Scala example source code file (GenASM.scala)
The GenASM.scala Scala example source code
/* NSC -- new Scala compiler
* Copyright 2005-2013 LAMP/EPFL
* @author Martin Odersky
*/
package scala
package tools.nsc
package backend.jvm
import scala.collection.{ mutable, immutable }
import scala.reflect.internal.pickling.{ PickleFormat, PickleBuffer }
import scala.tools.nsc.symtab._
import scala.tools.asm
import asm.Label
import scala.annotation.tailrec
/**
* @author Iulian Dragos (version 1.0, FJBG-based implementation)
* @author Miguel Garcia (version 2.0, ASM-based implementation)
*
* Documentation at http://lamp.epfl.ch/~magarcia/ScalaCompilerCornerReloaded/2012Q2/GenASM.pdf
*/
abstract class GenASM extends SubComponent with BytecodeWriters with GenJVMASM { self =>
import global._
import icodes._
import icodes.opcodes._
import definitions._
// Strangely I can't find this in the asm code
// 255, but reserving 1 for "this"
final val MaximumJvmParameters = 254
val phaseName = "jvm"
/** Create a new phase */
override def newPhase(p: Phase): Phase = new AsmPhase(p)
/** From the reference documentation of the Android SDK:
* The `Parcelable` interface identifies classes whose instances can be written to and restored from a `Parcel`.
* Classes implementing the `Parcelable` interface must also have a static field called `CREATOR`,
* which is an object implementing the `Parcelable.Creator` interface.
*/
private val androidFieldName = newTermName("CREATOR")
private lazy val AndroidParcelableInterface = rootMirror.getClassIfDefined("android.os.Parcelable")
private lazy val AndroidCreatorClass = rootMirror.getClassIfDefined("android.os.Parcelable$Creator")
/** JVM code generation phase
*/
class AsmPhase(prev: Phase) extends ICodePhase(prev) {
def name = phaseName
override def erasedTypes = true
def apply(cls: IClass) = sys.error("no implementation")
// An AsmPhase starts and ends within a Run, thus the caches in question will get populated and cleared within a Run, too), SI-7422
javaNameCache.clear()
javaNameCache ++= List(
NothingClass -> binarynme.RuntimeNothing,
RuntimeNothingClass -> binarynme.RuntimeNothing,
NullClass -> binarynme.RuntimeNull,
RuntimeNullClass -> binarynme.RuntimeNull
)
// unlike javaNameCache, reverseJavaName contains entries only for class symbols and their internal names.
reverseJavaName.clear()
reverseJavaName ++= List(
binarynme.RuntimeNothing.toString() -> RuntimeNothingClass, // RuntimeNothingClass is the bytecode-level return type of Scala methods with Nothing return-type.
binarynme.RuntimeNull.toString() -> RuntimeNullClass
)
// Lazy val; can't have eager vals in Phase constructors which may
// cause cycles before Global has finished initialization.
lazy val BeanInfoAttr = rootMirror.getRequiredClass("scala.beans.BeanInfo")
private def initBytecodeWriter(entryPoints: List[IClass]): BytecodeWriter = {
settings.outputDirs.getSingleOutput match {
case Some(f) if f hasExtension "jar" =>
// If no main class was specified, see if there's only one
// entry point among the classes going into the jar.
if (settings.mainClass.isDefault) {
entryPoints map (_.symbol fullName '.') match {
case Nil =>
log("No Main-Class designated or discovered.")
case name :: Nil =>
log("Unique entry point: setting Main-Class to " + name)
settings.mainClass.value = name
case names =>
log("No Main-Class due to multiple entry points:\n " + names.mkString("\n "))
}
}
else log("Main-Class was specified: " + settings.mainClass.value)
new DirectToJarfileWriter(f.file)
case _ => factoryNonJarBytecodeWriter()
}
}
override def run() {
if (settings.debug)
inform("[running phase " + name + " on icode]")
if (settings.Xdce)
for ((sym, cls) <- icodes.classes if inliner.isClosureClass(sym) && !deadCode.liveClosures(sym)) {
log(s"Optimizer eliminated ${sym.fullNameString}")
deadCode.elidedClosures += sym
icodes.classes -= sym
}
// For predictably ordered error messages.
var sortedClasses = classes.values.toList sortBy (_.symbol.fullName)
// Warn when classes will overwrite one another on case-insensitive systems.
for ((_, v1 :: v2 :: _) <- sortedClasses groupBy (_.symbol.javaClassName.toString.toLowerCase)) {
v1.cunit.warning(v1.symbol.pos,
s"Class ${v1.symbol.javaClassName} differs only in case from ${v2.symbol.javaClassName}. " +
"Such classes will overwrite one another on case-insensitive filesystems.")
}
debuglog(s"Created new bytecode generator for ${classes.size} classes.")
val bytecodeWriter = initBytecodeWriter(sortedClasses filter isJavaEntryPoint)
val needsOutfile = bytecodeWriter.isInstanceOf[ClassBytecodeWriter]
val plainCodeGen = new JPlainBuilder( bytecodeWriter, needsOutfile)
val mirrorCodeGen = new JMirrorBuilder( bytecodeWriter, needsOutfile)
val beanInfoCodeGen = new JBeanInfoBuilder(bytecodeWriter, needsOutfile)
def emitFor(c: IClass) {
if (isStaticModule(c.symbol) && isTopLevelModule(c.symbol)) {
if (c.symbol.companionClass == NoSymbol)
mirrorCodeGen genMirrorClass (c.symbol, c.cunit)
else
log(s"No mirror class for module with linked class: ${c.symbol.fullName}")
}
plainCodeGen genClass c
if (c.symbol hasAnnotation BeanInfoAttr) beanInfoCodeGen genBeanInfoClass c
}
while (!sortedClasses.isEmpty) {
val c = sortedClasses.head
try emitFor(c)
catch {
case e: FileConflictException =>
c.cunit.error(c.symbol.pos, s"error writing ${c.symbol}: ${e.getMessage}")
}
sortedClasses = sortedClasses.tail
classes -= c.symbol // GC opportunity
}
bytecodeWriter.close()
/* don't javaNameCache.clear() because that causes the following tests to fail:
* test/files/run/macro-repl-dontexpand.scala
* test/files/jvm/interpreter.scala
* TODO but why? what use could javaNameCache possibly see once GenASM is over?
*/
/* TODO After emitting all class files (e.g., in a separate compiler phase) ASM can perform bytecode verification:
*
* (1) call the asm.util.CheckAdapter.verify() overload:
* public static void verify(ClassReader cr, ClassLoader loader, boolean dump, PrintWriter pw)
*
* (2) passing a custom ClassLoader to verify inter-dependent classes.
*
* Alternatively, an offline-bytecode verifier could be used (e.g. Maxine brings one as separate tool).
*/
} // end of AsmPhase.run()
} // end of class AsmPhase
var pickledBytes = 0 // statistics
val javaNameCache = perRunCaches.newAnyRefMap[Symbol, Name]()
// unlike javaNameCache, reverseJavaName contains entries only for class symbols and their internal names.
val reverseJavaName = perRunCaches.newAnyRefMap[String, Symbol]()
private def mkFlags(args: Int*) = args.foldLeft(0)(_ | _)
private def hasPublicBitSet(flags: Int) = (flags & asm.Opcodes.ACC_PUBLIC) != 0
private def isRemote(s: Symbol) = s hasAnnotation RemoteAttr
/**
* Return the Java modifiers for the given symbol.
* Java modifiers for classes:
* - public, abstract, final, strictfp (not used)
* for interfaces:
* - the same as for classes, without 'final'
* for fields:
* - public, private (*)
* - static, final
* for methods:
* - the same as for fields, plus:
* - abstract, synchronized (not used), strictfp (not used), native (not used)
*
* (*) protected cannot be used, since inner classes 'see' protected members,
* and they would fail verification after lifted.
*/
def javaFlags(sym: Symbol): Int = {
// constructors of module classes should be private
// PP: why are they only being marked private at this stage and not earlier?
val privateFlag =
sym.isPrivate || (sym.isPrimaryConstructor && isTopLevelModule(sym.owner))
// Final: the only fields which can receive ACC_FINAL are eager vals.
// Neither vars nor lazy vals can, because:
//
// Source: http://docs.oracle.com/javase/specs/jls/se7/html/jls-17.html#jls-17.5.3
// "Another problem is that the specification allows aggressive
// optimization of final fields. Within a thread, it is permissible to
// reorder reads of a final field with those modifications of a final
// field that do not take place in the constructor."
//
// A var or lazy val which is marked final still has meaning to the
// scala compiler. The word final is heavily overloaded unfortunately;
// for us it means "not overridable". At present you can't override
// vars regardless; this may change.
//
// The logic does not check .isFinal (which checks flags for the FINAL flag,
// and includes symbols marked lateFINAL) instead inspecting rawflags so
// we can exclude lateFINAL. Such symbols are eligible for inlining, but to
// avoid breaking proxy software which depends on subclassing, we do not
// emit ACC_FINAL.
// Nested objects won't receive ACC_FINAL in order to allow for their overriding.
val finalFlag = (
(((sym.rawflags & Flags.FINAL) != 0) || isTopLevelModule(sym))
&& !sym.enclClass.isInterface
&& !sym.isClassConstructor
&& !sym.isMutable // lazy vals and vars both
)
// Primitives are "abstract final" to prohibit instantiation
// without having to provide any implementations, but that is an
// illegal combination of modifiers at the bytecode level so
// suppress final if abstract if present.
import asm.Opcodes._
mkFlags(
if (privateFlag) ACC_PRIVATE else ACC_PUBLIC,
if (sym.isDeferred || sym.hasAbstractFlag) ACC_ABSTRACT else 0,
if (sym.isInterface) ACC_INTERFACE else 0,
if (finalFlag && !sym.hasAbstractFlag) ACC_FINAL else 0,
if (sym.isStaticMember) ACC_STATIC else 0,
if (sym.isBridge) ACC_BRIDGE | ACC_SYNTHETIC else 0,
if (sym.isArtifact) ACC_SYNTHETIC else 0,
if (sym.isClass && !sym.isInterface) ACC_SUPER else 0,
if (sym.hasEnumFlag) ACC_ENUM else 0,
if (sym.isVarargsMethod) ACC_VARARGS else 0,
if (sym.hasFlag(Flags.SYNCHRONIZED)) ACC_SYNCHRONIZED else 0
)
}
def javaFieldFlags(sym: Symbol) = {
javaFlags(sym) | mkFlags(
if (sym hasAnnotation TransientAttr) asm.Opcodes.ACC_TRANSIENT else 0,
if (sym hasAnnotation VolatileAttr) asm.Opcodes.ACC_VOLATILE else 0,
if (sym.isMutable) 0 else asm.Opcodes.ACC_FINAL
)
}
def isTopLevelModule(sym: Symbol): Boolean =
exitingPickler { sym.isModuleClass && !sym.isImplClass && !sym.isNestedClass }
def isStaticModule(sym: Symbol): Boolean = {
sym.isModuleClass && !sym.isImplClass && !sym.isLifted
}
// -----------------------------------------------------------------------------------------
// finding the least upper bound in agreement with the bytecode verifier (given two internal names handed by ASM)
// Background:
// http://gallium.inria.fr/~xleroy/publi/bytecode-verification-JAR.pdf
// http://comments.gmane.org/gmane.comp.java.vm.languages/2293
// https://issues.scala-lang.org/browse/SI-3872
// -----------------------------------------------------------------------------------------
/**
* Given an internal name (eg "java/lang/Integer") returns the class symbol for it.
*
* Better not to need this method (an example where control flow arrives here is welcome).
* This method is invoked only upon both (1) and (2) below happening:
* (1) providing an asm.ClassWriter with an internal name by other means than javaName()
* (2) forgetting to track the corresponding class-symbol in reverseJavaName.
*
* (The first item is already unlikely because we rely on javaName()
* to do the bookkeeping for entries that should go in innerClassBuffer.)
*
* (We could do completely without this method at the expense of computing stack-map-frames ourselves and
* invoking visitFrame(), but that would require another pass over all instructions.)
*
* Right now I can't think of any invocation of visitSomething() on MethodVisitor
* where we hand an internal name not backed by a reverseJavaName.
* However, I'm leaving this note just in case any such oversight is discovered.
*/
def inameToSymbol(iname: String): Symbol = {
val name = global.newTypeName(iname)
val res0 =
if (nme.isModuleName(name)) rootMirror.getModuleByName(name.dropModule)
else rootMirror.getClassByName(name.replace('/', '.')) // TODO fails for inner classes (but this hasn't been tested).
assert(res0 != NoSymbol)
val res = jsymbol(res0)
res
}
def jsymbol(sym: Symbol): Symbol = {
if(sym.isJavaDefined && sym.isModuleClass) sym.linkedClassOfClass
else if(sym.isModule) sym.moduleClass
else sym // we track only module-classes and plain-classes
}
private def superClasses(s: Symbol): List[Symbol] = {
assert(!s.isInterface)
s.superClass match {
case NoSymbol => List(s)
case sc => s :: superClasses(sc)
}
}
private def firstCommonSuffix(as: List[Symbol], bs: List[Symbol]): Symbol = {
assert(!(as contains NoSymbol))
assert(!(bs contains NoSymbol))
var chainA = as
var chainB = bs
var fcs: Symbol = NoSymbol
do {
if (chainB contains chainA.head) fcs = chainA.head
else if (chainA contains chainB.head) fcs = chainB.head
else {
chainA = chainA.tail
chainB = chainB.tail
}
} while(fcs == NoSymbol)
fcs
}
private def jvmWiseLUB(a: Symbol, b: Symbol): Symbol = {
assert(a.isClass)
assert(b.isClass)
val res = (a.isInterface, b.isInterface) match {
case (true, true) =>
global.lub(List(a.tpe, b.tpe)).typeSymbol // TODO assert == firstCommonSuffix of resp. parents
case (true, false) =>
if(b isSubClass a) a else ObjectClass
case (false, true) =>
if(a isSubClass b) b else ObjectClass
case _ =>
firstCommonSuffix(superClasses(a), superClasses(b))
}
assert(res != NoSymbol)
res
}
/* The internal name of the least common ancestor of the types given by inameA and inameB.
It's what ASM needs to know in order to compute stack map frames, http://asm.ow2.org/doc/developer-guide.html#controlflow */
def getCommonSuperClass(inameA: String, inameB: String): String = {
val a = reverseJavaName.getOrElseUpdate(inameA, inameToSymbol(inameA))
val b = reverseJavaName.getOrElseUpdate(inameB, inameToSymbol(inameB))
// global.lub(List(a.tpe, b.tpe)).typeSymbol.javaBinaryName.toString()
// icodes.lub(icodes.toTypeKind(a.tpe), icodes.toTypeKind(b.tpe)).toType
val lcaSym = jvmWiseLUB(a, b)
val lcaName = lcaSym.javaBinaryName.toString // don't call javaName because that side-effects innerClassBuffer.
val oldsym = reverseJavaName.put(lcaName, lcaSym)
assert(oldsym.isEmpty || (oldsym.get == lcaSym), "somehow we're not managing to compute common-super-class for ASM consumption")
assert(lcaName != "scala/Any")
lcaName // TODO ASM caches the answer during the lifetime of a ClassWriter. We outlive that. Do some caching.
}
class CClassWriter(flags: Int) extends asm.ClassWriter(flags) {
override def getCommonSuperClass(iname1: String, iname2: String): String = {
GenASM.this.getCommonSuperClass(iname1, iname2)
}
}
// -----------------------------------------------------------------------------------------
// constants
// -----------------------------------------------------------------------------------------
private val classfileVersion: Int = settings.target.value match {
case "jvm-1.5" => asm.Opcodes.V1_5
case "jvm-1.6" => asm.Opcodes.V1_6
case "jvm-1.7" => asm.Opcodes.V1_7
}
private val majorVersion: Int = (classfileVersion & 0xFF)
private val emitStackMapFrame = (majorVersion >= 50)
private val extraProc: Int = mkFlags(
asm.ClassWriter.COMPUTE_MAXS,
if(emitStackMapFrame) asm.ClassWriter.COMPUTE_FRAMES else 0
)
val JAVA_LANG_OBJECT = asm.Type.getObjectType("java/lang/Object")
val JAVA_LANG_STRING = asm.Type.getObjectType("java/lang/String")
/**
* We call many Java varargs methods from ASM library that expect Arra[asm.Type] as argument so
* we override default (compiler-generated) ClassTag so we can provide specialized newArray implementation.
