--- old/src/jdk.scripting.nashorn/share/classes/jdk/nashorn/internal/runtime/ScriptFunctionData.java 2020-04-15 18:50:06.000000000 +0530 +++ /dev/null 2020-04-15 18:50:07.000000000 +0530 @@ -1,899 +0,0 @@ -/* - * Copyright (c) 2010, 2013, Oracle and/or its affiliates. All rights reserved. - * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. - * - * This code is free software; you can redistribute it and/or modify it - * under the terms of the GNU General Public License version 2 only, as - * published by the Free Software Foundation. Oracle designates this - * particular file as subject to the "Classpath" exception as provided - * by Oracle in the LICENSE file that accompanied this code. - * - * This code is distributed in the hope that it will be useful, but WITHOUT - * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or - * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License - * version 2 for more details (a copy is included in the LICENSE file that - * accompanied this code). - * - * You should have received a copy of the GNU General Public License version - * 2 along with this work; if not, write to the Free Software Foundation, - * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. - * - * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA - * or visit www.oracle.com if you need additional information or have any - * questions. - */ - -package jdk.nashorn.internal.runtime; - -import static jdk.nashorn.internal.lookup.Lookup.MH; -import static jdk.nashorn.internal.runtime.ECMAErrors.typeError; -import static jdk.nashorn.internal.runtime.ScriptRuntime.UNDEFINED; - -import java.io.IOException; -import java.io.ObjectInputStream; -import java.io.Serializable; -import java.lang.invoke.MethodHandle; -import java.lang.invoke.MethodHandles; -import java.lang.invoke.MethodType; -import java.util.Collection; -import java.util.LinkedList; -import java.util.List; -import jdk.nashorn.internal.runtime.linker.LinkerCallSite; - - -/** - * A container for data needed to instantiate a specific {@link ScriptFunction} at runtime. - * Instances of this class are created during codegen and stored in script classes' - * constants array to reduce function instantiation overhead during runtime. - */ -public abstract class ScriptFunctionData implements Serializable { - static final int MAX_ARITY = LinkerCallSite.ARGLIMIT; - static { - // Assert it fits in a byte, as that's what we store it in. It's just a size optimization though, so if needed - // "byte arity" field can be widened. - assert MAX_ARITY < 256; - } - - /** Name of the function or "" for anonymous functions */ - protected final String name; - - /** - * A list of code versions of a function sorted in ascending order of generic descriptors. - */ - protected transient LinkedList code = new LinkedList<>(); - - /** Function flags */ - protected int flags; - - // Parameter arity of the function, corresponding to "f.length". E.g. "function f(a, b, c) { ... }" arity is 3, and - // some built-in ECMAScript functions have their arity declared by the specification. Note that regardless of this - // value, the function might still be capable of receiving variable number of arguments, see isVariableArity. - private int arity; - - /** - * A pair of method handles used for generic invoker and constructor. Field is volatile as it can be initialized by - * multiple threads concurrently, but we still tolerate a race condition in it as all values stored into it are - * idempotent. - */ - private volatile transient GenericInvokers genericInvokers; - - private static final MethodHandle BIND_VAR_ARGS = findOwnMH("bindVarArgs", Object[].class, Object[].class, Object[].class); - - /** Is this a strict mode function? */ - public static final int IS_STRICT = 1 << 0; - /** Is this a built-in function? */ - public static final int IS_BUILTIN = 1 << 1; - /** Is this a constructor function? */ - public static final int IS_CONSTRUCTOR = 1 << 2; - /** Does this function expect a callee argument? */ - public static final int NEEDS_CALLEE = 1 << 3; - /** Does this function make use of the this-object argument? */ - public static final int USES_THIS = 1 << 4; - /** Is this a variable arity function? */ - public static final