1 /*
2 * Copyright (c) 2011, 2015, 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.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 */
23
24 package jdk.vm.ci.hotspot;
25
26 import static jdk.vm.ci.common.InitTimer.timer;
27 import static jdk.vm.ci.hotspot.HotSpotJVMCIRuntime.runtime;
28
29 import java.lang.reflect.Executable;
30 import java.lang.reflect.Field;
31
32 import jdk.vm.ci.code.BytecodeFrame;
33 import jdk.vm.ci.code.InstalledCode;
34 import jdk.vm.ci.code.InvalidInstalledCodeException;
35 import jdk.vm.ci.code.TargetDescription;
36 import jdk.vm.ci.code.stack.InspectedFrameVisitor;
37 import jdk.vm.ci.common.InitTimer;
38 import jdk.vm.ci.common.JVMCIError;
39 import jdk.vm.ci.meta.JavaType;
40 import jdk.vm.ci.meta.ResolvedJavaMethod;
41 import jdk.vm.ci.meta.ResolvedJavaType;
42
43 /**
44 * Calls from Java into HotSpot. The behavior of all the methods in this class that take a native
45 * pointer as an argument (e.g., {@link #getSymbol(long)}) is undefined if the argument does not
46 * denote a valid native object.
47 */
48 final class CompilerToVM {
49 /**
50 * Initializes the native part of the JVMCI runtime.
51 */
52 private static native void registerNatives();
53
54 static {
55 initialize();
56 }
57
58 @SuppressWarnings("try")
59 private static void initialize() {
60 try (InitTimer t = timer("CompilerToVM.registerNatives")) {
61 registerNatives();
62 }
63 }
64
65 /**
66 * Gets the {@link CompilerToVM} instance associated with the singleton
67 * {@link HotSpotJVMCIRuntime} instance.
68 */
69 public static CompilerToVM compilerToVM() {
70 return runtime().getCompilerToVM();
71 }
72
73 /**
74 * Copies the original bytecode of {@code method} into a new byte array and returns it.
75 *
76 * @return a new byte array containing the original bytecode of {@code method}
77 */
78 native byte[] getBytecode(HotSpotResolvedJavaMethodImpl method);
79
80 /**
81 * Gets the number of entries in {@code method}'s exception handler table or 0 if it has no
82 * exception handler table.
83 */
84 native int getExceptionTableLength(HotSpotResolvedJavaMethodImpl method);
85
86 /**
87 * Gets the address of the first entry in {@code method}'s exception handler table.
88 *
89 * Each entry is a native object described by these fields:
90 *
91 * <ul>
92 * <li>{@link HotSpotVMConfig#exceptionTableElementSize}</li>
93 * <li>{@link HotSpotVMConfig#exceptionTableElementStartPcOffset}</li>
94 * <li>{@link HotSpotVMConfig#exceptionTableElementEndPcOffset}</li>
95 * <li>{@link HotSpotVMConfig#exceptionTableElementHandlerPcOffset}</li>
96 * <li>{@link HotSpotVMConfig#exceptionTableElementCatchTypeIndexOffset}
97 * </ul>
98 *
99 * @return 0 if {@code method} has no exception handlers (i.e.
100 * {@code getExceptionTableLength(method) == 0})
101 */
102 native long getExceptionTableStart(HotSpotResolvedJavaMethodImpl method);
103
104 /**
105 * Determines whether {@code method} is currently compilable by the JVMCI compiler being used by
106 * the VM. This can return false if JVMCI compilation failed earlier for {@code method}, a
107 * breakpoint is currently set in {@code method} or {@code method} contains other bytecode
108 * features that require special handling by the VM.
109 */
110 native boolean isCompilable(HotSpotResolvedJavaMethodImpl method);
111
112 /**
113 * Determines if {@code method} is targeted by a VM directive (e.g.,
114 * {@code -XX:CompileCommand=dontinline,<pattern>}) or annotation (e.g.,
115 * {@code jdk.internal.vm.annotation.DontInline}) that specifies it should not be inlined.
