1 /*
2 * Copyright (c) 2011, 2016, 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
31 import jdk.vm.ci.code.BytecodeFrame;
32 import jdk.vm.ci.code.InstalledCode;
33 import jdk.vm.ci.code.InvalidInstalledCodeException;
34 import jdk.vm.ci.code.TargetDescription;
35 import jdk.vm.ci.common.InitTimer;
36 import jdk.vm.ci.common.JVMCIError;
37 import jdk.vm.ci.meta.JavaType;
38 import jdk.vm.ci.meta.ResolvedJavaMethod;
39 import jdk.vm.ci.meta.ResolvedJavaType;
40
41 /**
42 * Calls from Java into HotSpot. The behavior of all the methods in this class that take a native
43 * pointer as an argument (e.g., {@link #getSymbol(long)}) is undefined if the argument does not
44 * denote a valid native object.
45 */
46 final class CompilerToVM {
47 /**
48 * Initializes the native part of the JVMCI runtime.
49 */
50 private static native void registerNatives();
51
52 static {
53 initialize();
54 }
55
56 @SuppressWarnings("try")
57 private static void initialize() {
58 try (InitTimer t = timer("CompilerToVM.registerNatives")) {
59 registerNatives();
60 }
61 }
62
63 /**
64 * Gets the {@link CompilerToVM} instance associated with the singleton
65 * {@link HotSpotJVMCIRuntime} instance.
66 */
67 public static CompilerToVM compilerToVM() {
68 return runtime().getCompilerToVM();
69 }
70
71 /**
72 * Copies the original bytecode of {@code method} into a new byte array and returns it.
73 *
74 * @return a new byte array containing the original bytecode of {@code method}
75 */
76 native byte[] getBytecode(HotSpotResolvedJavaMethodImpl method);
77
78 /**
79 * Gets the number of entries in {@code method}'s exception handler table or 0 if it has no
80 * exception handler table.
81 */
82 native int getExceptionTableLength(HotSpotResolvedJavaMethodImpl method);
83
84 /**
85 * Gets the address of the first entry in {@code method}'s exception handler table.
86 *
87 * Each entry is a native object described by these fields:
88 *
89 * <ul>
90 * <li>{@link HotSpotVMConfig#exceptionTableElementSize}</li>
91 * <li>{@link HotSpotVMConfig#exceptionTableElementStartPcOffset}</li>
92 * <li>{@link HotSpotVMConfig#exceptionTableElementEndPcOffset}</li>
93 * <li>{@link HotSpotVMConfig#exceptionTableElementHandlerPcOffset}</li>
94 * <li>{@link HotSpotVMConfig#exceptionTableElementCatchTypeIndexOffset}
95 * </ul>
96 *
97 * @return 0 if {@code method} has no exception handlers (i.e.
98 * {@code getExceptionTableLength(method) == 0})
99 */
100 native long getExceptionTableStart(HotSpotResolvedJavaMethodImpl method);
101
102 /**
103 * Determines whether {@code method} is currently compilable by the JVMCI compiler being used by
104 * the VM. This can return false if JVMCI compilation failed earlier for {@code method}, a
105 * breakpoint is currently set in {@code method} or {@code method} contains other bytecode
106 * features that require special handling by the VM.
107 */
108 native boolean isCompilable(HotSpotResolvedJavaMethodImpl method);
109
110 /**
111 * Determines if {@code method} is targeted by a VM directive (e.g.,
112 * {@code -XX:CompileCommand=dontinline,<pattern>}) or annotation (e.g.,
113 * {@code jdk.internal.vm.annotation.DontInline}) that specifies it should not be inlined.
114 */
115 native boolean hasNeverInlineDirective(HotSpotResolvedJavaMethodImpl method);
116
117 /**
118 * Determines if {@code method} should be inlined at any cost. This could be because:
119 * <ul>
120 * <li>a CompileOracle directive may forces inlining of this methods</li>
121 * <li>an annotation forces inlining of this method</li>
122 * </ul>
123 */
124 native boolean shouldInlineMethod(HotSpotResolvedJavaMethodImpl method);
125
126 /**
127 * Used to implement {@link ResolvedJavaType#findUniqueConcreteMethod(ResolvedJavaMethod)}.
