1 /*
2 * Copyright (c) 2010, 2013, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package jdk.nashorn.internal.runtime.linker;
27
28 import java.lang.invoke.MethodHandles;
29 import java.lang.invoke.MethodHandles.Lookup;
30 import java.lang.invoke.MethodType;
31 import java.lang.ref.Reference;
32 import java.lang.ref.WeakReference;
33 import java.security.AccessControlContext;
34 import java.security.AccessController;
35 import java.security.PrivilegedAction;
36 import java.util.Collections;
37 import java.util.Map;
38 import java.util.WeakHashMap;
39 import java.util.concurrent.ConcurrentHashMap;
40 import java.util.concurrent.ConcurrentMap;
41 import java.util.stream.Stream;
42 import jdk.dynalink.CallSiteDescriptor;
43 import jdk.dynalink.CompositeOperation;
44 import jdk.dynalink.NamedOperation;
45 import jdk.dynalink.Operation;
46 import jdk.dynalink.StandardOperation;
47 import jdk.nashorn.internal.ir.debug.NashornTextifier;
48 import jdk.nashorn.internal.runtime.AccessControlContextFactory;
49 import jdk.nashorn.internal.runtime.ScriptRuntime;
50
51 /**
52 * Nashorn-specific implementation of Dynalink's {@link CallSiteDescriptor}.
53 * The reason we have our own subclass is that we're storing flags in an
54 * additional primitive field. The class also exposes some useful utilities in
55 * form of static methods.
56 */
57 public final class NashornCallSiteDescriptor extends CallSiteDescriptor {
58 // Lowest three bits describe the operation
59 /** Property getter operation {@code obj.prop} */
60 public static final int GET_PROPERTY = 0;
61 /** Element getter operation {@code obj[index]} */
62 public static final int GET_ELEMENT = 1;
63 /** Property getter operation, subsequently invoked {@code obj.prop()} */
64 public static final int GET_METHOD_PROPERTY = 2;
65 /** Element getter operation, subsequently invoked {@code obj[index]()} */
66 public static final int GET_METHOD_ELEMENT = 3;
67 /** Property setter operation {@code obj.prop = value} */
68 public static final int SET_PROPERTY = 4;
69 /** Element setter operation {@code obj[index] = value} */
70 public static final int SET_ELEMENT = 5;
71 /** Call operation {@code fn(args...)} */
72 public static final int CALL = 6;
73 /** New operation {@code new Constructor(args...)} */
74 public static final int NEW = 7;
75
76 private static final int OPERATION_MASK = 7;
77
78 // Correspond to the operation indices above.
79 private static final Operation[] OPERATIONS = new Operation[] {
80 new CompositeOperation(StandardOperation.GET_PROPERTY, StandardOperation.GET_ELEMENT, StandardOperation.GET_METHOD),
81 new CompositeOperation(StandardOperation.GET_ELEMENT, StandardOperation.GET_PROPERTY, StandardOperation.GET_METHOD),
82 new CompositeOperation(StandardOperation.GET_METHOD, StandardOperation.GET_PROPERTY, StandardOperation.GET_ELEMENT),
83 new CompositeOperation(StandardOperation.GET_METHOD, StandardOperation.GET_ELEMENT, StandardOperation.GET_PROPERTY),
84 new CompositeOperation(StandardOperation.SET_PROPERTY, StandardOperation.SET_ELEMENT),
85 new CompositeOperation(StandardOperation.SET_ELEMENT, StandardOperation.SET_PROPERTY),
86 StandardOperation.CALL,
87 StandardOperation.NEW
88 };
89
90 /** Flags that the call site references a scope variable (it's an identifier reference or a var declaration, not a
91 * property access expression. */
92 public static final int CALLSITE_SCOPE = 1 << 3;
93 /** Flags that the call site is in code that uses ECMAScript strict mode. */
94 public static final int CALLSITE_STRICT = 1 << 4;