116 */
117 native boolean hasNeverInlineDirective(HotSpotResolvedJavaMethodImpl method);
118
119 /**
120 * Determines if {@code method} should be inlined at any cost. This could be because:
121 * <ul>
122 * <li>a CompileOracle directive may forces inlining of this methods</li>
123 * <li>an annotation forces inlining of this method</li>
124 * </ul>
125 */
126 native boolean shouldInlineMethod(HotSpotResolvedJavaMethodImpl method);
127
128 /**
129 * Used to implement {@link ResolvedJavaType#findUniqueConcreteMethod(ResolvedJavaMethod)}.
130 *
131 * @param method the method on which to base the search
132 * @param actualHolderType the best known type of receiver
133 * @return the method result or 0 is there is no unique concrete method for {@code method}
134 */
135 native HotSpotResolvedJavaMethodImpl findUniqueConcreteMethod(HotSpotResolvedObjectTypeImpl actualHolderType, HotSpotResolvedJavaMethodImpl method);
136
137 /**
138 * Gets the implementor for the interface class {@code type}.
139 *
140 * @return the implementor if there is a single implementor, {@code null} if there is no
141 * implementor, or {@code type} itself if there is more than one implementor
142 * @throws IllegalArgumentException if type is not an interface type
143 */
144 native HotSpotResolvedObjectTypeImpl getImplementor(HotSpotResolvedObjectTypeImpl type);
145
146 /**
147 * Determines if {@code method} is ignored by security stack walks.
148 */
149 native boolean methodIsIgnoredBySecurityStackWalk(HotSpotResolvedJavaMethodImpl method);
150
151 /**
152 * Converts a name to a type.
153 *
154 * @param name a well formed Java type in {@linkplain JavaType#getName() internal} format
155 * @param accessingClass the context of resolution (must not be null)
156 * @param resolve force resolution to a {@link ResolvedJavaType}. If true, this method will
157 * either return a {@link ResolvedJavaType} or throw an exception
158 * @return the type for {@code name} or 0 if resolution failed and {@code resolve == false}
159 * @throws ClassNotFoundException if {@code resolve == true} and the resolution failed
160 */
161 native HotSpotResolvedObjectTypeImpl lookupType(String name, Class<?> accessingClass, boolean resolve) throws ClassNotFoundException;
162
163 /**
164 * Resolves the entry at index {@code cpi} in {@code constantPool} to an object.
165 *
166 * The behavior of this method is undefined if {@code cpi} does not denote one of the following
167 * entry types: {@code JVM_CONSTANT_MethodHandle}, {@code JVM_CONSTANT_MethodHandleInError},
168 * {@code JVM_CONSTANT_MethodType} and {@code JVM_CONSTANT_MethodTypeInError}.
169 */
170 native Object resolveConstantInPool(HotSpotConstantPool constantPool, int cpi);
171
172 /**
173 * Resolves the entry at index {@code cpi} in {@code constantPool} to an object, looking in the
174 * constant pool cache first.
175 *
176 * The behavior of this method is undefined if {@code cpi} does not denote a
177 * {@code JVM_CONSTANT_String} entry.
178 */
179 native Object resolvePossiblyCachedConstantInPool(HotSpotConstantPool constantPool, int cpi);
180
181 /**
182 * Gets the {@code JVM_CONSTANT_NameAndType} index from the entry at index {@code cpi} in
183 * {@code constantPool}.
184 *
185 * The behavior of this method is undefined if {@code cpi} does not denote an entry containing a
186 * {@code JVM_CONSTANT_NameAndType} index.
187 */
188 native int lookupNameAndTypeRefIndexInPool(HotSpotConstantPool constantPool, int cpi);
189
190 /**
191 * Gets the name of the {@code JVM_CONSTANT_NameAndType} entry referenced by another entry
192 * denoted by {@code which} in {@code constantPool}.
193 *
194 * The behavior of this method is undefined if {@code which} does not denote a entry that
195 * references a {@code JVM_CONSTANT_NameAndType} entry.
196 */
197 native String lookupNameInPool(HotSpotConstantPool constantPool, int which);
198
199 /**
200 * Gets the signature of the {@code JVM_CONSTANT_NameAndType} entry referenced by another entry
201 * denoted by {@code which} in {@code constantPool}.
202 *
203 * The behavior of this method is undefined if {@code which} does not denote a entry that
204 * references a {@code JVM_CONSTANT_NameAndType} entry.