128 *
129 * @param method the method on which to base the search
130 * @param actualHolderType the best known type of receiver
131 * @return the method result or 0 is there is no unique concrete method for {@code method}
132 */
133 native HotSpotResolvedJavaMethodImpl findUniqueConcreteMethod(HotSpotResolvedObjectTypeImpl actualHolderType, HotSpotResolvedJavaMethodImpl method);
134
135 /**
136 * Gets the implementor for the interface class {@code type}.
137 *
138 * @return the implementor if there is a single implementor, 0 if there is no implementor, or
139 * {@code type} itself if there is more than one implementor
140 */
141 native HotSpotResolvedObjectTypeImpl getImplementor(HotSpotResolvedObjectTypeImpl type);
142
143 /**
144 * Determines if {@code method} is ignored by security stack walks.
145 */
146 native boolean methodIsIgnoredBySecurityStackWalk(HotSpotResolvedJavaMethodImpl method);
147
148 /**
149 * Converts a name to a type.
150 *
151 * @param name a well formed Java type in {@linkplain JavaType#getName() internal} format
152 * @param accessingClass the context of resolution (must not be null)
153 * @param resolve force resolution to a {@link ResolvedJavaType}. If true, this method will
154 * either return a {@link ResolvedJavaType} or throw an exception
155 * @return the type for {@code name} or 0 if resolution failed and {@code resolve == false}
156 * @throws LinkageError if {@code resolve == true} and the resolution failed
157 */
158 native HotSpotResolvedObjectTypeImpl lookupType(String name, Class<?> accessingClass, boolean resolve);
159
160 /**
161 * Resolves the entry at index {@code cpi} in {@code constantPool} to an object.
162 *
163 * The behavior of this method is undefined if {@code cpi} does not denote one of the following
164 * entry types: {@code JVM_CONSTANT_MethodHandle}, {@code JVM_CONSTANT_MethodHandleInError},
165 * {@code JVM_CONSTANT_MethodType} and {@code JVM_CONSTANT_MethodTypeInError}.
166 */
167 native Object resolveConstantInPool(HotSpotConstantPool constantPool, int cpi);
168
169 /**
170 * Resolves the entry at index {@code cpi} in {@code constantPool} to an object, looking in the
171 * constant pool cache first.
172 *
173 * The behavior of this method is undefined if {@code cpi} does not denote a
174 * {@code JVM_CONSTANT_String} entry.
175 */
176 native Object resolvePossiblyCachedConstantInPool(HotSpotConstantPool constantPool, int cpi);
177
178 /**
179 * Gets the {@code JVM_CONSTANT_NameAndType} index from the entry at index {@code cpi} in
180 * {@code constantPool}.
181 *
182 * The behavior of this method is undefined if {@code cpi} does not denote an entry containing a
183 * {@code JVM_CONSTANT_NameAndType} index.
184 */
185 native int lookupNameAndTypeRefIndexInPool(HotSpotConstantPool constantPool, int cpi);
186
187 /**
188 * Gets the name of the {@code JVM_CONSTANT_NameAndType} entry referenced by another entry
189 * denoted by {@code which} in {@code constantPool}.
190 *
191 * The behavior of this method is undefined if {@code which} does not denote a entry that
192 * references a {@code JVM_CONSTANT_NameAndType} entry.
193 */
194 native String lookupNameInPool(HotSpotConstantPool constantPool, int which);
195
196 /**
197 * Gets the signature of the {@code JVM_CONSTANT_NameAndType} entry referenced by another entry
198 * denoted by {@code which} in {@code constantPool}.
199 *
200 * The behavior of this method is undefined if {@code which} does not denote a entry that
201 * references a {@code JVM_CONSTANT_NameAndType} entry.