95 /** Flags that a property getter or setter call site references a scope variable that is located at a known distance
96 * in the scope chain. Such getters and setters can often be linked more optimally using these assumptions. */
97 public static final int CALLSITE_FAST_SCOPE = 1 << 5;
98 /** Flags that a callsite type is optimistic, i.e. we might get back a wider return value than encoded in the
99 * descriptor, and in that case we have to throw an UnwarrantedOptimismException */
100 public static final int CALLSITE_OPTIMISTIC = 1 << 6;
101 /** Is this really an apply that we try to call as a call? */
102 public static final int CALLSITE_APPLY_TO_CALL = 1 << 7;
103 /** Does this a callsite for a variable declaration? */
104 public static final int CALLSITE_DECLARE = 1 << 8;
105
106 /** Flags that the call site is profiled; Contexts that have {@code "profile.callsites"} boolean property set emit
107 * code where call sites have this flag set. */
108 public static final int CALLSITE_PROFILE = 1 << 9;
109 /** Flags that the call site is traced; Contexts that have {@code "trace.callsites"} property set emit code where
110 * call sites have this flag set. */
111 public static final int CALLSITE_TRACE = 1 << 10;
112 /** Flags that the call site linkage miss (and thus, relinking) is traced; Contexts that have the keyword
113 * {@code "miss"} in their {@code "trace.callsites"} property emit code where call sites have this flag set. */
114 public static final int CALLSITE_TRACE_MISSES = 1 << 11;
115 /** Flags that entry/exit to/from the method linked at call site are traced; Contexts that have the keyword
116 * {@code "enterexit"} in their {@code "trace.callsites"} property emit code where call sites have this flag set. */
117 public static final int CALLSITE_TRACE_ENTEREXIT = 1 << 12;
118 /** Flags that values passed as arguments to and returned from the method linked at call site are traced; Contexts
119 * that have the keyword {@code "values"} in their {@code "trace.callsites"} property emit code where call sites
120 * have this flag set. */
121 public static final int CALLSITE_TRACE_VALUES = 1 << 13;
122
123 //we could have more tracing flags here, for example CALLSITE_TRACE_SCOPE, but bits are a bit precious
124 //right now given the program points
125
126 /**
127 * Number of bits the program point is shifted to the left in the flags (lowest bit containing a program point).
128 * Always one larger than the largest flag shift. Note that introducing a new flag halves the number of program
129 * points we can have.
130 * TODO: rethink if we need the various profile/trace flags or the linker can use the Context instead to query its
131 * trace/profile settings.
132 */
133 public static final int CALLSITE_PROGRAM_POINT_SHIFT = 14;
134
135 /**
136 * Maximum program point value. We have 18 bits left over after flags, and
137 * it should be plenty. Program points are local to a single function. Every
138 * function maps to a single JVM bytecode method that can have at most 65535
139 * bytes. (Large functions are synthetically split into smaller functions.)
140 * A single invokedynamic is 5 bytes; even if a method consists of only
141 * invokedynamic instructions that leaves us with at most 65535/5 = 13107
142 * program points for the largest single method; those can be expressed on
143 * 14 bits. It is true that numbering of program points is independent of
144 * bytecode representation, but if a function would need more than ~14 bits
145 * for the program points, then it is reasonable to presume splitter
146 * would've split it into several smaller functions already.