*
* Examples of methods that should pick our definition are: JBuilder.javaType and JPlainBuilder.genMethod.
*/
private implicit val asmTypeTag: scala.reflect.ClassTag[asm.Type] = new scala.reflect.ClassTag[asm.Type] {
def runtimeClass: java.lang.Class[asm.Type] = classOf[asm.Type]
final override def newArray(len: Int): Array[asm.Type] = new Array[asm.Type](len)
}
/** basic functionality for class file building */
abstract class JBuilder(bytecodeWriter: BytecodeWriter, needsOutfile: Boolean) {
val EMPTY_STRING_ARRAY = Array.empty[String]
val mdesc_arglessvoid = "()V"
val CLASS_CONSTRUCTOR_NAME = "<clinit>"
val INSTANCE_CONSTRUCTOR_NAME = "<init>"
val INNER_CLASSES_FLAGS =
(asm.Opcodes.ACC_PUBLIC | asm.Opcodes.ACC_PRIVATE | asm.Opcodes.ACC_PROTECTED |
asm.Opcodes.ACC_STATIC | asm.Opcodes.ACC_INTERFACE | asm.Opcodes.ACC_ABSTRACT | asm.Opcodes.ACC_FINAL)
// -----------------------------------------------------------------------------------------
// factory methods
// -----------------------------------------------------------------------------------------
/**
* Returns a new ClassWriter for the class given by arguments.
*
* @param access the class's access flags. This parameter also indicates if the class is deprecated.
*
* @param name the internal name of the class.
*
* @param signature the signature of this class. May be <tt>null</tt> if
* the class is not a generic one, and does not extend or implement
* generic classes or interfaces.
*
* @param superName the internal of name of the super class. For interfaces,
* the super class is {@link Object}. May be <tt>null</tt>, but
* only for the {@link Object} class.
*
* @param interfaces the internal names of the class's interfaces (see
* {@link Type#getInternalName() getInternalName}). May be
* <tt>null</tt>.
*/
def createJClass(access: Int, name: String, signature: String, superName: String, interfaces: Array[String]): asm.ClassWriter = {
val cw = new CClassWriter(extraProc)
cw.visit(classfileVersion,
access, name, signature,
superName, interfaces)
cw
}
def createJAttribute(name: String, b: Array[Byte], offset: Int, len: Int): asm.Attribute = {
val dest = new Array[Byte](len)
System.arraycopy(b, offset, dest, 0, len)
new asm.CustomAttr(name, dest)
}
// -----------------------------------------------------------------------------------------
// utilities useful when emitting plain, mirror, and beaninfo classes.
// -----------------------------------------------------------------------------------------
def writeIfNotTooBig(label: String, jclassName: String, jclass: asm.ClassWriter, sym: Symbol) {
try {
val arr = jclass.toByteArray()
val outF: scala.tools.nsc.io.AbstractFile = {
if(needsOutfile) getFile(sym, jclassName, ".class") else null
}
bytecodeWriter.writeClass(label, jclassName, arr, outF)
} catch {
case e: java.lang.RuntimeException if e != null && (e.getMessage contains "too large!") =>
reporter.error(sym.pos,
s"Could not write class $jclassName because it exceeds JVM code size limits. ${e.getMessage}")
}
}
/** Specialized array conversion to prevent calling
* java.lang.reflect.Array.newInstance via TraversableOnce.toArray
*/
def mkArray(xs: Traversable[String]): Array[String] = { val a = new Array[String](xs.size); xs.copyToArray(a); a }
// -----------------------------------------------------------------------------------------
// Getters for (JVMS 4.2) internal and unqualified names (represented as JType instances).
// These getters track behind the scenes the inner classes referred to in the class being emitted,
// so as to build the InnerClasses attribute (JVMS 4.7.6) via `addInnerClasses()`
// (which also adds as member classes those inner classes that have been declared,
// thus also covering the case of inner classes declared but otherwise not referred).
// -----------------------------------------------------------------------------------------
val innerClassBuffer = mutable.LinkedHashSet[Symbol]()
/** For given symbol return a symbol corresponding to a class that should be declared as inner class.
*
* For example:
* class A {
* class B
* object C
* }
*
* then method will return:
* NoSymbol for A,
* the same symbol for A.B (corresponding to A$B class), and
* A$C$ symbol for A.C.
*/
def innerClassSymbolFor(s: Symbol): Symbol =
if (s.isClass) s else if (s.isModule) s.moduleClass else NoSymbol
/** Return the name of this symbol that can be used on the Java platform. It removes spaces from names.
*
* Special handling:
* scala.Nothing erases to scala.runtime.Nothing$
* scala.Null erases to scala.runtime.Null$
*
* This is needed because they are not real classes, and they mean
* 'abrupt termination upon evaluation of that expression' or null respectively.
* This handling is done already in GenICode, but here we need to remove
* references from method signatures to these types, because such classes
* cannot exist in the classpath: the type checker will be very confused.
*/
def javaName(sym: Symbol): String = {
/*
* Checks if given symbol corresponds to inner class/object and add it to innerClassBuffer
*
* Note: This method is called recursively thus making sure that we add complete chain
* of inner class all until root class.
*/
def collectInnerClass(s: Symbol): Unit = {
// TODO: some enteringFlatten { ... } which accounts for
// being nested in parameterized classes (if we're going to selectively flatten.)
val x = innerClassSymbolFor(s)
if(x ne NoSymbol) {
assert(x.isClass, "not an inner-class symbol")
val isInner = !x.rawowner.isPackageClass
if (isInner) {
innerClassBuffer += x
collectInnerClass(x.rawowner)
}
}
}
collectInnerClass(sym)
val hasInternalName = sym.isClass || sym.isModuleNotMethod
val cachedJN = javaNameCache.getOrElseUpdate(sym, {
if (hasInternalName) { sym.javaBinaryName }
else { sym.javaSimpleName }
})
if(emitStackMapFrame && hasInternalName) {
val internalName = cachedJN.toString()
val trackedSym = jsymbol(sym)
reverseJavaName.get(internalName) match {
case Some(oldsym) if oldsym.exists && trackedSym.exists =>
assert(
// In contrast, neither NothingClass nor NullClass show up bytecode-level.
(oldsym == trackedSym) || (oldsym == RuntimeNothingClass) || (oldsym == RuntimeNullClass) || (oldsym.isModuleClass && (oldsym.sourceModule == trackedSym.sourceModule)),
s"""|Different class symbols have the same bytecode-level internal name:
| name: $internalName
| oldsym: ${oldsym.fullNameString}
| tracked: ${trackedSym.fullNameString}
""".stripMargin
)
case _ =>
reverseJavaName.put(internalName, trackedSym)
}
}
cachedJN.toString
}
def descriptor(t: Type): String = { javaType(t).getDescriptor }
def descriptor(k: TypeKind): String = { javaType(k).getDescriptor }
def descriptor(s: Symbol): String = { javaType(s).getDescriptor }
def javaType(tk: TypeKind): asm.Type = {
if(tk.isValueType) {
if(tk.isIntSizedType) {
(tk: @unchecked) match {
case BOOL => asm.Type.BOOLEAN_TYPE
case BYTE => asm.Type.BYTE_TYPE
case SHORT => asm.Type.SHORT_TYPE
case CHAR => asm.Type.CHAR_TYPE
case INT => asm.Type.INT_TYPE
}
} else {
(tk: @unchecked) match {
case UNIT => asm.Type.VOID_TYPE
case LONG => asm.Type.LONG_TYPE
case FLOAT => asm.Type.FLOAT_TYPE
case DOUBLE => asm.Type.DOUBLE_TYPE
}
}
} else {
assert(!tk.isBoxedType, tk) // documentation (BOXED matches none below anyway)
(tk: @unchecked) match {
case REFERENCE(cls) => asm.Type.getObjectType(javaName(cls))
case ARRAY(elem) => javaArrayType(javaType(elem))
}
}
}
def javaType(t: Type): asm.Type = javaType(toTypeKind(t))
def javaType(s: Symbol): asm.Type = {
if (s.isMethod) {
val resT: asm.Type = if (s.isClassConstructor) asm.Type.VOID_TYPE else javaType(s.tpe.resultType)
asm.Type.getMethodType( resT, (s.tpe.paramTypes map javaType): _*)
} else { javaType(s.tpe) }
}
def javaArrayType(elem: asm.Type): asm.Type = { asm.Type.getObjectType("[" + elem.getDescriptor) }
def isDeprecated(sym: Symbol): Boolean = { sym.annotations exists (_ matches definitions.DeprecatedAttr) }
def addInnerClasses(csym: Symbol, jclass: asm.ClassVisitor) {
/* The outer name for this inner class. Note that it returns null
* when the inner class should not get an index in the constant pool.
* That means non-member classes (anonymous). See Section 4.7.5 in the JVMS.
*/
def outerName(innerSym: Symbol): String = {
if (innerSym.originalEnclosingMethod != NoSymbol)
null
else {
val outerName = javaName(innerSym.rawowner)
if (isTopLevelModule(innerSym.rawowner)) "" + nme.stripModuleSuffix(newTermName(outerName))
else outerName
}
}
def innerName(innerSym: Symbol): String =
if (innerSym.isAnonymousClass || innerSym.isAnonymousFunction)
null
else
innerSym.rawname + innerSym.moduleSuffix
// add inner classes which might not have been referenced yet
exitingErasure {
for (sym <- List(csym, csym.linkedClassOfClass); m <- sym.info.decls.map(innerClassSymbolFor) if m.isClass)
innerClassBuffer += m
}
val allInners: List[Symbol] = innerClassBuffer.toList filterNot deadCode.elidedClosures
if (allInners.nonEmpty) {
debuglog(csym.fullName('.') + " contains " + allInners.size + " inner classes.")
// entries ready to be serialized into the classfile, used to detect duplicates.
val entries = mutable.Map.empty[String, String]
// sort them so inner classes succeed their enclosing class to satisfy the Eclipse Java compiler
for (innerSym <- allInners sortBy (_.name.length)) { // TODO why not sortBy (_.name.toString()) ??
val flagsWithFinal: Int = mkFlags(
if (innerSym.rawowner.hasModuleFlag) asm.Opcodes.ACC_STATIC else 0,
javaFlags(innerSym),
if(isDeprecated(innerSym)) asm.Opcodes.ACC_DEPRECATED else 0 // ASM pseudo-access flag
) & (INNER_CLASSES_FLAGS | asm.Opcodes.ACC_DEPRECATED)
val flags = if (innerSym.isModuleClass) flagsWithFinal & ~asm.Opcodes.ACC_FINAL else flagsWithFinal // For SI-5676, object overriding.
val jname = javaName(innerSym) // never null
val oname = outerName(innerSym) // null when method-enclosed
val iname = innerName(innerSym) // null for anonymous inner class
// Mimicking javap inner class output
debuglog(
if (oname == null || iname == null) "//class " + jname
else "//%s=class %s of class %s".format(iname, jname, oname)
)
assert(jname != null, "javaName is broken.") // documentation
val doAdd = entries.get(jname) match {
// TODO is it ok for prevOName to be null? (Someone should really document the invariants of the InnerClasses bytecode attribute)
case Some(prevOName) =>
// this occurs e.g. when innerClassBuffer contains both class Thread$State, object Thread$State,
// i.e. for them it must be the case that oname == java/lang/Thread
assert(prevOName == oname, "duplicate")
false
case None => true
}
if(doAdd) {
entries += (jname -> oname)
jclass.visitInnerClass(jname, oname, iname, flags)
}
/*
* TODO assert (JVMS 4.7.6 The InnerClasses attribute)
* If a class file has a version number that is greater than or equal to 51.0, and
* has an InnerClasses attribute in its attributes table, then for all entries in the
* classes array of the InnerClasses attribute, the value of the
* outer_class_info_index item must be zero if the value of the
* inner_name_index item is zero.
*/
}
}
}
} // end of class JBuilder
/** functionality for building plain and mirror classes */
abstract class JCommonBuilder(bytecodeWriter: BytecodeWriter, needsOutfile: Boolean) extends JBuilder(bytecodeWriter, needsOutfile) {
def debugLevel = settings.debuginfo.indexOfChoice
val emitSource = debugLevel >= 1
val emitLines = debugLevel >= 2
val emitVars = debugLevel >= 3
// -----------------------------------------------------------------------------------------
// more constants
// -----------------------------------------------------------------------------------------
val PublicStatic = asm.Opcodes.ACC_PUBLIC | asm.Opcodes.ACC_STATIC
val PublicStaticFinal = asm.Opcodes.ACC_PUBLIC | asm.Opcodes.ACC_STATIC | asm.Opcodes.ACC_FINAL
val strMODULE_INSTANCE_FIELD = nme.MODULE_INSTANCE_FIELD.toString
// -----------------------------------------------------------------------------------------
// Custom attribute (JVMS 4.7.1) "ScalaSig" used as marker only
// i.e., the pickle is contained in a custom annotation, see:
// (1) `addAnnotations()`,
// (2) SID # 10 (draft) - Storage of pickled Scala signatures in class files, http://www.scala-lang.org/sid/10
// (3) SID # 5 - Internals of Scala Annotations, http://www.scala-lang.org/sid/5
// That annotation in turn is not related to the "java-generic-signature" (JVMS 4.7.9)
// other than both ending up encoded as attributes (JVMS 4.7)
// (with the caveat that the "ScalaSig" attribute is associated to some classes,
// while the "Signature" attribute can be associated to classes, methods, and fields.)
// -----------------------------------------------------------------------------------------
val versionPickle = {
val vp = new PickleBuffer(new Array[Byte](16), -1, 0)
assert(vp.writeIndex == 0, vp)
vp writeNat PickleFormat.MajorVersion
vp writeNat PickleFormat.MinorVersion
vp writeNat 0
vp
}
def pickleMarkerLocal = {
createJAttribute(tpnme.ScalaSignatureATTR.toString, versionPickle.bytes, 0, versionPickle.writeIndex)
}
def pickleMarkerForeign = {
createJAttribute(tpnme.ScalaATTR.toString, new Array[Byte](0), 0, 0)
}
/** Returns a ScalaSignature annotation if it must be added to this class, none otherwise.
* This annotation must be added to the class' annotations list when generating them.
*
* Depending on whether the returned option is defined, it adds to `jclass` one of:
* (a) the ScalaSig marker attribute
* (indicating that a scala-signature-annotation aka pickle is present in this class); or
* (b) the Scala marker attribute
* (indicating that a scala-signature-annotation aka pickle is to be found in another file).
*
*
* @param jclassName The class file that is being readied.
* @param sym The symbol for which the signature has been entered in the symData map.
* This is different than the symbol
* that is being generated in the case of a mirror class.
* @return An option that is:
* - defined and contains an AnnotationInfo of the ScalaSignature type,
* instantiated with the pickle signature for sym.
* - empty if the jclass/sym pair must not contain a pickle.
*
*/
def getAnnotPickle(jclassName: String, sym: Symbol): Option[AnnotationInfo] = {
currentRun.symData get sym match {
case Some(pickle) if !nme.isModuleName(newTermName(jclassName)) =>
val scalaAnnot = {
val sigBytes = ScalaSigBytes(pickle.bytes.take(pickle.writeIndex))
AnnotationInfo(sigBytes.sigAnnot, Nil, List((nme.bytes, sigBytes)))
}
pickledBytes += pickle.writeIndex
currentRun.symData -= sym
currentRun.symData -= sym.companionSymbol
Some(scalaAnnot)
case _ =>
None
}
}
/**
* Quoting from JVMS 4.7.5 The Exceptions Attribute
* "The Exceptions attribute indicates which checked exceptions a method may throw.
* There may be at most one Exceptions attribute in each method_info structure."