202 */
203 native String lookupSignatureInPool(HotSpotConstantPool constantPool, int which);
204
205 /**
206 * Gets the {@code JVM_CONSTANT_Class} index from the entry at index {@code cpi} in
207 * {@code constantPool}.
208 *
209 * The behavior of this method is undefined if {@code cpi} does not denote an entry containing a
210 * {@code JVM_CONSTANT_Class} index.
211 */
212 native int lookupKlassRefIndexInPool(HotSpotConstantPool constantPool, int cpi);
213
214 /**
215 * Looks up a class denoted by the {@code JVM_CONSTANT_Class} entry at index {@code cpi} in
216 * {@code constantPool}. This method does not perform any resolution.
217 *
218 * The behavior of this method is undefined if {@code cpi} does not denote a
219 * {@code JVM_CONSTANT_Class} entry.
220 *
221 * @return the resolved class entry or a String otherwise
222 */
223 native Object lookupKlassInPool(HotSpotConstantPool constantPool, int cpi);
224
225 /**
226 * Looks up a method denoted by the entry at index {@code cpi} in {@code constantPool}. This
227 * method does not perform any resolution.
228 *
229 * The behavior of this method is undefined if {@code cpi} does not denote an entry representing
230 * a method.
231 *
232 * @param opcode the opcode of the instruction for which the lookup is being performed or
233 * {@code -1}. If non-negative, then resolution checks specific to the bytecode it
234 * denotes are performed if the method is already resolved. Should any of these
235 * checks fail, 0 is returned.
236 * @return the resolved method entry, 0 otherwise
237 */
238 native HotSpotResolvedJavaMethodImpl lookupMethodInPool(HotSpotConstantPool constantPool, int cpi, byte opcode);
239
240 /**
241 * Ensures that the type referenced by the specified {@code JVM_CONSTANT_InvokeDynamic} entry at
242 * index {@code cpi} in {@code constantPool} is loaded and initialized.
243 *
244 * The behavior of this method is undefined if {@code cpi} does not denote a
245 * {@code JVM_CONSTANT_InvokeDynamic} entry.
246 */
247 native void resolveInvokeDynamicInPool(HotSpotConstantPool constantPool, int cpi);
248
249 /**
250 * If {@code cpi} denotes an entry representing a
251 * <a href="https://docs.oracle.com/javase/specs/jvms/se8/html/jvms-2.html#jvms-2.9">signature
252 * polymorphic</a> method, this method ensures that the type referenced by the entry is loaded
253 * and initialized. It {@code cpi} does not denote a signature polymorphic method, this method
254 * does nothing.
255 */
256 native void resolveInvokeHandleInPool(HotSpotConstantPool constantPool, int cpi);
257
258 /**
259 * Gets the list of type names (in the format of {@link JavaType#getName()}) denoting the
260 * classes that define signature polymorphic methods.
261 */
262 native String[] getSignaturePolymorphicHolders();
263
264 /**
265 * Gets the resolved type denoted by the entry at index {@code cpi} in {@code constantPool}.
266 *
267 * The behavior of this method is undefined if {@code cpi} does not denote an entry representing
268 * a class.
269 *
270 * @throws LinkageError if resolution failed
271 */
272 native HotSpotResolvedObjectTypeImpl resolveTypeInPool(HotSpotConstantPool constantPool, int cpi) throws LinkageError;
273
274 /**
275 * Looks up and attempts to resolve the {@code JVM_CONSTANT_Field} entry for at index
276 * {@code cpi} in {@code constantPool}. For some opcodes, checks are performed that require the
277 * {@code method} that contains {@code opcode} to be specified. The values returned in
278 * {@code info} are:
279 *
280 * <pre>
281 * [ flags, // fieldDescriptor::access_flags()
282 * offset, // fieldDescriptor::offset()
283 * index // fieldDescriptor::index()
284 * ]
285 * </pre>
286 *
287 * The behavior of this method is undefined if {@code cpi} does not denote a
288 * {@code JVM_CONSTANT_Field} entry.
