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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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* particular file as subject to the "Classpath" exception as provided
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*
* 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).
*
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package jdk.nashorn.internal.runtime.linker;
import static jdk.nashorn.internal.runtime.JSType.isString;
import java.lang.invoke.MethodHandle;
import java.lang.invoke.MethodHandles;
import java.lang.invoke.MethodType;
import java.util.Map;
import javax.script.Bindings;
import jdk.dynalink.CallSiteDescriptor;
import jdk.dynalink.Operation;
import jdk.dynalink.StandardOperation;
import jdk.dynalink.linker.GuardedInvocation;
import jdk.dynalink.linker.LinkRequest;
import jdk.dynalink.linker.LinkerServices;
import jdk.dynalink.linker.TypeBasedGuardingDynamicLinker;
import jdk.nashorn.api.scripting.JSObject;
import jdk.nashorn.api.scripting.ScriptObjectMirror;
import jdk.nashorn.internal.lookup.MethodHandleFactory;
import jdk.nashorn.internal.lookup.MethodHandleFunctionality;
import jdk.nashorn.internal.runtime.Context;
import jdk.nashorn.internal.runtime.JSType;
import jdk.nashorn.internal.runtime.ScriptRuntime;
import jdk.nashorn.internal.objects.Global;
/**
* A Dynalink linker to handle web browser built-in JS (DOM etc.) objects as well
* as ScriptObjects from other Nashorn contexts.
*/
final class JSObjectLinker implements TypeBasedGuardingDynamicLinker {
private final NashornBeansLinker nashornBeansLinker;
JSObjectLinker(final NashornBeansLinker nashornBeansLinker) {
this.nashornBeansLinker = nashornBeansLinker;
}
@Override
public boolean canLinkType(final Class<?> type) {
return canLinkTypeStatic(type);
}
static boolean canLinkTypeStatic(final Class<?> type) {
// can link JSObject also handles Map, Bindings to make
// sure those are not JSObjects.
return Map.class.isAssignableFrom(type) ||
Bindings.class.isAssignableFrom(type) ||
JSObject.class.isAssignableFrom(type);
}
@Override
public GuardedInvocation getGuardedInvocation(final LinkRequest request, final LinkerServices linkerServices) throws Exception {
final Object self = request.getReceiver();
final CallSiteDescriptor desc = request.getCallSiteDescriptor();
if (self == null || !canLinkTypeStatic(self.getClass())) {
return null;
}
GuardedInvocation inv;
if (self instanceof JSObject) {
inv = lookup(desc, request, linkerServices);
inv = inv.replaceMethods(linkerServices.filterInternalObjects(inv.getInvocation()), inv.getGuard());
} else if (self instanceof Map || self instanceof Bindings) {
// guard to make sure the Map or Bindings does not turn into JSObject later!
final GuardedInvocation beanInv = nashornBeansLinker.getGuardedInvocation(request, linkerServices);
inv = new GuardedInvocation(beanInv.getInvocation(),
NashornGuards.combineGuards(beanInv.getGuard(), NashornGuards.getNotJSObjectGuard()));
} else {
throw new AssertionError("got instanceof: " + self.getClass()); // Should never reach here.
}
return Bootstrap.asTypeSafeReturn(inv, linkerServices, desc);
}
private GuardedInvocation lookup(final CallSiteDescriptor desc, final LinkRequest request, final LinkerServices linkerServices) throws Exception {
final Operation op = NashornCallSiteDescriptor.getBaseOperation(desc);
if (op instanceof StandardOperation) {
final String name = NashornCallSiteDescriptor.getOperand(desc);
switch ((StandardOperation)op) {
case GET:
if (NashornCallSiteDescriptor.hasStandardNamespace(desc)) {
if (name != null) {
return findGetMethod(name);
}
// For indexed get, we want get GuardedInvocation beans linker and pass it.
// JSObjectLinker.get uses this fallback getter for explicit signature method access.
return findGetIndexMethod(nashornBeansLinker.getGuardedInvocation(request, linkerServices));
}
break;
case SET:
if (NashornCallSiteDescriptor.hasStandardNamespace(desc)) {
return name != null ? findSetMethod(name) : findSetIndexMethod();
}
break;
case CALL:
return findCallMethod(desc);
case NEW:
return findNewMethod(desc);
default:
}
}
return null;
}
private static GuardedInvocation findGetMethod(final String name) {
final MethodHandle getter = MH.insertArguments(JSOBJECT_GETMEMBER, 1, name);
return new GuardedInvocation(getter, IS_JSOBJECT_GUARD);
}
private static GuardedInvocation findGetIndexMethod(final GuardedInvocation inv) {
final MethodHandle getter = MH.insertArguments(JSOBJECTLINKER_GET, 0, inv.getInvocation());
return inv.replaceMethods(getter, inv.getGuard());
}
private static GuardedInvocation findSetMethod(final String name) {
final MethodHandle getter = MH.insertArguments(JSOBJECT_SETMEMBER, 1, name);
return new GuardedInvocation(getter, IS_JSOBJECT_GUARD);
}
private static GuardedInvocation findSetIndexMethod() {
return new GuardedInvocation(JSOBJECTLINKER_PUT, IS_JSOBJECT_GUARD);
}
private static GuardedInvocation findCallMethod(final CallSiteDescriptor desc) {
MethodHandle mh = NashornCallSiteDescriptor.isScope(desc)? JSOBJECT_SCOPE_CALL : JSOBJECT_CALL;
if (NashornCallSiteDescriptor.isApplyToCall(desc)) {
mh = MH.insertArguments(JSOBJECT_CALL_TO_APPLY, 0, mh);
}
final MethodType type = desc.getMethodType();
mh = type.parameterType(type.parameterCount() - 1) == Object[].class ?
