1 /*
2 * Copyright (c) 1997, 2025, 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
25 #include "code/debugInfo.hpp"
26 #include "code/debugInfoRec.hpp"
27 #include "code/nmethod.hpp"
28 #include "gc/shared/collectedHeap.hpp"
29 #include "memory/universe.hpp"
30 #include "oops/oop.inline.hpp"
31 #include "runtime/stackValue.hpp"
32 #include "runtime/handles.inline.hpp"
33 #include "runtime/interfaceSupport.inline.hpp"
34 #include "runtime/javaThread.hpp"
35 #include "runtime/jniHandles.inline.hpp"
36
37 // Constructors
38
39 DebugInfoWriteStream::DebugInfoWriteStream(DebugInformationRecorder* recorder, int initial_size)
40 : CompressedWriteStream(initial_size) {
41 _recorder = recorder;
42 }
43
44 // Serializing oops
45
46 void DebugInfoWriteStream::write_handle(jobject h) {
47 write_int(recorder()->oop_recorder()->find_index(h));
48 }
49
50 void DebugInfoWriteStream::write_metadata(Metadata* h) {
51 write_int(recorder()->oop_recorder()->find_index(h));
52 }
53
54 oop DebugInfoReadStream::read_oop() {
55 // Despite these oops being found inside nmethods that are on-stack,
56 // they are not kept alive by all GCs (e.g. G1 and Shenandoah).
57 oop o = code()->oop_at_phantom(read_int());
58 assert(oopDesc::is_oop_or_null(o), "oop only");
59 return o;
60 }
61
62 ScopeValue* DebugInfoReadStream::read_object_value(bool is_auto_box) {
63 int id = read_int();
64 #ifdef ASSERT
65 assert(_obj_pool != nullptr, "object pool does not exist");
66 for (int i = _obj_pool->length() - 1; i >= 0; i--) {
67 assert(_obj_pool->at(i)->as_ObjectValue()->id() != id, "should not be read twice");
68 }
69 #endif
70 ObjectValue* result = is_auto_box ? new AutoBoxObjectValue(id) : new ObjectValue(id);
71 // Cache the object since an object field could reference it.
72 _obj_pool->push(result);
73 result->read_object(this);
74 return result;
75 }
76
77 ScopeValue* DebugInfoReadStream::read_object_merge_value() {
78 int id = read_int();
79 #ifdef ASSERT
80 assert(_obj_pool != nullptr, "object pool does not exist");
81 for (int i = _obj_pool->length() - 1; i >= 0; i--) {
82 assert(_obj_pool->at(i)->as_ObjectValue()->id() != id, "should not be read twice");
83 }
84 #endif
85 ObjectMergeValue* result = new ObjectMergeValue(id);
86 _obj_pool->push(result);
87 result->read_object(this);
88 return result;
89 }
90
91 ScopeValue* DebugInfoReadStream::get_cached_object() {
92 int id = read_int();
93 assert(_obj_pool != nullptr, "object pool does not exist");
94 for (int i = _obj_pool->length() - 1; i >= 0; i--) {
95 ObjectValue* ov = _obj_pool->at(i)->as_ObjectValue();
96 if (ov->id() == id) {
97 return ov;
98 }
99 }
100 ShouldNotReachHere();
101 return nullptr;
102 }
103
104 // Serializing scope values
105
106 enum { LOCATION_CODE = 0, CONSTANT_INT_CODE = 1, CONSTANT_OOP_CODE = 2,
107 CONSTANT_LONG_CODE = 3, CONSTANT_DOUBLE_CODE = 4,
108 OBJECT_CODE = 5, OBJECT_ID_CODE = 6,
109 AUTO_BOX_OBJECT_CODE = 7, MARKER_CODE = 8,
110 OBJECT_MERGE_CODE = 9 };
111
112 ScopeValue* ScopeValue::read_from(DebugInfoReadStream* stream) {
113 ScopeValue* result = nullptr;
114 switch(stream->read_int()) {
115 case LOCATION_CODE: result = new LocationValue(stream); break;
116 case CONSTANT_INT_CODE: result = new ConstantIntValue(stream); break;
117 case CONSTANT_OOP_CODE: result = new ConstantOopReadValue(stream); break;
118 case CONSTANT_LONG_CODE: result = new ConstantLongValue(stream); break;
119 case CONSTANT_DOUBLE_CODE: result = new ConstantDoubleValue(stream); break;
120 case OBJECT_CODE: result = stream->read_object_value(false /*is_auto_box*/); break;
121 case AUTO_BOX_OBJECT_CODE: result = stream->read_object_value(true /*is_auto_box*/); break;
122 case OBJECT_MERGE_CODE: result = stream->read_object_merge_value(); break;
