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 at index {@code cpi} in
271 * {@code constantPool}. The values returned in {@code info} are:
272 *
273 * <pre>
274 * [(int) flags, // only valid if field is resolved
275 * (int) offset] // only valid if field is resolved
276 * </pre>
277 *
278 * The behavior of this method is undefined if {@code cpi} does not denote a
279 * {@code JVM_CONSTANT_Field} entry.
280 *
281 * @param info an array in which the details of the field are returned
282 * @return the type defining the field if resolution is successful, 0 otherwise
283 */
284 native HotSpotResolvedObjectTypeImpl resolveFieldInPool(HotSpotConstantPool constantPool, int cpi, byte opcode, long[] info);
285
286 /**
287 * Converts {@code cpci} from an index into the cache for {@code constantPool} to an index
288 * directly into {@code constantPool}.
289 *
290 * The behavior of this method is undefined if {@code ccpi} is an invalid constant pool cache
291 * index.
292 */
293 native int constantPoolRemapInstructionOperandFromCache(HotSpotConstantPool constantPool, int cpci);
294
295 /**
296 * Gets the appendix object (if any) associated with the entry at index {@code cpi} in
297 * {@code constantPool}.
298 */
299 native Object lookupAppendixInPool(HotSpotConstantPool constantPool, int cpi);
300
301 /**
302 * Installs the result of a compilation into the code cache.
303 *
304 * @param target the target where this code should be installed
305 * @param compiledCode the result of a compilation
306 * @param code the details of the installed CodeBlob are written to this object
307 * @return the outcome of the installation which will be one of
308 * {@link HotSpotVMConfig#codeInstallResultOk},
309 * {@link HotSpotVMConfig#codeInstallResultCacheFull},
310 * {@link HotSpotVMConfig#codeInstallResultCodeTooLarge},
311 * {@link HotSpotVMConfig#codeInstallResultDependenciesFailed} or
312 * {@link HotSpotVMConfig#codeInstallResultDependenciesInvalid}.
313 * @throws JVMCIError if there is something wrong with the compiled code or the associated
314 * metadata.
315 */
316 native int installCode(TargetDescription target, HotSpotCompiledCode compiledCode, InstalledCode code, HotSpotSpeculationLog speculationLog);
317
318 /**
319 * Generates the VM metadata for some compiled code and copies them into {@code metaData}. This
320 * method does not install anything into the code cache.
321 *
322 * @param target the target where this code would be installed
323 * @param compiledCode the result of a compilation
324 * @param metaData the metadata is written to this object
325 * @return the outcome of the installation which will be one of
326 * {@link HotSpotVMConfig#codeInstallResultOk},
327 * {@link HotSpotVMConfig#codeInstallResultCacheFull},
328 * {@link HotSpotVMConfig#codeInstallResultCodeTooLarge},
329 * {@link HotSpotVMConfig#codeInstallResultDependenciesFailed} or
330 * {@link HotSpotVMConfig#codeInstallResultDependenciesInvalid}.
331 * @throws JVMCIError if there is something wrong with the compiled code or the metadata
332 */
333 public native int getMetadata(TargetDescription target, HotSpotCompiledCode compiledCode, HotSpotMetaData metaData);
334
335 /**
336 * Resets all compilation statistics.
337 */
338 native void resetCompilationStatistics();
339
340 /**
341 * Initializes the fields of {@code config}.
342 */
343 native long initializeConfiguration(HotSpotVMConfig config);
344
345 /**
346 * Resolves the implementation of {@code method} for virtual dispatches on objects of dynamic
347 * type {@code exactReceiver}. This resolution process only searches "up" the class hierarchy of
348 * {@code exactReceiver}.
349 *
350 * @param caller the caller or context type used to perform access checks
351 * @return the link-time resolved method (might be abstract) or {@code 0} if it can not be
352 * linked
353 */
354 native HotSpotResolvedJavaMethodImpl resolveMethod(HotSpotResolvedObjectTypeImpl exactReceiver, HotSpotResolvedJavaMethodImpl method, HotSpotResolvedObjectTypeImpl caller);
355
356 /**
357 * Gets the static initializer of {@code type}.
358 *
359 * @return 0 if {@code type} has no static initializer
360 */
361 native HotSpotResolvedJavaMethodImpl getClassInitializer(HotSpotResolvedObjectTypeImpl type);
362
363 /**
364 * Determines if {@code type} or any of its currently loaded subclasses overrides
365 * {@code Object.finalize()}.
366 */
367 native boolean hasFinalizableSubclass(HotSpotResolvedObjectTypeImpl type);
368
369 /**
370 * Gets the method corresponding to {@code holder} and slot number {@code slot} (i.e.
371 * {@link Method#slot} or {@link Constructor#slot}).
372 */
373 native HotSpotResolvedJavaMethodImpl getResolvedJavaMethodAtSlot(Class<?> holder, int slot);
374
375 /**
376 * Gets the maximum absolute offset of a PC relative call to {@code address} from any position
377 * in the code cache.