147 */
148 public static final int MAX_PROGRAM_POINT_VALUE = (1 << 32 - CALLSITE_PROGRAM_POINT_SHIFT) - 1;
149
150 /**
151 * Flag mask to get the program point flags
152 */
153 public static final int FLAGS_MASK = (1 << CALLSITE_PROGRAM_POINT_SHIFT) - 1;
154
155 private static final ClassValue<ConcurrentMap<NashornCallSiteDescriptor, NashornCallSiteDescriptor>> canonicals =
156 new ClassValue<ConcurrentMap<NashornCallSiteDescriptor,NashornCallSiteDescriptor>>() {
157 @Override
158 protected ConcurrentMap<NashornCallSiteDescriptor, NashornCallSiteDescriptor> computeValue(final Class<?> type) {
159 return new ConcurrentHashMap<>();
160 }
161 };
162
163 private static final AccessControlContext GET_LOOKUP_PERMISSION_CONTEXT =
164 AccessControlContextFactory.createAccessControlContext(CallSiteDescriptor.GET_LOOKUP_PERMISSION_NAME);
165
166 @SuppressWarnings("unchecked")
167 private static final Map<String, Reference<NamedOperation>>[] NAMED_OPERATIONS =
168 Stream.generate(() -> Collections.synchronizedMap(new WeakHashMap<>()))
169 .limit(OPERATIONS.length).toArray(Map[]::new);
170
171 private final int flags;
172
173 /**
174 * Function used by {@link NashornTextifier} to represent call site flags in
175 * human readable form
176 * @param flags call site flags
177 * @return human readable form of this callsite descriptor
178 */
179 public static String toString(final int flags) {
180 final StringBuilder sb = new StringBuilder();
181 if ((flags & CALLSITE_SCOPE) != 0) {
182 if ((flags & CALLSITE_FAST_SCOPE) != 0) {
183 sb.append("fastscope ");
184 } else {
185 assert (flags & CALLSITE_FAST_SCOPE) == 0 : "can't be fastscope without scope";
186 sb.append("scope ");
187 }
188 if ((flags & CALLSITE_DECLARE) != 0) {
189 sb.append("declare ");
190 }
191 }
192 if ((flags & CALLSITE_APPLY_TO_CALL) != 0) {
193 sb.append("apply2call ");
194 }
195 if ((flags & CALLSITE_STRICT) != 0) {
196 sb.append("strict ");
197 }
198 return sb.length() == 0 ? "" : " " + sb.toString().trim();
199 }
200
201 /**
202 * Given call site flags, returns the operation name encoded in them.
203 * @param flags flags
204 * @return the operation name
205 */
206 public static String getOperationName(final int flags) {
207 switch(flags & OPERATION_MASK) {
208 case 0: return "GET_PROPERTY";
209 case 1: return "GET_ELEMENT";
210 case 2: return "GET_METHOD_PROPERTY";
211 case 3: return "GET_METHOD_ELEMENT";
212 case 4: return "SET_PROPERTY";
213 case 5: return "SET_ELEMENT";
214 case 6: return "CALL";
215 case 7: return "NEW";
216 default: throw new AssertionError();
217 }
218 }
219
220 /**
221 * Retrieves a Nashorn call site descriptor with the specified values. Since call site descriptors are immutable
222 * this method is at liberty to retrieve canonicalized instances (although it is not guaranteed it will do so).
223 * @param lookup the lookup describing the script
224 * @param name the name at the call site. Can not be null, but it can be empty.
225 * @param methodType the method type at the call site
226 * @param flags Nashorn-specific call site flags
227 * @return a call site descriptor with the specified values.
228 */
229 public static NashornCallSiteDescriptor get(final MethodHandles.Lookup lookup, final String name,
230 final MethodType methodType, final int flags) {
231 final int opIndex = flags & OPERATION_MASK;
232 final Operation baseOp = OPERATIONS[opIndex];
233 final String decodedName = NameCodec.decode(name);
234 final Operation op = decodedName.isEmpty() ? baseOp : getNamedOperation(decodedName, opIndex, baseOp);
235 return get(lookup, op, methodType, flags);
236 }
237
238 private static NamedOperation getNamedOperation(final String name, final int opIndex, final Operation baseOp) {
239 final Map<String, Reference<NamedOperation>> namedOps = NAMED_OPERATIONS[opIndex];
240 final Reference<NamedOperation> ref = namedOps.get(name);
241 if (ref != null) {
242 final NamedOperation existing = ref.get();
243 if (existing != null) {
244 return existing;
245 }
246 }
247 final NamedOperation newOp = new NamedOperation(baseOp, name);
248 namedOps.put(name, new WeakReference<>(newOp));
249 return newOp;
250 }
251
252 private static NashornCallSiteDescriptor get(final MethodHandles.Lookup lookup, final Operation operation, final MethodType methodType, final int flags) {
253 final NashornCallSiteDescriptor csd = new NashornCallSiteDescriptor(lookup, operation, methodType, flags);
254 // Many of these call site descriptors are identical (e.g. every getter for a property color will be
255 // "GET_PROPERTY:color(Object)Object", so it makes sense canonicalizing them. Make an exception for
256 // optimistic call site descriptors, as they also carry a program point making them unique.