205 */
206 native String lookupSignatureInPool(HotSpotConstantPool constantPool, int which);
207
208 /**
209 * Gets the {@code JVM_CONSTANT_Class} index from the entry at index {@code cpi} in
210 * {@code constantPool}.
211 *
212 * The behavior of this method is undefined if {@code cpi} does not denote an entry containing a
213 * {@code JVM_CONSTANT_Class} index.
214 */
215 native int lookupKlassRefIndexInPool(HotSpotConstantPool constantPool, int cpi);
216
217 /**
218 * Looks up a class denoted by the {@code JVM_CONSTANT_Class} entry at index {@code cpi} in
219 * {@code constantPool}. This method does not perform any resolution.
220 *
221 * The behavior of this method is undefined if {@code cpi} does not denote a
222 * {@code JVM_CONSTANT_Class} entry.
223 *
224 * @return the resolved class entry or a String otherwise
225 */
226 native Object lookupKlassInPool(HotSpotConstantPool constantPool, int cpi);
227
228 /**
229 * Looks up a method denoted by the entry at index {@code cpi} in {@code constantPool}. This
230 * method does not perform any resolution.
231 *
232 * The behavior of this method is undefined if {@code cpi} does not denote an entry representing
233 * a method.
234 *
235 * @param opcode the opcode of the instruction for which the lookup is being performed or
236 * {@code -1}. If non-negative, then resolution checks specific to the bytecode it
237 * denotes are performed if the method is already resolved. Should any of these
238 * checks fail, 0 is returned.
239 * @return the resolved method entry, 0 otherwise
240 */
241 native HotSpotResolvedJavaMethodImpl lookupMethodInPool(HotSpotConstantPool constantPool, int cpi, byte opcode);
242
243 // TODO resolving JVM_CONSTANT_Dynamic
244
245 /**
246 * Ensures that the type referenced by the specified {@code JVM_CONSTANT_InvokeDynamic} entry at
247 * index {@code cpi} in {@code constantPool} is loaded and initialized.
248 *
249 * The behavior of this method is undefined if {@code cpi} does not denote a
250 * {@code JVM_CONSTANT_InvokeDynamic} entry.
251 */
252 native void resolveInvokeDynamicInPool(HotSpotConstantPool constantPool, int cpi);
253
254 /**
255 * If {@code cpi} denotes an entry representing a
256 * <a href="https://docs.oracle.com/javase/specs/jvms/se8/html/jvms-2.html#jvms-2.9">signature
257 * polymorphic</a> method, this method ensures that the type referenced by the entry is loaded
258 * and initialized. It {@code cpi} does not denote a signature polymorphic method, this method
259 * does nothing.
260 */
261 native void resolveInvokeHandleInPool(HotSpotConstantPool constantPool, int cpi);
262
263 /**
264 * If {@code cpi} denotes an entry representing a resolved dynamic adapter (see
265 * {@link #resolveInvokeDynamicInPool} and {@link #resolveInvokeHandleInPool}), return the
266 * opcode of the instruction for which the resolution was performed ({@code invokedynamic} or
267 * {@code invokevirtual}), or {@code -1} otherwise.
268 */
269 native int isResolvedInvokeHandleInPool(HotSpotConstantPool constantPool, int cpi);
270
271 /**
272 * Gets the list of type names (in the format of {@link JavaType#getName()}) denoting the
273 * classes that define signature polymorphic methods.
274 */
275 native String[] getSignaturePolymorphicHolders();
276
277 /**
278 * Gets the resolved type denoted by the entry at index {@code cpi} in {@code constantPool}.
279 *
280 * The behavior of this method is undefined if {@code cpi} does not denote an entry representing
281 * a class.
282 *
283 * @throws LinkageError if resolution failed
284 */
285 native HotSpotResolvedObjectTypeImpl resolveTypeInPool(HotSpotConstantPool constantPool, int cpi) throws LinkageError;
286
287 /**
288 * Looks up and attempts to resolve the {@code JVM_CONSTANT_Field} entry for at index
289 * {@code cpi} in {@code constantPool}. For some opcodes, checks are performed that require the
290 * {@code method} that contains {@code opcode} to be specified. The values returned in
291 * {@code info} are:
292 *
293 * <pre>
294 * [ flags, // fieldDescriptor::access_flags()
295 * offset, // fieldDescriptor::offset()
296 * index // fieldDescriptor::index()
297 * ]
298 * </pre>
299 *
300 * The behavior of this method is undefined if {@code cpi} does not denote a
301 * {@code JVM_CONSTANT_Field} entry.
