AndroidCreatorClass).getDescriptor
cnode.visitField(
asm.Opcodes.ACC_STATIC | asm.Opcodes.ACC_FINAL,
"CREATOR",
andrFieldDescr,
null,
null
)
// INVOKESTATIC CREATOR(): android.os.Parcelable$Creator; -- TODO where does this Android method come from?
val callee = definitions.getMember(claszSymbol.companionModule, androidFieldName)
val jowner = internalName(callee.owner)
val jname = callee.javaSimpleName.toString
val jtype = asmMethodType(callee).getDescriptor
insnParcA = new asm.tree.MethodInsnNode(asm.Opcodes.INVOKESTATIC, jowner, jname, jtype)
// PUTSTATIC `thisName`.CREATOR;
insnParcB = new asm.tree.FieldInsnNode(asm.Opcodes.PUTSTATIC, thisName, "CREATOR", andrFieldDescr)
}
// insert a few instructions for initialization before each return instruction
for(r <- rets) {
insertBefore(r, insnModA, insnModB)
insertBefore(r, insnParcA, insnParcB)
}
}
def emitLocalVarScope(sym: Symbol, start: asm.Label, end: asm.Label, force: Boolean = false) {
val Local(tk, name, idx, isSynth) = locals(sym)
if (force || !isSynth) {
mnode.visitLocalVariable(name, tk.getDescriptor, null, start, end, idx)
}
}
def genLoad(tree: Tree, expectedType: BType)
} // end of class PlainSkelBuilder
}
Other Scala source code examplesHere is a short list of links related to this Scala BCodeSkelBuilder.scala source code file: |
The search page
Other Scala source code examples at this package level
Click here to learn more about this project