257 if (csd.isOptimistic()) {
258 return csd;
259 }
260 final NashornCallSiteDescriptor canonical = canonicals.get(lookup.lookupClass()).putIfAbsent(csd, csd);
261 return canonical != null ? canonical : csd;
262 }
263
264 private NashornCallSiteDescriptor(final MethodHandles.Lookup lookup, final Operation operation, final MethodType methodType, final int flags) {
265 super(lookup, operation, methodType);
266 this.flags = flags;
267 }
268
269 static Lookup getLookupInternal(final CallSiteDescriptor csd) {
270 if (csd instanceof NashornCallSiteDescriptor) {
271 return ((NashornCallSiteDescriptor)csd).getLookupPrivileged();
272 }
273 return AccessController.doPrivileged((PrivilegedAction<Lookup>)()->csd.getLookup(), GET_LOOKUP_PERMISSION_CONTEXT);
274 }
275
276 @Override
277 public boolean equals(final Object obj) {
278 return super.equals(obj) && flags == ((NashornCallSiteDescriptor)obj).flags;
279 }
280
281 @Override
282 public int hashCode() {
283 return super.hashCode() ^ flags;
284 }
285
286 /**
287 * Returns the named operand in this descriptor's operation. Equivalent to
288 * {@code ((NamedOperation)getOperation()).getName().toString()} for call
289 * sites with a named operand. For call sites without named operands returns null.
290 * @return the named operand in this descriptor's operation.
291 */
292 public String getOperand() {
293 return getOperand(this);
294 }
295
296 /**
297 * Returns the named operand in the passed descriptor's operation.
298 * Equivalent to
299 * {@code ((NamedOperation)desc.getOperation()).getName().toString()} for
300 * descriptors with a named operand. For descriptors without named operands
301 * returns null.
302 * @param desc the call site descriptors
303 * @return the named operand in this descriptor's operation.
304 */
305 public static String getOperand(final CallSiteDescriptor desc) {
306 final Operation operation = desc.getOperation();
307 return operation instanceof NamedOperation ? ((NamedOperation)operation).getName().toString() : null;
308 }
309
310 /**
311 * Returns the first operation in this call site descriptor's potentially
312 * composite operation. E.g. if this call site descriptor has a composite
313 * operation {@code GET_PROPERTY|GET_METHOD|GET_ELEM}, it will return
314 * {@code GET_PROPERTY}. Nashorn - being a ECMAScript engine - does not
315 * distinguish between property, element, and method namespace; ECMAScript
316 * objects just have one single property namespace for all these, therefore
317 * it is largely irrelevant what the composite operation is structured like;
318 * if the first operation can't be satisfied, neither can the others. The
319 * first operation is however sometimes used to slightly alter the
320 * semantics; for example, a distinction between {@code GET_PROPERTY} and
321 * {@code GET_METHOD} being the first operation can translate into whether
322 * {@code "__noSuchProperty__"} or {@code "__noSuchMethod__"} will be
323 * executed in case the property is not found. Note that if a call site
324 * descriptor comes from outside of Nashorn, its class will be different,
325 * and there is no guarantee about the way it composes its operations. For
326 * that reason, for potentially foreign call site descriptors you should use
327 * {@link #getFirstStandardOperation(CallSiteDescriptor)} instead.
328 * @return the first operation in this call site descriptor. Note this will
329 * always be a {@code StandardOperation} as Nashorn internally only uses
330 * standard operations.
331 */
332 public StandardOperation getFirstOperation() {
333 final Operation base = NamedOperation.getBaseOperation(getOperation());
334 if (base instanceof CompositeOperation) {
335 return (StandardOperation)((CompositeOperation)base).getOperation(0);
336 }
337 return (StandardOperation)base;
338 }
339
340 /**
341 * Returns the first standard operation in the (potentially composite)
342 * operation of the passed call site descriptor.
343 * @param desc the call site descriptor.
344 * @return Returns the first standard operation in the (potentially
345 * composite) operation of the passed call site descriptor. Can return null
346 * if the call site contains no standard operations.
