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