*
* The contents of that attribute are determined by the `String[] exceptions` argument to ASM's ClassVisitor.visitMethod()
* This method returns such list of internal names.
*/
def getExceptions(excs: List[AnnotationInfo]): List[String] =
for (ThrownException(exc) <- excs.distinct)
yield javaName(exc)
/** Whether an annotation should be emitted as a Java annotation
* .initialize: if 'annot' is read from pickle, atp might be un-initialized
*/
private def shouldEmitAnnotation(annot: AnnotationInfo) =
annot.symbol.initialize.isJavaDefined &&
annot.matches(ClassfileAnnotationClass) &&
annot.args.isEmpty &&
!annot.matches(DeprecatedAttr)
def getCurrentCUnit(): CompilationUnit
def getGenericSignature(sym: Symbol, owner: Symbol) = self.getGenericSignature(sym, owner, getCurrentCUnit())
def emitArgument(av: asm.AnnotationVisitor,
name: String,
arg: ClassfileAnnotArg) {
(arg: @unchecked) match {
case LiteralAnnotArg(const) =>
if(const.isNonUnitAnyVal) { av.visit(name, const.value) }
else {
const.tag match {
case StringTag =>
assert(const.value != null, const) // TODO this invariant isn't documented in `case class Constant`
av.visit(name, const.stringValue) // `stringValue` special-cases null, but that execution path isn't exercised for a const with StringTag
case ClazzTag => av.visit(name, javaType(const.typeValue))
case EnumTag =>
val edesc = descriptor(const.tpe) // the class descriptor of the enumeration class.
val evalue = const.symbolValue.name.toString // value the actual enumeration value.
av.visitEnum(name, edesc, evalue)
}
}
case sb@ScalaSigBytes(bytes) =>
// see http://www.scala-lang.org/sid/10 (Storage of pickled Scala signatures in class files)
// also JVMS Sec. 4.7.16.1 The element_value structure and JVMS Sec. 4.4.7 The CONSTANT_Utf8_info Structure.
if (sb.fitsInOneString)
av.visit(name, strEncode(sb))
else {
val arrAnnotV: asm.AnnotationVisitor = av.visitArray(name)
for(arg <- arrEncode(sb)) { arrAnnotV.visit(name, arg) }
arrAnnotV.visitEnd()
}
// for the lazy val in ScalaSigBytes to be GC'ed, the invoker of emitAnnotations() should hold the ScalaSigBytes in a method-local var that doesn't escape.
case ArrayAnnotArg(args) =>
val arrAnnotV: asm.AnnotationVisitor = av.visitArray(name)
for(arg <- args) { emitArgument(arrAnnotV, null, arg) }
arrAnnotV.visitEnd()
case NestedAnnotArg(annInfo) =>
val AnnotationInfo(typ, args, assocs) = annInfo
assert(args.isEmpty, args)
val desc = descriptor(typ) // the class descriptor of the nested annotation class
val nestedVisitor = av.visitAnnotation(name, desc)
emitAssocs(nestedVisitor, assocs)
}
}
def emitAssocs(av: asm.AnnotationVisitor, assocs: List[(Name, ClassfileAnnotArg)]) {
for ((name, value) <- assocs) {
emitArgument(av, name.toString(), value)
}
av.visitEnd()
}
def emitAnnotations(cw: asm.ClassVisitor, annotations: List[AnnotationInfo]) {
for(annot <- annotations; if shouldEmitAnnotation(annot)) {
val AnnotationInfo(typ, args, assocs) = annot
assert(args.isEmpty, args)
val av = cw.visitAnnotation(descriptor(typ), true)
emitAssocs(av, assocs)
}
}
def emitAnnotations(mw: asm.MethodVisitor, annotations: List[AnnotationInfo]) {
for(annot <- annotations; if shouldEmitAnnotation(annot)) {
val AnnotationInfo(typ, args, assocs) = annot
assert(args.isEmpty, args)
val av = mw.visitAnnotation(descriptor(typ), true)
emitAssocs(av, assocs)
}
}
def emitAnnotations(fw: asm.FieldVisitor, annotations: List[AnnotationInfo]) {
for(annot <- annotations; if shouldEmitAnnotation(annot)) {
val AnnotationInfo(typ, args, assocs) = annot
assert(args.isEmpty, args)
val av = fw.visitAnnotation(descriptor(typ), true)
emitAssocs(av, assocs)
}
}
def emitParamAnnotations(jmethod: asm.MethodVisitor, pannotss: List[List[AnnotationInfo]]) {
val annotationss = pannotss map (_ filter shouldEmitAnnotation)
if (annotationss forall (_.isEmpty)) return
for ((annots, idx) <- annotationss.zipWithIndex;
annot <- annots) {
val AnnotationInfo(typ, args, assocs) = annot
assert(args.isEmpty, args)
val pannVisitor: asm.AnnotationVisitor = jmethod.visitParameterAnnotation(idx, descriptor(typ), true)
emitAssocs(pannVisitor, assocs)
}
}
/** Adds a @remote annotation, actual use unknown.
*
* Invoked from genMethod() and addForwarder().
*/
def addRemoteExceptionAnnot(isRemoteClass: Boolean, isJMethodPublic: Boolean, meth: Symbol) {
val needsAnnotation = (
( isRemoteClass ||
isRemote(meth) && isJMethodPublic
) && !(meth.throwsAnnotations contains RemoteExceptionClass)
)
if (needsAnnotation) {
val c = Constant(RemoteExceptionClass.tpe)
val arg = Literal(c) setType c.tpe
meth.addAnnotation(appliedType(ThrowsClass, c.tpe), arg)
}
}
// -----------------------------------------------------------------------------------------
// Static forwarders (related to mirror classes but also present in
// a plain class lacking companion module, for details see `isCandidateForForwarders`).
// -----------------------------------------------------------------------------------------
/** Add a forwarder for method m. Used only from addForwarders(). */
private def addForwarder(isRemoteClass: Boolean, jclass: asm.ClassVisitor, module: Symbol, m: Symbol) {
val moduleName = javaName(module)
val methodInfo = module.thisType.memberInfo(m)
val paramJavaTypes: List[asm.Type] = methodInfo.paramTypes map javaType
// val paramNames = 0 until paramJavaTypes.length map ("x_" + _)
/* Forwarders must not be marked final,
* as the JVM will not allow redefinition of a final static method,
* and we don't know what classes might be subclassing the companion class. See SI-4827.
*/
// TODO: evaluate the other flags we might be dropping on the floor here.
// TODO: ACC_SYNTHETIC ?
val flags = PublicStatic | (
if (m.isVarargsMethod) asm.Opcodes.ACC_VARARGS else 0
)
// TODO needed? for(ann <- m.annotations) { ann.symbol.initialize }
val jgensig = staticForwarderGenericSignature(m, module, getCurrentCUnit())
addRemoteExceptionAnnot(isRemoteClass, hasPublicBitSet(flags), m)
val (throws, others) = m.annotations partition (_.symbol == ThrowsClass)
val thrownExceptions: List[String] = getExceptions(throws)
val jReturnType = javaType(methodInfo.resultType)
val mdesc = asm.Type.getMethodDescriptor(jReturnType, paramJavaTypes: _*)
val mirrorMethodName = javaName(m)
val mirrorMethod: asm.MethodVisitor = jclass.visitMethod(
flags,
mirrorMethodName,
mdesc,
jgensig,
mkArray(thrownExceptions)
)
// typestate: entering mode with valid call sequences:
// [ visitAnnotationDefault ] ( visitAnnotation | visitParameterAnnotation | visitAttribute )*
emitAnnotations(mirrorMethod, others)
emitParamAnnotations(mirrorMethod, m.info.params.map(_.annotations))
// typestate: entering mode with valid call sequences:
// visitCode ( visitFrame | visitXInsn | visitLabel | visitTryCatchBlock | visitLocalVariable | visitLineNumber )* visitMaxs ] visitEnd
mirrorMethod.visitCode()
mirrorMethod.visitFieldInsn(asm.Opcodes.GETSTATIC, moduleName, strMODULE_INSTANCE_FIELD, descriptor(module))
var index = 0
for(jparamType <- paramJavaTypes) {
mirrorMethod.visitVarInsn(jparamType.getOpcode(asm.Opcodes.ILOAD), index)
assert(jparamType.getSort() != asm.Type.METHOD, jparamType)
index += jparamType.getSize()
}
mirrorMethod.visitMethodInsn(asm.Opcodes.INVOKEVIRTUAL, moduleName, mirrorMethodName, javaType(m).getDescriptor)
mirrorMethod.visitInsn(jReturnType.getOpcode(asm.Opcodes.IRETURN))
mirrorMethod.visitMaxs(0, 0) // just to follow protocol, dummy arguments
mirrorMethod.visitEnd()
}
/** Add forwarders for all methods defined in `module` that don't conflict
* with methods in the companion class of `module`. A conflict arises when
* a method with the same name is defined both in a class and its companion object:
* method signature is not taken into account.
*/
def addForwarders(isRemoteClass: Boolean, jclass: asm.ClassVisitor, jclassName: String, moduleClass: Symbol) {
assert(moduleClass.isModuleClass, moduleClass)
debuglog("Dumping mirror class for object: " + moduleClass)
val linkedClass = moduleClass.companionClass
lazy val conflictingNames: Set[Name] = {
(linkedClass.info.members collect { case sym if sym.name.isTermName => sym.name }).toSet
}
debuglog("Potentially conflicting names for forwarders: " + conflictingNames)
for (m <- moduleClass.info.membersBasedOnFlags(ExcludedForwarderFlags, Flags.METHOD)) {
if (m.isType || m.isDeferred || (m.owner eq ObjectClass) || m.isConstructor)
debuglog(s"No forwarder for '$m' from $jclassName to '$moduleClass'")
else if (conflictingNames(m.name))
log(s"No forwarder for $m due to conflict with " + linkedClass.info.member(m.name))
else if (m.hasAccessBoundary)
log(s"No forwarder for non-public member $m")
else {
debuglog(s"Adding static forwarder for '$m' from $jclassName to '$moduleClass'")
addForwarder(isRemoteClass, jclass, moduleClass, m)
}
}
}
} // end of class JCommonBuilder
trait JAndroidBuilder {
self: JPlainBuilder =>
def isAndroidParcelableClass(sym: Symbol) =
(AndroidParcelableInterface != NoSymbol) &&
(sym.parentSymbols contains AndroidParcelableInterface)
/* Typestate: should be called before emitting fields (because it adds an IField to the current IClass). */
def addCreatorCode(block: BasicBlock) {
val fieldSymbol = (
clasz.symbol.newValue(androidFieldName, NoPosition, Flags.STATIC | Flags.FINAL)
setInfo AndroidCreatorClass.tpe
)
val methodSymbol = definitions.getMember(clasz.symbol.companionModule, androidFieldName)
clasz addField new IField(fieldSymbol)
block emit CALL_METHOD(methodSymbol, Static(onInstance = false))
block emit STORE_FIELD(fieldSymbol, isStatic = true)
}
def legacyAddCreatorCode(clinit: asm.MethodVisitor) {
val creatorType: asm.Type = javaType(AndroidCreatorClass)
val tdesc_creator = creatorType.getDescriptor
jclass.visitField(
PublicStaticFinal,
androidFieldName.toString,
tdesc_creator,
null, // no java-generic-signature
null // no initial value
).visitEnd()
val moduleName = javaName(clasz.symbol)+"$"
// GETSTATIC `moduleName`.MODULE$ : `moduleName`;
clinit.visitFieldInsn(
asm.Opcodes.GETSTATIC,
moduleName,
strMODULE_INSTANCE_FIELD,
asm.Type.getObjectType(moduleName).getDescriptor
)
// INVOKEVIRTUAL `moduleName`.CREATOR() : android.os.Parcelable$Creator;
clinit.visitMethodInsn(
asm.Opcodes.INVOKEVIRTUAL,
moduleName,
androidFieldName.toString,
asm.Type.getMethodDescriptor(creatorType, Array.empty[asm.Type]: _*)
)
// PUTSTATIC `thisName`.CREATOR;
clinit.visitFieldInsn(
asm.Opcodes.PUTSTATIC,
thisName,
androidFieldName.toString,
tdesc_creator
)
}
} // end of trait JAndroidBuilder
/** Map from type kinds to the Java reference types.
* It is used to push class literals onto the operand stack.
* @see Predef.classOf
* @see genConstant()
*/
private val classLiteral = immutable.Map[TypeKind, asm.Type](
UNIT -> asm.Type.getObjectType("java/lang/Void"),
BOOL -> asm.Type.getObjectType("java/lang/Boolean"),
BYTE -> asm.Type.getObjectType("java/lang/Byte"),
SHORT -> asm.Type.getObjectType("java/lang/Short"),
CHAR -> asm.Type.getObjectType("java/lang/Character"),
INT -> asm.Type.getObjectType("java/lang/Integer"),
LONG -> asm.Type.getObjectType("java/lang/Long"),
FLOAT -> asm.Type.getObjectType("java/lang/Float"),
DOUBLE -> asm.Type.getObjectType("java/lang/Double")
)
def isNonUnitValueTK(tk: TypeKind): Boolean = { tk.isValueType && tk != UNIT }
case class MethodNameAndType(mname: String, mdesc: String)
private val jBoxTo: Map[TypeKind, MethodNameAndType] = {
Map(
BOOL -> MethodNameAndType("boxToBoolean", "(Z)Ljava/lang/Boolean;" ) ,
BYTE -> MethodNameAndType("boxToByte", "(B)Ljava/lang/Byte;" ) ,
CHAR -> MethodNameAndType("boxToCharacter", "(C)Ljava/lang/Character;") ,
SHORT -> MethodNameAndType("boxToShort", "(S)Ljava/lang/Short;" ) ,
INT -> MethodNameAndType("boxToInteger", "(I)Ljava/lang/Integer;" ) ,
LONG -> MethodNameAndType("boxToLong", "(J)Ljava/lang/Long;" ) ,
FLOAT -> MethodNameAndType("boxToFloat", "(F)Ljava/lang/Float;" ) ,
DOUBLE -> MethodNameAndType("boxToDouble", "(D)Ljava/lang/Double;" )
)
}
private val jUnboxTo: Map[TypeKind, MethodNameAndType] = {
Map(
BOOL -> MethodNameAndType("unboxToBoolean", "(Ljava/lang/Object;)Z") ,
BYTE -> MethodNameAndType("unboxToByte", "(Ljava/lang/Object;)B") ,
CHAR -> MethodNameAndType("unboxToChar", "(Ljava/lang/Object;)C") ,
SHORT -> MethodNameAndType("unboxToShort", "(Ljava/lang/Object;)S") ,
INT -> MethodNameAndType("unboxToInt", "(Ljava/lang/Object;)I") ,
LONG -> MethodNameAndType("unboxToLong", "(Ljava/lang/Object;)J") ,
FLOAT -> MethodNameAndType("unboxToFloat", "(Ljava/lang/Object;)F") ,
DOUBLE -> MethodNameAndType("unboxToDouble", "(Ljava/lang/Object;)D")
)
}
case class BlockInteval(start: BasicBlock, end: BasicBlock)
/** builder of plain classes */
class JPlainBuilder(bytecodeWriter: BytecodeWriter, needsOutfile: Boolean)
extends JCommonBuilder(bytecodeWriter, needsOutfile)
with JAndroidBuilder {
val MIN_SWITCH_DENSITY = 0.7
val StringBuilderClassName = javaName(definitions.StringBuilderClass)
val BoxesRunTime = "scala/runtime/BoxesRunTime"
val StringBuilderType = asm.Type.getObjectType(StringBuilderClassName)
val mdesc_toString = "()Ljava/lang/String;"
val mdesc_arrayClone = "()Ljava/lang/Object;"
val tdesc_long = asm.Type.LONG_TYPE.getDescriptor // ie. "J"
def isParcelableClass = isAndroidParcelableClass(clasz.symbol)
def serialVUID: Option[Long] = genBCode.serialVUID(clasz.symbol)
private def getSuperInterfaces(c: IClass): Array[String] = {
// Additional interface parents based on annotations and other cues
def newParentForAttr(ann: AnnotationInfo): Symbol = ann.symbol match {
case RemoteAttr => RemoteInterfaceClass
case _ => NoSymbol
}
/* Drop redundant interfaces (ones which are implemented by some other parent) from the immediate parents.