347 */
348 public static StandardOperation getFirstStandardOperation(final CallSiteDescriptor desc) {
349 final Operation base = NamedOperation.getBaseOperation(desc.getOperation());
350 if (base instanceof StandardOperation) {
351 return (StandardOperation)base;
352 } else if (base instanceof CompositeOperation) {
353 final CompositeOperation cop = (CompositeOperation)base;
354 for(int i = 0; i < cop.getOperationCount(); ++i) {
355 final Operation op = cop.getOperation(i);
356 if (op instanceof StandardOperation) {
357 return (StandardOperation)op;
358 }
359 }
360 }
361 return null;
362 }
363
364 /**
365 * Returns true if the passed call site descriptor's operation contains (or
366 * is) the specified standard operation.
367 * @param desc the call site descriptor.
368 * @param operation the operation whose presence is tested.
369 * @return Returns true if the call site descriptor's operation contains (or
370 * is) the specified standard operation.
371 */
372 public static boolean contains(final CallSiteDescriptor desc, final StandardOperation operation) {
373 return CompositeOperation.contains(NamedOperation.getBaseOperation(desc.getOperation()), operation);
374 }
375
376 /**
377 * Returns the error message to be used when CALL or NEW is used on a non-function.
378 *
379 * @param obj object on which CALL or NEW is used
380 * @return error message
381 */
382 public String getFunctionErrorMessage(final Object obj) {
383 final String funcDesc = getOperand();
384 return funcDesc != null? funcDesc : ScriptRuntime.safeToString(obj);
385 }
386
387 /**
388 * Returns the error message to be used when CALL or NEW is used on a non-function.
389 *
390 * @param desc call site descriptor
391 * @param obj object on which CALL or NEW is used
392 * @return error message
393 */
394 public static String getFunctionErrorMessage(final CallSiteDescriptor desc, final Object obj) {
395 return desc instanceof NashornCallSiteDescriptor ?
396 ((NashornCallSiteDescriptor)desc).getFunctionErrorMessage(obj) :
397 ScriptRuntime.safeToString(obj);
398 }
399
400 /**
401 * Returns the Nashorn-specific flags for this call site descriptor.
402 * @param desc the descriptor. It can be any kind of a call site descriptor, not necessarily a
403 * {@code NashornCallSiteDescriptor}. This allows for graceful interoperability when linking Nashorn with code
404 * generated outside of Nashorn.
405 * @return the Nashorn-specific flags for the call site, or 0 if the passed descriptor is not a Nashorn call site
406 * descriptor.
407 */
408 public static int getFlags(final CallSiteDescriptor desc) {
409 return desc instanceof NashornCallSiteDescriptor ? ((NashornCallSiteDescriptor)desc).flags : 0;
410 }
411
412 /**
413 * Returns true if this descriptor has the specified flag set, see {@code CALLSITE_*} constants in this class.
414 * @param flag the tested flag
415 * @return true if the flag is set, false otherwise
416 */
417 private boolean isFlag(final int flag) {
418 return (flags & flag) != 0;
419 }
420
421 /**
422 * Returns true if this descriptor has the specified flag set, see {@code CALLSITE_*} constants in this class.
423 * @param desc the descriptor. It can be any kind of a call site descriptor, not necessarily a
424 * {@code NashornCallSiteDescriptor}. This allows for graceful interoperability when linking Nashorn with code
425 * generated outside of Nashorn.
426 * @param flag the tested flag
427 * @return true if the flag is set, false otherwise (it will be false if the descriptor is not a Nashorn call site
428 * descriptor).
429 */
430 private static boolean isFlag(final CallSiteDescriptor desc, final int flag) {
431 return (getFlags(desc) & flag) != 0;
432 }
433
434 /**
435 * Returns true if this descriptor is a Nashorn call site descriptor and has the {@link #CALLSITE_SCOPE} flag set.
436 * @param desc the descriptor. It can be any kind of a call site descriptor, not necessarily a
437 * {@code NashornCallSiteDescriptor}. This allows for graceful interoperability when linking Nashorn with code
438 * generated outside of Nashorn.
439 * @return true if the descriptor is a Nashorn call site descriptor, and the flag is set, false otherwise.