int IS_VARIABLE_ARITY = 1 << 5; - /** Is this a object literal property getter or setter? */ - public static final int IS_PROPERTY_ACCESSOR = 1 << 6; - /** Is this an ES6 method? */ - public static final int IS_ES6_METHOD = 1 << 7; - - /** Flag for strict or built-in functions */ - public static final int IS_STRICT_OR_BUILTIN = IS_STRICT | IS_BUILTIN; - /** Flag for built-in constructors */ - public static final int IS_BUILTIN_CONSTRUCTOR = IS_BUILTIN | IS_CONSTRUCTOR; - - private static final long serialVersionUID = 4252901245508769114L; - - /** - * Constructor - * - * @param name script function name - * @param arity arity - * @param flags the function flags - */ - ScriptFunctionData(final String name, final int arity, final int flags) { - this.name = name; - this.flags = flags; - setArity(arity); - } - - final int getArity() { - return arity; - } - - String getDocumentation() { - return toSource(); - } - - String getDocumentationKey() { - return null; - } - - final boolean isVariableArity() { - return (flags & IS_VARIABLE_ARITY) != 0; - } - - /** - * Used from e.g. Native*$Constructors as an explicit call. TODO - make arity immutable and final - * @param arity new arity - */ - void setArity(final int arity) { - if(arity < 0 || arity > MAX_ARITY) { - throw new IllegalArgumentException(String.valueOf(arity)); - } - this.arity = arity; - } - - /** - * Used from nasgen generated code. - * - * @param docKey documentation key for this function - */ - void setDocumentationKey(final String docKey) { - } - - - CompiledFunction bind(final CompiledFunction originalInv, final ScriptFunction fn, final Object self, final Object[] args) { - final MethodHandle boundInvoker = bindInvokeHandle(originalInv.createComposableInvoker(), fn, self, args); - - if (isConstructor()) { - return new CompiledFunction(boundInvoker, bindConstructHandle(originalInv.createComposableConstructor(), fn, args), null); - } - - return new CompiledFunction(boundInvoker); - } - - /** - * Is this a ScriptFunction generated with strict semantics? - * @return true if strict, false otherwise - */ - public final boolean isStrict() { - return (flags & IS_STRICT) != 0; - } - - /** - * Return the complete internal function name for this - * data, not anonymous or similar. May be identical - * @return internal function name - */ - protected String getFunctionName() { - return getName(); - } - - final boolean isBuiltin() { - return (flags & IS_BUILTIN) != 0; - } - - final boolean isConstructor() { - return (flags & IS_CONSTRUCTOR) != 0; - } - - abstract boolean needsCallee(); - - /** - * Returns true if this is a non-strict, non-built-in function that requires non-primitive this argument - * according to ECMA 10.4.3. - * @return true if this argument must be an object - */ - final boolean needsWrappedThis() { - return (flags & USES_THIS) != 0 && (flags & IS_STRICT_OR_BUILTIN) == 0; - } - - String toSource() { - return "function " + (name == null ? "" : name) + "() { [native code] }"; - } - - String getName() { - return name; - } - - /** - * Get this function as a String containing its source code. If no source code - * exists in this ScriptFunction, its contents will be displayed as {@code [native code]} - * - * @return string representation of this function - */ - @Override - public String toString() { - return name.isEmpty() ? "" : name; - } - - /** - * Verbose description of data - * @return verbose description - */ - public String toStringVerbose() { - final StringBuilder sb = new StringBuilder(); - - sb.append("name='"). - append(name.isEmpty() ? "" : name). - append("' "). - append(code.size()). - append(" invokers="). - append(code); - - return sb.toString(); - } - - /** - * Pick the best invoker, i.e. the one version of this method with as narrow and specific - * types as possible. If the call site arguments are objects, but boxed primitives we can - * also try to get a primitive version of the method and do an unboxing filter, but then - * we need to insert a guard that checks the argument is really always a boxed primitive - * and not suddenly a "real" object - * - * @param callSiteType callsite type - * @return compiled function object representing the best invoker. - */ - final CompiledFunction