123 case OBJECT_ID_CODE: result = stream->get_cached_object(); break;
124 case MARKER_CODE: result = new MarkerValue(); break;
125 default: ShouldNotReachHere();
126 }
127 return result;
128 }
129
130 // LocationValue
131
132 LocationValue::LocationValue(DebugInfoReadStream* stream) {
133 _location = Location(stream);
134 }
135
136 void LocationValue::write_on(DebugInfoWriteStream* stream) {
137 stream->write_int(LOCATION_CODE);
138 location().write_on(stream);
139 }
140
141 void LocationValue::print_on(outputStream* st) const {
142 location().print_on(st);
143 }
144
145 // MarkerValue
146
147 void MarkerValue::write_on(DebugInfoWriteStream* stream) {
148 stream->write_int(MARKER_CODE);
149 }
150
151 void MarkerValue::print_on(outputStream* st) const {
152 st->print("marker");
153 }
154
155 // ObjectValue
156
157 void ObjectValue::set_value(oop value) {
158 _value = Handle(Thread::current(), value);
159 }
160
161 void ObjectValue::read_object(DebugInfoReadStream* stream) {
162 _is_root = stream->read_bool();
163 _klass = read_from(stream);
164 _is_init = read_from(stream);
165 assert(_klass->is_constant_oop(), "should be constant java mirror oop");
166 int length = stream->read_int();
167 for (int i = 0; i < length; i++) {
168 ScopeValue* val = read_from(stream);
169 _field_values.append(val);
170 }
171 }
172
173 void ObjectValue::write_on(DebugInfoWriteStream* stream) {
174 if (is_visited()) {
175 stream->write_int(OBJECT_ID_CODE);
176 stream->write_int(_id);
177 } else {
178 set_visited(true);
179 stream->write_int(is_auto_box() ? AUTO_BOX_OBJECT_CODE : OBJECT_CODE);
180 stream->write_int(_id);
181 stream->write_bool(_is_root);
182 _klass->write_on(stream);
183 if (_is_init == nullptr) {
184 // MarkerValue is used for null-free objects
185 _is_init = new MarkerValue();
186 }
187 _is_init->write_on(stream);
188 int length = _field_values.length();
189 stream->write_int(length);
190 for (int i = 0; i < length; i++) {
191 _field_values.at(i)->write_on(stream);
192 }
193 }
194 }
195
196 void ObjectValue::print_on(outputStream* st) const {
197 st->print("%s[%d]", is_auto_box() ? "box_obj" : is_object_merge() ? "merge_obj" : "obj", _id);
198 }
199
200 void ObjectValue::print_fields_on(outputStream* st) const {
201 #ifndef PRODUCT
202 if (is_object_merge()) {
203 ObjectMergeValue* omv = (ObjectMergeValue*)this;
204 st->print("selector=\"");
205 omv->selector()->print_on(st);
206 st->print("\"");
207 ScopeValue* merge_pointer = omv->merge_pointer();
208 if (!(merge_pointer->is_object() && merge_pointer->as_ObjectValue()->value()() == nullptr) &&
209 !(merge_pointer->is_constant_oop() && merge_pointer->as_ConstantOopReadValue()->value()() == nullptr)) {
210 st->print(", merge_pointer=\"");
211 merge_pointer->print_on(st);
212 st->print("\"");
213 }
214 GrowableArray<ScopeValue*>* possible_objects = omv->possible_objects();
215 st->print(", candidate_objs=[%d", possible_objects->at(0)->as_ObjectValue()->id());
216 int ncandidates = possible_objects->length();
217 for (int i = 1; i < ncandidates; i++) {
218 st->print(", %d", possible_objects->at(i)->as_ObjectValue()->id());
219 }
220 st->print("]");
221 } else {
222 st->print("\n Fields: ");
223 if (_field_values.length() > 0) {
224 _field_values.at(0)->print_on(st);
225 }
226 for (int i = 1; i < _field_values.length(); i++) {
227 st->print(", ");
228 _field_values.at(i)->print_on(st);
229 }
230 }
231 #endif
232 }
233
234
235 // ObjectMergeValue
236
237 // Returns the ObjectValue that should be used for the local that this
238 // ObjectMergeValue represents. ObjectMergeValue represents allocation
239 // merges in C2. This method will select which path the allocation merge
240 // took during execution of the Trap that triggered the rematerialization
241 // of the object.