* This is important on Android because there is otherwise an interface explosion.
*/
def minimizeInterfaces(lstIfaces: List[Symbol]): List[Symbol] = {
var rest = lstIfaces
var leaves = List.empty[Symbol]
while(!rest.isEmpty) {
val candidate = rest.head
val nonLeaf = leaves exists { lsym => lsym isSubClass candidate }
if(!nonLeaf) {
leaves = candidate :: (leaves filterNot { lsym => candidate isSubClass lsym })
}
rest = rest.tail
}
leaves
}
val ps = c.symbol.info.parents
val superInterfaces0: List[Symbol] = if(ps.isEmpty) Nil else c.symbol.mixinClasses
val superInterfaces = existingSymbols(superInterfaces0 ++ c.symbol.annotations.map(newParentForAttr)).distinct
if(superInterfaces.isEmpty) EMPTY_STRING_ARRAY
else mkArray(minimizeInterfaces(superInterfaces) map javaName)
}
var clasz: IClass = _ // this var must be assigned only by genClass()
var jclass: asm.ClassWriter = _ // the classfile being emitted
var thisName: String = _ // the internal name of jclass
def thisDescr: String = {
assert(thisName != null, "thisDescr invoked too soon.")
asm.Type.getObjectType(thisName).getDescriptor
}
def getCurrentCUnit(): CompilationUnit = { clasz.cunit }
def genClass(c: IClass) {
clasz = c
innerClassBuffer.clear()
thisName = javaName(c.symbol) // the internal name of the class being emitted
val ps = c.symbol.info.parents
val superClass: String = if(ps.isEmpty) JAVA_LANG_OBJECT.getInternalName else javaName(ps.head.typeSymbol)
val ifaces = getSuperInterfaces(c)
val thisSignature = getGenericSignature(c.symbol, c.symbol.owner)
val flags = mkFlags(
javaFlags(c.symbol),
if(isDeprecated(c.symbol)) asm.Opcodes.ACC_DEPRECATED else 0 // ASM pseudo access flag
)
jclass = createJClass(flags,
thisName, thisSignature,
superClass, ifaces)
// typestate: entering mode with valid call sequences:
// [ visitSource ] [ visitOuterClass ] ( visitAnnotation | visitAttribute )*
if(emitSource) {
jclass.visitSource(c.cunit.source.toString,
null /* SourceDebugExtension */)
}
val enclM = getEnclosingMethodAttribute()
if(enclM != null) {
val EnclMethodEntry(className, methodName, methodType) = enclM
jclass.visitOuterClass(className, methodName, methodType.getDescriptor)
}
// typestate: entering mode with valid call sequences:
// ( visitAnnotation | visitAttribute )*
val ssa = getAnnotPickle(thisName, c.symbol)
jclass.visitAttribute(if(ssa.isDefined) pickleMarkerLocal else pickleMarkerForeign)
emitAnnotations(jclass, c.symbol.annotations ++ ssa)
// typestate: entering mode with valid call sequences:
// ( visitInnerClass | visitField | visitMethod )* visitEnd
if (isStaticModule(c.symbol) || isParcelableClass) {
if (isStaticModule(c.symbol)) { addModuleInstanceField() }
addStaticInit(c.lookupStaticCtor)
} else {
for (constructor <- c.lookupStaticCtor) {
addStaticInit(Some(constructor))
}
val skipStaticForwarders = (c.symbol.isInterface || settings.noForwarders)
if (!skipStaticForwarders) {
val lmoc = c.symbol.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("Adding static forwarders from '%s' to implementations in '%s'".format(c.symbol, lmoc))
addForwarders(isRemote(clasz.symbol), jclass, thisName, lmoc.moduleClass)
}
}
}
}
// add static serialVersionUID field if `clasz` annotated with `@SerialVersionUID(uid: Long)`
serialVUID foreach { value =>
val fieldName = "serialVersionUID"
jclass.visitField(
PublicStaticFinal,
fieldName,
tdesc_long,
null, // no java-generic-signature
value
).visitEnd()
}
clasz.fields foreach genField
clasz.methods foreach { im => genMethod(im, c.symbol.isInterface) }
addInnerClasses(clasz.symbol, jclass)
jclass.visitEnd()
writeIfNotTooBig("" + c.symbol.name, thisName, jclass, c.symbol)
}
/**
* @param owner internal name of the enclosing class of the class.
*
* @param name the name of the method that contains the class.
* @param methodType the method that contains the class.
*/
case class EnclMethodEntry(owner: String, name: String, methodType: asm.Type)
/**
* @return null if the current class is not internal to a method
*
* Quoting from JVMS 4.7.7 The EnclosingMethod Attribute
* A class must have an EnclosingMethod attribute if and only if it is a local class or an anonymous class.
* A class may have no more than one EnclosingMethod attribute.
*
*/
private def getEnclosingMethodAttribute(): EnclMethodEntry = { // JVMS 4.7.7
var res: EnclMethodEntry = null
val clazz = clasz.symbol
val sym = clazz.originalEnclosingMethod
if (sym.isMethod) {
debuglog("enclosing method for %s is %s (in %s)".format(clazz, sym, sym.enclClass))
res = EnclMethodEntry(javaName(sym.enclClass), javaName(sym), javaType(sym))
} else if (clazz.isAnonymousClass) {
val enclClass = clazz.rawowner
assert(enclClass.isClass, enclClass)
val sym = enclClass.primaryConstructor
if (sym == NoSymbol) {
log("Ran out of room looking for an enclosing method for %s: no constructor here.".format(enclClass))
} else {
debuglog("enclosing method for %s is %s (in %s)".format(clazz, sym, enclClass))
res = EnclMethodEntry(javaName(enclClass), javaName(sym), javaType(sym))
}
}
res
}
def genField(f: IField) {
debuglog("Adding field: " + f.symbol.fullName)
val javagensig = getGenericSignature(f.symbol, clasz.symbol)
val flags = mkFlags(
javaFieldFlags(f.symbol),
if(isDeprecated(f.symbol)) asm.Opcodes.ACC_DEPRECATED else 0 // ASM pseudo access flag
)
val jfield: asm.FieldVisitor = jclass.visitField(
flags,
javaName(f.symbol),
javaType(f.symbol.tpe).getDescriptor(),
javagensig,
null // no initial value
)
emitAnnotations(jfield, f.symbol.annotations)
jfield.visitEnd()
}
var method: IMethod = _
var jmethod: asm.MethodVisitor = _
var jMethodName: String = _
final def emit(opc: Int) { jmethod.visitInsn(opc) }
def genMethod(m: IMethod, isJInterface: Boolean) {
def isClosureApply(sym: Symbol): Boolean = {
(sym.name == nme.apply) &&
sym.owner.isSynthetic &&
sym.owner.tpe.parents.exists { t =>
val TypeRef(_, sym, _) = t
FunctionClass.seq contains sym
}
}
if (m.symbol.isStaticConstructor || definitions.isGetClass(m.symbol)) return
if (m.params.size > MaximumJvmParameters) {
getCurrentCUnit().error(m.symbol.pos, s"Platform restriction: a parameter list's length cannot exceed $MaximumJvmParameters.")
return
}
debuglog("Generating method " + m.symbol.fullName)
method = m
computeLocalVarsIndex(m)
var resTpe: asm.Type = javaType(m.symbol.tpe.resultType)
if (m.symbol.isClassConstructor)
resTpe = asm.Type.VOID_TYPE
val flags = mkFlags(
javaFlags(m.symbol),
if (isJInterface) asm.Opcodes.ACC_ABSTRACT else 0,
if (m.symbol.isStrictFP) asm.Opcodes.ACC_STRICT else 0,
if (method.native) asm.Opcodes.ACC_NATIVE else 0, // native methods of objects are generated in mirror classes
if(isDeprecated(m.symbol)) asm.Opcodes.ACC_DEPRECATED else 0 // ASM pseudo access flag
)
// TODO needed? for(ann <- m.symbol.annotations) { ann.symbol.initialize }
val jgensig = getGenericSignature(m.symbol, clasz.symbol)
addRemoteExceptionAnnot(isRemote(clasz.symbol), hasPublicBitSet(flags), m.symbol)
val (excs, others) = m.symbol.annotations partition (_.symbol == ThrowsClass)
val thrownExceptions: List[String] = getExceptions(excs)
jMethodName = javaName(m.symbol)
val mdesc = asm.Type.getMethodDescriptor(resTpe, (m.params map (p => javaType(p.kind))): _*)
jmethod = jclass.visitMethod(
flags,
jMethodName,
mdesc,
jgensig,
mkArray(thrownExceptions)
)
// TODO param names: (m.params map (p => javaName(p.sym)))
// typestate: entering mode with valid call sequences:
// [ visitAnnotationDefault ] ( visitAnnotation | visitParameterAnnotation | visitAttribute )*
emitAnnotations(jmethod, others)
emitParamAnnotations(jmethod, m.params.map(_.sym.annotations))
// typestate: entering mode with valid call sequences:
// [ visitCode ( visitFrame | visitXInsn | visitLabel | visitTryCatchBlock | visitLocalVariable | visitLineNumber )* visitMaxs ] visitEnd
// In addition, the visitXInsn and visitLabel methods must be called in the sequential order of the bytecode instructions of the visited code,
// visitTryCatchBlock must be called before the labels passed as arguments have been visited, and
// the visitLocalVariable and visitLineNumber methods must be called after the labels passed as arguments have been visited.
val hasAbstractBitSet = ((flags & asm.Opcodes.ACC_ABSTRACT) != 0)
val hasCodeAttribute = (!hasAbstractBitSet && !method.native)
if (hasCodeAttribute) {
jmethod.visitCode()
if (emitVars && isClosureApply(method.symbol)) {
// add a fake local for debugging purposes
val outerField = clasz.symbol.info.decl(nme.OUTER_LOCAL)
if (outerField != NoSymbol) {
log("Adding fake local to represent outer 'this' for closure " + clasz)
val _this =
new Local(method.symbol.newVariable(nme.FAKE_LOCAL_THIS),
toTypeKind(outerField.tpe),
false)
m.locals = m.locals ::: List(_this)
computeLocalVarsIndex(m) // since we added a new local, we need to recompute indexes
jmethod.visitVarInsn(asm.Opcodes.ALOAD, 0)
jmethod.visitFieldInsn(asm.Opcodes.GETFIELD,
javaName(clasz.symbol), // field owner
javaName(outerField), // field name
descriptor(outerField) // field descriptor
)
assert(_this.kind.isReferenceType, _this.kind)
jmethod.visitVarInsn(asm.Opcodes.ASTORE, indexOf(_this))
}
}
assert( m.locals forall { local => (m.params contains local) == local.arg }, m.locals )
val hasStaticBitSet = ((flags & asm.Opcodes.ACC_STATIC) != 0)
genCode(m, emitVars, hasStaticBitSet)
jmethod.visitMaxs(0, 0) // just to follow protocol, dummy arguments
}
jmethod.visitEnd()
}
def addModuleInstanceField() {
val fv =
jclass.visitField(PublicStaticFinal, // TODO confirm whether we really don't want ACC_SYNTHETIC nor ACC_DEPRECATED
strMODULE_INSTANCE_FIELD,
thisDescr,
null, // no java-generic-signature
null // no initial value
)
// typestate: entering mode with valid call sequences:
// ( visitAnnotation | visitAttribute )* visitEnd.
fv.visitEnd()
}
/* Typestate: should be called before being done with emitting fields (because it invokes addCreatorCode() which adds an IField to the current IClass). */
def addStaticInit(mopt: Option[IMethod]) {
val clinitMethod: asm.MethodVisitor = jclass.visitMethod(
PublicStatic, // TODO confirm whether we really don't want ACC_SYNTHETIC nor ACC_DEPRECATED
CLASS_CONSTRUCTOR_NAME,
mdesc_arglessvoid,
null, // no java-generic-signature
null // no throwable exceptions
)
mopt match {
case Some(m) =>
val oldLastBlock = m.lastBlock
val lastBlock = m.newBlock()
oldLastBlock.replaceInstruction(oldLastBlock.length - 1, JUMP(lastBlock))
if (isStaticModule(clasz.symbol)) {
// call object's private ctor from static ctor
lastBlock emit NEW(REFERENCE(m.symbol.enclClass))
lastBlock emit CALL_METHOD(m.symbol.enclClass.primaryConstructor, Static(onInstance = true))
}
if (isParcelableClass) { addCreatorCode(lastBlock) }
lastBlock emit RETURN(UNIT)
lastBlock.close()
method = m
jmethod = clinitMethod
jMethodName = CLASS_CONSTRUCTOR_NAME
jmethod.visitCode()
computeLocalVarsIndex(m)
genCode(m, emitVars = false, isStatic = true)
jmethod.visitMaxs(0, 0) // just to follow protocol, dummy arguments
jmethod.visitEnd()
case None =>
clinitMethod.visitCode()
legacyStaticInitializer(clinitMethod)
clinitMethod.visitMaxs(0, 0) // just to follow protocol, dummy arguments
clinitMethod.visitEnd()
}
}
/* used only from addStaticInit() */
private def legacyStaticInitializer(clinit: asm.MethodVisitor) {
if (isStaticModule(clasz.symbol)) {
clinit.visitTypeInsn(asm.Opcodes.NEW, thisName)
clinit.visitMethodInsn(asm.Opcodes.INVOKESPECIAL,
thisName, INSTANCE_CONSTRUCTOR_NAME, mdesc_arglessvoid)
}
if (isParcelableClass) { legacyAddCreatorCode(clinit) }
clinit.visitInsn(asm.Opcodes.RETURN)
}
// -----------------------------------------------------------------------------------------
// Emitting bytecode instructions.
// -----------------------------------------------------------------------------------------
private def genConstant(mv: asm.MethodVisitor, const: Constant) {
const.tag match {
case BooleanTag => jcode.boolconst(const.booleanValue)
case ByteTag => jcode.iconst(const.byteValue.toInt)
case ShortTag => jcode.iconst(const.shortValue.toInt)
case CharTag => jcode.iconst(const.charValue)
case IntTag => jcode.iconst(const.intValue)
case LongTag => jcode.lconst(const.longValue)
case FloatTag => jcode.fconst(const.floatValue)
case DoubleTag => jcode.dconst(const.doubleValue)
case UnitTag => ()
case StringTag =>
assert(const.value != null, const) // TODO this invariant isn't documented in `case class Constant`
mv.visitLdcInsn(const.stringValue) // `stringValue` special-cases null, but not for a const with StringTag
case NullTag => mv.visitInsn(asm.Opcodes.ACONST_NULL)
case ClazzTag =>
val kind = toTypeKind(const.typeValue)
val toPush: asm.Type =
if (kind.isValueType) classLiteral(kind)
else javaType(kind)
mv.visitLdcInsn(toPush)
case EnumTag =>
val sym = const.symbolValue
mv.visitFieldInsn(
asm.Opcodes.GETSTATIC,
javaName(sym.owner),
javaName(sym),
javaType(sym.tpe.underlying).getDescriptor()
)
case _ => abort("Unknown constant value: " + const)
}
}
/** Just a namespace for utilities that encapsulate MethodVisitor idioms.
* In the ASM world, org.objectweb.asm.commons.InstructionAdapter plays a similar role,
* but the methods here allow choosing when to transition from ICode to ASM types
* (including not at all, e.g. for performance).