289 *
290 * @param info an array in which the details of the field are returned
291 * @return the type defining the field if resolution is successful, 0 otherwise
292 */
293 native HotSpotResolvedObjectTypeImpl resolveFieldInPool(HotSpotConstantPool constantPool, int cpi, HotSpotResolvedJavaMethodImpl method, byte opcode, int[] info);
294
295 /**
296 * Converts {@code cpci} from an index into the cache for {@code constantPool} to an index
297 * directly into {@code constantPool}.
298 *
299 * The behavior of this method is undefined if {@code ccpi} is an invalid constant pool cache
300 * index.
301 */
302 native int constantPoolRemapInstructionOperandFromCache(HotSpotConstantPool constantPool, int cpci);
303
304 /**
305 * Gets the appendix object (if any) associated with the entry at index {@code cpi} in
306 * {@code constantPool}.
307 */
308 native Object lookupAppendixInPool(HotSpotConstantPool constantPool, int cpi);
309
310 /**
311 * Installs the result of a compilation into the code cache.
312 *
313 * @param target the target where this code should be installed
314 * @param compiledCode the result of a compilation
315 * @param code the details of the installed CodeBlob are written to this object
316 * @return the outcome of the installation which will be one of
317 * {@link HotSpotVMConfig#codeInstallResultOk},
318 * {@link HotSpotVMConfig#codeInstallResultCacheFull},
319 * {@link HotSpotVMConfig#codeInstallResultCodeTooLarge},
320 * {@link HotSpotVMConfig#codeInstallResultDependenciesFailed} or
321 * {@link HotSpotVMConfig#codeInstallResultDependenciesInvalid}.
322 * @throws JVMCIError if there is something wrong with the compiled code or the associated
323 * metadata.
324 */
325 native int installCode(TargetDescription target, HotSpotCompiledCode compiledCode, InstalledCode code, HotSpotSpeculationLog speculationLog);
326
327 /**
328 * Generates the VM metadata for some compiled code and copies them into {@code metaData}. This
329 * method does not install anything into the code cache.
330 *
331 * @param target the target where this code would be installed
332 * @param compiledCode the result of a compilation
333 * @param metaData the metadata is written to this object
334 * @return the outcome of the installation which will be one of
335 * {@link HotSpotVMConfig#codeInstallResultOk},
336 * {@link HotSpotVMConfig#codeInstallResultCacheFull},
337 * {@link HotSpotVMConfig#codeInstallResultCodeTooLarge},
338 * {@link HotSpotVMConfig#codeInstallResultDependenciesFailed} or
339 * {@link HotSpotVMConfig#codeInstallResultDependenciesInvalid}.
340 * @throws JVMCIError if there is something wrong with the compiled code or the metadata
341 */
342 native int getMetadata(TargetDescription target, HotSpotCompiledCode compiledCode, HotSpotMetaData metaData);
343
344 /**
345 * Resets all compilation statistics.
346 */
347 native void resetCompilationStatistics();
348
349 /**
350 * Reads the database of VM info. The return value encodes the info in a nested object array
351 * that is described by the pseudo Java object {@code info} below:
352 *
353 * <pre>
354 * info = [
355 * VMField[] vmFields,
356 * [String name, Long size, ...] vmTypeSizes,
357 * [String name, Long value, ...] vmConstants,
358 * [String name, Long value, ...] vmAddresses,
359 * VMFlag[] vmFlags
360 * VMIntrinsicMethod[] vmIntrinsics
361 * ]
362 * </pre>
363 *
364 * @return VM info as encoded above
365 */
366 native Object[] readConfiguration();
367
368 /**
369 * Resolves the implementation of {@code method} for virtual dispatches on objects of dynamic
370 * type {@code exactReceiver}. This resolution process only searches "up" the class hierarchy of
371 * {@code exactReceiver}.
372 *
373 * @param caller the caller or context type used to perform access checks
374 * @return the link-time resolved method (might be abstract) or {@code null} if it is either a
375 * signature polymorphic method or can not be linked.