302 *
303 * @param info an array in which the details of the field are returned
304 * @return the type defining the field if resolution is successful, 0 otherwise
305 */
306 native HotSpotResolvedObjectTypeImpl resolveFieldInPool(HotSpotConstantPool constantPool, int cpi, HotSpotResolvedJavaMethodImpl method, byte opcode, int[] info);
307
308 /**
309 * Converts {@code cpci} from an index into the cache for {@code constantPool} to an index
310 * directly into {@code constantPool}.
311 *
312 * The behavior of this method is undefined if {@code ccpi} is an invalid constant pool cache
313 * index.
314 */
315 native int constantPoolRemapInstructionOperandFromCache(HotSpotConstantPool constantPool, int cpci);
316
317 /**
318 * Gets the appendix object (if any) associated with the entry at index {@code cpi} in
319 * {@code constantPool}.
320 */
321 native Object lookupAppendixInPool(HotSpotConstantPool constantPool, int cpi);
322
323 /**
324 * Installs the result of a compilation into the code cache.
325 *
326 * @param target the target where this code should be installed
327 * @param compiledCode the result of a compilation
328 * @param code the details of the installed CodeBlob are written to this object
329 * @return the outcome of the installation which will be one of
330 * {@link HotSpotVMConfig#codeInstallResultOk},
331 * {@link HotSpotVMConfig#codeInstallResultCacheFull},
332 * {@link HotSpotVMConfig#codeInstallResultCodeTooLarge},
333 * {@link HotSpotVMConfig#codeInstallResultDependenciesFailed} or
334 * {@link HotSpotVMConfig#codeInstallResultDependenciesInvalid}.
335 * @throws JVMCIError if there is something wrong with the compiled code or the associated
336 * metadata.
337 */
338 native int installCode(TargetDescription target, HotSpotCompiledCode compiledCode, InstalledCode code, HotSpotSpeculationLog speculationLog);
339
340 /**
341 * Generates the VM metadata for some compiled code and copies them into {@code metaData}. This
342 * method does not install anything into the code cache.
343 *
344 * @param target the target where this code would be installed
345 * @param compiledCode the result of a compilation
346 * @param metaData the metadata is written to this object
347 * @return the outcome of the installation which will be one of
348 * {@link HotSpotVMConfig#codeInstallResultOk},
349 * {@link HotSpotVMConfig#codeInstallResultCacheFull},
350 * {@link HotSpotVMConfig#codeInstallResultCodeTooLarge},
351 * {@link HotSpotVMConfig#codeInstallResultDependenciesFailed} or
352 * {@link HotSpotVMConfig#codeInstallResultDependenciesInvalid}.
353 * @throws JVMCIError if there is something wrong with the compiled code or the metadata
354 */
355 native int getMetadata(TargetDescription target, HotSpotCompiledCode compiledCode, HotSpotMetaData metaData);
356
357 /**
358 * Resets all compilation statistics.
359 */
360 native void resetCompilationStatistics();
361
362 /**
363 * Reads the database of VM info. The return value encodes the info in a nested object array
364 * that is described by the pseudo Java object {@code info} below:
365 *
366 * <pre>
367 * info = [
368 * VMField[] vmFields,
369 * [String name, Long size, ...] vmTypeSizes,
370 * [String name, Long value, ...] vmConstants,
371 * [String name, Long value, ...] vmAddresses,
372 * VMFlag[] vmFlags
373 * VMIntrinsicMethod[] vmIntrinsics
374 * ]
375 * </pre>
376 *
377 * @return VM info as encoded above
378 */
379 native Object[] readConfiguration();
380
381 /**
382 * Resolves the implementation of {@code method} for virtual dispatches on objects of dynamic
383 * type {@code exactReceiver}. This resolution process only searches "up" the class hierarchy of
384 * {@code exactReceiver}.
