diff options
Diffstat (limited to 'src/compiler/scala/tools/nsc/backend/icode/GenICode.scala')
-rw-r--r-- | src/compiler/scala/tools/nsc/backend/icode/GenICode.scala | 2239 |
1 files changed, 0 insertions, 2239 deletions
diff --git a/src/compiler/scala/tools/nsc/backend/icode/GenICode.scala b/src/compiler/scala/tools/nsc/backend/icode/GenICode.scala deleted file mode 100644 index b6f9bcc9ab..0000000000 --- a/src/compiler/scala/tools/nsc/backend/icode/GenICode.scala +++ /dev/null @@ -1,2239 +0,0 @@ -/* NSC -- new Scala compiler - * Copyright 2005-2013 LAMP/EPFL - * @author Martin Odersky - */ - - -package scala -package tools.nsc -package backend -package icode - -import scala.collection.{ mutable, immutable } -import scala.collection.mutable.{ ListBuffer, Buffer } -import scala.tools.nsc.symtab._ -import scala.annotation.switch - -/** - * @author Iulian Dragos - * @version 1.0 - */ -abstract class GenICode extends SubComponent { - import global._ - import icodes._ - import icodes.opcodes._ - import definitions._ - import scalaPrimitives.{ - isArrayOp, isComparisonOp, isLogicalOp, - isUniversalEqualityOp, isReferenceEqualityOp - } - import platform.isMaybeBoxed - - private val bCodeICodeCommon: jvm.BCodeICodeCommon[global.type] = new jvm.BCodeICodeCommon(global) - import bCodeICodeCommon._ - - val phaseName = "icode" - - override def newPhase(prev: Phase) = new ICodePhase(prev) - - @inline private def debugassert(cond: => Boolean, msg: => Any) { - if (settings.debug) - assert(cond, msg) - } - - class ICodePhase(prev: Phase) extends StdPhase(prev) { - - override def description = "Generate ICode from the AST" - - var unit: CompilationUnit = NoCompilationUnit - - override def run() { - if (!settings.isBCodeActive) { - scalaPrimitives.init() - classes.clear() - } - super.run() - } - - override def apply(unit: CompilationUnit): Unit = { - if (settings.isBCodeActive) { return } - this.unit = unit - unit.icode.clear() - informProgress("Generating icode for " + unit) - gen(unit.body) - this.unit = NoCompilationUnit - } - - def gen(tree: Tree): Context = gen(tree, new Context()) - - def gen(trees: List[Tree], ctx: Context): Context = { - var ctx1 = ctx - for (t <- trees) ctx1 = gen(t, ctx1) - ctx1 - } - - /** If the selector type has a member with the right name, - * it is the host class; otherwise the symbol's owner. - */ - def findHostClass(selector: Type, sym: Symbol) = selector member sym.name match { - case NoSymbol => debuglog(s"Rejecting $selector as host class for $sym") ; sym.owner - case _ => selector.typeSymbol - } - - /////////////////// Code generation /////////////////////// - - def gen(tree: Tree, ctx: Context): Context = tree match { - case EmptyTree => ctx - - case PackageDef(pid, stats) => - gen(stats, ctx setPackage pid.name) - - case ClassDef(mods, name, _, impl) => - debuglog("Generating class: " + tree.symbol.fullName) - val outerClass = ctx.clazz - ctx setClass (new IClass(tree.symbol) setCompilationUnit unit) - addClassFields(ctx, tree.symbol) - classes += (tree.symbol -> ctx.clazz) - unit.icode += ctx.clazz - gen(impl, ctx) - ctx.clazz.methods = ctx.clazz.methods.reverse // preserve textual order - ctx.clazz.fields = ctx.clazz.fields.reverse // preserve textual order - ctx setClass outerClass - - // !! modules should be eliminated by refcheck... or not? - case ModuleDef(mods, name, impl) => - abort("Modules should not reach backend! " + tree) - - case ValDef(mods, name, tpt, rhs) => - ctx // we use the symbol to add fields - - case DefDef(mods, name, tparams, vparamss, tpt, rhs) => - debuglog("Entering method " + name) - val m = new IMethod(tree.symbol) - m.sourceFile = unit.source - m.returnType = if (tree.symbol.isConstructor) UNIT - else toTypeKind(tree.symbol.info.resultType) - ctx.clazz.addMethod(m) - - var ctx1 = ctx.enterMethod(m, tree.asInstanceOf[DefDef]) - addMethodParams(ctx1, vparamss) - m.native = m.symbol.hasAnnotation(definitions.NativeAttr) - - if (!m.isAbstractMethod && !m.native) { - ctx1 = genLoad(rhs, ctx1, m.returnType) - - // reverse the order of the local variables, to match the source-order - m.locals = m.locals.reverse - - rhs match { - case Block(_, Return(_)) => () - case Return(_) => () - case EmptyTree => - globalError("Concrete method has no definition: " + tree + ( - if (settings.debug) "(found: " + m.symbol.owner.info.decls.toList.mkString(", ") + ")" - else "") - ) - case _ => if (ctx1.bb.isEmpty) - ctx1.bb.closeWith(RETURN(m.returnType), rhs.pos) - else - ctx1.bb.closeWith(RETURN(m.returnType)) - } - if (!ctx1.bb.closed) ctx1.bb.close() - prune(ctx1.method) - } else - ctx1.method.setCode(NoCode) - ctx1 - - case Template(_, _, body) => - gen(body, ctx) - - case _ => - abort("Illegal tree in gen: " + tree) - } - - private def genStat(trees: List[Tree], ctx: Context): Context = - trees.foldLeft(ctx)((currentCtx, t) => genStat(t, currentCtx)) - - /** - * Generate code for the given tree. The trees should contain statements - * and not produce any value. Use genLoad for expressions which leave - * a value on top of the stack. - * - * @return a new context. This is necessary for control flow instructions - * which may change the current basic block. - */ - private def genStat(tree: Tree, ctx: Context): Context = tree match { - case Assign(lhs @ Select(_, _), rhs) => - val isStatic = lhs.symbol.isStaticMember - var ctx1 = if (isStatic) ctx else genLoadQualifier(lhs, ctx) - - ctx1 = genLoad(rhs, ctx1, toTypeKind(lhs.symbol.info)) - ctx1.bb.emit(STORE_FIELD(lhs.symbol, isStatic), tree.pos) - ctx1 - - case Assign(lhs, rhs) => - val ctx1 = genLoad(rhs, ctx, toTypeKind(lhs.symbol.info)) - val Some(l) = ctx.method.lookupLocal(lhs.symbol) - ctx1.bb.emit(STORE_LOCAL(l), tree.pos) - ctx1 - - case _ => - genLoad(tree, ctx, UNIT) - } - - private def genThrow(expr: Tree, ctx: Context): (Context, TypeKind) = { - require(expr.tpe <:< ThrowableTpe, expr.tpe) - - val thrownKind = toTypeKind(expr.tpe) - val ctx1 = genLoad(expr, ctx, thrownKind) - ctx1.bb.emit(THROW(expr.tpe.typeSymbol), expr.pos) - ctx1.bb.enterIgnoreMode() - - (ctx1, NothingReference) - } - - /** - * Generate code for primitive arithmetic operations. - * Returns (Context, Generated Type) - */ - private def genArithmeticOp(tree: Tree, ctx: Context, code: Int): (Context, TypeKind) = { - val Apply(fun @ Select(larg, _), args) = tree - var ctx1 = ctx - var resKind = toTypeKind(larg.tpe) - - debugassert(args.length <= 1, - "Too many arguments for primitive function: " + fun.symbol) - debugassert(resKind.isNumericType | resKind == BOOL, - resKind.toString() + " is not a numeric or boolean type " + - "[operation: " + fun.symbol + "]") - - args match { - // unary operation - case Nil => - ctx1 = genLoad(larg, ctx1, resKind) - code match { - case scalaPrimitives.POS => - () // nothing - case scalaPrimitives.NEG => - ctx1.bb.emit(CALL_PRIMITIVE(Negation(resKind)), larg.pos) - case scalaPrimitives.NOT => - ctx1.bb.emit(CALL_PRIMITIVE(Arithmetic(NOT, resKind)), larg.pos) - case _ => - abort("Unknown unary operation: " + fun.symbol.fullName + - " code: " + code) - } - - // binary operation - case rarg :: Nil => - resKind = getMaxType(larg.tpe :: rarg.tpe :: Nil) - if (scalaPrimitives.isShiftOp(code) || scalaPrimitives.isBitwiseOp(code)) - assert(resKind.isIntegralType | resKind == BOOL, - resKind.toString() + " incompatible with arithmetic modulo operation: " + ctx1) - - ctx1 = genLoad(larg, ctx1, resKind) - ctx1 = genLoad(rarg, - ctx1, // check .NET size of shift arguments! - if (scalaPrimitives.isShiftOp(code)) INT else resKind) - - val primitiveOp = code match { - case scalaPrimitives.ADD => Arithmetic(ADD, resKind) - case scalaPrimitives.SUB => Arithmetic(SUB, resKind) - case scalaPrimitives.MUL => Arithmetic(MUL, resKind) - case scalaPrimitives.DIV => Arithmetic(DIV, resKind) - case scalaPrimitives.MOD => Arithmetic(REM, resKind) - case scalaPrimitives.OR => Logical(OR, resKind) - case scalaPrimitives.XOR => Logical(XOR, resKind) - case scalaPrimitives.AND => Logical(AND, resKind) - case scalaPrimitives.LSL => Shift(LSL, resKind) - case scalaPrimitives.LSR => Shift(LSR, resKind) - case scalaPrimitives.ASR => Shift(ASR, resKind) - case _ => abort("Unknown primitive: " + fun.symbol + "[" + code + "]") - } - ctx1.bb.emit(CALL_PRIMITIVE(primitiveOp), tree.pos) - - case _ => - abort("Too many arguments for primitive function: " + tree) - } - (ctx1, resKind) - } - - /** Generate primitive array operations. - */ - private def genArrayOp(tree: Tree, ctx: Context, code: Int, expectedType: TypeKind): (Context, TypeKind) = { - import scalaPrimitives._ - val Apply(Select(arrayObj, _), args) = tree - val k = toTypeKind(arrayObj.tpe) - val ARRAY(elem) = k - var ctx1 = genLoad(arrayObj, ctx, k) - val elementType = typeOfArrayOp.getOrElse(code, abort("Unknown operation on arrays: " + tree + " code: " + code)) - - var generatedType = expectedType - - if (scalaPrimitives.isArrayGet(code)) { - // load argument on stack - debugassert(args.length == 1, - "Too many arguments for array get operation: " + tree) - ctx1 = genLoad(args.head, ctx1, INT) - generatedType = elem - ctx1.bb.emit(LOAD_ARRAY_ITEM(elementType), tree.pos) - // it's tempting to just drop array loads of type Null instead - // of adapting them but array accesses can cause - // ArrayIndexOutOfBounds so we can't. Besides, Array[Null] - // probably isn't common enough to figure out an optimization - adaptNullRef(generatedType, expectedType, ctx1, tree.pos) - } - else