getBestInvoker(final MethodType callSiteType, final ScriptObject runtimeScope) { - return getBestInvoker(callSiteType, runtimeScope, CompiledFunction.NO_FUNCTIONS); - } - - final CompiledFunction getBestInvoker(final MethodType callSiteType, final ScriptObject runtimeScope, final Collection forbidden) { - final CompiledFunction cf = getBest(callSiteType, runtimeScope, forbidden); - assert cf != null; - return cf; - } - - final CompiledFunction getBestConstructor(final MethodType callSiteType, final ScriptObject runtimeScope, final Collection forbidden) { - if (!isConstructor()) { - throw typeError("not.a.constructor", toSource()); - } - // Constructor call sites don't have a "this", but getBest is meant to operate on "callee, this, ..." style - final CompiledFunction cf = getBest(callSiteType.insertParameterTypes(1, Object.class), runtimeScope, forbidden); - return cf; - } - - /** - * If we can have lazy code generation, this is a hook to ensure that the code has been compiled. - * This does not guarantee the code been installed in this {@code ScriptFunctionData} instance - */ - protected void ensureCompiled() { - //empty - } - - /** - * Return a generic Object/Object invoker for this method. It will ensure code - * is generated, get the most generic of all versions of this function and adapt it - * to Objects. - * - * @param runtimeScope the runtime scope. It can be used to evaluate types of scoped variables to guide the - * optimistic compilation, should the call to this method trigger code compilation. Can be null if current runtime - * scope is not known, but that might cause compilation of code that will need more deoptimization passes. - * @return generic invoker of this script function - */ - final MethodHandle getGenericInvoker(final ScriptObject runtimeScope) { - // This method has race conditions both on genericsInvoker and genericsInvoker.invoker, but even if invoked - // concurrently, they'll create idempotent results, so it doesn't matter. We could alternatively implement this - // using java.util.concurrent.AtomicReferenceFieldUpdater, but it's hardly worth it. - final GenericInvokers lgenericInvokers = ensureGenericInvokers(); - MethodHandle invoker = lgenericInvokers.invoker; - if(invoker == null) { - lgenericInvokers.invoker = invoker = createGenericInvoker(runtimeScope); - } - return invoker; - } - - private MethodHandle createGenericInvoker(final ScriptObject runtimeScope) { - return makeGenericMethod(getGeneric(runtimeScope).createComposableInvoker()); - } - - final MethodHandle getGenericConstructor(final ScriptObject runtimeScope) { - // This method has race conditions both on genericsInvoker and genericsInvoker.constructor, but even if invoked - // concurrently, they'll create idempotent results, so it doesn't matter. We could alternatively implement this - // using java.util.concurrent.AtomicReferenceFieldUpdater, but it's hardly worth it. - final GenericInvokers lgenericInvokers = ensureGenericInvokers(); - MethodHandle constructor = lgenericInvokers.constructor; - if(constructor == null) { - lgenericInvokers.constructor = constructor = createGenericConstructor(runtimeScope); - } - return constructor; - } - - private MethodHandle createGenericConstructor(final ScriptObject runtimeScope) { - return makeGenericMethod(getGeneric(runtimeScope).createComposableConstructor()); - } - - private GenericInvokers ensureGenericInvokers() { - GenericInvokers lgenericInvokers = genericInvokers; - if(lgenericInvokers == null) { - genericInvokers = lgenericInvokers = new GenericInvokers(); - } - return lgenericInvokers; - } - - private static MethodType widen(final MethodType cftype) { - final Class[] paramTypes = new Class[cftype.parameterCount()]; - for (int i = 0; i < cftype.parameterCount(); i++) { - paramTypes[i] = cftype.parameterType(i).isPrimitive() ? cftype.parameterType(i) : Object.class; - } - return MH.type(cftype.returnType(), paramTypes); - } - - /** - * Used to find an apply to call version that fits this callsite. - * We cannot just, as in the normal matcher case, return e.g. (Object, Object, int) - * for (Object, Object, int, int, int) or we will destroy the semantics and get - * a function that, when padded with undefined