378 *
379 * @param address an address that may be called from any code in the code cache
380 * @return -1 if {@code address == 0}
381 */
382 native long getMaxCallTargetOffset(long address);
383
384 /**
385 * Gets a textual disassembly of {@code codeBlob}.
386 *
387 * @return a non-zero length string containing a disassembly of {@code codeBlob} or null if
388 * {@code codeBlob} could not be disassembled for some reason
389 */
390 // The HotSpot disassembler seems not to be thread safe so it's better to synchronize its usage
391 synchronized native String disassembleCodeBlob(InstalledCode installedCode);
392
393 /**
394 * Gets a stack trace element for {@code method} at bytecode index {@code bci}.
395 */
396 native StackTraceElement getStackTraceElement(HotSpotResolvedJavaMethodImpl method, int bci);
397
398 /**
399 * Executes some {@code installedCode} with arguments {@code args}.
400 *
401 * @return the result of executing {@code installedCode}
402 * @throws InvalidInstalledCodeException if {@code installedCode} has been invalidated
403 */
404 native Object executeInstalledCode(Object[] args, InstalledCode installedCode) throws InvalidInstalledCodeException;
405
406 /**
407 * Gets the line number table for {@code method}. The line number table is encoded as (bci,
408 * source line number) pairs.
409 *
410 * @return the line number table for {@code method} or null if it doesn't have one
411 */
412 native long[] getLineNumberTable(HotSpotResolvedJavaMethodImpl method);
413
414 /**
415 * Gets the number of entries in the local variable table for {@code method}.
416 *
417 * @return the number of entries in the local variable table for {@code method}
418 */
419 native int getLocalVariableTableLength(HotSpotResolvedJavaMethodImpl method);
420
421 /**
422 * Gets the address of the first entry in the local variable table for {@code method}.
423 *
424 * Each entry is a native object described by these fields:
425 *
426 * <ul>
427 * <li>{@link HotSpotVMConfig#localVariableTableElementSize}</li>
428 * <li>{@link HotSpotVMConfig#localVariableTableElementLengthOffset}</li>
429 * <li>{@link HotSpotVMConfig#localVariableTableElementNameCpIndexOffset}</li>
430 * <li>{@link HotSpotVMConfig#localVariableTableElementDescriptorCpIndexOffset}</li>
431 * <li>{@link HotSpotVMConfig#localVariableTableElementSignatureCpIndexOffset}
432 * <li>{@link HotSpotVMConfig#localVariableTableElementSlotOffset}
433 * <li>{@link HotSpotVMConfig#localVariableTableElementStartBciOffset}
434 * </ul>
435 *
436 * @return 0 if {@code method} does not have a local variable table
437 */
438 native long getLocalVariableTableStart(HotSpotResolvedJavaMethodImpl method);
439
440 /**
441 * Determines if {@code method} should not be inlined or compiled.
442 */
443 native void doNotInlineOrCompile(HotSpotResolvedJavaMethodImpl method);
444
445 /**
446 * Invalidates the profiling information for {@code method} and (re)initializes it such that
447 * profiling restarts upon its next invocation.
448 */
449 native void reprofile(HotSpotResolvedJavaMethodImpl method);
450
451 /**
452 * Invalidates {@code installedCode} such that {@link InvalidInstalledCodeException} will be
453 * raised the next time {@code installedCode} is executed.
454 */
455 native void invalidateInstalledCode(InstalledCode installedCode);
456
457 /**
458 * Collects the current values of all JVMCI benchmark counters, summed up over all threads.
459 */
460 native long[] collectCounters();
461
462 /**
463 * Determines if {@code metaspaceMethodData} is mature.
464 */
465 native boolean isMature(long metaspaceMethodData);
466
467 /**
468 * Generate a unique id to identify the result of the compile.
469 */
470 native int allocateCompileId(HotSpotResolvedJavaMethodImpl method, int entryBCI);
471
472 /**
473 * Determines if {@code method} has OSR compiled code identified by {@code entryBCI} for
474 * compilation level {@code level}.
475 */
476 native boolean hasCompiledCodeForOSR(HotSpotResolvedJavaMethodImpl method, int entryBCI, int level);
477
478 /**
479 * Gets the value of {@code metaspaceSymbol} as a String.
480 */
481 native String getSymbol(long metaspaceSymbol);
482
483 /**
484 * Looks for the next Java stack frame matching an entry in {@code methods}.
485 *
486 * @param frame the starting point of the search, where {@code null} refers to the topmost frame
487 * @param methods the methods to look for, where {@code null} means that any frame is returned
488 * @return the frame, or {@code null} if the end of the stack was reached during the search
489 */
490 native HotSpotStackFrameReference getNextStackFrame(HotSpotStackFrameReference frame, ResolvedJavaMethod[] methods, int initialSkip);
491
492 /**
493 * Materializes all virtual objects within {@code stackFrame} and updates its locals.