if (scalaPrimitives.isArraySet(code)) { - debugassert(args.length == 2, - "Too many arguments for array set operation: " + tree) - ctx1 = genLoad(args.head, ctx1, INT) - ctx1 = genLoad(args.tail.head, ctx1, toTypeKind(args.tail.head.tpe)) - // the following line should really be here, but because of bugs in erasure - // we pretend we generate whatever type is expected from us. - //generatedType = UNIT - - ctx1.bb.emit(STORE_ARRAY_ITEM(elementType), tree.pos) - } - else { - generatedType = INT - ctx1.bb.emit(CALL_PRIMITIVE(ArrayLength(elementType)), tree.pos) - } - - (ctx1, generatedType) - } - private def genSynchronized(tree: Apply, ctx: Context, expectedType: TypeKind): (Context, TypeKind) = { - val Apply(fun, args) = tree - val monitor = ctx.makeLocal(tree.pos, ObjectTpe, "monitor") - var monitorResult: Local = null - val argTpe = args.head.tpe - val hasResult = expectedType != UNIT - if (hasResult) - monitorResult = ctx.makeLocal(tree.pos, argTpe, "monitorResult") - - var ctx1 = genLoadQualifier(fun, ctx) - ctx1.bb.emit(Seq( - DUP(ObjectReference), - STORE_LOCAL(monitor), - MONITOR_ENTER() setPos tree.pos - )) - ctx1.enterSynchronized(monitor) - debuglog("synchronized block start") - - ctx1 = ctx1.Try( - bodyCtx => { - val ctx2 = genLoad(args.head, bodyCtx, expectedType /* toTypeKind(tree.tpe.resultType) */) - if (hasResult) - ctx2.bb.emit(STORE_LOCAL(monitorResult)) - ctx2.bb.emit(Seq( - LOAD_LOCAL(monitor), - MONITOR_EXIT() setPos tree.pos - )) - ctx2 - }, List( - // tree.tpe / fun.tpe is object, which is no longer true after this transformation - (ThrowableClass, expectedType, exhCtx => { - exhCtx.bb.emit(Seq( - LOAD_LOCAL(monitor), - MONITOR_EXIT() setPos tree.pos, - THROW(ThrowableClass) - )) - exhCtx.bb.enterIgnoreMode() - exhCtx - })), EmptyTree, tree) - - debuglog("synchronized block end with block %s closed=%s".format(ctx1.bb, ctx1.bb.closed)) - ctx1.exitSynchronized(monitor) - if (hasResult) - ctx1.bb.emit(LOAD_LOCAL(monitorResult)) - (ctx1, expectedType) - } - - private def genLoadIf(tree: If, ctx: Context, expectedType: TypeKind): (Context, TypeKind) = { - val If(cond, thenp, elsep) = tree - - var thenCtx = ctx.newBlock() - var elseCtx = ctx.newBlock() - val contCtx = ctx.newBlock() - - genCond(cond, ctx, thenCtx, elseCtx) - - val ifKind = toTypeKind(tree.tpe) - val thenKind = toTypeKind(thenp.tpe) - val elseKind = if (elsep == EmptyTree) UNIT else toTypeKind(elsep.tpe) - - // we need to drop unneeded results, if one branch gives - // unit and the other gives something on the stack, because - // the type of 'if' is scala.Any, and its erasure would be Object. - // But unboxed units are not Objects... - def hasUnitBranch = thenKind == UNIT || elseKind == UNIT - val resKind = if (hasUnitBranch) UNIT else ifKind - - if (hasUnitBranch) - debuglog("Will drop result from an if branch") - - thenCtx = genLoad(thenp, thenCtx, resKind) - elseCtx = genLoad(elsep, elseCtx, resKind) - - debugassert(!hasUnitBranch || expectedType == UNIT, - "I produce UNIT in a context where " + expectedType + " is expected!") - - // alternatives may be already closed by a tail-recursive jump - val contReachable = !(thenCtx.bb.ignore && elseCtx.bb.ignore) - thenCtx.bb.closeWith(JUMP(contCtx.bb)) - elseCtx.bb.closeWith( - if (elsep == EmptyTree) JUMP(contCtx.bb) - else JUMP(contCtx.bb) setPos tree.pos - ) - - contCtx.bb killUnless contReachable - (contCtx, resKind) - } - private def genLoadTry(tree: Try, ctx: Context, setGeneratedType: TypeKind => Unit): Context = { - val Try(block, catches, finalizer) = tree - val kind = toTypeKind(tree.tpe) - - val caseHandlers = - for (CaseDef(pat, _, body) <- catches.reverse) yield { - def genWildcardHandler(sym: Symbol): (Symbol, TypeKind, Context => Context) = - (sym, kind, ctx => { - ctx.bb.emit(DROP(REFERENCE(sym))) // drop the loaded exception - genLoad(body, ctx, kind) - }) - - pat match { - case Typed(Ident(nme.WILDCARD), tpt) => genWildcardHandler(tpt.tpe.typeSymbol) - case Ident(nme.WILDCARD) => genWildcardHandler(ThrowableClass) - case Bind(_, _) => - val exception = ctx.method addLocal new Local(pat.symbol, toTypeKind(pat.symbol.tpe), false) // the exception will be loaded and stored into this local - - (pat.symbol.tpe.typeSymbol, kind, { - ctx: Context => - ctx.bb.emit(STORE_LOCAL(exception), pat.pos) - genLoad(body, ctx, kind) - }) - } - } - - ctx.Try( - bodyCtx => { - setGeneratedType(kind) - genLoad(block, bodyCtx, kind) - }, - caseHandlers, - finalizer, - tree) - } - - private def genPrimitiveOp(tree: Apply, ctx: Context, expectedType: TypeKind): (Context, TypeKind) = { - val sym = tree.symbol - val Apply(fun @ Select(receiver, _), _) = tree - val code = scalaPrimitives.getPrimitive(sym, receiver.tpe) - - if (scalaPrimitives.isArithmeticOp(code)) - genArithmeticOp(tree, ctx, code) - else if (code == scalaPrimitives.CONCAT) - (genStringConcat(tree, ctx), StringReference) - else if (code == scalaPrimitives.HASH) - (genScalaHash(receiver, ctx), INT) - else if (isArrayOp(code)) - genArrayOp(tree, ctx, code, expectedType) - else if (isLogicalOp(code) || isComparisonOp(code)) { - val trueCtx, falseCtx, afterCtx = ctx.newBlock() - - genCond(tree, ctx, trueCtx, falseCtx) - trueCtx.bb.emitOnly( - CONSTANT(Constant(true)) setPos tree.pos, - JUMP(afterCtx.bb) - ) - falseCtx.bb.emitOnly( - CONSTANT(Constant(false)) setPos tree.pos, - JUMP(afterCtx.bb) - ) - (afterCtx, BOOL) - } - else if (code == scalaPrimitives.SYNCHRONIZED) - genSynchronized(tree, ctx, expectedType) - else if (scalaPrimitives.isCoercion(code)) { - val ctx1 = genLoad(receiver, ctx, toTypeKind(receiver.tpe)) - genCoercion(tree, ctx1, code) - (ctx1, scalaPrimitives.generatedKind(code)) - } - else abort( - "Primitive operation not handled yet: " + sym.fullName + "(" + - fun.symbol.simpleName + ") " + " at: " + (tree.pos) - ) - } - - /** - * Generate code for trees that produce values on the stack - * - * @param tree The tree to be translated - * @param ctx The current context - * @param expectedType The type of the value to be generated on top of the - * stack. - * @return The new context. The only thing that may change is the current - * basic block (as the labels map is mutable). - */ - private def genLoad(tree: Tree, ctx: Context, expectedType: TypeKind): Context = { - var generatedType = expectedType - debuglog("at line: " + (if (tree.pos.isDefined) tree.pos.line else tree.pos)) - - val resCtx: Context = tree match { - case LabelDef(name, params, rhs) => - def genLoadLabelDef = { - val ctx1 = ctx.newBlock() // note: we cannot kill ctx1 if ctx is in ignore mode because - // label defs can be the target of jumps from other locations. - // that means label defs can lead to unreachable code without - // proper reachability analysis - - if (nme.isLoopHeaderLabel(name)) - ctx1.bb.loopHeader = true - - ctx1.labels.get(tree.symbol) match { - case Some(label) => - debuglog("Found existing label for " + tree.symbol.fullLocationString) - label.anchor(ctx1.bb) - label.patch(ctx.method.code) - - case None => - val pair = (tree.symbol -> (new Label(tree.symbol) anchor ctx1.bb setParams (params map (_.symbol)))) - debuglog("Adding label " + tree.symbol.fullLocationString + " in genLoad.") - ctx1.labels += pair - ctx.method.addLocals(params map (p => new Local(p.symbol, toTypeKind(p.symbol.info), false))) - } - - ctx.bb.closeWith(JUMP(ctx1.bb), tree.pos) - genLoad(rhs, ctx1, expectedType /*toTypeKind(tree.symbol.info.resultType)*/) - } - genLoadLabelDef - - case ValDef(_, name, _, rhs) => - def genLoadValDef = - if (name == nme.THIS) { - debuglog("skipping trivial assign to _$this: " + tree) - ctx - } else { - val sym = tree.symbol - val local = ctx.method.addLocal(new Local(sym, toTypeKind(sym.info), false)) - - if (rhs == EmptyTree) { - debuglog("Uninitialized variable " + tree + " at: " + (tree.pos)) - ctx.bb.emit(getZeroOf(local.kind)) - } - - var ctx1 = ctx - if (rhs != EmptyTree) - ctx1 = genLoad(rhs, ctx, local.kind) - - ctx1.bb.emit(STORE_LOCAL(local), tree.pos) - ctx1.scope.add(local) - ctx1.bb.emit(SCOPE_ENTER(local)) - generatedType = UNIT - ctx1 - } - genLoadValDef - - case t @ If(cond, thenp, elsep) => - val (newCtx, resKind) = genLoadIf(t, ctx, expectedType) - generatedType = resKind - newCtx - - case Return(expr) => - def genLoadReturn = { - val returnedKind = toTypeKind(expr.tpe) - debuglog("Return(" + expr + ") with returnedKind = " + returnedKind) - - var ctx1 = genLoad(expr, ctx, returnedKind) - lazy val tmp = ctx1.makeLocal(tree.pos, expr.tpe, "tmp") - val saved = savingCleanups(ctx1) { - var savedFinalizer = false - ctx1.cleanups foreach { - case MonitorRelease(m) => - debuglog("removing " + m + " from cleanups: " + ctx1.cleanups) - ctx1.bb.emit(Seq(LOAD_LOCAL(m), MONITOR_EXIT())) - ctx1.exitSynchronized(m) - - case Finalizer(f, finalizerCtx) => - debuglog("removing " + f + " from cleanups: " + ctx1.cleanups) - if (returnedKind != UNIT && mayCleanStack(f)) { - log("Emitting STORE_LOCAL for " + tmp + " to save finalizer.") - ctx1.bb.emit(STORE_LOCAL(tmp)) - savedFinalizer = true - } - - // duplicate finalizer (takes care of anchored labels) - val f1 = duplicateFinalizer(Set.empty ++ ctx1.labels.keySet, ctx1, f) - - // we have to run this without the same finalizer in - // the list, otherwise infinite recursion happens for - // finalizers that contain 'return' - val fctx = finalizerCtx.newBlock() - fctx.bb killIf ctx1.bb.ignore - ctx1.bb.closeWith(JUMP(fctx.bb)) - ctx1 = genLoad(f1, fctx, UNIT) - } - savedFinalizer - } - - if (saved) { - log("Emitting LOAD_LOCAL for " + tmp + " after saving finalizer.") - ctx1.bb.emit(LOAD_LOCAL(tmp)) - } - adapt(returnedKind, ctx1.method.returnType, ctx1, tree.pos) - ctx1.bb.emit(RETURN(ctx.method.returnType), tree.pos) - ctx1.bb.enterIgnoreMode() - generatedType = expectedType - ctx1 - } - genLoadReturn - - case t @ Try(_, _, _) => - genLoadTry(t, ctx, generatedType = _) - - case Throw(expr) => - val (ctx1, expectedType) = genThrow(expr, ctx) - generatedType = expectedType - ctx1 - - case New(tpt) => - abort("Unexpected New(" + tpt.summaryString + "/" + tpt + ") received in icode.