440 */
441 public static boolean isScope(final CallSiteDescriptor desc) {
442 return isFlag(desc, CALLSITE_SCOPE);
443 }
444
445 /**
446 * Returns true if this descriptor is a Nashorn call site descriptor and has the {@link #CALLSITE_FAST_SCOPE} flag set.
447 * @param desc the descriptor. It can be any kind of a call site descriptor, not necessarily a
448 * {@code NashornCallSiteDescriptor}. This allows for graceful interoperability when linking Nashorn with code
449 * generated outside of Nashorn.
450 * @return true if the descriptor is a Nashorn call site descriptor, and the flag is set, false otherwise.
451 */
452 public static boolean isFastScope(final CallSiteDescriptor desc) {
453 return isFlag(desc, CALLSITE_FAST_SCOPE);
454 }
455
456 /**
457 * Returns true if this descriptor is a Nashorn call site descriptor and has the {@link #CALLSITE_STRICT} flag set.
458 * @param desc the descriptor. It can be any kind of a call site descriptor, not necessarily a
459 * {@code NashornCallSiteDescriptor}. This allows for graceful interoperability when linking Nashorn with code
460 * generated outside of Nashorn.
461 * @return true if the descriptor is a Nashorn call site descriptor, and the flag is set, false otherwise.
462 */
463 public static boolean isStrict(final CallSiteDescriptor desc) {
464 return isFlag(desc, CALLSITE_STRICT);
465 }
466
467 /**
468 * Returns true if this is an apply call that we try to call as
469 * a "call"
470 * @param desc descriptor
471 * @return true if apply to call
472 */
473 public static boolean isApplyToCall(final CallSiteDescriptor desc) {
474 return isFlag(desc, CALLSITE_APPLY_TO_CALL);
475 }
476
477 /**
478 * Is this an optimistic call site
479 * @param desc descriptor
480 * @return true if optimistic
481 */
482 public static boolean isOptimistic(final CallSiteDescriptor desc) {
483 return isFlag(desc, CALLSITE_OPTIMISTIC);
484 }
485
486 /**
487 * Does this callsite contain a declaration for its target?
488 * @param desc descriptor
489 * @return true if contains declaration
490 */
491 public static boolean isDeclaration(final CallSiteDescriptor desc) {
492 return isFlag(desc, CALLSITE_DECLARE);
493 }
494
495 /**
496 * Returns true if {@code flags} has the {@link #CALLSITE_STRICT} bit set.
497 * @param flags the flags
498 * @return true if the flag is set, false otherwise.
499 */
500 public static boolean isStrictFlag(final int flags) {
501 return (flags & CALLSITE_STRICT) != 0;
502 }
503
504 /**
505 * Returns true if {@code flags} has the {@link #CALLSITE_SCOPE} bit set.
506 * @param flags the flags
507 * @return true if the flag is set, false otherwise.
508 */
509 public static boolean isScopeFlag(final int flags) {
510 return (flags & CALLSITE_SCOPE) != 0;
511 }
512
513 /**
514 * Get a program point from a descriptor (must be optimistic)
515 * @param desc descriptor
516 * @return program point
517 */
518 public static int getProgramPoint(final CallSiteDescriptor desc) {
519 assert isOptimistic(desc) : "program point requested from non-optimistic descriptor " + desc;
520 return getFlags(desc) >> CALLSITE_PROGRAM_POINT_SHIFT;
521 }
522
523 boolean isProfile() {
524 return isFlag(CALLSITE_PROFILE);
525 }
526
527 boolean isTrace() {
528 return isFlag(CALLSITE_TRACE);
529 }
530
531 boolean isTraceMisses() {
532 return isFlag(CALLSITE_TRACE_MISSES);
533 }
534
535 boolean isTraceEnterExit() {
536 return isFlag(CALLSITE_TRACE_ENTEREXIT);
537 }
538
539 boolean isTraceObjects() {
540 return isFlag(CALLSITE_TRACE_VALUES);
541 }
542
543 boolean isOptimistic() {
544 return isFlag(CALLSITE_OPTIMISTIC);
545 }
546
547 @Override
548 public CallSiteDescriptor changeMethodTypeInternal(final MethodType newMethodType) {
549 return get(getLookupPrivileged(), getOperation(), newMethodType, flags);
550 }
551 }