376 */
377 native HotSpotResolvedJavaMethodImpl resolveMethod(HotSpotResolvedObjectTypeImpl exactReceiver, HotSpotResolvedJavaMethodImpl method, HotSpotResolvedObjectTypeImpl caller);
378
379 /**
380 * Gets the static initializer of {@code type}.
381 *
382 * @return 0 if {@code type} has no static initializer
383 */
384 native HotSpotResolvedJavaMethodImpl getClassInitializer(HotSpotResolvedObjectTypeImpl type);
385
386 /**
387 * Determines if {@code type} or any of its currently loaded subclasses overrides
388 * {@code Object.finalize()}.
389 */
390 native boolean hasFinalizableSubclass(HotSpotResolvedObjectTypeImpl type);
391
392 /**
393 * Gets the method corresponding to {@code executable}.
394 */
395 native HotSpotResolvedJavaMethodImpl asResolvedJavaMethod(Executable executable);
396
397 /**
398 * Gets the maximum absolute offset of a PC relative call to {@code address} from any position
399 * in the code cache.
400 *
401 * @param address an address that may be called from any code in the code cache
402 * @return -1 if {@code address == 0}
403 */
404 native long getMaxCallTargetOffset(long address);
405
406 /**
407 * Gets a textual disassembly of {@code codeBlob}.
408 *
409 * @return a non-zero length string containing a disassembly of {@code codeBlob} or null if
410 * {@code codeBlob} could not be disassembled for some reason
411 */
412 // The HotSpot disassembler seems not to be thread safe so it's better to synchronize its usage
413 synchronized native String disassembleCodeBlob(InstalledCode installedCode);
414
415 /**
416 * Gets a stack trace element for {@code method} at bytecode index {@code bci}.
417 */
418 native StackTraceElement getStackTraceElement(HotSpotResolvedJavaMethodImpl method, int bci);
419
420 /**
421 * Executes some {@code installedCode} with arguments {@code args}.
422 *
423 * @return the result of executing {@code installedCode}
424 * @throws InvalidInstalledCodeException if {@code installedCode} has been invalidated
425 */
426 native Object executeInstalledCode(Object[] args, InstalledCode installedCode) throws InvalidInstalledCodeException;
427
428 /**
429 * Gets the line number table for {@code method}. The line number table is encoded as (bci,
430 * source line number) pairs.
431 *
432 * @return the line number table for {@code method} or null if it doesn't have one
433 */
434 native long[] getLineNumberTable(HotSpotResolvedJavaMethodImpl method);
435
436 /**
437 * Gets the number of entries in the local variable table for {@code method}.
438 *
439 * @return the number of entries in the local variable table for {@code method}
440 */
441 native int getLocalVariableTableLength(HotSpotResolvedJavaMethodImpl method);
442
443 /**
444 * Gets the address of the first entry in the local variable table for {@code method}.
445 *
446 * Each entry is a native object described by these fields:
447 *
448 * <ul>
449 * <li>{@link HotSpotVMConfig#localVariableTableElementSize}</li>
450 * <li>{@link HotSpotVMConfig#localVariableTableElementLengthOffset}</li>
451 * <li>{@link HotSpotVMConfig#localVariableTableElementNameCpIndexOffset}</li>
452 * <li>{@link HotSpotVMConfig#localVariableTableElementDescriptorCpIndexOffset}</li>
453 * <li>{@link HotSpotVMConfig#localVariableTableElementSlotOffset}
454 * <li>{@link HotSpotVMConfig#localVariableTableElementStartBciOffset}
455 * </ul>
456 *
457 * @return 0 if {@code method} does not have a local variable table
458 */
459 native long getLocalVariableTableStart(HotSpotResolvedJavaMethodImpl method);
460
461 /**
462 * Determines if {@code method} should not be inlined or compiled.
463 */
464 native void doNotInlineOrCompile(HotSpotResolvedJavaMethodImpl method);
465
466 /**
467 * Invalidates the profiling information for {@code method} and (re)initializes it such that
468 * profiling restarts upon its next invocation.