values, behaves differently - * @param type actual call site type - * @return apply to call that perfectly fits this callsite or null if none found - */ - CompiledFunction lookupExactApplyToCall(final MethodType type) { - // Callsite type always has callee, drop it if this function doesn't need it. - final MethodType adaptedType = needsCallee() ? type : type.dropParameterTypes(0, 1); - - for (final CompiledFunction cf : code) { - if (!cf.isApplyToCall()) { - continue; - } - - final MethodType cftype = cf.type(); - if (cftype.parameterCount() != adaptedType.parameterCount()) { - continue; - } - - if (widen(cftype).equals(widen(adaptedType))) { - return cf; - } - } - - return null; - } - - CompiledFunction pickFunction(final MethodType callSiteType, final boolean canPickVarArg) { - for (final CompiledFunction candidate : code) { - if (candidate.matchesCallSite(callSiteType, canPickVarArg)) { - return candidate; - } - } - return null; - } - - /** - * Returns the best function for the specified call site type. - * @param callSiteType The call site type. Call site types are expected to have the form - * {@code (callee, this[, args...])}. - * @param runtimeScope the runtime scope. It can be used to evaluate types of scoped variables to guide the - * optimistic compilation, should the call to this method trigger code compilation. Can be null if current runtime - * scope is not known, but that might cause compilation of code that will need more deoptimization passes. - * @param linkLogicOkay is a CompiledFunction with a LinkLogic acceptable? - * @return the best function for the specified call site type. - */ - abstract CompiledFunction getBest(final MethodType callSiteType, final ScriptObject runtimeScope, final Collection forbidden, final boolean linkLogicOkay); - - /** - * Returns the best function for the specified call site type. - * @param callSiteType The call site type. Call site types are expected to have the form - * {@code (callee, this[, args...])}. - * @param runtimeScope the runtime scope. It can be used to evaluate types of scoped variables to guide the - * optimistic compilation, should the call to this method trigger code compilation. Can be null if current runtime - * scope is not known, but that might cause compilation of code that will need more deoptimization passes. - * @return the best function for the specified call site type. - */ - final CompiledFunction getBest(final MethodType callSiteType, final ScriptObject runtimeScope, final Collection forbidden) { - return getBest(callSiteType, runtimeScope, forbidden, true); - } - - boolean isValidCallSite(final MethodType callSiteType) { - return callSiteType.parameterCount() >= 2 && // Must have at least (callee, this) - callSiteType.parameterType(0).isAssignableFrom(ScriptFunction.class); // Callee must be assignable from script function - } - - CompiledFunction getGeneric(final ScriptObject runtimeScope) { - return getBest(getGenericType(), runtimeScope, CompiledFunction.NO_FUNCTIONS, false); - } - - /** - * Get a method type for a generic invoker. - * @return the method type for the generic invoker - */ - abstract MethodType getGenericType(); - - /** - * Allocates an object using this function's allocator. - * - * @param map the property map for the allocated object. - * @return the object allocated using this function's allocator, or null if the function doesn't have an allocator. - */ - ScriptObject allocate(final PropertyMap map) { - return null; - } - - /** - * Get the property map to use for objects allocated by this function. - * - * @param prototype the prototype of the allocated object - * @return the property map for allocated objects. - */ - PropertyMap getAllocatorMap(final ScriptObject prototype) { - return null; - } - - /** - * This method is used to create the immutable portion of a bound function. - * See {@link ScriptFunction#createBound(Object, Object[])} - * - * @param fn the original function being bound - * @param self this reference to bind. Can be null. - * @param args additional arguments to bind. Can be null. - */ - ScriptFunctionData makeBoundFunctionData(final ScriptFunction fn, final Object self, final Object[] args) { - final Object[] allArgs = args == null ? ScriptRuntime.EMPTY_ARRAY : args; - final int length = args == null ? 