\n" + - " Call was genLoad" + ((tree, ctx, expectedType))) - - case Apply(TypeApply(fun, targs), _) => - def genLoadApply1 = { - val sym = fun.symbol - val cast = sym match { - case Object_isInstanceOf => false - case Object_asInstanceOf => true - case _ => abort("Unexpected type application " + fun + "[sym: " + sym.fullName + "]" + " in: " + tree) - } - - val Select(obj, _) = fun - val l = toTypeKind(obj.tpe) - val r = toTypeKind(targs.head.tpe) - val ctx1 = genLoadQualifier(fun, ctx) - - if (l.isValueType && r.isValueType) - genConversion(l, r, ctx1, cast) - else if (l.isValueType) { - ctx1.bb.emit(DROP(l), fun.pos) - if (cast) { - ctx1.bb.emit(Seq( - NEW(REFERENCE(definitions.ClassCastExceptionClass)), - DUP(ObjectReference), - THROW(definitions.ClassCastExceptionClass) - )) - } else - ctx1.bb.emit(CONSTANT(Constant(false))) - } else if (r.isValueType && cast) { - /* Erasure should have added an unboxing operation to prevent that. */ - abort("should have been unboxed by erasure: " + tree) - } else if (r.isValueType) { - ctx.bb.emit(IS_INSTANCE(REFERENCE(definitions.boxedClass(r.toType.typeSymbol)))) - } else { - genCast(l, r, ctx1, cast) - } - generatedType = if (cast) r else BOOL - ctx1 - } - genLoadApply1 - - // 'super' call: Note: since constructors are supposed to - // return an instance of what they construct, we have to take - // special care. On JVM they are 'void', and Scala forbids (syntactically) - // to call super constructors explicitly and/or use their 'returned' value. - // therefore, we can ignore this fact, and generate code that leaves nothing - // on the stack (contrary to what the type in the AST says). - case Apply(fun @ Select(Super(_, mix), _), args) => - def genLoadApply2 = { - debuglog("Call to super: " + tree) - val invokeStyle = SuperCall(mix) - // if (fun.symbol.isConstructor) Static(true) else SuperCall(mix); - - ctx.bb.emit(THIS(ctx.clazz.symbol), tree.pos) - val ctx1 = genLoadArguments(args, fun.symbol.info.paramTypes, ctx) - - ctx1.bb.emit(CALL_METHOD(fun.symbol, invokeStyle), tree.pos) - generatedType = - if (fun.symbol.isConstructor) UNIT - else toTypeKind(fun.symbol.info.resultType) - ctx1 - } - genLoadApply2 - - // 'new' constructor call: Note: since constructors are - // thought to return an instance of what they construct, - // we have to 'simulate' it by DUPlicating the freshly created - // instance (on JVM, <init> methods return VOID). - case Apply(fun @ Select(New(tpt), nme.CONSTRUCTOR), args) => - def genLoadApply3 = { - val ctor = fun.symbol - debugassert(ctor.isClassConstructor, - "'new' call to non-constructor: " + ctor.name) - - generatedType = toTypeKind(tpt.tpe) - debugassert(generatedType.isReferenceType || generatedType.isArrayType, - "Non reference type cannot be instantiated: " + generatedType) - - generatedType match { - case arr @ ARRAY(elem) => - val ctx1 = genLoadArguments(args, ctor.info.paramTypes, ctx) - val dims = arr.dimensions - var elemKind = arr.elementKind - if (args.length > dims) - reporter.error(tree.pos, "too many arguments for array constructor: found " + args.length + - " but array has only " + dims + " dimension(s)") - if (args.length != dims) - for (i <- args.length until dims) elemKind = ARRAY(elemKind) - ctx1.bb.emit(CREATE_ARRAY(elemKind, args.length), tree.pos) - ctx1 - - case rt @ REFERENCE(cls) => - debugassert(ctor.owner == cls, - "Symbol " + ctor.owner.fullName + " is different than " + tpt) - - val nw = NEW(rt) - ctx.bb.emit(nw, tree.pos) - ctx.bb.emit(DUP(generatedType)) - val ctx1 = genLoadArguments(args, ctor.info.paramTypes, ctx) - - val init = CALL_METHOD(ctor, Static(onInstance = true)) - nw.init = init - ctx1.bb.emit(init, tree.pos) - ctx1 - case _ => - abort("Cannot instantiate " + tpt + " of kind: " + generatedType) - } - } - genLoadApply3 - - case Apply(fun @ _, List(expr)) if currentRun.runDefinitions.isBox(fun.symbol) => - def genLoadApply4 = { - debuglog("BOX : " + fun.symbol.fullName) - val ctx1 = genLoad(expr, ctx, toTypeKind(expr.tpe)) - val nativeKind = toTypeKind(expr.tpe) - if (settings.Xdce) { - // we store this boxed value to a local, even if not really needed. - // boxing optimization might use it, and dead code elimination will - // take care of unnecessary stores - val loc1 = ctx.makeLocal(tree.pos, expr.tpe, "boxed") - ctx1.bb.emit(STORE_LOCAL(loc1)) - ctx1.bb.emit(LOAD_LOCAL(loc1)) - } - ctx1.bb.emit(BOX(nativeKind), expr.pos) - generatedType = toTypeKind(fun.symbol.tpe.resultType) - ctx1 - } - genLoadApply4 - - case Apply(fun @ _, List(expr)) if (currentRun.runDefinitions.isUnbox(fun.symbol)) => - debuglog("UNBOX : " + fun.symbol.fullName) - val ctx1 = genLoad(expr, ctx, toTypeKind(expr.tpe)) - val boxType = toTypeKind(fun.symbol.owner.linkedClassOfClass.tpe) - generatedType = boxType - ctx1.bb.emit(UNBOX(boxType), expr.pos) - ctx1 - - case app @ Apply(fun, args) => - def genLoadApply6 = { - val sym = fun.symbol - - if (sym.isLabel) { // jump to a label - val label = ctx.labels.getOrElse(sym, { - // it is a forward jump, scan for labels - resolveForwardLabel(ctx.defdef, ctx, sym) - ctx.labels.get(sym) match { - case Some(l) => - debuglog("Forward jump for " + sym.fullLocationString + ": scan found label " + l) - l - case _ => - abort("Unknown label target: " + sym + " at: " + (fun.pos) + ": ctx: " + ctx) - } - }) - // note: when one of the args to genLoadLabelArguments is a jump to a label, - // it will call back into genLoad and arrive at this case, which will then set ctx1.bb.ignore to true, - // this is okay, since we're jumping unconditionally, so the loads and jumps emitted by the outer - // call to genLoad (by calling genLoadLabelArguments and emitOnly) can safely be ignored, - // however, as emitOnly will close the block, which reverses its instructions (when it's still open), - // we better not reverse when the block has already been closed but is in ignore mode - // (if it's not in ignore mode, double-closing is an error) - val ctx1 = genLoadLabelArguments(args, label, ctx) - ctx1.bb.emitOnly(if (label.anchored) JUMP(label.block) else PJUMP(label)) - ctx1.bb.enterIgnoreMode() - ctx1 - } else if (isPrimitive(sym)) { // primitive method call - val (newCtx, resKind) = genPrimitiveOp(app, ctx, expectedType) - generatedType = resKind - newCtx - } else { // normal method call - debuglog("Gen CALL_METHOD with sym: " + sym + " isStaticSymbol: " + sym.isStaticMember) - val invokeStyle = - if (sym.isStaticMember) - Static(onInstance = false) - else if (sym.isPrivate || sym.isClassConstructor) - Static(onInstance = true) - else - Dynamic - - var ctx1 = if (invokeStyle.hasInstance) genLoadQualifier(fun, ctx) else ctx - ctx1 = genLoadArguments(args, sym.info.paramTypes, ctx1) - val cm = CALL_METHOD(sym, invokeStyle) - - /* In a couple cases, squirrel away a little extra information in the - * CALL_METHOD for use by GenASM. - */ - fun match { - case Select(qual, _) => - val qualSym = findHostClass(qual.tpe, sym) - if (qualSym == ArrayClass) { - val kind = toTypeKind(qual.tpe) - cm setTargetTypeKind kind - log(s"Stored target type kind for {$sym.fullName} as $kind") - } - else { - cm setHostClass qualSym - if (qual.tpe.typeSymbol != qualSym) - log(s"Precisified host class for $sym from ${qual.tpe.typeSymbol.fullName} to ${qualSym.fullName}") - } - case _ => - } - ctx1.bb.emit(cm, tree.pos) - ctx1.method.updateRecursive(sym) - generatedType = - if (sym.isClassConstructor) UNIT - else toTypeKind(sym.info.resultType) - // deal with methods that return Null - adaptNullRef(generatedType, expectedType, ctx1, tree.pos) - ctx1 - } - } - genLoadApply6 - - case ApplyDynamic(qual, args) => - // TODO - this is where we'd catch dynamic applies for invokedynamic. - sys.error("No invokedynamic support yet.") - // val ctx1 = genLoad(qual, ctx, ObjectReference) - // genLoadArguments(args, tree.symbol.info.paramTypes, ctx1) - // ctx1.bb.emit(CALL_METHOD(tree.symbol, InvokeDynamic), tree.pos) - // ctx1 - - case This(qual) => - def genLoadThis = { - assert(tree.symbol == ctx.clazz.symbol || tree.symbol.isModuleClass, - "Trying to access the this of another class: " + - "tree.symbol = " + tree.symbol + ", ctx.clazz.symbol = " + ctx.clazz.symbol + " compilation unit:"+unit) - if (tree.symbol.isModuleClass && tree.symbol != ctx.clazz.symbol) { - genLoadModule(ctx, tree) - generatedType = REFERENCE(tree.symbol) - } else { - ctx.bb.emit(THIS(ctx.clazz.symbol), tree.pos) - generatedType = REFERENCE( - if (tree.symbol == ArrayClass) ObjectClass else ctx.clazz.symbol - ) - } - ctx - } - genLoadThis - - case Select(Ident(nme.EMPTY_PACKAGE_NAME), module) => - debugassert(tree.symbol.isModule, - "Selection of non-module from empty package: " + tree + - " sym: " + tree.symbol + " at: " + (tree.pos) - ) - genLoadModule(ctx, tree) - - case