469 */
470 native void reprofile(HotSpotResolvedJavaMethodImpl method);
471
472 /**
473 * Invalidates {@code installedCode} such that {@link InvalidInstalledCodeException} will be
474 * raised the next time {@code installedCode} is executed.
475 */
476 native void invalidateInstalledCode(InstalledCode installedCode);
477
478 /**
479 * Collects the current values of all JVMCI benchmark counters, summed up over all threads.
480 */
481 native long[] collectCounters();
482
483 /**
484 * Determines if {@code metaspaceMethodData} is mature.
485 */
486 native boolean isMature(long metaspaceMethodData);
487
488 /**
489 * Generate a unique id to identify the result of the compile.
490 */
491 native int allocateCompileId(HotSpotResolvedJavaMethodImpl method, int entryBCI);
492
493 /**
494 * Determines if {@code method} has OSR compiled code identified by {@code entryBCI} for
495 * compilation level {@code level}.
496 */
497 native boolean hasCompiledCodeForOSR(HotSpotResolvedJavaMethodImpl method, int entryBCI, int level);
498
499 /**
500 * Gets the value of {@code metaspaceSymbol} as a String.
501 */
502 native String getSymbol(long metaspaceSymbol);
503
504 /**
505 * Looks for the next Java stack frame matching an entry in {@code methods}.
506 *
507 * @param frame the starting point of the search, where {@code null} refers to the topmost frame
508 * @param methods the methods to look for, where {@code null} means that any frame is returned
509 * @return the frame, or {@code null} if the end of the stack was reached during the search
510 */
511 native HotSpotStackFrameReference getNextStackFrame(HotSpotStackFrameReference frame, ResolvedJavaMethod[] methods, int initialSkip);
512
513 /**
514 * Materializes all virtual objects within {@code stackFrame} and updates its locals.
515 *
516 * @param invalidate if {@code true}, the compiled method for the stack frame will be
517 * invalidated
518 */
519 native void materializeVirtualObjects(HotSpotStackFrameReference stackFrame, boolean invalidate);
520
521 /**
522 * Gets the v-table index for interface method {@code method} in the receiver {@code type} or
523 * {@link HotSpotVMConfig#invalidVtableIndex} if {@code method} is not in {@code type}'s
524 * v-table.
525 *
526 * @throws InternalError if {@code type} is an interface or {@code method} is not held by an
527 * interface or class represented by {@code type} is not initialized
528 */
529 native int getVtableIndexForInterfaceMethod(HotSpotResolvedObjectTypeImpl type, HotSpotResolvedJavaMethodImpl method);
530
531 /**
532 * Determines if debug info should also be emitted at non-safepoint locations.
533 */
534 native boolean shouldDebugNonSafepoints();
535
536 /**
537 * Writes {@code length} bytes from {@code bytes} starting at offset {@code offset} to the
538 * HotSpot's log stream.
539 *
540 * @exception NullPointerException if {@code bytes == null}
541 * @exception IndexOutOfBoundsException if copying would cause access of data outside array
542 * bounds
543 */
544 native void writeDebugOutput(byte[] bytes, int offset, int length);
545
546 /**
547 * Flush HotSpot's log stream.
548 */
549 native void flushDebugOutput();
550
551 /**
552 * Read a HotSpot Method* value from the memory location described by {@code base} plus
553 * {@code displacement} and return the {@link HotSpotResolvedJavaMethodImpl} wrapping it. This
554 * method does no checking that the memory location actually contains a valid pointer and may
555 * crash the VM if an invalid location is provided. If the {@code base} is null then
556 * {@code displacement} is used by itself. If {@code base} is a
557 * {@link HotSpotResolvedJavaMethodImpl}, {@link HotSpotConstantPool} or
558 * {@link HotSpotResolvedObjectTypeImpl} then the metaspace pointer is fetched from that object
559 * and added to {@code displacement}. Any other non-null object type causes an
560 * {@link IllegalArgumentException} to be thrown.