*/
object jcode {
import asm.Opcodes
final def boolconst(b: Boolean) { iconst(if(b) 1 else 0) }
def iconst(cst: Char) { iconst(cst.toInt) }
def iconst(cst: Int) {
if (cst >= -1 && cst <= 5) {
jmethod.visitInsn(Opcodes.ICONST_0 + cst)
} else if (cst >= java.lang.Byte.MIN_VALUE && cst <= java.lang.Byte.MAX_VALUE) {
jmethod.visitIntInsn(Opcodes.BIPUSH, cst)
} else if (cst >= java.lang.Short.MIN_VALUE && cst <= java.lang.Short.MAX_VALUE) {
jmethod.visitIntInsn(Opcodes.SIPUSH, cst)
} else {
jmethod.visitLdcInsn(new Integer(cst))
}
}
def lconst(cst: Long) {
if (cst == 0L || cst == 1L) {
jmethod.visitInsn(Opcodes.LCONST_0 + cst.asInstanceOf[Int])
} else {
jmethod.visitLdcInsn(new java.lang.Long(cst))
}
}
def fconst(cst: Float) {
val bits: Int = java.lang.Float.floatToIntBits(cst)
if (bits == 0L || bits == 0x3f800000 || bits == 0x40000000) { // 0..2
jmethod.visitInsn(Opcodes.FCONST_0 + cst.asInstanceOf[Int])
} else {
jmethod.visitLdcInsn(new java.lang.Float(cst))
}
}
def dconst(cst: Double) {
val bits: Long = java.lang.Double.doubleToLongBits(cst)
if (bits == 0L || bits == 0x3ff0000000000000L) { // +0.0d and 1.0d
jmethod.visitInsn(Opcodes.DCONST_0 + cst.asInstanceOf[Int])
} else {
jmethod.visitLdcInsn(new java.lang.Double(cst))
}
}
def newarray(elem: TypeKind) {
if(elem.isRefOrArrayType) {
jmethod.visitTypeInsn(Opcodes.ANEWARRAY, javaType(elem).getInternalName)
} else {
val rand = {
if(elem.isIntSizedType) {
(elem: @unchecked) match {
case BOOL => Opcodes.T_BOOLEAN
case BYTE => Opcodes.T_BYTE
case SHORT => Opcodes.T_SHORT
case CHAR => Opcodes.T_CHAR
case INT => Opcodes.T_INT
}
} else {
(elem: @unchecked) match {
case LONG => Opcodes.T_LONG
case FLOAT => Opcodes.T_FLOAT
case DOUBLE => Opcodes.T_DOUBLE
}
}
}
jmethod.visitIntInsn(Opcodes.NEWARRAY, rand)
}
}
def load( idx: Int, tk: TypeKind) { emitVarInsn(Opcodes.ILOAD, idx, tk) }
def store(idx: Int, tk: TypeKind) { emitVarInsn(Opcodes.ISTORE, idx, tk) }
def aload( tk: TypeKind) { emitTypeBased(aloadOpcodes, tk) }
def astore(tk: TypeKind) { emitTypeBased(astoreOpcodes, tk) }
def neg(tk: TypeKind) { emitPrimitive(negOpcodes, tk) }
def add(tk: TypeKind) { emitPrimitive(addOpcodes, tk) }
def sub(tk: TypeKind) { emitPrimitive(subOpcodes, tk) }
def mul(tk: TypeKind) { emitPrimitive(mulOpcodes, tk) }
def div(tk: TypeKind) { emitPrimitive(divOpcodes, tk) }
def rem(tk: TypeKind) { emitPrimitive(remOpcodes, tk) }
def invokespecial(owner: String, name: String, desc: String) {
jmethod.visitMethodInsn(Opcodes.INVOKESPECIAL, owner, name, desc)
}
def invokestatic(owner: String, name: String, desc: String) {
jmethod.visitMethodInsn(Opcodes.INVOKESTATIC, owner, name, desc)
}
def invokeinterface(owner: String, name: String, desc: String) {
jmethod.visitMethodInsn(Opcodes.INVOKEINTERFACE, owner, name, desc)
}
def invokevirtual(owner: String, name: String, desc: String) {
jmethod.visitMethodInsn(Opcodes.INVOKEVIRTUAL, owner, name, desc)
}
def goTo(label: asm.Label) { jmethod.visitJumpInsn(Opcodes.GOTO, label) }
def emitIF(cond: TestOp, label: asm.Label) { jmethod.visitJumpInsn(cond.opcodeIF(), label) }
def emitIF_ICMP(cond: TestOp, label: asm.Label) { jmethod.visitJumpInsn(cond.opcodeIFICMP(), label) }
def emitIF_ACMP(cond: TestOp, label: asm.Label) {
assert((cond == EQ) || (cond == NE), cond)
val opc = (if(cond == EQ) Opcodes.IF_ACMPEQ else Opcodes.IF_ACMPNE)
jmethod.visitJumpInsn(opc, label)
}
def emitIFNONNULL(label: asm.Label) { jmethod.visitJumpInsn(Opcodes.IFNONNULL, label) }
def emitIFNULL (label: asm.Label) { jmethod.visitJumpInsn(Opcodes.IFNULL, label) }
def emitRETURN(tk: TypeKind) {
if(tk == UNIT) { jmethod.visitInsn(Opcodes.RETURN) }
else { emitTypeBased(returnOpcodes, tk) }
}
/** Emits one of tableswitch or lookoupswitch. */
def emitSWITCH(keys: Array[Int], branches: Array[asm.Label], defaultBranch: asm.Label, minDensity: Double) {
assert(keys.length == branches.length)
// For empty keys, it makes sense emitting LOOKUPSWITCH with defaultBranch only.
// Similar to what javac emits for a switch statement consisting only of a default case.
if (keys.length == 0) {
jmethod.visitLookupSwitchInsn(defaultBranch, keys, branches)
return
}
// sort `keys` by increasing key, keeping `branches` in sync. TODO FIXME use quicksort
var i = 1
while (i < keys.length) {
var j = 1
while (j <= keys.length - i) {
if (keys(j) < keys(j - 1)) {
val tmp = keys(j)
keys(j) = keys(j - 1)
keys(j - 1) = tmp
val tmpL = branches(j)
branches(j) = branches(j - 1)
branches(j - 1) = tmpL
}
j += 1
}
i += 1
}
// check for duplicate keys to avoid "VerifyError: unsorted lookupswitch" (SI-6011)
i = 1
while (i < keys.length) {
if(keys(i-1) == keys(i)) {
abort("duplicate keys in SWITCH, can't pick arbitrarily one of them to evict, see SI-6011.")
}
i += 1
}
val keyMin = keys(0)
val keyMax = keys(keys.length - 1)
val isDenseEnough: Boolean = {
/* Calculate in long to guard against overflow. TODO what overflow??? */
val keyRangeD: Double = (keyMax.asInstanceOf[Long] - keyMin + 1).asInstanceOf[Double]
val klenD: Double = keys.length.toDouble
val kdensity: Double = (klenD / keyRangeD)
kdensity >= minDensity
}
if (isDenseEnough) {
// use a table in which holes are filled with defaultBranch.
val keyRange = (keyMax - keyMin + 1)
val newBranches = new Array[asm.Label](keyRange)
var oldPos = 0
var i = 0
while(i < keyRange) {
val key = keyMin + i
if (keys(oldPos) == key) {
newBranches(i) = branches(oldPos)
oldPos += 1
} else {
newBranches(i) = defaultBranch
}
i += 1
}
assert(oldPos == keys.length, "emitSWITCH")
jmethod.visitTableSwitchInsn(keyMin, keyMax, defaultBranch, newBranches: _*)
} else {
jmethod.visitLookupSwitchInsn(defaultBranch, keys, branches)
}
}
// internal helpers -- not part of the public API of `jcode`
// don't make private otherwise inlining will suffer
def emitVarInsn(opc: Int, idx: Int, tk: TypeKind) {
assert((opc == Opcodes.ILOAD) || (opc == Opcodes.ISTORE), opc)
jmethod.visitVarInsn(javaType(tk).getOpcode(opc), idx)
}
// ---------------- array load and store ----------------
val aloadOpcodes = { import Opcodes._; Array(AALOAD, BALOAD, SALOAD, CALOAD, IALOAD, LALOAD, FALOAD, DALOAD) }
val astoreOpcodes = { import Opcodes._; Array(AASTORE, BASTORE, SASTORE, CASTORE, IASTORE, LASTORE, FASTORE, DASTORE) }
val returnOpcodes = { import Opcodes._; Array(ARETURN, IRETURN, IRETURN, IRETURN, IRETURN, LRETURN, FRETURN, DRETURN) }
def emitTypeBased(opcs: Array[Int], tk: TypeKind) {
assert(tk != UNIT, tk)
val opc = {
if(tk.isRefOrArrayType) { opcs(0) }
else if(tk.isIntSizedType) {
(tk: @unchecked) match {
case BOOL | BYTE => opcs(1)
case SHORT => opcs(2)
case CHAR => opcs(3)
case INT => opcs(4)
}
} else {
(tk: @unchecked) match {
case LONG => opcs(5)
case FLOAT => opcs(6)
case DOUBLE => opcs(7)
}
}
}
jmethod.visitInsn(opc)
}
// ---------------- primitive operations ----------------
val negOpcodes: Array[Int] = { import Opcodes._; Array(INEG, LNEG, FNEG, DNEG) }
val addOpcodes: Array[Int] = { import Opcodes._; Array(IADD, LADD, FADD, DADD) }
val subOpcodes: Array[Int] = { import Opcodes._; Array(ISUB, LSUB, FSUB, DSUB) }
val mulOpcodes: Array[Int] = { import Opcodes._; Array(IMUL, LMUL, FMUL, DMUL) }
val divOpcodes: Array[Int] = { import Opcodes._; Array(IDIV, LDIV, FDIV, DDIV) }
val remOpcodes: Array[Int] = { import Opcodes._; Array(IREM, LREM, FREM, DREM) }
def emitPrimitive(opcs: Array[Int], tk: TypeKind) {
val opc = {
if(tk.isIntSizedType) { opcs(0) }
else {
(tk: @unchecked) match {
case LONG => opcs(1)
case FLOAT => opcs(2)
case DOUBLE => opcs(3)
}
}
}
jmethod.visitInsn(opc)
}
}
/** Invoked from genMethod() and addStaticInit() */
def genCode(m: IMethod,
emitVars: Boolean, // this param name hides the instance-level var
isStatic: Boolean) {
newNormal.normalize(m)
// ------------------------------------------------------------------------------------------------------------
// Part 1 of genCode(): setting up one-to-one correspondence between ASM Labels and BasicBlocks `linearization`
// ------------------------------------------------------------------------------------------------------------
val linearization: List[BasicBlock] = linearizer.linearize(m)
if(linearization.isEmpty) { return }
var isModuleInitialized = false
val labels: scala.collection.Map[BasicBlock, asm.Label] = mutable.HashMap(linearization map (_ -> new asm.Label()) : _*)
val onePastLast = new asm.Label // token for the mythical instruction past the last instruction in the method being emitted
// maps a BasicBlock b to the Label that corresponds to b's successor in the linearization. The last BasicBlock is mapped to the onePastLast label.
val linNext: scala.collection.Map[BasicBlock, asm.Label] = {
val result = mutable.HashMap.empty[BasicBlock, asm.Label]
var rest = linearization
var prev = rest.head
rest = rest.tail
while(!rest.isEmpty) {
result += (prev -> labels(rest.head))
prev = rest.head
rest = rest.tail
}
assert(!result.contains(prev))
result += (prev -> onePastLast)
result
}
// ------------------------------------------------------------------------------------------------------------
// Part 2 of genCode(): demarcating exception handler boundaries (visitTryCatchBlock() must be invoked before visitLabel() in genBlock())
// ------------------------------------------------------------------------------------------------------------
/* Generate exception handlers for the current method.
*
* Quoting from the JVMS 4.7.3 The Code Attribute
* The items of the Code_attribute structure are as follows:
* . . .
* exception_table[]
* Each entry in the exception_table array describes one
* exception handler in the code array. The order of the handlers in
* the exception_table array is significant.
* Each exception_table entry contains the following four items:
* start_pc, end_pc:
* ... The value of end_pc either must be a valid index into
* the code array of the opcode of an instruction or must be equal to code_length,
* the length of the code array.
* handler_pc:
* The value of the handler_pc item indicates the start of the exception handler
* catch_type:
* ... If the value of the catch_type item is zero,
* this exception handler is called for all exceptions.
* This is used to implement finally
*/
def genExceptionHandlers() {
/* Return a list of pairs of intervals where the handler is active.
* Each interval is closed on both ends, ie. inclusive both in the left and right endpoints: [start, end].
* Preconditions:
* - e.covered non-empty
* Postconditions for the result:
* - always non-empty
* - intervals are sorted as per `linearization`
* - the argument's `covered` blocks have been grouped into maximally contiguous intervals,
* ie. between any two intervals in the result there is a non-empty gap.
* - each of the `covered` blocks in the argument is contained in some interval in the result
*/
def intervals(e: ExceptionHandler): List[BlockInteval] = {
assert(e.covered.nonEmpty, e)
var result: List[BlockInteval] = Nil
var rest = linearization
// find intervals
while(!rest.isEmpty) {
// find interval start
var start: BasicBlock = null
while(!rest.isEmpty && (start eq null)) {
if(e.covered(rest.head)) { start = rest.head }
rest = rest.tail
}
if(start ne null) {
// find interval end
var end = start // for the time being
while(!rest.isEmpty && (e.covered(rest.head))) {
end = rest.head
rest = rest.tail
}
result = BlockInteval(start, end) :: result
}
}
assert(result.nonEmpty, e)
result
}
/* TODO test/files/run/exceptions-2.scala displays an ExceptionHandler.covered that contains
* blocks not in the linearization (dead-code?). Is that well-formed or not?
* For now, we ignore those blocks (after all, that's what `genBlocks(linearization)` in effect does).
*/
for (e <- this.method.exh) {
val ignore: Set[BasicBlock] = (e.covered filterNot { b => linearization contains b } )
// TODO someday assert(ignore.isEmpty, "an ExceptionHandler.covered contains blocks not in the linearization (dead-code?)")
if(ignore.nonEmpty) {
e.covered = e.covered filterNot ignore
}
}
// an ExceptionHandler lacking covered blocks doesn't get an entry in the Exceptions table.
// TODO in that case, ExceptionHandler.cls doesn't go through javaName(). What if cls is an inner class?
for (e <- this.method.exh ; if e.covered.nonEmpty ; p <- intervals(e)) {
debuglog("Adding exception handler " + e + "at block: " + e.startBlock + " for " + method +
" from: " + p.start + " to: " + p.end + " catching: " + e.cls)
val cls: String = if (e.cls == NoSymbol || e.cls == ThrowableClass) null
else javaName(e.cls)
jmethod.visitTryCatchBlock(labels(p.start), linNext(p.end), labels(e.startBlock), cls)
}
} // end of genCode()'s genExceptionHandlers()
if (m.exh.nonEmpty) { genExceptionHandlers() }
// ------------------------------------------------------------------------------------------------------------
// Part 3 of genCode(): "Infrastructure" to later emit debug info for local variables and method params (LocalVariablesTable bytecode attribute).