0 : args.length; - // Clear the callee and this flags - final int boundFlags = flags & ~NEEDS_CALLEE & ~USES_THIS; - - final List boundList = new LinkedList<>(); - final ScriptObject runtimeScope = fn.getScope(); - final CompiledFunction bindTarget = new CompiledFunction(getGenericInvoker(runtimeScope), getGenericConstructor(runtimeScope), null); - boundList.add(bind(bindTarget, fn, self, allArgs)); - - return new FinalScriptFunctionData(name, Math.max(0, getArity() - length), boundList, boundFlags); - } - - /** - * Convert this argument for non-strict functions according to ES 10.4.3 - * - * @param thiz the this argument - * - * @return the converted this object - */ - private Object convertThisObject(final Object thiz) { - return needsWrappedThis() ? wrapThis(thiz) : thiz; - } - - static Object wrapThis(final Object thiz) { - if (!(thiz instanceof ScriptObject)) { - if (JSType.nullOrUndefined(thiz)) { - return Context.getGlobal(); - } - - if (isPrimitiveThis(thiz)) { - return Context.getGlobal().wrapAsObject(thiz); - } - } - - return thiz; - } - - static boolean isPrimitiveThis(final Object obj) { - return JSType.isString(obj) || obj instanceof Number || obj instanceof Boolean; - } - - /** - * Creates an invoker method handle for a bound function. - * - * @param targetFn the function being bound - * @param originalInvoker an original invoker method handle for the function. This can be its generic invoker or - * any of its specializations. - * @param self the "this" value being bound - * @param args additional arguments being bound - * - * @return a bound invoker method handle that will bind the self value and the specified arguments. The resulting - * invoker never needs a callee; if the original invoker needed it, it will be bound to {@code fn}. The resulting - * invoker still takes an initial {@code this} parameter, but it is always dropped and the bound {@code self} passed - * to the original invoker on invocation. - */ - private MethodHandle bindInvokeHandle(final MethodHandle originalInvoker, final ScriptFunction targetFn, final Object self, final Object[] args) { - // Is the target already bound? If it is, we won't bother binding either callee or self as they're already bound - // in the target and will be ignored anyway. - final boolean isTargetBound = targetFn.isBoundFunction(); - - final boolean needsCallee = needsCallee(originalInvoker); - assert needsCallee == needsCallee() : "callee contract violation 2"; - assert !(isTargetBound && needsCallee); // already bound functions don't need a callee - - final Object boundSelf = isTargetBound ? null : convertThisObject(self); - final MethodHandle boundInvoker; - - if (isVarArg(originalInvoker)) { - // First, bind callee and this without arguments - final MethodHandle noArgBoundInvoker; - - if (isTargetBound) { - // Don't bind either callee or this - noArgBoundInvoker = originalInvoker; - } else if (needsCallee) { - // Bind callee and this - noArgBoundInvoker = MH.insertArguments(originalInvoker, 0, targetFn, boundSelf); - } else { - // Only bind this - noArgBoundInvoker = MH.bindTo(originalInvoker, boundSelf); - } - // Now bind arguments - if (args.length > 0) { - boundInvoker = varArgBinder(noArgBoundInvoker, args); - } else { - boundInvoker = noArgBoundInvoker; - } - } else { - // If target is already bound, insert additional bound arguments after "this" argument, at position 1. - final int argInsertPos = isTargetBound ? 1 : 0; - final Object[] boundArgs = new Object[Math.min(originalInvoker.type().parameterCount() - argInsertPos, args.length + (isTargetBound ? 0 : needsCallee ? 