mh :
MH.asCollector(mh, Object[].class, type.parameterCount() - 2);
return new GuardedInvocation(mh, IS_JSOBJECT_GUARD);
}
private static GuardedInvocation findNewMethod(final CallSiteDescriptor desc) {
final MethodHandle func = MH.asCollector(JSOBJECT_NEW, Object[].class, desc.getMethodType().parameterCount() - 1);
return new GuardedInvocation(func, IS_JSOBJECT_GUARD);
}
@SuppressWarnings("unused")
private static boolean isJSObject(final Object self) {
return self instanceof JSObject;
}
@SuppressWarnings("unused")
private static Object get(final MethodHandle fallback, final Object jsobj, final Object key)
throws Throwable {
if (key instanceof Integer) {
return ((JSObject)jsobj).getSlot((Integer)key);
} else if (key instanceof Number) {
final int index = getIndex((Number)key);
if (index > -1) {
return ((JSObject)jsobj).getSlot(index);
}
} else if (isString(key)) {
final String name = key.toString();
// get with method name and signature. delegate it to beans linker!
if (name.indexOf('(') != -1) {
return fallback.invokeExact(jsobj, (Object) name);
}
return ((JSObject)jsobj).getMember(name);
}
return null;
}
@SuppressWarnings("unused")
private static void put(final Object jsobj, final Object key, final Object value) {
if (key instanceof Integer) {
((JSObject)jsobj).setSlot((Integer)key, value);
} else if (key instanceof Number) {
((JSObject)jsobj).setSlot(getIndex((Number)key), value);
} else if (isString(key)) {
((JSObject)jsobj).setMember(key.toString(), value);
}
}
private static int getIndex(final Number n) {
final double value = n.doubleValue();
return JSType.isRepresentableAsInt(value) ? (int)value : -1;
}
@SuppressWarnings("unused")
private static Object callToApply(final MethodHandle mh, final JSObject obj, final Object thiz, final Object... args) {
assert args.length >= 2;
final Object receiver = args[0];
final Object[] arguments = new Object[args.length - 1];
System.arraycopy(args, 1, arguments, 0, arguments.length);
try {
return mh.invokeExact(obj, thiz, new Object[] { receiver, arguments });
} catch (final RuntimeException | Error e) {
throw e;
} catch (final Throwable e) {
throw new RuntimeException(e);
}
}
// This is used when a JSObject is called as scope call to do undefined -> Global this translation.
@SuppressWarnings("unused")
private static Object jsObjectScopeCall(final JSObject jsObj, final Object thiz, final Object[] args) {
final Object modifiedThiz;
if (thiz == ScriptRuntime.UNDEFINED && !jsObj.isStrictFunction()) {
final Global global = Context.getGlobal();
modifiedThiz = ScriptObjectMirror.wrap(global, global);
} else {
modifiedThiz = thiz;
}
return jsObj.call(modifiedThiz, args);
}
private static final MethodHandleFunctionality MH = MethodHandleFactory.getFunctionality();
// method handles of the current class
private static final MethodHandle IS_JSOBJECT_GUARD = findOwnMH_S("isJSObject", boolean.class, Object.class);
private static final MethodHandle JSOBJECTLINKER_GET = findOwnMH_S("get", Object.class, MethodHandle.class, Object.class, Object.class);
private static final MethodHandle JSOBJECTLINKER_PUT = findOwnMH_S("put", Void.TYPE, Object.class, Object.class, Object.class);
// method handles of JSObject class
private static final MethodHandle JSOBJECT_GETMEMBER = findJSObjectMH_V("getMember", Object.class, String.class);
private static final MethodHandle JSOBJECT_SETMEMBER = findJSObjectMH_V("setMember", Void.TYPE, String.class, Object.class);
private static final MethodHandle JSOBJECT_CALL = findJSObjectMH_V("call", Object.class, Object.class, Object[].class);
private static final MethodHandle JSOBJECT_SCOPE_CALL = findOwnMH_S("jsObjectScopeCall", Object.class, JSObject.class, Object.class, Object[].class);
private static final MethodHandle JSOBJECT_CALL_TO_APPLY = findOwnMH_S("callToApply", Object.class, MethodHandle.class, JSObject.class, Object.class, Object[].class);
private static final MethodHandle JSOBJECT_NEW = findJSObjectMH_V("newObject", Object.class, Object[].class);
private static MethodHandle findJSObjectMH_V(final String name, final Class<?> rtype, final Class<?>... types) {
return MH.findVirtual(MethodHandles.lookup(), JSObject.class, name, MH.type(rtype, types));
}
private static MethodHandle findOwnMH_S(final String name, final Class<?> rtype, final Class<?>... types) {
return MH.findStatic(MethodHandles.lookup(), JSObjectLinker.class, name, MH.type(rtype, types));
}
}