// ------------------------------------------------------------------------------------------------------------
case class LocVarEntry(local: Local, start: asm.Label, end: asm.Label) // start is inclusive while end exclusive.
case class Interval(lstart: asm.Label, lend: asm.Label) {
final def start = lstart.getOffset
final def end = lend.getOffset
def precedes(that: Interval): Boolean = { this.end < that.start }
def overlaps(that: Interval): Boolean = { !(this.precedes(that) || that.precedes(this)) }
def mergeWith(that: Interval): Interval = {
val newStart = if(this.start <= that.start) this.lstart else that.lstart
val newEnd = if(this.end <= that.end) that.lend else this.lend
Interval(newStart, newEnd)
}
def repOK: Boolean = { start <= end }
}
/** Track those instruction ranges where certain locals are in scope. Used to later emit the LocalVariableTable attribute (JVMS 4.7.13) */
object scoping {
private val pending = mutable.Map.empty[Local, mutable.Stack[Label]]
private var seen: List[LocVarEntry] = Nil
private def fuse(ranges: List[Interval], added: Interval): List[Interval] = {
assert(added.repOK, added)
if(ranges.isEmpty) { return List(added) }
// precond: ranges is sorted by increasing start
var fused: List[Interval] = Nil
var done = false
var rest = ranges
while(!done && rest.nonEmpty) {
val current = rest.head
assert(current.repOK, current)
rest = rest.tail
if(added precedes current) {
fused = fused ::: ( added :: current :: rest )
done = true
} else if(current overlaps added) {
fused = fused ::: ( added.mergeWith(current) :: rest )
done = true
}
}
if(!done) { fused = fused ::: List(added) }
assert(repOK(fused), fused)
fused
}
def pushScope(lv: Local, start: Label) {
val st = pending.getOrElseUpdate(lv, mutable.Stack.empty[Label])
st.push(start)
}
def popScope(lv: Local, end: Label, iPos: Position) {
pending.get(lv) match {
case Some(st) if st.nonEmpty =>
val start = st.pop()
seen ::= LocVarEntry(lv, start, end)
case _ =>
// TODO SI-6049 track down the cause for these.
debugwarn(s"$iPos: Visited SCOPE_EXIT before visiting corresponding SCOPE_ENTER. SI-6191")
}
}
def getMerged(): scala.collection.Map[Local, List[Interval]] = {
// TODO should but isn't: unbalanced start(s) of scope(s)
val shouldBeEmpty = pending filter { p => val (_, st) = p; st.nonEmpty }
val merged = mutable.Map[Local, List[Interval]]()
def addToMerged(lv: Local, start: Label, end: Label) {
val intv = Interval(start, end)
merged(lv) = if (merged contains lv) fuse(merged(lv), intv) else intv :: Nil
}
for(LocVarEntry(lv, start, end) <- seen) { addToMerged(lv, start, end) }
/* for each var with unbalanced start(s) of scope(s):
(a) take the earliest start (among unbalanced and balanced starts)
(b) take the latest end (onePastLast if none available)
(c) merge the thus made-up interval
*/
for((k, st) <- shouldBeEmpty) {
var start = st.toList.sortBy(_.getOffset).head
if(merged.isDefinedAt(k)) {
val balancedStart = merged(k).head.lstart
if(balancedStart.getOffset < start.getOffset) {
start = balancedStart
}
}
val endOpt: Option[Label] = for(ranges <- merged.get(k)) yield ranges.last.lend
val end = endOpt.getOrElse(onePastLast)
addToMerged(k, start, end)
}
merged
}
private def repOK(fused: List[Interval]): Boolean = {
fused match {
case Nil => true
case h :: Nil => h.repOK
case h :: n :: rest =>
h.repOK && h.precedes(n) && !h.overlaps(n) && repOK(n :: rest)
}
}
}
def genLocalVariableTable() {
// adding `this` and method params.
if (!isStatic) {
jmethod.visitLocalVariable("this", thisDescr, null, labels(m.startBlock), onePastLast, 0)
}
for(lv <- m.params) {
jmethod.visitLocalVariable(javaName(lv.sym), descriptor(lv.kind), null, labels(m.startBlock), onePastLast, indexOf(lv))
}
// adding non-param locals
var anonCounter = 0
var fltnd: List[Tuple3[String, Local, Interval]] = Nil
for((local, ranges) <- scoping.getMerged()) {
var name = javaName(local.sym)
if (name == null) {
anonCounter += 1
name = "<anon" + anonCounter + ">"
}
for(intrvl <- ranges) {
fltnd ::= (name, local, intrvl)
}
}
// quest for deterministic output that Map.toList doesn't provide (so that ant test.stability doesn't complain).
val srtd = fltnd.sortBy { kr =>
val (name: String, _, intrvl: Interval) = kr
(intrvl.start, intrvl.end - intrvl.start, name) // ie sort by (start, length, name)
}
for((name, local, Interval(start, end)) <- srtd) {
jmethod.visitLocalVariable(name, descriptor(local.kind), null, start, end, indexOf(local))
}
// "There may be no more than one LocalVariableTable attribute per local variable in the Code attribute"
}
// ------------------------------------------------------------------------------------------------------------
// Part 4 of genCode(): Bookkeeping (to later emit debug info) of association between line-number and instruction position.
// ------------------------------------------------------------------------------------------------------------
case class LineNumberEntry(line: Int, start: asm.Label)
var lastLineNr: Int = -1
var lnEntries: List[LineNumberEntry] = Nil
// ------------------------------------------------------------------------------------------------------------
// Part 5 of genCode(): "Utilities" to emit code proper (most prominently: genBlock()).
// ------------------------------------------------------------------------------------------------------------
var nextBlock: BasicBlock = linearization.head
def genBlocks(l: List[BasicBlock]): Unit = l match {
case Nil => ()
case x :: Nil => nextBlock = null; genBlock(x)
case x :: y :: ys => nextBlock = y; genBlock(x); genBlocks(y :: ys)
}
def genCallMethod(call: CALL_METHOD) {
val CALL_METHOD(method, style) = call
val siteSymbol = clasz.symbol
val hostSymbol = call.hostClass
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 != Dynamic
|| hostSymbol.isBottomClass
|| methodOwner == ObjectClass
)
val receiver = if (useMethodOwner) methodOwner else hostSymbol
val jowner = javaName(receiver)
val jname = javaName(method)
val jtype = javaType(method).getDescriptor()
def dbg(invoke: String) {
debuglog("%s %s %s.%s:%s".format(invoke, receiver.accessString, jowner, jname, jtype))
}
def initModule() {
// we initialize the MODULE$ field immediately after the super ctor
if (isStaticModule(siteSymbol) && !isModuleInitialized &&
jMethodName == INSTANCE_CONSTRUCTOR_NAME &&
jname == INSTANCE_CONSTRUCTOR_NAME) {
isModuleInitialized = true
jmethod.visitVarInsn(asm.Opcodes.ALOAD, 0)
jmethod.visitFieldInsn(asm.Opcodes.PUTSTATIC, thisName, strMODULE_INSTANCE_FIELD, thisDescr)
}
}
style match {
case Static(true) => dbg("invokespecial"); jcode.invokespecial (jowner, jname, jtype)
case Static(false) => dbg("invokestatic"); jcode.invokestatic (jowner, jname, jtype)
case Dynamic if needsInterfaceCall(receiver) => dbg("invokinterface"); jcode.invokeinterface(jowner, jname, jtype)
case Dynamic => dbg("invokevirtual"); jcode.invokevirtual (jowner, jname, jtype)
case SuperCall(_) =>
dbg("invokespecial")
jcode.invokespecial(jowner, jname, jtype)
initModule()
}
} // end of genCode()'s genCallMethod()
def genBlock(b: BasicBlock) {
jmethod.visitLabel(labels(b))
debuglog("Generating code for block: " + b)
// val lastInstr = b.lastInstruction
for (instr <- b) {
if(instr.pos.isDefined) {
val iPos = instr.pos
val currentLineNr = iPos.line
val skip = (currentLineNr == lastLineNr) // if(iPos.isRange) iPos.sameRange(lastPos) else
if(!skip) {
lastLineNr = currentLineNr
val lineLab = new asm.Label
jmethod.visitLabel(lineLab)
lnEntries ::= LineNumberEntry(iPos.finalPosition.line, lineLab)
}
}
genInstr(instr, b)
}
}
def genInstr(instr: Instruction, b: BasicBlock) {
import asm.Opcodes
(instr.category: @scala.annotation.switch) match {
case icodes.localsCat =>
def genLocalInstr() = (instr: @unchecked) match {
case THIS(_) => jmethod.visitVarInsn(Opcodes.ALOAD, 0)
case LOAD_LOCAL(local) => jcode.load(indexOf(local), local.kind)
case STORE_LOCAL(local) => jcode.store(indexOf(local), local.kind)
case STORE_THIS(_) =>
// this only works for impl classes because the self parameter comes first
// in the method signature. If that changes, this code has to be revisited.
jmethod.visitVarInsn(Opcodes.ASTORE, 0)
case SCOPE_ENTER(lv) =>
// locals removed by closelim (via CopyPropagation) may have left behind SCOPE_ENTER, SCOPE_EXIT that are to be ignored
val relevant = (!lv.sym.isSynthetic && m.locals.contains(lv))
if (relevant) { // TODO check: does GenICode emit SCOPE_ENTER, SCOPE_EXIT for synthetic vars?
// this label will have DEBUG bit set in its flags (ie ASM ignores it for dataflow purposes)
// similarly, these labels aren't tracked in the `labels` map.
val start = new asm.Label
jmethod.visitLabel(start)
scoping.pushScope(lv, start)
}
case SCOPE_EXIT(lv) =>
val relevant = (!lv.sym.isSynthetic && m.locals.contains(lv))
if (relevant) {
// this label will have DEBUG bit set in its flags (ie ASM ignores it for dataflow purposes)
// similarly, these labels aren't tracked in the `labels` map.
val end = new asm.Label
jmethod.visitLabel(end)
scoping.popScope(lv, end, instr.pos)
}
}
genLocalInstr()
case icodes.stackCat =>
def genStackInstr() = (instr: @unchecked) match {
case LOAD_MODULE(module) =>
// assert(module.isModule, "Expected module: " + module)
debuglog("generating LOAD_MODULE for: " + module + " flags: " + module.flagString)
def inStaticMethod = this.method != null && this.method.symbol.isStaticMember
if (clasz.symbol == module.moduleClass && jMethodName != nme.readResolve.toString && !inStaticMethod) {
jmethod.visitVarInsn(Opcodes.ALOAD, 0)
} else {
jmethod.visitFieldInsn(
Opcodes.GETSTATIC,
javaName(module) /* + "$" */ ,
strMODULE_INSTANCE_FIELD,
descriptor(module))
}
case DROP(kind) => emit(if (kind.isWideType) Opcodes.POP2 else Opcodes.POP)
case DUP(kind) => emit(if (kind.isWideType) Opcodes.DUP2 else Opcodes.DUP)
case LOAD_EXCEPTION(_) => ()
}
genStackInstr()
case icodes.constCat => genConstant(jmethod, instr.asInstanceOf[CONSTANT].constant)
case icodes.arilogCat => genPrimitive(instr.asInstanceOf[CALL_PRIMITIVE].primitive, instr.pos)
case icodes.castsCat =>
def genCastInstr() = (instr: @unchecked) match {
case IS_INSTANCE(tpe) =>
val jtyp: asm.Type =
tpe match {
case REFERENCE(cls) => asm.Type.getObjectType(javaName(cls))
case ARRAY(elem) => javaArrayType(javaType(elem))
case _ => abort("Unknown reference type in IS_INSTANCE: " + tpe)
}
jmethod.visitTypeInsn(Opcodes.INSTANCEOF, jtyp.getInternalName)
case CHECK_CAST(tpe) =>
tpe match {
case REFERENCE(cls) =>
if (cls != ObjectClass) { // No need to checkcast for Objects
jmethod.visitTypeInsn(Opcodes.CHECKCAST, javaName(cls))
}
case ARRAY(elem) =>
val iname = javaArrayType(javaType(elem)).getInternalName
jmethod.visitTypeInsn(Opcodes.CHECKCAST, iname)
case _ => abort("Unknown reference type in IS_INSTANCE: " + tpe)
}
}
genCastInstr()
case icodes.objsCat =>
def genObjsInstr() = (instr: @unchecked) match {
case BOX(kind) =>
val MethodNameAndType(mname, mdesc) = jBoxTo(kind)
jcode.invokestatic(BoxesRunTime, mname, mdesc)
case UNBOX(kind) =>
val MethodNameAndType(mname, mdesc) = jUnboxTo(kind)
jcode.invokestatic(BoxesRunTime, mname, mdesc)
case NEW(REFERENCE(cls)) =>
val className = javaName(cls)
jmethod.visitTypeInsn(Opcodes.NEW, className)
case MONITOR_ENTER() => emit(Opcodes.MONITORENTER)
case MONITOR_EXIT() => emit(Opcodes.MONITOREXIT)
}
genObjsInstr()
case icodes.fldsCat =>
def genFldsInstr() = (instr: @unchecked) match {
case lf @ LOAD_FIELD(field, isStatic) =>
val owner = javaName(lf.hostClass)
debuglog("LOAD_FIELD with owner: " + owner + " flags: " + field.owner.flagString)
val fieldJName = javaName(field)
val fieldDescr = descriptor(field)
val opc = if (isStatic) Opcodes.GETSTATIC else Opcodes.GETFIELD
jmethod.visitFieldInsn(opc, owner, fieldJName, fieldDescr)
case STORE_FIELD(field, isStatic) =>
val owner = javaName(field.owner)
val fieldJName = javaName(field)
val fieldDescr = descriptor(field)
val opc = if (isStatic) Opcodes.PUTSTATIC else Opcodes.PUTFIELD
jmethod.visitFieldInsn(opc, owner, fieldJName, fieldDescr)
}
genFldsInstr()
case icodes.mthdsCat =>
def genMethodsInstr() = (instr: @unchecked) match {
/* Special handling to access native Array.clone() */
case call @ CALL_METHOD(definitions.Array_clone, Dynamic) =>
val target: String = javaType(call.targetTypeKind).getInternalName
jcode.invokevirtual(target, "clone", mdesc_arrayClone)
case call @ CALL_METHOD(method, style) => genCallMethod(call)
}
genMethodsInstr()
case icodes.arraysCat =>
def genArraysInstr() = (instr: @unchecked) match {
case LOAD_ARRAY_ITEM(kind) => jcode.aload(kind)
case STORE_ARRAY_ITEM(kind) => jcode.astore(kind)
case CREATE_ARRAY(elem, 1) => jcode newarray elem
case CREATE_ARRAY(elem, dims) => jmethod.visitMultiANewArrayInsn(descriptor(ArrayN(elem, dims)), dims)
}
genArraysInstr()
case icodes.jumpsCat =>
def genJumpInstr() = (instr: @unchecked) match {
case sw @ SWITCH(tagss, branches) =>
assert(branches.length == tagss.length + 1, sw)
val flatSize = sw.flatTagsCount
val flatKeys = new Array[Int](flatSize)
val flatBranches = new Array[asm.Label](flatSize)
var restTagss = tagss
var restBranches = branches
var k = 0 // ranges over flatKeys and flatBranches
while (restTagss.nonEmpty) {
val currLabel = labels(restBranches.head)
for (cTag <- restTagss.head) {
flatKeys(k) = cTag
flatBranches(k) = currLabel
k += 1
}
restTagss = restTagss.tail
restBranches = restBranches.tail
}
val defaultLabel = labels(restBranches.head)
assert(restBranches.tail.isEmpty)
debuglog("Emitting SWITCH:\ntags: " + tagss + "\nbranches: " + branches)
jcode.emitSWITCH(flatKeys, flatBranches, defaultLabel, MIN_SWITCH_DENSITY)
case JUMP(whereto) =>
if (nextBlock != whereto)
jcode goTo labels(whereto)
// SI-6102: Determine whether eliding this JUMP results in an empty range being covered by some EH.
// If so, emit a NOP in place of the elided JUMP, to avoid "java.lang.ClassFormatError: Illegal exception table range"
else if (newNormal.isJumpOnly(b) && m.exh.exists(eh => eh.covers(b))) {
debugwarn("Had a jump only block that wasn't collapsed")
emit(asm.Opcodes.NOP)
}
case CJUMP(success, failure, cond, kind) =>
if (kind.isIntSizedType) { // BOOL, BYTE, CHAR, SHORT, or INT
if (nextBlock == success) {
jcode.emitIF_ICMP(cond.negate(), labels(failure))
// .. and fall through to success label
} else {
jcode.emitIF_ICMP(cond, labels(success))
if (nextBlock != failure) { jcode goTo labels(failure) }
}
} else if (kind.isRefOrArrayType) { // REFERENCE(_) | ARRAY(_)
if (nextBlock == success) {
jcode.emitIF_ACMP(cond.negate(), labels(failure))
// .. and fall through to success label
} else {
jcode.emitIF_ACMP(cond, labels(success))
if (nextBlock != failure) { jcode goTo labels(failure) }
}
} else {
(kind: @unchecked) match {
case LONG => emit(Opcodes.LCMP)
case FLOAT =>
if (cond == LT || cond == LE) emit(Opcodes.FCMPG)
else emit(Opcodes.FCMPL)
case DOUBLE =>
if (cond == LT || cond == LE) emit(Opcodes.DCMPG)
else emit(Opcodes.DCMPL)
}
if (nextBlock == success) {
jcode.emitIF(cond.negate(), labels(failure))
// .. and fall through to success label
} else {
jcode.emitIF(cond, labels(success))
if (nextBlock != failure) { jcode goTo labels(failure) }
}
}
case CZJUMP(success, failure, cond, kind) =>
if (kind.isIntSizedType) { // BOOL, BYTE, CHAR, SHORT, or INT
if (nextBlock == success) {
jcode.emitIF(cond.negate(), labels(failure))
} else {
jcode.emitIF(cond, labels(success))
if (nextBlock != failure) { jcode goTo labels(failure) }
}
} else if (kind.isRefOrArrayType) { // REFERENCE(_) | ARRAY(_)
val Success = success
val Failure = failure
// @unchecked because references aren't compared with GT, GE, LT, LE.