Select(qualifier, selector) => - def genLoadSelect = { - val sym = tree.symbol - generatedType = toTypeKind(sym.info) - val hostClass = findHostClass(qualifier.tpe, sym) - debuglog(s"Host class of $sym with qual $qualifier (${qualifier.tpe}) is $hostClass") - val qualSafeToElide = treeInfo isQualifierSafeToElide qualifier - - def genLoadQualUnlessElidable: Context = - if (qualSafeToElide) ctx else genLoadQualifier(tree, ctx) - - if (sym.isModule) { - genLoadModule(genLoadQualUnlessElidable, tree) - } else { - val isStatic = sym.isStaticMember - val ctx1 = if (isStatic) genLoadQualUnlessElidable - else genLoadQualifier(tree, ctx) - ctx1.bb.emit(LOAD_FIELD(sym, isStatic) setHostClass hostClass, tree.pos) - // it's tempting to drop field accesses of type Null instead of adapting them, - // but field access can cause static class init so we can't. Besides, fields - // of type Null probably aren't common enough to figure out an optimization - adaptNullRef(generatedType, expectedType, ctx1, tree.pos) - ctx1 - } - } - genLoadSelect - - case Ident(name) => - def genLoadIdent = { - val sym = tree.symbol - if (!sym.hasPackageFlag) { - if (sym.isModule) { - genLoadModule(ctx, tree) - generatedType = toTypeKind(sym.info) - } else { - ctx.method.lookupLocal(sym) match { - case Some(l) => - ctx.bb.emit(LOAD_LOCAL(l), tree.pos) - generatedType = l.kind - case None => - val saved = settings.uniqid - settings.uniqid.value = true - try { - val methodCode = unit.body.collect { case dd: DefDef - if dd.symbol == ctx.method.symbol => showCode(dd); - }.headOption.getOrElse("<unknown>") - abort(s"symbol $sym does not exist in ${ctx.method}, which contains locals ${ctx.method.locals.mkString(",")}. \nMethod code: $methodCode") - } - finally settings.uniqid.value = saved - } - } - } - ctx - } - genLoadIdent - - case Literal(value) => - def genLoadLiteral = { - if (value.tag != UnitTag) (value.tag, expectedType) match { - case (IntTag, LONG) => - ctx.bb.emit(CONSTANT(Constant(value.longValue)), tree.pos) - generatedType = LONG - case (FloatTag, DOUBLE) => - ctx.bb.emit(CONSTANT(Constant(value.doubleValue)), tree.pos) - generatedType = DOUBLE - case (NullTag, _) => - ctx.bb.emit(CONSTANT(value), tree.pos) - generatedType = NullReference - case _ => - ctx.bb.emit(CONSTANT(value), tree.pos) - generatedType = toTypeKind(tree.tpe) - } - ctx - } - genLoadLiteral - - case Block(stats, expr) => - ctx.enterScope() - var ctx1 = genStat(stats, ctx) - ctx1 = genLoad(expr, ctx1, expectedType) - ctx1.exitScope() - ctx1 - - case Typed(Super(_, _), _) => - genLoad(This(ctx.clazz.symbol), ctx, expectedType) - - case Typed(expr, _) => - genLoad(expr, ctx, expectedType) - - case Assign(_, _) => - generatedType = UNIT - genStat(tree, ctx) - - case ArrayValue(tpt @ TypeTree(), _elems) => - def genLoadArrayValue = { - var ctx1 = ctx - val elmKind = toTypeKind(tpt.tpe) - generatedType = ARRAY(elmKind) - val elems = _elems.toIndexedSeq - - ctx1.bb.emit(CONSTANT(new Constant(elems.length)), tree.pos) - ctx1.bb.emit(CREATE_ARRAY(elmKind, 1)) - // inline array literals - var i = 0 - while (i < elems.length) { - ctx1.bb.emit(DUP(generatedType), tree.pos) - ctx1.bb.emit(CONSTANT(new Constant(i))) - ctx1 = genLoad(elems(i), ctx1, elmKind) - ctx1.bb.emit(STORE_ARRAY_ITEM(elmKind)) - i = i + 1 - } - ctx1 - } - genLoadArrayValue - - case Match(selector, cases) => - def genLoadMatch = { - debuglog("Generating SWITCH statement.") - val ctx1 = genLoad(selector, ctx, INT) // TODO: Java 7 allows strings in switches (so, don't assume INT and don't convert the literals using intValue) - val afterCtx = ctx1.newBlock() - afterCtx.bb killIf ctx1.bb.ignore - var afterCtxReachable = false - var caseCtx: Context = null - generatedType = toTypeKind(tree.tpe) - - var targets: List[BasicBlock] = Nil - var tags: List[Int] = Nil - var default: BasicBlock = afterCtx.bb - - for (caze @ CaseDef(pat, guard, body) <- cases) { - assert(guard == EmptyTree, guard) - val tmpCtx = ctx1.newBlock() - tmpCtx.bb killIf ctx1.bb.ignore - pat match { - case Literal(value) => - tags = value.intValue :: tags - targets = tmpCtx.bb :: targets - case Ident(nme.WILDCARD) => - default = tmpCtx.bb - case Alternative(alts) => - alts foreach { - case Literal(value) => - tags = value.intValue :: tags - targets = tmpCtx.bb :: targets - case _ => - abort("Invalid case in alternative in switch-like pattern match: " + - tree + " at: " + tree.pos) - } - case _ => - abort("Invalid case statement in switch-like pattern match: " + - tree + " at: " + (tree.pos)) - } - - caseCtx = genLoad(body, tmpCtx, generatedType) - afterCtxReachable ||= !caseCtx.bb.ignore - // close the block unless it's already been closed by the body, which closes the block if it ends in a jump (which is emitted to have alternatives share their body) - caseCtx.bb.closeWith(JUMP(afterCtx.bb) setPos caze.pos) - } - afterCtxReachable ||= (default == afterCtx) - ctx1.bb.emitOnly( - SWITCH(tags.reverse map (x => List(x)), (default :: targets).reverse) setPos tree.pos - ) - afterCtx.bb killUnless afterCtxReachable - afterCtx - } - genLoadMatch - - case EmptyTree => - if (expectedType != UNIT) - ctx.bb.emit(getZeroOf(expectedType)) - ctx - - case _ => - abort("Unexpected tree in genLoad: " + tree + "/" + tree.getClass + " at: " + tree.pos) - } - - // emit conversion - if (generatedType != expectedType) { - tree match { - case Literal(Constant(null)) if generatedType == NullReference && expectedType != UNIT => - // literal null on the stack (as opposed to a boxed null, see SI-8233), - // we can bypass `adapt` which would otherwise emit a redundant [DROP, CONSTANT(null)] - // except one case: when expected type is UNIT (unboxed) where we need to emit just a DROP - case _ => - adapt(generatedType, expectedType, resCtx, tree.pos) - } - } - - resCtx - } - - /** - * If we have a method call, field load, or array element load of type Null then - * we need to convince the JVM that we have a null value because in Scala - * land Null is a subtype of all ref types, but in JVM land scala.runtime.Null$ - * is not. Note we don't have to adapt loads of locals because the JVM type - * system for locals does have a null type which it tracks internally. As - * long as we adapt these other things, the JVM will know that a Scala local of - * type Null is holding a null. - */ - private def adaptNullRef(from: TypeKind, to: TypeKind, ctx: Context, pos: Position) { - debuglog(s"GenICode#adaptNullRef($from, $to, $ctx, $pos)") - - // Don't need to adapt null to unit because we'll just drop it anyway. Don't - // need to adapt to Object or AnyRef because the JVM is happy with - // upcasting Null to them. - // We do have to adapt from NullReference to NullReference because we could be storing - // this value into a local of type Null and we want the JVM to see that it's - // a null value so we don't have to also adapt local loads. - if (from == NullReference && to != UNIT && to != ObjectReference && to != AnyRefReference) { - assert(to.isRefOrArrayType, s"Attempt to adapt a null to a non reference type $to.") - // adapt by dropping what we've got and pushing a null which - // will convince the JVM we really do have null - ctx.bb.emit(DROP(from), pos) - ctx.bb.emit(CONSTANT(Constant(null)), pos) - } - } - - private def adapt(from: TypeKind, to: TypeKind, ctx: Context, pos: Position) { - // An awful lot of bugs explode here - let's leave ourselves more clues. - // A typical example is an overloaded type assigned after typer. - debuglog(s"GenICode#adapt($from, $to, $ctx, $pos)") - - def coerce(from: TypeKind, to: TypeKind) = ctx.bb.emit(CALL_PRIMITIVE(Conversion(from, to)), pos) - - (from, to) match { - // The JVM doesn't have a Nothing equivalent, so it doesn't know that a method of type Nothing can't actually return. So for instance, with - // def f: String = ??? - // we need - // 0: getstatic #25; //Field scala/Predef$.MODULE$:Lscala/Predef$; - // 3: invokevirtual #29; //Method scala/Predef$.$qmark$qmark$qmark:()Lscala/runtime/Nothing$; - // 6: athrow - // So this case tacks on the ahtrow which makes the JVM happy because class Nothing is declared as a subclass of Throwable - case (NothingReference, _) => - ctx.bb.emit(THROW(ThrowableClass)) - ctx.bb.enterIgnoreMode() - case (NullReference, REFERENCE(_)) => - // SI-8223 we can't assume that the stack contains a `null`, it might contain a Null$ - ctx.bb.emit(Seq(DROP(from), CONSTANT(Constant(null)))) - case _ if from isAssignabledTo to => - () - case (_, UNIT) => - ctx.bb.emit(DROP(from), pos) - // otherwise we'd better be doing a primitive -> primitive coercion or there's a problem - case _ if !from.isRefOrArrayType && !to.isRefOrArrayType => - coerce(from, to) - case _ => - assert(false, s"Can't convert from $from to $to in unit ${unit.source} at $pos") - } - } - - /** Load the qualifier of `tree` on top of the stack. */ - private def genLoadQualifier(tree: Tree, ctx: Context): Context = - tree match { - case Select(qualifier, _) => - genLoad(qualifier, ctx, toTypeKind(qualifier.tpe)) - case _ => - abort("Unknown qualifier " + tree) - } - - /** - * Generate code that loads args into label parameters. - */ - private def genLoadLabelArguments(args: List[Tree], label: Label, ctx: Context): Context = { - debugassert( - args.length == label.params.length, - "Wrong number of arguments in call to label " + label.symbol - ) - var ctx1 = ctx - - def isTrivial(kv: (Tree, Symbol)) = kv match { - case (This(_), p) if p.name == nme.THIS => true - case (arg @ Ident(_), p) if arg.symbol == p => true - case _ => false - } - - val stores = args zip label.params filterNot isTrivial map { - case (arg, param) => - val local = ctx.method.lookupLocal(param).get - ctx1 = genLoad(arg, ctx1, local.kind) - - val store = - if (param.name == nme.THIS) STORE_THIS(toTypeKind(ctx1.clazz.symbol.tpe)) - else STORE_LOCAL(local) - - store setPos arg.pos - } - - // store arguments in reverse order on the stack - ctx1.bb.emit(stores.reverse) - ctx1 - } - - private def genLoadArguments(args: List[Tree], tpes: List[Type], ctx: Context): Context = - (args zip tpes).foldLeft(ctx) { - case (res, (arg, tpe)) => - genLoad(arg, res, toTypeKind(tpe)) - } - - private def genLoadModule(ctx: Context, tree: Tree): Context = { - // Working around SI-5604. Rather than failing the compile when we see - // a package here, check if there's a package object. - val sym = ( - if (!tree.symbol.isPackageClass) tree.symbol - else tree.symbol.info.member(nme.PACKAGE) match { - case NoSymbol => abort("Cannot use package as value: " + tree) - case s => - devWarning(s"Found ${tree.symbol} where a package object is required. Converting to ${s.moduleClass}") - s.moduleClass - } - ) - debuglog("LOAD_MODULE from %s: %s".format(tree.shortClass, sym)) - ctx.bb.emit(LOAD_MODULE(sym), tree.pos) - ctx - } - - def genConversion(from: TypeKind, to: TypeKind, ctx: Context, cast: Boolean) = { - if (cast) - ctx.bb.emit(CALL_PRIMITIVE(Conversion(from, to))) - else { - ctx.bb.emit(DROP(from)) - ctx.bb.emit(CONSTANT(Constant(from == to))) - } - } - - def genCast(from: TypeKind, to: TypeKind, ctx: Context, cast: Boolean) = - ctx.bb.emit(if (cast) CHECK_CAST(to) else IS_INSTANCE(to)) - - def getZeroOf(k: TypeKind): Instruction = k match { - case UNIT => CONSTANT(Constant(())) - case BOOL => CONSTANT(Constant(false)) - case BYTE => CONSTANT(Constant(0: Byte)) - case SHORT => CONSTANT(Constant(0: Short)) - case CHAR => CONSTANT(Constant(0: Char)) - case INT => CONSTANT(Constant(0: Int)) - case LONG => CONSTANT(Constant(0: Long)) - case FLOAT => CONSTANT(Constant(0.0f)) - case DOUBLE => CONSTANT(Constant(0.0d)) - case REFERENCE(cls) => CONSTANT(Constant(null: Any)) - case ARRAY(elem) => CONSTANT(Constant(null: Any)) - case BOXED(_) => CONSTANT(Constant(null: Any)) - case ConcatClass => abort("no zero of ConcatClass") - } - - - /** Is the given symbol a primitive operation? */ - def isPrimitive(fun: Symbol): Boolean = scalaPrimitives.isPrimitive(fun) - - /** Generate coercion denoted by "code" - */ - def genCoercion(tree: Tree, ctx: Context, code: Int) = { - import scalaPrimitives._ - (code: @switch) match { - case B2B => () - case B2C => ctx.bb.emit(CALL_PRIMITIVE(Conversion(BYTE, CHAR)), tree.pos) - case B2S => ctx.bb.emit(CALL_PRIMITIVE(Conversion(BYTE, SHORT)), tree.pos) - case B2I => ctx.bb.emit(CALL_PRIMITIVE(Conversion(BYTE, INT)), tree.pos) - case B2L => ctx.bb.emit(CALL_PRIMITIVE(Conversion(BYTE, LONG)), tree.pos) - case B2F => ctx.bb.emit(CALL_PRIMITIVE(Conversion(BYTE, FLOAT)), tree.pos) - case B2D => ctx.bb.emit(CALL_PRIMITIVE(Conversion(BYTE, DOUBLE)), tree.pos) - - case S2B => ctx.bb.emit(CALL_PRIMITIVE(Conversion(SHORT, BYTE)), tree.pos) - case S2S => () - case S2C => ctx.bb.emit(CALL_PRIMITIVE(Conversion(SHORT, CHAR)), tree.pos) - case S2I => ctx.bb.emit(CALL_PRIMITIVE(Conversion(SHORT, INT)), tree.pos) - case S2L => ctx.bb.emit(CALL_PRIMITIVE(Conversion(SHORT, LONG)), tree.pos) - case S2F => ctx.bb.emit(CALL_PRIMITIVE(Conversion(SHORT, FLOAT)), tree.pos) - case S2D => ctx.bb.emit(CALL_PRIMITIVE(Conversion(SHORT, DOUBLE)), tree.pos) - - case C2B => ctx.bb.emit(CALL_PRIMITIVE(Conversion(CHAR, BYTE)), tree.pos) - case C2S => ctx.bb.emit(CALL_PRIMITIVE(Conversion(CHAR, SHORT)), tree.pos) - case C2C => () - case C2I => ctx.bb.emit(CALL_PRIMITIVE(Conversion(CHAR, INT)), tree.pos) - case C2L => ctx.bb.emit(CALL_PRIMITIVE(Conversion(CHAR, LONG)), tree.pos) - case C2F => ctx.bb.emit(CALL_PRIMITIVE(Conversion(CHAR, FLOAT)), tree.pos) - case C2D => ctx.bb.emit(CALL_PRIMITIVE(Conversion(CHAR, DOUBLE)), tree.pos) - - case I2B => ctx.bb.emit(CALL_PRIMITIVE(Conversion(INT, BYTE)), tree.pos) - case I2S => ctx.bb.emit(CALL_PRIMITIVE(Conversion(INT, SHORT)), tree.pos) - case I2C => ctx.bb.emit(CALL_PRIMITIVE(Conversion(INT, CHAR)), tree.pos) - case I2I => () - case I2L => ctx.bb.emit(CALL_PRIMITIVE(Conversion(INT, LONG)), tree.pos) - case I2F => ctx.bb.emit(CALL_PRIMITIVE(Conversion(INT, FLOAT)), tree.pos) - case I2D => ctx.bb.emit(CALL_PRIMITIVE(Conversion(INT, DOUBLE)), tree.pos) - - case L2B => ctx.bb.emit(CALL_PRIMITIVE(Conversion(LONG, BYTE)), tree.pos) - case L2S => ctx.bb.emit(CALL_PRIMITIVE(Conversion(LONG, SHORT)), tree.pos) - case L2C => ctx.bb.emit(CALL_PRIMITIVE(Conversion(LONG, CHAR)), tree.pos) - case L2I => ctx.bb.emit(CALL_PRIMITIVE(Conversion(LONG, INT)), tree.pos) - case L2L => () - case L2F => ctx.bb.emit(CALL_PRIMITIVE(Conversion(LONG, FLOAT)), tree.pos) - case L2D => ctx.bb.emit(CALL_PRIMITIVE(Conversion(LONG, DOUBLE)), tree.pos) - - case F2B => ctx.bb.emit(CALL_PRIMITIVE(Conversion(FLOAT, BYTE)), tree.pos) - case F2S => ctx.bb.emit(CALL_PRIMITIVE(Conversion(FLOAT, SHORT)), tree.pos) - case F2C => ctx.bb.emit(CALL_PRIMITIVE(Conversion(FLOAT, CHAR)), tree.pos) - case F2I => ctx.bb.emit(CALL_PRIMITIVE(Conversion(FLOAT, INT)), tree.pos) - case F2L => ctx.bb.emit(CALL_PRIMITIVE(Conversion(FLOAT, LONG)), tree.pos) - case F2F => () - case F2D => ctx.bb.emit(CALL_PRIMITIVE(Conversion(FLOAT, DOUBLE)), tree.pos) - - case D2B => ctx.bb.emit(CALL_PRIMITIVE(Conversion(DOUBLE, BYTE)), tree.pos) - case D2S => ctx.bb.emit(CALL_PRIMITIVE(Conversion(DOUBLE, SHORT)), tree.pos) - case D2C => ctx.bb.emit(CALL_PRIMITIVE(Conversion(DOUBLE, CHAR)), tree.pos) - case D2I => ctx.bb.emit(CALL_PRIMITIVE(Conversion(DOUBLE, INT)), tree.pos) - case D2L => ctx.bb.emit(CALL_PRIMITIVE(Conversion(DOUBLE, LONG)), tree.pos) - case D2F => ctx.bb.emit(CALL_PRIMITIVE(Conversion(DOUBLE, FLOAT)), tree.pos) - case D2D => () - - case _ => abort("Unknown coercion primitive: " + code) - } - } - - /** The Object => String overload. - */ - private lazy val String_valueOf: Symbol = getMember(StringModule, nme.valueOf) filter (sym => - sym.info.paramTypes match { - case List(pt) => pt.typeSymbol == ObjectClass - case _ => false - } - ) - - // I wrote it this way before I realized all the primitive types are - // boxed at this point, so I'd have to unbox them. Keeping it around in - // case we want to get more precise. - // - // private def valueOfForType(tp: Type): Symbol = { - // val xs = getMember(StringModule, nme.valueOf) filter (sym => - // // We always exclude the Array[Char] overload because java throws an NPE if - // // you pass it a null. It will instead find the Object one, which doesn't. - // sym.info.paramTypes match { - // case List(pt) => pt.typeSymbol != ArrayClass && (tp <:< pt) - // case _ => false - // } - // ) - // xs.alternatives match { - // case List(sym) => sym - // case _ => NoSymbol - // } - // } - - /** Generate string concatenation. - */ - def genStringConcat(tree: Tree, ctx: Context): Context = { - liftStringConcat(tree) match { - // Optimization for expressions of the form "" + x. We can avoid the StringBuilder. - case List(Literal(Constant("")), arg) => - debuglog("Rewriting \"\" + x as String.valueOf(x) for: " + arg) - val ctx1 = genLoad(arg, ctx, ObjectReference) - ctx1.bb.emit(CALL_METHOD(String_valueOf, Static(onInstance = false)), arg.pos) - ctx1 - case concatenations => - debuglog("Lifted string concatenations for " + tree + "\n to: " + concatenations) - var ctx1 = ctx - ctx1.bb.emit(CALL_PRIMITIVE(StartConcat), tree.pos) - for (elem <- concatenations) { - val kind = toTypeKind(elem.tpe) - ctx1 = genLoad(elem, ctx1, kind) - ctx1.bb.emit(CALL_PRIMITIVE(StringConcat(kind)), elem.pos) - } - ctx1.bb.emit(CALL_PRIMITIVE(EndConcat), tree.pos) - ctx1 - } - } - - /** Generate the scala ## method. - */ - def genScalaHash(tree: Tree, ctx: Context): Context = { - val hashMethod = { - ctx.bb.emit(LOAD_MODULE(ScalaRunTimeModule)) - getMember(ScalaRunTimeModule, nme.hash_) - } - - val ctx1 = genLoad(tree, ctx, ObjectReference) - ctx1.bb.emit(CALL_METHOD(hashMethod, Static(onInstance = false))) - ctx1 - } - - /** - * Returns a list of trees that each should be concatenated, from - * left to right. It turns a chained call like "a".+("b").