385 *
386 * @param caller the caller or context type used to perform access checks
387 * @return the link-time resolved method (might be abstract) or {@code null} if it is either a
388 * signature polymorphic method or can not be linked.
389 */
390 native HotSpotResolvedJavaMethodImpl resolveMethod(HotSpotResolvedObjectTypeImpl exactReceiver, HotSpotResolvedJavaMethodImpl method, HotSpotResolvedObjectTypeImpl caller);
391
392 /**
393 * Gets the static initializer of {@code type}.
394 *
395 * @return {@code null} if {@code type} has no static initializer
396 */
397 native HotSpotResolvedJavaMethodImpl getClassInitializer(HotSpotResolvedObjectTypeImpl type);
398
399 /**
400 * Determines if {@code type} or any of its currently loaded subclasses overrides
401 * {@code Object.finalize()}.
402 */
403 native boolean hasFinalizableSubclass(HotSpotResolvedObjectTypeImpl type);
404
405 /**
406 * Gets the method corresponding to {@code executable}.
407 */
408 native HotSpotResolvedJavaMethodImpl asResolvedJavaMethod(Executable executable);
409
410 /**
411 * Gets the maximum absolute offset of a PC relative call to {@code address} from any position
412 * in the code cache.
413 *
414 * @param address an address that may be called from any code in the code cache
415 * @return -1 if {@code address == 0}
416 */
417 native long getMaxCallTargetOffset(long address);
418
419 /**
420 * Gets a textual disassembly of {@code codeBlob}.
421 *
422 * @return a non-zero length string containing a disassembly of {@code codeBlob} or null if
423 * {@code codeBlob} could not be disassembled for some reason
424 */
425 // The HotSpot disassembler seems not to be thread safe so it's better to synchronize its usage
426 synchronized native String disassembleCodeBlob(InstalledCode installedCode);
427
428 /**
429 * Gets a stack trace element for {@code method} at bytecode index {@code bci}.
430 */
431 native StackTraceElement getStackTraceElement(HotSpotResolvedJavaMethodImpl method, int bci);
432
433 /**
434 * Executes some {@code installedCode} with arguments {@code args}.
435 *
436 * @return the result of executing {@code installedCode}
437 * @throws InvalidInstalledCodeException if {@code installedCode} has been invalidated
438 */
439 native Object executeInstalledCode(Object[] args, InstalledCode installedCode) throws InvalidInstalledCodeException;
440
441 /**
442 * Gets the line number table for {@code method}. The line number table is encoded as (bci,
443 * source line number) pairs.
444 *
445 * @return the line number table for {@code method} or null if it doesn't have one
446 */
447 native long[] getLineNumberTable(HotSpotResolvedJavaMethodImpl method);
448
449 /**
450 * Gets the number of entries in the local variable table for {@code method}.
451 *
452 * @return the number of entries in the local variable table for {@code method}
453 */
454 native int getLocalVariableTableLength(HotSpotResolvedJavaMethodImpl method);
455
456 /**
457 * Gets the address of the first entry in the local variable table for {@code method}.
458 *
459 * Each entry is a native object described by these fields:
460 *
461 * <ul>
462 * <li>{@link HotSpotVMConfig#localVariableTableElementSize}</li>
463 * <li>{@link HotSpotVMConfig#localVariableTableElementLengthOffset}</li>
464 * <li>{@link HotSpotVMConfig#localVariableTableElementNameCpIndexOffset}</li>
465 * <li>{@link HotSpotVMConfig#localVariableTableElementDescriptorCpIndexOffset}</li>
466 * <li>{@link HotSpotVMConfig#localVariableTableElementSlotOffset}
467 * <li>{@link HotSpotVMConfig#localVariableTableElementStartBciOffset}
468 * </ul>
469 *
470 * @return 0 if {@code method} does not have a local variable table
471 */
472 native long getLocalVariableTableStart(HotSpotResolvedJavaMethodImpl method);
473
474 /**
475 * Sets flags on {@code method} indicating that it should never be inlined or compiled by the
476 * VM.
477 */
478 native void setNotInlinableOrCompilable(HotSpotResolvedJavaMethodImpl method);
479
480 /**
481 * Invalidates the profiling information for {@code method} and (re)initializes it such that
482 * profiling restarts upon its next invocation.