494 *
495 * @param invalidate if {@code true}, the compiled method for the stack frame will be
496 * invalidated
497 */
498 native void materializeVirtualObjects(HotSpotStackFrameReference stackFrame, boolean invalidate);
499
500 /**
501 * Gets the v-table index for interface method {@code method} in the receiver {@code type} or
502 * {@link HotSpotVMConfig#invalidVtableIndex} if {@code method} is not in {@code type}'s
503 * v-table.
504 *
505 * @throws InternalError if {@code type} is an interface or {@code method} is not held by an
506 * interface or class represented by {@code type} is not initialized
507 */
508 native int getVtableIndexForInterfaceMethod(HotSpotResolvedObjectTypeImpl type, HotSpotResolvedJavaMethodImpl method);
509
510 /**
511 * Determines if debug info should also be emitted at non-safepoint locations.
512 */
513 native boolean shouldDebugNonSafepoints();
514
515 /**
516 * Writes {@code length} bytes from {@code bytes} starting at offset {@code offset} to the
517 * HotSpot's log stream.
518 *
519 * @exception NullPointerException if {@code bytes == null}
520 * @exception IndexOutOfBoundsException if copying would cause access of data outside array
521 * bounds
522 */
523 native void writeDebugOutput(byte[] bytes, int offset, int length);
524
525 /**
526 * Flush HotSpot's log stream.
527 */
528 native void flushDebugOutput();
529
530 /**
531 * Read a HotSpot Method* value from the memory location described by {@code base} plus
532 * {@code displacement} and return the {@link HotSpotResolvedJavaMethodImpl} wrapping it. This
533 * method does no checking that the memory location actually contains a valid pointer and may
534 * crash the VM if an invalid location is provided. If the {@code base} is null then
535 * {@code displacement} is used by itself. If {@code base} is a
536 * {@link HotSpotResolvedJavaMethodImpl}, {@link HotSpotConstantPool} or
537 * {@link HotSpotResolvedObjectTypeImpl} then the metaspace pointer is fetched from that object
538 * and added to {@code displacement}. Any other non-null object type causes an
539 * {@link IllegalArgumentException} to be thrown.
540 *
541 * @param base an object to read from or null
542 * @param displacement
543 * @return null or the resolved method for this location
544 */
545 native HotSpotResolvedJavaMethodImpl getResolvedJavaMethod(Object base, long displacement);
546
547 /**
548 * Read a HotSpot ConstantPool* value from the memory location described by {@code base} plus
549 * {@code displacement} and return the {@link HotSpotConstantPool} wrapping it. This method does
550 * no checking that the memory location actually contains a valid pointer and may crash the VM
551 * if an invalid location is provided. If the {@code base} is null then {@code displacement} is
552 * used by itself. If {@code base} is a {@link HotSpotResolvedJavaMethodImpl},
553 * {@link HotSpotConstantPool} or {@link HotSpotResolvedObjectTypeImpl} then the metaspace
554 * pointer is fetched from that object and added to {@code displacement}. Any other non-null
555 * object type causes an {@link IllegalArgumentException} to be thrown.
556 *
557 * @param base an object to read from or null
558 * @param displacement
559 * @return null or the resolved method for this location
560 */
561 native HotSpotConstantPool getConstantPool(Object base, long displacement);
562
563 /**
564 * Read a HotSpot Klass* value from the memory location described by {@code base} plus
565 * {@code displacement} and return the {@link HotSpotResolvedObjectTypeImpl} wrapping it. This
566 * method does no checking that the memory location actually contains a valid pointer and may
567 * crash the VM if an invalid location is provided. If the {@code base} is null then
568 * {@code displacement} is used by itself. If {@code base} is a
569 * {@link HotSpotResolvedJavaMethodImpl}, {@link HotSpotConstantPool} or
570 * {@link HotSpotResolvedObjectTypeImpl} then the metaspace pointer is fetched from that object
571 * and added to {@code displacement}. Any other non-null object type causes an
572 * {@link IllegalArgumentException} to be thrown.
573 *
574 * @param base an object to read from or null
575 * @param displacement
576 * @param compressed true if the location contains a compressed Klass*
577 * @return null or the resolved method for this location
578 */
579 native HotSpotResolvedObjectTypeImpl getResolvedJavaType(Object base, long displacement, boolean compressed);
580
581 /**
582 * Return the size of the HotSpot ProfileData* pointed at by {@code position}. If
583 * {@code position} is outside the space of the MethodData then an
584 * {@link IllegalArgumentException} is thrown. A {@code position} inside the MethodData but that
585 * isn't pointing at a valid ProfileData will crash the VM.
586 *
587 * @param metaspaceMethodData
588 * @param position
589 * @return the size of the ProfileData item pointed at by {@code position}
590 * @throws IllegalArgumentException if an out of range position is given
591 */
592 native int methodDataProfileDataSize(long metaspaceMethodData, int position);
593
594 /**
595 * Return the amount of native stack required for the interpreter frames represented by
596 * {@code frame}. This is used when emitting the stack banging code to ensure that there is
597 * enough space for the frames during deoptimization.
598 *
599 * @param frame
600 * @return the number of bytes required for deoptimization of this frame state
601 */
602 native int interpreterFrameSize(BytecodeFrame frame);
603 }