+("c") into - * a list of arguments. - */ - def liftStringConcat(tree: Tree): List[Tree] = tree match { - case Apply(fun @ Select(larg, method), rarg) => - if (isPrimitive(fun.symbol) && - scalaPrimitives.getPrimitive(fun.symbol) == scalaPrimitives.CONCAT) - liftStringConcat(larg) ::: rarg - else - List(tree) - case _ => - List(tree) - } - - /** - * Find the label denoted by `lsym` and enter it in context `ctx`. - * - * We only enter one symbol at a time, even though we might traverse the same - * tree more than once per method. That's because we cannot enter labels that - * might be duplicated (for instance, inside finally blocks). - * - * TODO: restrict the scanning to smaller subtrees than the whole method. - * It is sufficient to scan the trees of the innermost enclosing block. - */ - private def resolveForwardLabel(tree: Tree, ctx: Context, lsym: Symbol): Unit = tree foreachPartial { - case t @ LabelDef(_, params, rhs) if t.symbol == lsym => - ctx.labels.getOrElseUpdate(t.symbol, { - val locals = params map (p => new Local(p.symbol, toTypeKind(p.symbol.info), false)) - ctx.method addLocals locals - - new Label(t.symbol) setParams (params map (_.symbol)) - }) - rhs - } - - /** - * Generate code for conditional expressions. The two basic blocks - * represent the continuation in case of success/failure of the - * test. - */ - private def genCond(tree: Tree, - ctx: Context, - thenCtx: Context, - elseCtx: Context): Boolean = - { - /** - * Generate the de-sugared comparison mechanism that will underly an '==' - * - * @param l left-hand side of the '==' - * @param r right-hand side of the '==' - * @param code the comparison operator to use - * @return true if either branch can continue normally to a follow on block, false otherwise - */ - def genComparisonOp(l: Tree, r: Tree, code: Int): Boolean = { - val op: TestOp = code match { - case scalaPrimitives.LT => LT - case scalaPrimitives.LE => LE - case scalaPrimitives.GT => GT - case scalaPrimitives.GE => GE - case scalaPrimitives.ID | scalaPrimitives.EQ => EQ - case scalaPrimitives.NI | scalaPrimitives.NE => NE - - case _ => abort("Unknown comparison primitive: " + code) - } - - // special-case reference (in)equality test for null (null eq x, x eq null) - lazy val nonNullSide = ifOneIsNull(l, r) - if (isReferenceEqualityOp(code) && nonNullSide != null) { - val ctx1 = genLoad(nonNullSide, ctx, ObjectReference) - val branchesReachable = !ctx1.bb.ignore - ctx1.bb.emitOnly( - CZJUMP(thenCtx.bb, elseCtx.bb, op, ObjectReference) - ) - branchesReachable - } - else { - val kind = getMaxType(l.tpe :: r.tpe :: Nil) - var ctx1 = genLoad(l, ctx, kind) - ctx1 = genLoad(r, ctx1, kind) - val branchesReachable = !ctx1.bb.ignore - - ctx1.bb.emitOnly( - CJUMP(thenCtx.bb, elseCtx.bb, op, kind) setPos r.pos - ) - branchesReachable - } - } - - debuglog("Entering genCond with tree: " + tree) - - // the default emission - def default(): Boolean = { - val ctx1 = genLoad(tree, ctx, BOOL) - val branchesReachable = !ctx1.bb.ignore - ctx1.bb.closeWith(CZJUMP(thenCtx.bb, elseCtx.bb, NE, BOOL) setPos tree.pos) - branchesReachable - } - - tree match { - // The comparison symbol is in ScalaPrimitives's "primitives" map - case Apply(fun, args) if isPrimitive(fun.symbol) => - import scalaPrimitives.{ ZNOT, ZAND, ZOR, EQ, getPrimitive } - - // lhs and rhs of test - lazy val Select(lhs, _) = fun - lazy val rhs = args.head - - def genZandOrZor(and: Boolean): Boolean = { - val ctxInterm = ctx.newBlock() - - val lhsBranchesReachable = if (and) genCond(lhs, ctx, ctxInterm, elseCtx) - else genCond(lhs, ctx, thenCtx, ctxInterm) - // If lhs is known to throw, we can kill the just created ctxInterm. - ctxInterm.bb killUnless lhsBranchesReachable - - val rhsBranchesReachable = genCond(rhs, ctxInterm, thenCtx, elseCtx) - - // Reachable means "it does not always throw", i.e. "it might not throw". - // In an expression (a && b) or (a || b), the b branch might not be evaluated. - // Such an expression is therefore known to throw only if both expressions throw. Or, - // successors are reachable if either of the two is reachable (SI-8625). - lhsBranchesReachable || rhsBranchesReachable - } - def genRefEq(isEq: Boolean) = { - val f = genEqEqPrimitive(lhs, rhs, ctx) _ - if (isEq) f(thenCtx, elseCtx) - else f(elseCtx, thenCtx) - } - - getPrimitive(fun.symbol) match { - case ZNOT => genCond(lhs, ctx, elseCtx, thenCtx) - case ZAND => genZandOrZor(and = true) - case ZOR => genZandOrZor(and = false) - case code => - // x == y where LHS is reference type - if (isUniversalEqualityOp(code) && toTypeKind(lhs.tpe).isReferenceType) { - if (code == EQ) genRefEq(isEq = true) - else genRefEq(isEq = false) - } - else if (isComparisonOp(code)) - genComparisonOp(lhs, rhs, code) - else - default() - } - - case _ => default() - } - } - - /** - * Generate the "==" code for object references. It is equivalent of - * if (l eq null) r eq null else l.equals(r); - * - * @param l left-hand side of the '==' - * @param r right-hand side of the '==' - * @param ctx current context - * @param thenCtx target context if the comparison yields true - * @param elseCtx target context if the comparison yields false - * @return true if either branch can continue normally to a follow on block, false otherwise - */ - def genEqEqPrimitive(l: Tree, r: Tree, ctx: Context)(thenCtx: Context, elseCtx: Context): Boolean = { - def getTempLocal = ctx.method.lookupLocal(nme.EQEQ_LOCAL_VAR) getOrElse { - ctx.makeLocal(l.pos, AnyRefTpe, nme.EQEQ_LOCAL_VAR.toString) - } - - /* True if the equality comparison is between values that require the use of the rich equality - * comparator (scala.runtime.Comparator.equals). This is the case when either side of the - * comparison might have a run-time type subtype of java.lang.Number or java.lang.Character. - * When it is statically known that both sides are equal and subtypes of Number of Character, - * not using the rich equality is possible (their own equals method will do ok.)*/ - def mustUseAnyComparator: Boolean = { - def areSameFinals = l.tpe.isFinalType && r.tpe.isFinalType && (l.tpe =:= r.tpe) - !areSameFinals && isMaybeBoxed(l.tpe.typeSymbol) && isMaybeBoxed(r.tpe.typeSymbol) - } - - if (mustUseAnyComparator) { - // when -optimise is on we call the @inline-version of equals, found in ScalaRunTime - val equalsMethod: Symbol = { - if (!settings.optimise) { - if (l.tpe <:< BoxedNumberClass.tpe) { - if (r.tpe <:< BoxedNumberClass.tpe) platform.externalEqualsNumNum - else if (r.tpe <:< BoxedCharacterClass.tpe) platform.externalEqualsNumObject // will be externalEqualsNumChar in 2.12, SI-9030 - else platform.externalEqualsNumObject - } else platform.externalEquals - } else { - ctx.bb.emit(LOAD_MODULE(ScalaRunTimeModule)) - getMember(ScalaRunTimeModule, nme.inlinedEquals) - } - } - - val ctx1 = genLoad(l, ctx, ObjectReference) - val ctx2 = genLoad(r, ctx1, ObjectReference) - val branchesReachable = !ctx2.bb.ignore - ctx2.bb.emitOnly( - CALL_METHOD(equalsMethod, if (settings.optimise) Dynamic else Static(onInstance = false)), - CZJUMP(thenCtx.bb, elseCtx.bb, NE, BOOL) - ) - branchesReachable - } - else { - if (isNull(l)) { - // null == expr -> expr eq null - val ctx1 = genLoad(r, ctx, ObjectReference) - val branchesReachable = !ctx1.bb.ignore - ctx1.bb emitOnly CZJUMP(thenCtx.bb, elseCtx.bb, EQ, ObjectReference) - branchesReachable - } else if (isNull(r)) { - // expr == null -> expr eq null - val ctx1 = genLoad(l, ctx, ObjectReference) - val branchesReachable = !ctx1.bb.ignore - ctx1.bb emitOnly CZJUMP(thenCtx.bb, elseCtx.bb, EQ, ObjectReference) - branchesReachable - } else if (isNonNullExpr(l)) { - // Avoid null check if L is statically non-null. - // - // "" == expr -> "".equals(expr) - // Nil == expr -> Nil.equals(expr) - // - // Common enough (through pattern matching) to treat this specially here rather than - // hoping that -Yconst-opt is enabled. The impossible branches for null checks lead - // to spurious "branch not covered" warnings in Jacoco code coverage. - var ctx1 = genLoad(l, ctx, ObjectReference) - val branchesReachable = !ctx1.bb.ignore - ctx1 = genLoad(r, ctx1, ObjectReference) - ctx1.bb emitOnly( - CALL_METHOD(Object_equals, Dynamic), - CZJUMP(thenCtx.bb, elseCtx.bb, NE, BOOL) - ) - branchesReachable - } else { - val eqEqTempLocal = getTempLocal - var ctx1 = genLoad(l, ctx, ObjectReference) - val branchesReachable = !ctx1.bb.ignore - lazy val nonNullCtx = { - val block = ctx1.newBlock() - block.bb killUnless branchesReachable - block - } - - // l == r -> if (l eq null) r eq null else l.equals(r) - ctx1 = genLoad(r, ctx1, ObjectReference) - val nullCtx = ctx1.newBlock() - nullCtx.bb killUnless branchesReachable - - ctx1.bb.emitOnly( - STORE_LOCAL(eqEqTempLocal) setPos l.pos, - DUP(ObjectReference), - CZJUMP(nullCtx.bb, nonNullCtx.bb, EQ, ObjectReference) - ) - nullCtx.bb.emitOnly( - DROP(ObjectReference) setPos l.pos, // type of AnyRef - LOAD_LOCAL(eqEqTempLocal), - CZJUMP(thenCtx.bb, elseCtx.bb, EQ, ObjectReference) - ) - nonNullCtx.bb.emitOnly( - LOAD_LOCAL(eqEqTempLocal) setPos l.pos, - CALL_METHOD(Object_equals, Dynamic), - CZJUMP(thenCtx.bb, elseCtx.bb, NE, BOOL) - ) - branchesReachable - } - } - } - - /** - * Add all fields of the given class symbol to the current ICode - * class. - */ - private def addClassFields(ctx: Context, cls: Symbol) { - debugassert(ctx.clazz.symbol eq cls, - "Classes are not the same: " + ctx.clazz.symbol + ", " + cls) - - /* Non-method term members are fields, except for module members. Module - * members can only happen on .NET (no flatten) for inner traits. There, - * a module symbol is generated (transformInfo in mixin) which is used - * as owner for the members of the implementation class (so that the - * backend emits them as static). - * No code is needed for this module symbol. - */ - for (f <- cls.info.decls ; if !f.isMethod && f.isTerm && !f.isModule) - ctx.clazz addField new IField(f) - } - - /** - * Add parameters to the current ICode method. It is assumed the methods - * have been uncurried, so the list of lists contains just one list. - */ - private def addMethodParams(ctx: Context, vparamss: List[List[ValDef]]) { - vparamss match { - case Nil => () - - case vparams :: Nil => - for (p <- vparams) { - val lv = new Local(p.symbol, toTypeKind(p.symbol.info), true) - ctx.method.addParam(lv) - ctx.scope.add(lv) - ctx.bb.varsInScope += lv - } - ctx.method.params = ctx.method.params.reverse - - case _ => - abort("Malformed parameter list: " + vparamss) - } - } - - /** Does this tree have a try-catch block? */ - def mayCleanStack(tree: Tree): Boolean = tree exists { - case Try(_, _, _) => true - case _ => false - } - - /** - * If the block consists of a single unconditional jump, prune - * it by replacing the instructions in the predecessor to jump - * directly to the JUMP target of the block. - */ - def prune(method: IMethod) = { - var changed = false - var n = 0 - - def prune0(block: BasicBlock): Unit = { - val optCont = block.lastInstruction match { - case JUMP(b) if (b != block) => Some(b) - case _ => None - } - if (block.size == 1 && optCont.isDefined) { - val Some(cont) = optCont - val pred = block.predecessors - debuglog("Preds: " + pred + " of " + block + " (" + optCont + ")") - pred foreach { p => - changed = true - p.lastInstruction match { - case CJUMP(succ, fail, cond, kind) if (succ == block || fail == block) => - debuglog("Pruning empty if branch.") - p.replaceInstruction(p.lastInstruction, - if (block == succ) - if (block == fail) - CJUMP(cont, cont, cond, kind) - else - CJUMP(cont, fail, cond, kind) - else if (block == fail) - CJUMP(succ, cont, cond, kind) - else - abort("Could not find block in preds: " + method + " " + block + " " + pred + " " + p)) - - case CZJUMP(succ, fail, cond, kind) if (succ == block || fail == block) => - debuglog("Pruning empty ifz branch.") - p.replaceInstruction(p.lastInstruction, - if (block == succ) - if (block == fail) - CZJUMP(cont, cont, cond, kind) - else - CZJUMP(cont, fail, cond, kind) - else if (block == fail) - CZJUMP(succ, cont, cond, kind) - else - abort("Could not find block in preds")) - - case JUMP(b) if (b == block) => - debuglog("Pruning empty JMP branch.") - val replaced = p.replaceInstruction(p.lastInstruction, JUMP(cont)) - debugassert(replaced, "Didn't find p.lastInstruction") - - case SWITCH(tags, labels) if (labels contains block) => - debuglog("Pruning empty SWITCH branch.") - p.replaceInstruction(p.lastInstruction, - SWITCH(tags, labels map (l => if (l == block) cont else l))) - - // the last instr of the predecessor `p` is not a jump to the block `block`. - // this happens when `block` is part of an exception handler covering `b`. - case _ => () - } - } - if (changed) { - debuglog("Removing block: " + block) - method.code.removeBlock(block) - for (e <- method.exh) { - e.covered = e.covered filter (_ != block) - e.blocks = e.blocks filter (_ != block) - if (e.startBlock eq block) - e setStartBlock cont - } - } - } - } - - do { - changed = false - n += 1 - method.blocks foreach prune0 - } while (changed) - - debuglog("Prune fixpoint reached in " + n + " iterations.") - } - - def getMaxType(ts: List[Type]): TypeKind = - ts map toTypeKind reduceLeft (_ maxType _) - - /** Tree transformer that duplicates code and at the same time creates - * fresh symbols for existing labels. Since labels may be used before - * they are defined (forward jumps), all labels found are mapped to fresh - * symbols. References to the same label (use or definition) will remain - * consistent after this transformation (both the use and the definition of - * some label l will be mapped to the same label l'). - * - * Note: If the tree fragment passed to the duplicator contains unbound - * label names, the bind to the outer labeldef will be lost! That's because - * a use of an unbound label l will be transformed to l', and the corresponding - * label def, being outside the scope of this transformation, will not be updated. - * - * All LabelDefs are entered into the context label map, since it makes no sense - * to delay it any more: they will be used at some point. - */ - class DuplicateLabels(boundLabels: Set[Symbol]) extends Transformer { - val labels = perRunCaches.newMap[Symbol, Symbol]() - var method: Symbol = _ - var ctx: Context = _ - - def apply(ctx: Context, t: Tree) = { - this.method = ctx.method.symbol - this.ctx = ctx - transform(t) - } - - override def transform(t: Tree): Tree = { - val sym = t.symbol - def getLabel(pos: Position, name: Name) = - labels.getOrElseUpdate(sym, - method.newLabel(unit.freshTermName(name.toString), sym.pos) setInfo sym.tpe - ) - - t match { - case t @ Apply(_, args) if sym.isLabel && !boundLabels(sym) => - val newSym = getLabel(sym.pos, sym.name) - Apply(global.gen.mkAttributedRef(newSym), transformTrees(args)) setPos t.pos setType t.tpe - - case t @ LabelDef(name, params, rhs) => - val newSym = getLabel(t.pos, name) - val tree = treeCopy.LabelDef(t, newSym.name, params, transform(rhs)) - tree.symbol = newSym - - val pair = (newSym -> (new Label(newSym) setParams (params map (_.symbol)))) - log("Added " + pair + " to labels.") - ctx.labels += pair - ctx.method.addLocals(params map (p => new Local(p.symbol, toTypeKind(p.symbol.info), false))) - - tree - - case _ => super.transform(t) - } - } - } - - /////////////////////// Context //////////////////////////////// - - sealed abstract class Cleanup(val value: AnyRef) { - def contains(x: AnyRef) = value == x - } - case class MonitorRelease(m: Local) extends Cleanup(m) { } - case class Finalizer(f: Tree, ctx: Context) extends Cleanup (f) { } - - def duplicateFinalizer(boundLabels: Set[Symbol], targetCtx: Context, finalizer: Tree) = { - (new DuplicateLabels(boundLabels))(targetCtx, finalizer) - } - - def savingCleanups[T](ctx: Context)(body: => T): T = { - val saved = ctx.cleanups - try body - finally ctx.cleanups = saved - } - - /** - * The Context class keeps information relative to the current state - * in code generation - */ - class Context { - /** The current package. */ - var packg: Name = _ - - /** The current class. */ - var clazz: IClass = _ - - /** The current method. */ - var method: IMethod = _ - - /** The current basic block. */ - var bb: BasicBlock = _ - - /** Map from label symbols to label objects. */ - var labels = perRunCaches.newMap[Symbol, Label]() - - /** Current method definition. */ - var defdef: DefDef = _ - - /** current exception handlers */ - var handlers: List[ExceptionHandler] = Nil - - /** The current monitors or finalizers, to be cleaned up upon `return`. */ - var cleanups: List[Cleanup] = Nil - - /** The exception handlers we are currently generating code for */ - var currentExceptionHandlers: List[ExceptionHandler] = Nil - - /** The current local variable scope. */ - var scope: Scope = EmptyScope - - var handlerCount = 0 - - override def toString = - s"package $packg { class $clazz { def $method { bb=$bb } } }" - - def loadException(ctx: Context, exh: ExceptionHandler, pos: Position) = { - debuglog("Emitting LOAD_EXCEPTION for class: " + exh.loadExceptionClass) - ctx.bb.emit(LOAD_EXCEPTION(exh.loadExceptionClass) setPos pos, pos) - } - - def this(other: Context) = { - this() - this.packg = other.packg - this.clazz = other.clazz - this.method = other.method - this.bb = other.bb - this.labels = other.labels - this.defdef = other.defdef - this.handlers = other.handlers - this.handlerCount = other.handlerCount - this.cleanups = other.cleanups - this.currentExceptionHandlers = other.currentExceptionHandlers - this.scope = other.scope - } - - def setPackage(p: Name): this.type = { - this.packg = p - this - } - - def setClass(c: IClass): this.type = { - this.clazz = c - this - } - - def setMethod(m: IMethod): this.type = { - this.method = m - this - } - - def setBasicBlock(b: BasicBlock): this.type = { - this.bb = b - this - } - - def enterSynchronized(monitor: Local): this.type = { - cleanups = MonitorRelease(monitor) :: cleanups - this - } - - def exitSynchronized(monitor: Local): this.type = { - assert(cleanups.head contains monitor, - "Bad nesting of cleanup operations: " + cleanups + " trying to exit from monitor: " + monitor) - cleanups = cleanups.tail - this - } - - def addFinalizer(f: Tree, ctx: Context): this.type = { - cleanups = Finalizer(f, ctx) :: cleanups - this - } - - /** Prepare a new context upon entry into a method. - */ - def enterMethod(m: IMethod, d: DefDef): Context = { - val ctx1 = new Context(this) setMethod(m) - ctx1.labels = mutable.HashMap() - ctx1.method.code = new Code(m) - ctx1.bb = ctx1.method.startBlock - ctx1.defdef = d - ctx1.scope = EmptyScope - ctx1.enterScope() - ctx1 - } - - /** Return a new context for a new basic block. */ - def newBlock(): Context = { - val block = method.code.newBlock() - handlers foreach (_ addCoveredBlock block) - currentExceptionHandlers foreach (_ addBlock block) - block.varsInScope.clear() - block.varsInScope ++= scope.varsInScope - new Context(this) setBasicBlock block - } - - def enterScope() { - scope = new Scope(scope) - } - - def exitScope() { - if (bb.nonEmpty) { - scope.locals foreach { lv => bb.emit(SCOPE_EXIT(lv)) } - } - scope = scope.outer - } - - /** Create a new exception handler and adds it in the list - * of current exception handlers. All new blocks will be - * 'covered' by this exception handler (in addition to the - * previously active handlers). - */ - private def newExceptionHandler(cls: Symbol, pos: Position): ExceptionHandler = { - handlerCount += 1 - val exh = new ExceptionHandler(method, newTermNameCached("" + handlerCount), cls, pos) - method.addHandler(exh) - handlers = exh :: handlers - debuglog("added handler: " + exh) - - exh - } - - /** Add an active exception handler in this context. It will cover all new basic blocks - * created from now on. */ - private def addActiveHandler(exh: ExceptionHandler) { - handlerCount += 1 - handlers = exh :: handlers - debuglog("added