483 */
484 native void reprofile(HotSpotResolvedJavaMethodImpl method);
485
486 /**
487 * Invalidates {@code installedCode} such that {@link InvalidInstalledCodeException} will be
488 * raised the next time {@code installedCode} is executed.
489 */
490 native void invalidateInstalledCode(InstalledCode installedCode);
491
492 /**
493 * Collects the current values of all JVMCI benchmark counters, summed up over all threads.
494 */
495 native long[] collectCounters();
496
497 /**
498 * Determines if {@code metaspaceMethodData} is mature.
499 */
500 native boolean isMature(long metaspaceMethodData);
501
502 /**
503 * Generate a unique id to identify the result of the compile.
504 */
505 native int allocateCompileId(HotSpotResolvedJavaMethodImpl method, int entryBCI);
506
507 /**
508 * Determines if {@code method} has OSR compiled code identified by {@code entryBCI} for
509 * compilation level {@code level}.
510 */
511 native boolean hasCompiledCodeForOSR(HotSpotResolvedJavaMethodImpl method, int entryBCI, int level);
512
513 /**
514 * Gets the value of {@code metaspaceSymbol} as a String.
515 */
516 native String getSymbol(long metaspaceSymbol);
517
518 /**
519 * @see jdk.vm.ci.code.stack.StackIntrospection#iterateFrames
520 */
521 native <T> T iterateFrames(ResolvedJavaMethod[] initialMethods, ResolvedJavaMethod[] matchingMethods, int initialSkip, InspectedFrameVisitor<T> visitor);
522
523 /**
524 * Materializes all virtual objects within {@code stackFrame} and updates its locals.
525 *
526 * @param invalidate if {@code true}, the compiled method for the stack frame will be
527 * invalidated
528 */
529 native void materializeVirtualObjects(HotSpotStackFrameReference stackFrame, boolean invalidate);
530
531 /**
532 * Gets the v-table index for interface method {@code method} in the receiver {@code type} or
533 * {@link HotSpotVMConfig#invalidVtableIndex} if {@code method} is not in {@code type}'s
534 * v-table.
535 *
536 * @throws InternalError if {@code type} is an interface or {@code method} is not held by an
537 * interface or class represented by {@code type} is not initialized
538 */
539 native int getVtableIndexForInterfaceMethod(HotSpotResolvedObjectTypeImpl type, HotSpotResolvedJavaMethodImpl method);
540
541 /**
542 * Determines if debug info should also be emitted at non-safepoint locations.
543 */
544 native boolean shouldDebugNonSafepoints();
545
546 /**
547 * Writes {@code length} bytes from {@code bytes} starting at offset {@code offset} to HotSpot's
548 * log stream.
549 *
550 * @throws NullPointerException if {@code bytes == null}
551 * @throws IndexOutOfBoundsException if copying would cause access of data outside array bounds
552 */
553 native void writeDebugOutput(byte[] bytes, int offset, int length);
554
555 /**
556 * Flush HotSpot's log stream.
557 */
558 native void flushDebugOutput();
559
560 /**
561 * Read a HotSpot Method* value from the memory location described by {@code base} plus
562 * {@code displacement} and return the {@link HotSpotResolvedJavaMethodImpl} wrapping it. This
563 * method does no checking that the memory location actually contains a valid pointer and may
564 * crash the VM if an invalid location is provided. If the {@code base} is null then
565 * {@code displacement} is used by itself. If {@code base} is a
566 * {@link HotSpotResolvedJavaMethodImpl}, {@link HotSpotConstantPool} or
567 * {@link HotSpotResolvedObjectTypeImpl} then the metaspace pointer is fetched from that object
568 * and added to {@code displacement}. Any other non-null object type causes an
569 * {@link IllegalArgumentException} to be thrown.
570 *
571 * @param base an object to read from or null
572 * @param displacement
573 * @return null or the resolved method for this location
574 */
575 native HotSpotResolvedJavaMethodImpl getResolvedJavaMethod(Object base, long displacement);
576
577 /**
578 * Gets the {@code ConstantPool*} associated with {@code object} and returns a
579 * {@link HotSpotConstantPool} wrapping it.