561 *
562 * @param base an object to read from or null
563 * @param displacement
564 * @return null or the resolved method for this location
565 */
566 native HotSpotResolvedJavaMethodImpl getResolvedJavaMethod(Object base, long displacement);
567
568 /**
569 * Gets the {@code ConstantPool*} associated with {@code object} and returns a
570 * {@link HotSpotConstantPool} wrapping it.
571 *
572 * @param object a {@link HotSpotResolvedJavaMethodImpl} or
573 * {@link HotSpotResolvedObjectTypeImpl} object
574 * @return a {@link HotSpotConstantPool} wrapping the {@code ConstantPool*} associated with
575 * {@code object}
576 * @throws NullPointerException if {@code object == null}
577 * @throws IllegalArgumentException if {@code object} is neither a
578 * {@link HotSpotResolvedJavaMethodImpl} nor a {@link HotSpotResolvedObjectTypeImpl}
579 */
580 native HotSpotConstantPool getConstantPool(Object object);
581
582 /**
583 * Read a HotSpot Klass* value from the memory location described by {@code base} plus
584 * {@code displacement} and return the {@link HotSpotResolvedObjectTypeImpl} wrapping it. This
585 * method does no checking that the memory location actually contains a valid pointer and may
586 * crash the VM if an invalid location is provided. If the {@code base} is null then
587 * {@code displacement} is used by itself. If {@code base} is a
588 * {@link HotSpotResolvedJavaMethodImpl}, {@link HotSpotConstantPool} or
589 * {@link HotSpotResolvedObjectTypeImpl} then the metaspace pointer is fetched from that object
590 * and added to {@code displacement}. Any other non-null object type causes an
591 * {@link IllegalArgumentException} to be thrown.
592 *
593 * @param base an object to read from or null
594 * @param displacement
595 * @param compressed true if the location contains a compressed Klass*
596 * @return null or the resolved method for this location
597 */
598 native HotSpotResolvedObjectTypeImpl getResolvedJavaType(Object base, long displacement, boolean compressed);
599
600 /**
601 * Return the size of the HotSpot ProfileData* pointed at by {@code position}. If
602 * {@code position} is outside the space of the MethodData then an
603 * {@link IllegalArgumentException} is thrown. A {@code position} inside the MethodData but that
604 * isn't pointing at a valid ProfileData will crash the VM.
605 *
606 * @param metaspaceMethodData
607 * @param position
608 * @return the size of the ProfileData item pointed at by {@code position}
609 * @throws IllegalArgumentException if an out of range position is given
610 */
611 native int methodDataProfileDataSize(long metaspaceMethodData, int position);
612
613 /**
614 * Gets the fingerprint for a given Klass*
615 *
616 * @param metaspaceKlass
617 * @return the value of the fingerprint (zero for arrays and synthetic classes).
618 */
619 native long getFingerprint(long metaspaceKlass);
620
621 /**
622 * Return the amount of native stack required for the interpreter frames represented by
623 * {@code frame}. This is used when emitting the stack banging code to ensure that there is
624 * enough space for the frames during deoptimization.
625 *
626 * @param frame
627 * @return the number of bytes required for deoptimization of this frame state
628 */
629 native int interpreterFrameSize(BytecodeFrame frame);
630
631 /**
632 * Invokes non-public method {@code java.lang.invoke.LambdaForm.compileToBytecode()} on
633 * {@code lambdaForm} (which must be a {@code java.lang.invoke.LambdaForm} instance).
634 */
635 native void compileToBytecode(Object lambdaForm);
636
637 /**
638 * Gets the value of the VM flag named {@code name}.
639 *
640 * @param name name of a VM option
641 * @return {@code this} if the named VM option doesn't exist, a {@link String} or {@code null}
642 * if its type is {@code ccstr} or {@code ccstrlist}, a {@link Double} if its type is
643 * {@code double}, a {@link Boolean} if its type is {@code bool} otherwise a
644 * {@link Long}
645 */
646 native Object getFlagValue(String name);
647 }