handler: " + exh) - } - - /** Return a new context for generating code for the given - * exception handler. - */ - private def enterExceptionHandler(exh: ExceptionHandler): Context = { - currentExceptionHandlers ::= exh - val ctx = newBlock() - exh.setStartBlock(ctx.bb) - ctx - } - - def endHandler() { - currentExceptionHandlers = currentExceptionHandlers.tail - } - - /** Clone the current context */ - def dup: Context = new Context(this) - - /** Make a fresh local variable. It ensures the 'name' is unique. */ - def makeLocal(pos: Position, tpe: Type, name: String): Local = { - val sym = method.symbol.newVariable(unit.freshTermName(name), pos, Flags.SYNTHETIC) setInfo tpe - this.method.addLocal(new Local(sym, toTypeKind(tpe), false)) - } - - - /** - * Generate exception handlers for the body. Body is evaluated - * with a context where all the handlers are active. Handlers are - * evaluated in the 'outer' context. - * - * It returns the resulting context, with the same active handlers as - * before the call. Use it like: - * - * ` ctx.Try( ctx => { - * ctx.bb.emit(...) // protected block - * }, (ThrowableClass, - * ctx => { - * ctx.bb.emit(...); // exception handler - * }), (AnotherExceptionClass, - * ctx => {... - * } ))` - * - * The resulting structure will look something like - * - * outer: - * // this 'useless' jump will be removed later, - * // for now it separates the try body's blocks from previous - * // code since the try body needs its own exception handlers - * JUMP body - * - * body: - * [ try body ] - * JUMP normalExit - * - * catch[i]: - * [ handler[i] body ] - * JUMP normalExit - * - * catchAll: - * STORE exception - * [ finally body ] - * THROW exception - * - * normalExit: - * [ finally body ] - * - * each catch[i] will cover body. catchAll will cover both body and each catch[i] - * Additional finally copies are created on the emission of every RETURN in the try body and exception handlers. - * - * This could result in unreachable code which has to be cleaned up later, e.g. if the try and all the exception - * handlers always end in RETURN then there will be no "normal" flow out of the try/catch/finally. - * Later reachability analysis will remove unreachable code. - */ - def Try(body: Context => Context, - handlers: List[(Symbol, TypeKind, Context => Context)], - finalizer: Tree, - tree: Tree) = { - - val outerCtx = this.dup // context for generating exception handlers, covered by the catch-all finalizer - val finalizerCtx = this.dup // context for generating finalizer handler - val normalExitCtx = outerCtx.newBlock() // context where flow will go on a "normal" (non-return, non-throw) exit from a try or catch handler - var normalExitReachable = false - var tmp: Local = null - val kind = toTypeKind(tree.tpe) - val guardResult = kind != UNIT && mayCleanStack(finalizer) - // we need to save bound labels before any code generation is performed on - // the current context (otherwise, any new labels in the finalizer that need to - // be duplicated would be incorrectly considered bound -- see #2850). - val boundLabels: Set[Symbol] = Set.empty ++ labels.keySet - - if (guardResult) { - tmp = this.makeLocal(tree.pos, tree.tpe, "tmp") - } - - def emitFinalizer(ctx: Context): Context = if (!finalizer.isEmpty) { - val ctx1 = finalizerCtx.dup.newBlock() - ctx1.bb killIf ctx.bb.ignore - ctx.bb.closeWith(JUMP(ctx1.bb)) - - if (guardResult) { - ctx1.bb.emit(STORE_LOCAL(tmp)) - val ctx2 = genLoad(duplicateFinalizer(boundLabels, ctx1, finalizer), ctx1, UNIT) - ctx2.bb.emit(LOAD_LOCAL(tmp)) - ctx2 - } else - genLoad(duplicateFinalizer(boundLabels, ctx1, finalizer), ctx1, UNIT) - } else ctx - - - // Generate the catch-all exception handler that deals with uncaught exceptions coming - // from the try or exception handlers. It catches the exception, runs the finally code, then rethrows - // the exception - if (settings.YdisableUnreachablePrevention || !outerCtx.bb.ignore) { - if (finalizer != EmptyTree) { - val exh = outerCtx.newExceptionHandler(NoSymbol, finalizer.pos) // finalizer covers exception handlers - this.addActiveHandler(exh) // .. and body as well - val exhStartCtx = finalizerCtx.enterExceptionHandler(exh) - exhStartCtx.bb killIf outerCtx.bb.ignore - val exception = exhStartCtx.makeLocal(finalizer.pos, ThrowableTpe, "exc") - loadException(exhStartCtx, exh, finalizer.pos) - exhStartCtx.bb.emit(STORE_LOCAL(exception)) - val exhEndCtx = genLoad(finalizer, exhStartCtx, UNIT) - exhEndCtx.bb.emit(LOAD_LOCAL(exception)) - exhEndCtx.bb.closeWith(THROW(ThrowableClass)) - exhEndCtx.bb.enterIgnoreMode() - finalizerCtx.endHandler() - } - - // Generate each exception handler - for ((sym, kind, handler) <- handlers) { - val exh = this.newExceptionHandler(sym, tree.pos) - val exhStartCtx = outerCtx.enterExceptionHandler(exh) - exhStartCtx.bb killIf outerCtx.bb.ignore - exhStartCtx.addFinalizer(finalizer, finalizerCtx) - loadException(exhStartCtx, exh, tree.pos) - val exhEndCtx = handler(exhStartCtx) - normalExitReachable ||= !exhEndCtx.bb.ignore - exhEndCtx.bb.closeWith(JUMP(normalExitCtx.bb)) - outerCtx.endHandler() - } - } - - val bodyCtx = this.newBlock() - bodyCtx.bb killIf outerCtx.bb.ignore - if (finalizer != EmptyTree) - bodyCtx.addFinalizer(finalizer, finalizerCtx) - - val bodyEndCtx = body(bodyCtx) - - outerCtx.bb.closeWith(JUMP(bodyCtx.bb)) - - normalExitReachable ||= !bodyEndCtx.bb.ignore - normalExitCtx.bb killUnless normalExitReachable - bodyEndCtx.bb.closeWith(JUMP(normalExitCtx.bb)) - - emitFinalizer(normalExitCtx) - } - } - } - - /** - * Represent a label in the current method code. In order - * to support forward jumps, labels can be created without - * having a designated target block. They can later be attached - * by calling `anchor`. - */ - class Label(val symbol: Symbol) { - var anchored = false - var block: BasicBlock = _ - var params: List[Symbol] = _ - - private var toPatch: List[Instruction] = Nil - - /** Fix this label to the given basic block. */ - def anchor(b: BasicBlock): Label = { - assert(!anchored, "Cannot anchor an already anchored label!") - anchored = true - this.block = b - this - } - - def setParams(p: List[Symbol]): Label = { - assert(params eq null, "Cannot set label parameters twice!") - params = p - this - } - - /** Add an instruction that refers to this label. */ - def addCallingInstruction(i: Instruction) = - toPatch = i :: toPatch - - /** - * Patch the code by replacing pseudo call instructions with - * jumps to the given basic block. - */ - def patch(code: Code) { - val map = mapFrom(toPatch)(patch) - code.blocks foreach (_ subst map) - } - - /** - * Return the patched instruction. If the given instruction - * jumps to this label, replace it with the basic block. Otherwise, - * return the same instruction. Conditional jumps have more than one - * label, so they are replaced only if all labels are anchored. - */ - def patch(instr: Instruction): Instruction = { - assert(anchored, "Cannot patch until this label is anchored: " + this) - - instr match { - case PJUMP(self) - if (self == this) => JUMP(block) - - case PCJUMP(self, failure, cond, kind) - if (self == this && failure.anchored) => - CJUMP(block, failure.block, cond, kind) - - case PCJUMP(success, self, cond, kind) - if (self == this && success.anchored) => - CJUMP(success.block, block, cond, kind) - - case PCZJUMP(self, failure, cond, kind) - if (self == this && failure.anchored) => - CZJUMP(block, failure.block, cond, kind) - - case PCZJUMP(success, self, cond, kind) - if (self == this && success.anchored) => - CZJUMP(success.block, block, cond, kind) - - case _ => instr - } - } - - override def toString() = symbol.toString() - } - - ///////////////// Fake instructions ////////////////////////// - - /** - * Pseudo jump: it takes a Label instead of a basic block. - * It is used temporarily during code generation. It is replaced - * by a real JUMP instruction when all labels are resolved. - */ - abstract class PseudoJUMP(label: Label) extends Instruction { - override def toString = s"PJUMP(${label.symbol})" - override def consumed = 0 - override def produced = 0 - - // register with the given label - if (!label.anchored) - label.addCallingInstruction(this) - } - - case class PJUMP(whereto: Label) extends PseudoJUMP(whereto) - - case class PCJUMP(success: Label, failure: Label, cond: TestOp, kind: TypeKind) - extends PseudoJUMP(success) { - override def toString(): String = - "PCJUMP (" + kind + ") " + success.symbol.simpleName + - " : " + failure.symbol.simpleName - - if (!failure.anchored) - failure.addCallingInstruction(this) - } - - case class PCZJUMP(success: Label, failure: Label, cond: TestOp, kind: TypeKind) - extends PseudoJUMP(success) { - override def toString(): String = - "PCZJUMP (" + kind + ") " + success.symbol.simpleName + - " : " + failure.symbol.simpleName - - if (!failure.anchored) - failure.addCallingInstruction(this) - } - - /** Local variable scopes. Keep track of line numbers for debugging info. */ - class Scope(val outer: Scope) { - val locals: ListBuffer[Local] = new ListBuffer - - def add(l: Local) = locals += l - - /** Return all locals that are in scope. */ - def varsInScope: Buffer[Local] = outer.varsInScope.clone() ++= locals - - override def toString() = locals.mkString(outer.toString + "[", ", ", "]") - } - - object EmptyScope extends Scope(null) { - override def toString() = "[]" - override def varsInScope: Buffer[Local] = new ListBuffer - } -} |