580 *
581 * @param object a {@link HotSpotResolvedJavaMethodImpl} or
582 * {@link HotSpotResolvedObjectTypeImpl} object
583 * @return a {@link HotSpotConstantPool} wrapping the {@code ConstantPool*} associated with
584 * {@code object}
585 * @throws NullPointerException if {@code object == null}
586 * @throws IllegalArgumentException if {@code object} is neither a
587 * {@link HotSpotResolvedJavaMethodImpl} nor a {@link HotSpotResolvedObjectTypeImpl}
588 */
589 native HotSpotConstantPool getConstantPool(Object object);
590
591 /**
592 * Read a HotSpot Klass* value from the memory location described by {@code base} plus
593 * {@code displacement} and return the {@link HotSpotResolvedObjectTypeImpl} wrapping it. This
594 * method does no checking that the memory location actually contains a valid pointer and may
595 * crash the VM if an invalid location is provided. If the {@code base} is null then
596 * {@code displacement} is used by itself. If {@code base} is a
597 * {@link HotSpotResolvedJavaMethodImpl}, {@link HotSpotConstantPool} or
598 * {@link HotSpotResolvedObjectTypeImpl} then the metaspace pointer is fetched from that object
599 * and added to {@code displacement}. Any other non-null object type causes an
600 * {@link IllegalArgumentException} to be thrown.
601 *
602 * @param base an object to read from or null
603 * @param displacement
604 * @param compressed true if the location contains a compressed Klass*
605 * @return null or the resolved method for this location
606 */
607 native HotSpotResolvedObjectTypeImpl getResolvedJavaType(Object base, long displacement, boolean compressed);
608
609 /**
610 * Return the size of the HotSpot ProfileData* pointed at by {@code position}. If
611 * {@code position} is outside the space of the MethodData then an
612 * {@link IllegalArgumentException} is thrown. A {@code position} inside the MethodData but that
613 * isn't pointing at a valid ProfileData will crash the VM.
614 *
615 * @param metaspaceMethodData
616 * @param position
617 * @return the size of the ProfileData item pointed at by {@code position}
618 * @throws IllegalArgumentException if an out of range position is given
619 */
620 native int methodDataProfileDataSize(long metaspaceMethodData, int position);
621
622 /**
623 * Gets the fingerprint for a given Klass*.
624 *
625 * @param metaspaceKlass
626 * @return the value of the fingerprint (zero for arrays and synthetic classes).
627 */
628 native long getFingerprint(long metaspaceKlass);
629
630 /**
631 * Return the amount of native stack required for the interpreter frames represented by
632 * {@code frame}. This is used when emitting the stack banging code to ensure that there is
633 * enough space for the frames during deoptimization.
634 *
635 * @param frame
636 * @return the number of bytes required for deoptimization of this frame state
637 */
638 native int interpreterFrameSize(BytecodeFrame frame);
639
640 /**
641 * Invokes non-public method {@code java.lang.invoke.LambdaForm.compileToBytecode()} on
642 * {@code lambdaForm} (which must be a {@code java.lang.invoke.LambdaForm} instance).
643 */
644 native void compileToBytecode(Object lambdaForm);
645
646 /**
647 * Gets the value of the VM flag named {@code name}.
648 *
649 * @param name name of a VM option
650 * @return {@code this} if the named VM option doesn't exist, a {@link String} or {@code null}
651 * if its type is {@code ccstr} or {@code ccstrlist}, a {@link Double} if its type is
652 * {@code double}, a {@link Boolean} if its type is {@code bool} otherwise a
653 * {@link Long}
654 */
655 native Object getFlagValue(String name);
656
657 /**
658 * Gets the host class for {@code type}.
659 */
660 native HotSpotResolvedObjectTypeImpl getHostClass(HotSpotResolvedObjectTypeImpl type);
661
662 /**
663 * Gets a {@link Executable} corresponding to {@code method}.
664 */
665 native Executable asReflectionExecutable(HotSpotResolvedJavaMethodImpl method);
666
667 /**
668 * Gets a {@link Field} denoted by {@code holder} and {@code index}.
669 *
670 * @param holder the class in which the requested field is declared
671 * @param fieldIndex the {@code fieldDescriptor::index()} denoting the field
672 */
673 native Field asReflectionField(HotSpotResolvedObjectTypeImpl holder, int fieldIndex);
674 }