2 : 1))]; - int next = 0; - if (!isTargetBound) { - if (needsCallee) { - boundArgs[next++] = targetFn; - } - boundArgs[next++] = boundSelf; - } - // If more bound args were specified than the function can take, we'll just drop those. - System.arraycopy(args, 0, boundArgs, next, boundArgs.length - next); - // If target is already bound, insert additional bound arguments after "this" argument, at position 1; - // "this" will get dropped anyway by the target invoker. We previously asserted that already bound functions - // don't take a callee parameter, so we can know that the signature is (this[, args...]) therefore args - // start at position 1. If the function is not bound, we start inserting arguments at position 0. - boundInvoker = MH.insertArguments(originalInvoker, argInsertPos, boundArgs); - } - - if (isTargetBound) { - return boundInvoker; - } - - // If the target is not already bound, add a dropArguments that'll throw away the passed this - return MH.dropArguments(boundInvoker, 0, Object.class); - } - - /** - * Creates a constructor method handle for a bound function using the passed constructor handle. - * - * @param originalConstructor the constructor handle to bind. It must be a composed constructor. - * @param fn the function being bound - * @param args arguments being bound - * - * @return a bound constructor method handle that will bind the specified arguments. The resulting constructor never - * needs a callee; if the original constructor needed it, it will be bound to {@code fn}. The resulting constructor - * still takes an initial {@code this} parameter and passes it to the underlying original constructor. Finally, if - * this script function data object has no constructor handle, null is returned. - */ - private static MethodHandle bindConstructHandle(final MethodHandle originalConstructor, final ScriptFunction fn, final Object[] args) { - assert originalConstructor != null; - - // If target function is already bound, don't bother binding the callee. - final MethodHandle calleeBoundConstructor = fn.isBoundFunction() ? originalConstructor : - MH.dropArguments(MH.bindTo(originalConstructor, fn), 0, ScriptFunction.class); - - if (args.length == 0) { - return calleeBoundConstructor; - } - - if (isVarArg(calleeBoundConstructor)) { - return varArgBinder(calleeBoundConstructor, args); - } - - final Object[] boundArgs; - - final int maxArgCount = calleeBoundConstructor.type().parameterCount() - 1; - if (args.length <= maxArgCount) { - boundArgs = args; - } else { - boundArgs = new Object[maxArgCount]; - System.arraycopy(args, 0, boundArgs, 0, maxArgCount); - } - - return MH.insertArguments(calleeBoundConstructor, 1, boundArgs); - } - - /** - * Takes a method handle, and returns a potentially different method handle that can be used in - * {@code ScriptFunction#invoke(Object, Object...)} or {code ScriptFunction#construct(Object, Object...)}. - * The returned method handle will be sure to return {@code Object}, and will have all its parameters turned into - * {@code Object} as well, except for the following ones: - *
    - *
  • a last parameter of type {@code Object[]} which is used for vararg functions,
    • - *
  • the first argument, which is forced to be {@link ScriptFunction}, in case the function receives itself - * (callee) as an argument.
    • - *
- * - * @param mh the original method handle - * - * @return the new handle, conforming to the rules above. - */ - private static MethodHandle makeGenericMethod(final MethodHandle mh) { - final MethodType type = mh.type(); - final MethodType newType = makeGenericType(type); - return type.equals(newType) ? mh : mh.asType(newType); - } - - private static MethodType makeGenericType(final MethodType type) { - MethodType newType = type.generic(); - if (isVarArg(type)) { - newType = newType.changeParameterType(type.parameterCount() - 1, Object[].class); - } - if (needsCallee(type)) { - newType = newType.changeParameterType(0, ScriptFunction.class); - } - return newType; - } - - /** - * Execute this script function. - * - * @param self Target object. - * @param arguments Call arguments. - * @return ScriptFunction result. - * - * @throws Throwable if there is an exception/error with the invocation or thrown from it - */ - Object invoke(final ScriptFunction fn, final Object self, final Object... arguments) throws Throwable { - final MethodHandle mh = getGenericInvoker(fn.getScope()); - final Object selfObj = convertThisObject(self); - final Object[] args = arguments == null ? ScriptRuntime.EMPTY_ARRAY : arguments; - - DebuggerSupport.notifyInvoke(mh); - - if (isVarArg(mh)) { - if (needsCallee(mh)) { - return mh.invokeExact(fn, selfObj, args); - } - return mh.invokeExact(selfObj, args); - } - - final int paramCount = mh.type().parameterCount(); - if (needsCallee(mh)) { - switch (paramCount) { - case 2: - return mh.invokeExact(fn, selfObj); - case 3: - return mh.invokeExact(fn, selfObj, getArg(args, 0)); - case 4: - return mh.invokeExact(fn, selfObj, getArg(args, 0), getArg(args, 1)); - case 5: - return mh.invokeExact(fn, selfObj, getArg(args, 0), getArg(args, 1), getArg(args, 2)); - case 6: - return mh.invokeExact(fn, selfObj, getArg(args, 0), getArg(args, 1), getArg(args, 2), getArg(args, 3)); - case 7: - return mh.invokeExact(fn, selfObj, getArg(args, 0), getArg(args, 1), getArg(args, 2), getArg(args, 3), getArg(args, 4)); - case 8: - return mh.invokeExact(fn, selfObj, getArg(args, 0), getArg(args, 1), getArg(args, 2), getArg(args, 3), getArg(args, 4), getArg(args, 5)); - default: - return mh.invokeWithArguments(withArguments(fn, selfObj, paramCount, args)); - } - } - - switch (paramCount) { - case 1: - return mh.invokeExact(selfObj); - case 2: - return mh.invokeExact(selfObj, getArg(args, 0)); - case 3: - return mh.invokeExact(selfObj, getArg(args, 0), getArg(args, 1)); - case 4: - return mh.invokeExact(selfObj, getArg(args, 0), getArg(args, 1), getArg(args, 2)); - case 5: - return mh.invokeExact(selfObj, getArg(args, 0), getArg(args, 1), getArg(args, 2), getArg(args, 3)); - case 6: - return mh.invokeExact(selfObj, getArg(args, 0), getArg(args, 1), getArg(args, 2), getArg(args, 3), getArg(args, 4)); - case 7: - return mh.invokeExact(selfObj, getArg(args, 0), getArg(args, 1), getArg(args, 2), getArg(args, 3), getArg(args, 4), getArg(args, 5)); - default: - return mh.invokeWithArguments(withArguments(null, selfObj, paramCount, args)); - } - } - - Object construct(final ScriptFunction fn, final Object... arguments) throws Throwable { - final MethodHandle mh = getGenericConstructor(fn.getScope()); - final Object[] args = arguments == null ? ScriptRuntime.EMPTY_ARRAY : arguments; - - DebuggerSupport.notifyInvoke(mh); - - if (isVarArg(mh)) { - if (needsCallee(mh)) { - return mh.invokeExact(fn, args); - } - return mh.invokeExact(args); - } - - final int paramCount = mh.type().parameterCount(); - if (needsCallee(mh)) { - switch (paramCount) { - case 1: - return mh.invokeExact(fn); - case 2: - return mh.invokeExact(fn, getArg(args, 0)); - case 3: - return mh.invokeExact(fn, getArg(args, 0), getArg(args, 1)); - case 4: - return mh.invokeExact(fn, getArg(args, 0), getArg(args, 1), getArg(args, 2)); - case 5: - return mh.invokeExact(fn, getArg(args, 0), getArg(args, 1), getArg(args, 2), getArg(args, 3)); - case 6: - return mh.invokeExact(fn, getArg(args, 0), getArg(args, 1), getArg(args, 2), getArg(args, 3), getArg(args, 4)); - case 7: - return mh.invokeExact(fn, getArg(args, 0), getArg(args, 1), getArg(args, 2), getArg(args, 3), getArg(args, 4), getArg(args, 5)); - default: - return mh.invokeWithArguments(withArguments(fn, paramCount, args)); - } - } - - switch (paramCount) { - case 0: - return mh.invokeExact(); - case 1: - return mh.invokeExact(getArg(args, 0)); - case 2: - return mh.invokeExact(getArg(args, 0), getArg(args, 1)); - case 3: - return mh.invokeExact(getArg(args, 0), getArg(args, 1), getArg(args, 2)); - case 4: - return mh.invokeExact(getArg(args, 0), getArg(args, 1), getArg(args, 2), getArg(args, 3)); - case 5: - return mh.invokeExact(getArg(args, 0), getArg(args, 1), getArg(args, 2), getArg(args, 3), getArg(args, 4)); - case 6: - return mh.invokeExact(getArg(args, 0), getArg(args, 1), getArg(args, 2), getArg(args, 3), getArg(args, 4), getArg(args, 5)); - default: - return mh.invokeWithArguments(withArguments(null, paramCount, args)); - } - } - - private static Object getArg(final Object[] args, final int i) { - return i < args.length ? args[i] : UNDEFINED; - } - - private static Object[] withArguments(final ScriptFunction fn, final int argCount, final Object[] args) { - final Object[] finalArgs = new Object[argCount]; - - int nextArg = 0; - if (fn != null) { - //needs callee - finalArgs[nextArg++] = fn; - } - - // Don't add more args that there is argCount in the handle (including self and callee). - for (int i = 0; i < args.length && nextArg < argCount;) { - finalArgs[nextArg++] = args[i++]; - } - - // If we have fewer args than argCount, pad with undefined. - while (nextArg < argCount) { - finalArgs[nextArg++] = UNDEFINED; - } - - return finalArgs; - } - - private static Object[] withArguments(final ScriptFunction fn, final Object self, final int argCount, final Object[] args) { - final Object[] finalArgs = new Object[argCount]; - - int nextArg = 0; - if (fn != null) { - //needs callee - finalArgs[nextArg++] = fn; - } - finalArgs[nextArg++] = self; - - // Don't add more args that there is argCount in the handle (including self and callee). - for (int i = 0; i < args.length && nextArg < argCount;) { - finalArgs[nextArg++] = args[i++]; - } - - // If we have fewer args than argCount, pad with undefined. - while (nextArg < argCount) { - finalArgs[nextArg++] = UNDEFINED; - } - - return finalArgs; - } - /** - * Takes a variable-arity method and binds a variable number of arguments in it. The returned method will filter the - * vararg array and pass a different array that prepends the bound arguments in front of the arguments passed on - * invocation - * - * @param mh the handle - * @param args the bound arguments - * - * @return the bound method handle - */ - private static MethodHandle varArgBinder(final MethodHandle mh, final Object[] args) { - assert args != null; - assert args.length > 0; - return MH.filterArguments(mh, mh.type().parameterCount() - 1, MH.bindTo(BIND_VAR_ARGS, args)); - } - - /** - * Heuristic to figure out if the method handle has a callee argument. If it's type is - * {@code (ScriptFunction, ...)}, then we'll assume it has a callee argument. We need this as - * the constructor above is not passed this information, and can't just blindly assume it's false - * (notably, it's being invoked for creation of new scripts, and scripts have scopes, therefore - * they also always receive a callee). - * - * @param mh the examined method handle - * - * @return true if the method handle expects a callee, false otherwise - */ - protected static boolean needsCallee(final MethodHandle mh) { - return needsCallee(mh.type()); - } - - static boolean needsCallee(final MethodType type) { - final int length = type.parameterCount(); - - if (length == 0) { - return false; - } - - final Class param0 = type.parameterType(0); - return param0 == ScriptFunction.class || param0 == boolean.class && length > 1 && type.parameterType(1) == ScriptFunction.class; - } - - /** - * Check if a javascript function methodhandle is a vararg handle - * - * @param mh method handle to check - * - * @return true if vararg - */ - protected static boolean isVarArg(final MethodHandle mh) { - return isVarArg(mh.type()); - } - - static boolean isVarArg(final MethodType type) { - return type.parameterType(type.parameterCount() - 1).isArray(); - } - - /** - * Is this ScriptFunction declared in a dynamic context - * @return true if in dynamic context, false if not or irrelevant - */ - public boolean inDynamicContext() { - return false; - } - - @SuppressWarnings("unused") - private static Object[] bindVarArgs(final Object[] array1, final Object[] array2) { - if (array2 == null) { - // Must clone it, as we can't allow the receiving method to alter the array - return array1.clone(); - } - - final int l2 = array2.length; - if (l2 == 0) { - return array1.clone(); - } - - final int l1 = array1.length; - final Object[] concat = new Object[l1 + l2]; - System.arraycopy(array1, 0, concat, 0, l1); - System.arraycopy(array2, 0, concat, l1, l2); - - return concat; - } - - private static MethodHandle findOwnMH(final String name, final Class rtype, final Class... types) { - return MH.findStatic(MethodHandles.lookup(), ScriptFunctionData.class, name, MH.type(rtype, types)); - } - - /** - * This class is used to hold the generic invoker and generic constructor pair. It is structured in this way since - * most functions will never use them, so this way ScriptFunctionData only pays storage cost for one null reference - * to the GenericInvokers object, instead of two null references for the two method handles. - */ - private static final class GenericInvokers { - volatile MethodHandle invoker; - volatile MethodHandle constructor; - } - - private void readObject(final ObjectInputStream in) throws IOException, ClassNotFoundException { - in.defaultReadObject(); - code = new LinkedList<>(); - } -}