((cond, nextBlock): @unchecked) match {
case (EQ, Success) => jcode emitIFNONNULL labels(failure)
case (NE, Failure) => jcode emitIFNONNULL labels(success)
case (EQ, Failure) => jcode emitIFNULL labels(success)
case (NE, Success) => jcode emitIFNULL labels(failure)
case (EQ, _) =>
jcode emitIFNULL labels(success)
jcode goTo labels(failure)
case (NE, _) =>
jcode emitIFNONNULL labels(success)
jcode goTo labels(failure)
}
} else {
(kind: @unchecked) match {
case LONG =>
emit(Opcodes.LCONST_0)
emit(Opcodes.LCMP)
case FLOAT =>
emit(Opcodes.FCONST_0)
if (cond == LT || cond == LE) emit(Opcodes.FCMPG)
else emit(Opcodes.FCMPL)
case DOUBLE =>
emit(Opcodes.DCONST_0)
if (cond == LT || cond == LE) emit(Opcodes.DCMPG)
else emit(Opcodes.DCMPL)
}
if (nextBlock == success) {
jcode.emitIF(cond.negate(), labels(failure))
} else {
jcode.emitIF(cond, labels(success))
if (nextBlock != failure) { jcode goTo labels(failure) }
}
}
}
genJumpInstr()
case icodes.retCat =>
def genRetInstr() = (instr: @unchecked) match {
case RETURN(kind) => jcode emitRETURN kind
case THROW(_) => emit(Opcodes.ATHROW)
}
genRetInstr()
}
}
/*
* Emits one or more conversion instructions based on the types given as arguments.
*
* @param from The type of the value to be converted into another type.
* @param to The type the value will be converted into.
*/
def emitT2T(from: TypeKind, to: TypeKind) {
assert(isNonUnitValueTK(from) && isNonUnitValueTK(to), s"Cannot emit primitive conversion from $from to $to")
def pickOne(opcs: Array[Int]) {
val chosen = (to: @unchecked) match {
case BYTE => opcs(0)
case SHORT => opcs(1)
case CHAR => opcs(2)
case INT => opcs(3)
case LONG => opcs(4)
case FLOAT => opcs(5)
case DOUBLE => opcs(6)
}
if(chosen != -1) { emit(chosen) }
}
if(from == to) { return }
// the only conversion involving BOOL that is allowed is (BOOL -> BOOL)
assert(from != BOOL && to != BOOL, s"inconvertible types : $from -> $to")
if(from.isIntSizedType) { // BYTE, CHAR, SHORT, and INT. (we're done with BOOL already)
val fromByte = { import asm.Opcodes._; Array( -1, -1, I2C, -1, I2L, I2F, I2D) } // do nothing for (BYTE -> SHORT) and for (BYTE -> INT)
val fromChar = { import asm.Opcodes._; Array(I2B, I2S, -1, -1, I2L, I2F, I2D) } // for (CHAR -> INT) do nothing
val fromShort = { import asm.Opcodes._; Array(I2B, -1, I2C, -1, I2L, I2F, I2D) } // for (SHORT -> INT) do nothing
val fromInt = { import asm.Opcodes._; Array(I2B, I2S, I2C, -1, I2L, I2F, I2D) }
(from: @unchecked) match {
case BYTE => pickOne(fromByte)
case SHORT => pickOne(fromShort)
case CHAR => pickOne(fromChar)
case INT => pickOne(fromInt)
}
} else { // FLOAT, LONG, DOUBLE
(from: @unchecked) match {
case FLOAT =>
import asm.Opcodes.{ F2L, F2D, F2I }
(to: @unchecked) match {
case LONG => emit(F2L)
case DOUBLE => emit(F2D)
case _ => emit(F2I); emitT2T(INT, to)
}
case LONG =>
import asm.Opcodes.{ L2F, L2D, L2I }
(to: @unchecked) match {
case FLOAT => emit(L2F)
case DOUBLE => emit(L2D)
case _ => emit(L2I); emitT2T(INT, to)
}
case DOUBLE =>
import asm.Opcodes.{ D2L, D2F, D2I }
(to: @unchecked) match {
case FLOAT => emit(D2F)
case LONG => emit(D2L)
case _ => emit(D2I); emitT2T(INT, to)
}
}
}
} // end of genCode()'s emitT2T()
def genPrimitive(primitive: Primitive, pos: Position) {
import asm.Opcodes
primitive match {
case Negation(kind) => jcode.neg(kind)
case Arithmetic(op, kind) =>
def genArith() = {
op match {
case ADD => jcode.add(kind)
case SUB => jcode.sub(kind)
case MUL => jcode.mul(kind)
case DIV => jcode.div(kind)
case REM => jcode.rem(kind)
case NOT =>
if(kind.isIntSizedType) {
emit(Opcodes.ICONST_M1)
emit(Opcodes.IXOR)
} else if(kind == LONG) {
jmethod.visitLdcInsn(new java.lang.Long(-1))
jmethod.visitInsn(Opcodes.LXOR)
} else {
abort("Impossible to negate an " + kind)
}
case _ =>
abort("Unknown arithmetic primitive " + primitive)
}
}
genArith()
// TODO Logical's 2nd elem should be declared ValueTypeKind, to better approximate its allowed values (isIntSized, its comments appears to convey)
// TODO GenICode uses `toTypeKind` to define that elem, `toValueTypeKind` would be needed instead.
// TODO How about adding some asserts to Logical and similar ones to capture the remaining constraint (UNIT not allowed).
case Logical(op, kind) =>
def genLogical() = op match {
case AND =>
kind match {
case LONG => emit(Opcodes.LAND)
case INT => emit(Opcodes.IAND)
case _ =>
emit(Opcodes.IAND)
if (kind != BOOL) { emitT2T(INT, kind) }
}
case OR =>
kind match {
case LONG => emit(Opcodes.LOR)
case INT => emit(Opcodes.IOR)
case _ =>
emit(Opcodes.IOR)
if (kind != BOOL) { emitT2T(INT, kind) }
}
case XOR =>
kind match {
case LONG => emit(Opcodes.LXOR)
case INT => emit(Opcodes.IXOR)
case _ =>
emit(Opcodes.IXOR)
if (kind != BOOL) { emitT2T(INT, kind) }
}
}
genLogical()
case Shift(op, kind) =>
def genShift() = op match {
case LSL =>
kind match {
case LONG => emit(Opcodes.LSHL)
case INT => emit(Opcodes.ISHL)
case _ =>
emit(Opcodes.ISHL)
emitT2T(INT, kind)
}
case ASR =>
kind match {
case LONG => emit(Opcodes.LSHR)
case INT => emit(Opcodes.ISHR)
case _ =>
emit(Opcodes.ISHR)
emitT2T(INT, kind)
}
case LSR =>
kind match {
case LONG => emit(Opcodes.LUSHR)
case INT => emit(Opcodes.IUSHR)
case _ =>
emit(Opcodes.IUSHR)
emitT2T(INT, kind)
}
}
genShift()
case Comparison(op, kind) =>
def genCompare() = op match {
case CMP =>
(kind: @unchecked) match {
case LONG => emit(Opcodes.LCMP)
}
case CMPL =>
(kind: @unchecked) match {
case FLOAT => emit(Opcodes.FCMPL)
case DOUBLE => emit(Opcodes.DCMPL)
}
case CMPG =>
(kind: @unchecked) match {
case FLOAT => emit(Opcodes.FCMPG)
case DOUBLE => emit(Opcodes.DCMPL) // TODO bug? why not DCMPG? http://docs.oracle.com/javase/specs/jvms/se5.0/html/Instructions2.doc3.html
}
}
genCompare()
case Conversion(src, dst) =>
debuglog("Converting from: " + src + " to: " + dst)
emitT2T(src, dst)
case ArrayLength(_) => emit(Opcodes.ARRAYLENGTH)
case StartConcat =>
jmethod.visitTypeInsn(Opcodes.NEW, StringBuilderClassName)
jmethod.visitInsn(Opcodes.DUP)
jcode.invokespecial(
StringBuilderClassName,
INSTANCE_CONSTRUCTOR_NAME,
mdesc_arglessvoid
)
case StringConcat(el) =>
val jtype = el match {
case REFERENCE(_) | ARRAY(_) => JAVA_LANG_OBJECT
case _ => javaType(el)
}
jcode.invokevirtual(
StringBuilderClassName,
"append",
asm.Type.getMethodDescriptor(StringBuilderType, Array(jtype): _*)
)
case EndConcat =>
jcode.invokevirtual(StringBuilderClassName, "toString", mdesc_toString)
case _ => abort("Unimplemented primitive " + primitive)
}
} // end of genCode()'s genPrimitive()
// ------------------------------------------------------------------------------------------------------------
// Part 6 of genCode(): the executable part of genCode() starts here.
// ------------------------------------------------------------------------------------------------------------
genBlocks(linearization)
jmethod.visitLabel(onePastLast)
if(emitLines) {
for(LineNumberEntry(line, start) <- lnEntries.sortBy(_.start.getOffset)) { jmethod.visitLineNumber(line, start) }
}
if(emitVars) { genLocalVariableTable() }
} // end of BytecodeGenerator.genCode()
////////////////////// local vars ///////////////////////
def sizeOf(k: TypeKind): Int = if(k.isWideType) 2 else 1
final def indexOf(local: Local): Int = {
assert(local.index >= 0, "Invalid index for: " + local + "{" + local.## + "}: ")
local.index
}
/**
* Compute the indexes of each local variable of the given method.
* *Does not assume the parameters come first!*
*/
def computeLocalVarsIndex(m: IMethod) {
var idx = if (m.symbol.isStaticMember) 0 else 1
for (l <- m.params) {
debuglog("Index value for " + l + "{" + l.## + "}: " + idx)
l.index = idx
idx += sizeOf(l.kind)
}
for (l <- m.locals if !l.arg) {
debuglog("Index value for " + l + "{" + l.## + "}: " + idx)
l.index = idx
idx += sizeOf(l.kind)
}
}
} // end of class JPlainBuilder
/** builder of mirror classes */
class JMirrorBuilder(bytecodeWriter: BytecodeWriter, needsOutfile: Boolean) extends JCommonBuilder(bytecodeWriter, needsOutfile) {
private var cunit: CompilationUnit = _
def getCurrentCUnit(): CompilationUnit = cunit
/** Generate a mirror class for a top-level module. A mirror class is a class
* containing only static methods that forward to the corresponding method
* on the MODULE instance of the given Scala object. It will only be
* generated if there is no companion class: if there is, an attempt will
* instead be made to add the forwarder methods to the companion class.
*/
def genMirrorClass(modsym: Symbol, cunit: CompilationUnit) {
assert(modsym.companionClass == NoSymbol, modsym)
innerClassBuffer.clear()
this.cunit = cunit
val moduleName = javaName(modsym) // + "$"
val mirrorName = moduleName.substring(0, moduleName.length() - 1)
val flags = (asm.Opcodes.ACC_SUPER | asm.Opcodes.ACC_PUBLIC | asm.Opcodes.ACC_FINAL)
val mirrorClass = createJClass(flags,
mirrorName,
null /* no java-generic-signature */,
JAVA_LANG_OBJECT.getInternalName,
EMPTY_STRING_ARRAY)
log(s"Dumping mirror class for '$mirrorName'")
// typestate: entering mode with valid call sequences:
// [ visitSource ] [ visitOuterClass ] ( visitAnnotation | visitAttribute )*
if(emitSource) {
mirrorClass.visitSource("" + cunit.source,
null /* SourceDebugExtension */)
}
val ssa = getAnnotPickle(mirrorName, modsym.companionSymbol)
mirrorClass.visitAttribute(if(ssa.isDefined) pickleMarkerLocal else pickleMarkerForeign)
emitAnnotations(mirrorClass, modsym.annotations ++ ssa)
// typestate: entering mode with valid call sequences:
// ( visitInnerClass | visitField | visitMethod )* visitEnd
addForwarders(isRemote(modsym), mirrorClass, mirrorName, modsym)
addInnerClasses(modsym, mirrorClass)
mirrorClass.visitEnd()
writeIfNotTooBig("" + modsym.name, mirrorName, mirrorClass, modsym)
}
} // end of class JMirrorBuilder
/** builder of bean info classes */
class JBeanInfoBuilder(bytecodeWriter: BytecodeWriter, needsOutfile: Boolean) extends JBuilder(bytecodeWriter, needsOutfile) {
/**
* Generate a bean info class that describes the given class.
*
* @author Ross Judson (ross.judson@soletta.com)
*/
def genBeanInfoClass(clasz: IClass) {
// val BeanInfoSkipAttr = definitions.getRequiredClass("scala.beans.BeanInfoSkip")
// val BeanDisplayNameAttr = definitions.getRequiredClass("scala.beans.BeanDisplayName")
// val BeanDescriptionAttr = definitions.getRequiredClass("scala.beans.BeanDescription")
// val description = c.symbol getAnnotation BeanDescriptionAttr
// informProgress(description.toString)
innerClassBuffer.clear()
val flags = mkFlags(
javaFlags(clasz.symbol),
if(isDeprecated(clasz.symbol)) asm.Opcodes.ACC_DEPRECATED else 0 // ASM pseudo access flag
)
val beanInfoName = (javaName(clasz.symbol) + "BeanInfo")
val beanInfoClass = createJClass(
flags,
beanInfoName,
null, // no java-generic-signature
"scala/beans/ScalaBeanInfo",
EMPTY_STRING_ARRAY
)
// beanInfoClass typestate: entering mode with valid call sequences:
// [ visitSource ] [ visitOuterClass ] ( visitAnnotation | visitAttribute )*
beanInfoClass.visitSource(
clasz.cunit.source.toString,
null /* SourceDebugExtension */
)
var fieldList = List[String]()
for (f <- clasz.fields if f.symbol.hasGetter;
g = f.symbol.getter(clasz.symbol);
s = f.symbol.setter(clasz.symbol)
if g.isPublic && !(f.symbol.name startsWith "$")
) {
// inserting $outer breaks the bean
fieldList = javaName(f.symbol) :: javaName(g) :: (if (s != NoSymbol) javaName(s) else null) :: fieldList
}
val methodList: List[String] =
for (m <- clasz.methods
if !m.symbol.isConstructor &&
m.symbol.isPublic &&
!(m.symbol.name startsWith "$") &&
!m.symbol.isGetter &&
!m.symbol.isSetter)
yield javaName(m.symbol)
// beanInfoClass typestate: entering mode with valid call sequences:
// ( visitInnerClass | visitField | visitMethod )* visitEnd
val constructor = beanInfoClass.visitMethod(
asm.Opcodes.ACC_PUBLIC,
INSTANCE_CONSTRUCTOR_NAME,
mdesc_arglessvoid,
null, // no java-generic-signature
EMPTY_STRING_ARRAY // no throwable exceptions
)
// constructor typestate: entering mode with valid call sequences:
// [ visitAnnotationDefault ] ( visitAnnotation | visitParameterAnnotation | visitAttribute )*
val stringArrayJType: asm.Type = javaArrayType(JAVA_LANG_STRING)
val conJType: asm.Type =
asm.Type.getMethodType(
asm.Type.VOID_TYPE,
Array(javaType(ClassClass), stringArrayJType, stringArrayJType): _*
)
def push(lst: List[String]) {
var fi = 0
for (f <- lst) {
constructor.visitInsn(asm.Opcodes.DUP)
constructor.visitLdcInsn(new java.lang.Integer(fi))
if (f == null) { constructor.visitInsn(asm.Opcodes.ACONST_NULL) }
else { constructor.visitLdcInsn(f) }
constructor.visitInsn(JAVA_LANG_STRING.getOpcode(asm.Opcodes.IASTORE))
fi += 1
}
}
// constructor typestate: entering mode with valid call sequences:
// [ visitCode ( visitFrame | visitXInsn | visitLabel | visitTryCatchBlock | visitLocalVariable | visitLineNumber )* visitMaxs ] visitEnd
constructor.visitCode()
constructor.visitVarInsn(asm.Opcodes.ALOAD, 0)
// push the class
constructor.visitLdcInsn(javaType(clasz.symbol))
// push the string array of field information
constructor.visitLdcInsn(new java.lang.Integer(fieldList.length))
constructor.visitTypeInsn(asm.Opcodes.ANEWARRAY, JAVA_LANG_STRING.getInternalName)
push(fieldList)
// push the string array of method information
constructor.visitLdcInsn(new java.lang.Integer(methodList.length))
constructor.visitTypeInsn(asm.Opcodes.ANEWARRAY, JAVA_LANG_STRING.getInternalName)
push(methodList)
// invoke the superclass constructor, which will do the
// necessary java reflection and create Method objects.
constructor.visitMethodInsn(asm.Opcodes.INVOKESPECIAL, "scala/beans/ScalaBeanInfo", INSTANCE_CONSTRUCTOR_NAME, conJType.getDescriptor)
constructor.visitInsn(asm.Opcodes.RETURN)
constructor.visitMaxs(0, 0) // just to follow protocol, dummy arguments
constructor.visitEnd()
addInnerClasses(clasz.symbol, beanInfoClass)
beanInfoClass.visitEnd()
writeIfNotTooBig("BeanInfo ", beanInfoName, beanInfoClass, clasz.symbol)
}
} // end of class JBeanInfoBuilder
/** A namespace for utilities to normalize the code of an IMethod, over and beyond what IMethod.normalize() strives for.
* In particualr, IMethod.normalize() doesn't collapseJumpChains().
*
* TODO Eventually, these utilities should be moved to IMethod and reused from normalize() (there's nothing JVM-specific about them).
*/
object newNormal {
/**
* True if a block is "jump only" which is defined
* as being a block that consists only of 0 or more instructions that
* won't make it to the JVM followed by a JUMP.
*/
def isJumpOnly(b: BasicBlock): Boolean = {
val nonICode = firstNonIcodeOnlyInstructions(b)
// by definition a block has to have a jump, conditional jump, return, or throw
assert(nonICode.hasNext, "empty block")
nonICode.next.isInstanceOf[JUMP]
}
/**
* Returns the list of instructions in a block that follow all ICode only instructions,
* where an ICode only instruction is one that won't make it to the JVM
*/
private def firstNonIcodeOnlyInstructions(b: BasicBlock): Iterator[Instruction] = {
def isICodeOnlyInstruction(i: Instruction) = i match {
case LOAD_EXCEPTION(_) | SCOPE_ENTER(_) | SCOPE_EXIT(_) => true
case _ => false
}
b.iterator dropWhile isICodeOnlyInstruction
}
/**
* Returns the target of a block that is "jump only" which is defined
* as being a block that consists only of 0 or more instructions that
* won't make it to the JVM followed by a JUMP.
*
* @param b The basic block to examine
* @return Some(target) if b is a "jump only" block or None if it's not
*/
private def getJumpOnlyTarget(b: BasicBlock): Option[BasicBlock] = {
val nonICode = firstNonIcodeOnlyInstructions(b)
// by definition a block has to have a jump, conditional jump, return, or throw
assert(nonICode.nonEmpty, "empty block")
nonICode.next match {
case JUMP(whereto) =>
assert(!nonICode.hasNext, "A block contains instructions after JUMP (looks like enterIgnoreMode() was itself ignored.)")
Some(whereto)
case _ => None
}
}
/**
* Collapse a chain of "jump-only" blocks such as:
*
* JUMP b1;
* b1: JUMP b2;
* b2: JUMP ... etc.
*
* by re-wiring predecessors to target directly the "final destination".
* Even if covered by an exception handler, a "non-self-loop jump-only block" can always be removed.
* Returns true if any replacement was made, false otherwise.
*
* In more detail:
* Starting at each of the entry points (m.startBlock, the start block of each exception handler)
* rephrase those control-flow instructions targeting a jump-only block (which jumps to a final destination D) to target D.
* The blocks thus skipped become eligible to removed by the reachability analyzer
*
* Rationale for this normalization:
* test/files/run/private-inline.scala after -optimize is chock full of
* BasicBlocks containing just JUMP(whereTo), where no exception handler straddles them.
* They should be collapsed by IMethod.normalize() but aren't.
* That was fine in FJBG times when by the time the exception table was emitted,
* it already contained "anchored" labels (ie instruction offsets were known)
* and thus ranges with identical (start, end) (i.e, identical after GenJVM omitted the JUMPs in question)
* could be weeded out to avoid "java.lang.ClassFormatError: Illegal exception table range"
* Now that visitTryCatchBlock() must be called before Labels are resolved,
* renders the BasicBlocks described above (to recap, consisting of just a JUMP) unreachable.
*/
private def collapseJumpOnlyBlocks(m: IMethod) {
assert(m.hasCode, "code-less method")
def rephraseGotos(detour: mutable.Map[BasicBlock, BasicBlock]) {
def lookup(b: BasicBlock) = detour.getOrElse(b, b)
m.code.startBlock = lookup(m.code.startBlock)
for(eh <- m.exh)
eh.setStartBlock(lookup(eh.startBlock))
for (b <- m.blocks) {
def replaceLastInstruction(i: Instruction) = {
if (b.lastInstruction != i) {
val idxLast = b.size - 1
debuglog(s"In block $b, replacing last instruction ${b.lastInstruction} with ${i}")
b.replaceInstruction(idxLast, i)
}
}
b.lastInstruction match {
case JUMP(whereto) =>
replaceLastInstruction(JUMP(lookup(whereto)))
case CJUMP(succ, fail, cond, kind) =>
replaceLastInstruction(CJUMP(lookup(succ), lookup(fail), cond, kind))
case CZJUMP(succ, fail, cond, kind) =>
replaceLastInstruction(CZJUMP(lookup(succ), lookup(fail), cond, kind))
case SWITCH(tags, labels) =>
val newLabels = (labels map lookup)
replaceLastInstruction(SWITCH(tags, newLabels))
case _ => ()
}
}
}
/*
* Computes a mapping from jump only block to its
* final destination which is either a non-jump-only
* block or, if it's in a jump-only block cycle, is
* itself
*/
def computeDetour: mutable.Map[BasicBlock, BasicBlock] = {
// fetch the jump only blocks and their immediate destinations
val pairs = for {
block <- m.blocks.toIterator
target <- getJumpOnlyTarget(block)
} yield(block, target)
// mapping from a jump-only block to our current knowledge of its
// final destination. Initially it's just jump block to immediate jump
// target
val detour = mutable.Map[BasicBlock, BasicBlock](pairs.toSeq:_*)
// for each jump-only block find its final destination
// taking advantage of the destinations we found for previous
// blocks
for (key <- detour.keySet) {
// we use the Robert Floyd's classic Tortoise and Hare algorithm
@tailrec
def findDestination(tortoise: BasicBlock, hare: BasicBlock): BasicBlock = {
if (tortoise == hare)
// cycle detected, map key to key
key
else if (detour contains hare) {
// advance hare once
val hare1 = detour(hare)
// make sure we can advance hare a second time
if (detour contains hare1)
// advance tortoise once and hare a second time
findDestination(detour(tortoise), detour(hare1))
else
// hare1 is not in the map so it's not a jump-only block, it's the destination
hare1
} else
// hare is not in the map so it's not a jump-only block, it's the destination
hare
}
// update the mapping for key based on its final destination
detour(key) = findDestination(key, detour(key))
}
detour
}
val detour = computeDetour
rephraseGotos(detour)
if (settings.debug) {
val (remappings, cycles) = detour partition {case (source, target) => source != target}
for ((source, target) <- remappings) {
debuglog(s"Will elide jump only block $source because it can be jumped around to get to $target.")
if (m.startBlock == source) debugwarn("startBlock should have been re-wired by now")
}
val sources = remappings.keySet
val targets = remappings.values.toSet
val intersection = sources intersect targets
if (intersection.nonEmpty) debugwarn(s"contradiction: we seem to have some source and target overlap in blocks ${intersection.mkString}. Map was ${detour.mkString}")
for ((source, _) <- cycles) {
debuglog(s"Block $source is in a do-nothing infinite loop. Did the user write 'while(true){}'?")
}
}
}
/**
* Removes all blocks that are unreachable in a method using a standard reachability analysis.
*/
def elimUnreachableBlocks(m: IMethod) {
assert(m.hasCode, "code-less method")
// assume nothing is reachable until we prove it can be reached
val reachable = mutable.Set[BasicBlock]()
// the set of blocks that we know are reachable but have
// yet to be marked reachable, initially only the start block
val worklist = mutable.Set(m.startBlock)
while (worklist.nonEmpty) {
val block = worklist.head
worklist remove block
// we know that one is reachable
reachable add block
// so are its successors, so go back around and add the ones we still
// think are unreachable
worklist ++= (block.successors filterNot reachable)
}
// exception handlers need to be told not to cover unreachable blocks
// and exception handlers that no longer cover any blocks need to be
// removed entirely
val unusedExceptionHandlers = mutable.Set[ExceptionHandler]()
for (exh <- m.exh) {
exh.covered = exh.covered filter reachable
if (exh.covered.isEmpty) {
unusedExceptionHandlers += exh
}
}
// remove the unusued exception handler references
if (settings.debug)
for (exh <- unusedExceptionHandlers) debuglog(s"eliding exception handler $exh because it does not cover any reachable blocks")
m.exh = m.exh filterNot unusedExceptionHandlers
// everything not in the reachable set is unreachable, unused, and unloved. buh bye
for (b <- m.blocks filterNot reachable) {
debuglog(s"eliding block $b because it is unreachable")
m.code removeBlock b
}
}
def normalize(m: IMethod) {
if(!m.hasCode) { return }
collapseJumpOnlyBlocks(m)
if (settings.optimise)
elimUnreachableBlocks(m)
icodes checkValid m
}
}
// @M don't generate java generics sigs for (members of) implementation
// classes, as they are monomorphic (TODO: ok?)
private def needsGenericSignature(sym: Symbol) = !(
// PP: This condition used to include sym.hasExpandedName, but this leads
// to the total loss of generic information if a private member is
// accessed from a closure: both the field and the accessor were generated
// without it. This is particularly bad because the availability of
// generic information could disappear as a consequence of a seemingly
// unrelated change.
settings.Ynogenericsig
|| sym.isArtifact
|| sym.isLiftedMethod
|| sym.isBridge
|| (sym.ownerChain exists (_.isImplClass))
)
final def staticForwarderGenericSignature(sym: Symbol, moduleClass: Symbol, unit: CompilationUnit): String = {
if (sym.isDeferred) null // only add generic signature if method concrete; bug #1745
else {
// SI-3452 Static forwarder generation uses the same erased signature as the method if forwards to.
// By rights, it should use the signature as-seen-from the module class, and add suitable
// primitive and value-class boxing/unboxing.
// But for now, just like we did in mixin, we just avoid writing a wrong generic signature
// (one that doesn't erase to the actual signature). See run/t3452b for a test case.
val memberTpe = enteringErasure(moduleClass.thisType.memberInfo(sym))
val erasedMemberType = erasure.erasure(sym)(memberTpe)
if (erasedMemberType =:= sym.info)
getGenericSignature(sym, moduleClass, memberTpe, unit)
else null
}
}
/** @return
* - `null` if no Java signature is to be added (`null` is what ASM expects in these cases).
* - otherwise the signature in question
*/
def getGenericSignature(sym: Symbol, owner: Symbol, unit: CompilationUnit): String = {
val memberTpe = enteringErasure(owner.thisType.memberInfo(sym))
getGenericSignature(sym, owner, memberTpe, unit)
}
def getGenericSignature(sym: Symbol, owner: Symbol, memberTpe: Type, unit: CompilationUnit): String = {
if (!needsGenericSignature(sym)) { return null }
val jsOpt: Option[String] = erasure.javaSig(sym, memberTpe)
if (jsOpt.isEmpty) { return null }
val sig = jsOpt.get
log(sig) // This seems useful enough in the general case.
def wrap(op: => Unit) = {
try { op; true }
catch { case _: Throwable => false }
}
if (settings.Xverify) {
// Run the signature parser to catch bogus signatures.
val isValidSignature = wrap {
// Alternative: scala.tools.reflect.SigParser (frontend to sun.reflect.generics.parser.SignatureParser)
import scala.tools.asm.util.CheckClassAdapter
if (sym.isMethod) { CheckClassAdapter checkMethodSignature sig } // requires asm-util.jar
else if (sym.isTerm) { CheckClassAdapter checkFieldSignature sig }
else { CheckClassAdapter checkClassSignature sig }
}
if(!isValidSignature) {
unit.warning(sym.pos,
"""|compiler bug: created invalid generic signature for %s in %s
|signature: %s
|if this is reproducible, please report bug at https://issues.scala-lang.org/
""".trim.stripMargin.format(sym, sym.owner.skipPackageObject.fullName, sig))
return null
}
}
if ((settings.check containsName phaseName)) {
val normalizedTpe = enteringErasure(erasure.prepareSigMap(memberTpe))
val bytecodeTpe = owner.thisType.memberInfo(sym)
if (!sym.isType && !sym.isConstructor && !(erasure.erasure(sym)(normalizedTpe) =:= bytecodeTpe)) {
unit.warning(sym.pos,
"""|compiler bug: created generic signature for %s in %s that does not conform to its erasure
|signature: %s
|original type: %s
|normalized type: %s
|erasure type: %s
|if this is reproducible, please report bug at http://issues.scala-lang.org/
""".trim.stripMargin.format(sym, sym.owner.skipPackageObject.fullName, sig, memberTpe, normalizedTpe, bytecodeTpe))
return null
}
}
sig
}
def ubytesToCharArray(bytes: Array[Byte]): Array[Char] = {
val ca = new Array[Char](bytes.length)
var idx = 0
while(idx < bytes.length) {
val b: Byte = bytes(idx)
assert((b & ~0x7f) == 0)
ca(idx) = b.asInstanceOf[Char]
idx += 1
}
ca
}
final def arrEncode(sb: ScalaSigBytes): Array[String] = {
var strs: List[String] = Nil
val bSeven: Array[Byte] = sb.sevenBitsMayBeZero
// chop into slices of at most 65535 bytes, counting 0x00 as taking two bytes (as per JVMS 4.4.7 The CONSTANT_Utf8_info Structure)
var prevOffset = 0
var offset = 0
var encLength = 0
while(offset < bSeven.length) {
val deltaEncLength = (if(bSeven(offset) == 0) 2 else 1)
val newEncLength = encLength.toLong + deltaEncLength
if(newEncLength >= 65535) {
val ba = bSeven.slice(prevOffset, offset)
strs ::= new java.lang.String(ubytesToCharArray(ba))
encLength = 0
prevOffset = offset
} else {
encLength += deltaEncLength
offset += 1
}
}
if(prevOffset < offset) {
assert(offset == bSeven.length)
val ba = bSeven.slice(prevOffset, offset)
strs ::= new java.lang.String(ubytesToCharArray(ba))
}
assert(strs.size > 1, "encode instead as one String via strEncode()") // TODO too strict?
strs.reverse.toArray
}
private def strEncode(sb: ScalaSigBytes): String = {
val ca = ubytesToCharArray(sb.sevenBitsMayBeZero)
new java.lang.String(ca)
// debug val bvA = new asm.ByteVector; bvA.putUTF8(s)
// debug val enc: Array[Byte] = scala.reflect.internal.pickling.ByteCodecs.encode(bytes)
// debug assert(enc(idx) == bvA.getByte(idx + 2))
// debug assert(bvA.getLength == enc.size + 2)
}
}
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