242 ObjectValue* ObjectMergeValue::select(frame& fr, RegisterMap& reg_map) {
243 StackValue* sv_selector = StackValue::create_stack_value(&fr, ®_map, _selector);
244 jint selector = sv_selector->get_jint();
245
246 // If the selector is '-1' it means that execution followed the path
247 // where no scalar replacement happened.
248 // Otherwise, it is the index in _possible_objects array that holds
249 // the description of the scalar replaced object.
250 if (selector == -1) {
251 StackValue* sv_merge_pointer = StackValue::create_stack_value(&fr, ®_map, _merge_pointer);
252 _selected = new ObjectValue(id(), nullptr, false);
253
254 // Retrieve the pointer to the real object and use it as if we had
255 // allocated it during the deoptimization
256 _selected->set_value(sv_merge_pointer->get_obj()());
257
258 return _selected;
259 } else {
260 assert(selector < _possible_objects.length(), "sanity");
261 _selected = (ObjectValue*) _possible_objects.at(selector);
262 return _selected;
263 }
264 }
265
266 Handle ObjectMergeValue::value() const {
267 if (_selected != nullptr) {
268 return _selected->value();
269 } else {
270 return Handle();
271 }
272 }
273
274 void ObjectMergeValue::read_object(DebugInfoReadStream* stream) {
275 _selector = read_from(stream);
276 _merge_pointer = read_from(stream);
277 int ncandidates = stream->read_int();
278 for (int i = 0; i < ncandidates; i++) {
279 ScopeValue* result = read_from(stream);
280 assert(result->is_object(), "Candidate is not an object!");
281 ObjectValue* obj = result->as_ObjectValue();
282 _possible_objects.append(obj);
283 }
284 }
285
286 void ObjectMergeValue::write_on(DebugInfoWriteStream* stream) {
287 if (is_visited()) {
288 stream->write_int(OBJECT_ID_CODE);
289 stream->write_int(_id);
290 } else {
291 set_visited(true);
292 stream->write_int(OBJECT_MERGE_CODE);
293 stream->write_int(_id);
294 _selector->write_on(stream);
295 _merge_pointer->write_on(stream);
296 int ncandidates = _possible_objects.length();
297 stream->write_int(ncandidates);
298 for (int i = 0; i < ncandidates; i++) {
299 _possible_objects.at(i)->as_ObjectValue()->write_on(stream);
300 }
301 }
302 }
303
304 // ConstantIntValue
305
306 ConstantIntValue::ConstantIntValue(DebugInfoReadStream* stream) {
307 _value = stream->read_signed_int();
308 }
309
310 void ConstantIntValue::write_on(DebugInfoWriteStream* stream) {
311 stream->write_int(CONSTANT_INT_CODE);
312 stream->write_signed_int(value());
313 }
314
315 void ConstantIntValue::print_on(outputStream* st) const {
316 st->print("%d", value());
317 }
318
319 // ConstantLongValue
320
321 ConstantLongValue::ConstantLongValue(DebugInfoReadStream* stream) {
322 _value = stream->read_long();
323 }
324
325 void ConstantLongValue::write_on(DebugInfoWriteStream* stream) {
326 stream->write_int(CONSTANT_LONG_CODE);
327 stream->write_long(value());
328 }
329
330 void ConstantLongValue::print_on(outputStream* st) const {
331 st->print(JLONG_FORMAT, value());
332 }
333
334 // ConstantDoubleValue
335
336 ConstantDoubleValue::ConstantDoubleValue(DebugInfoReadStream* stream) {
337 _value = stream->read_double();
338 }
339
340 void ConstantDoubleValue::write_on(DebugInfoWriteStream* stream) {
341 stream->write_int(CONSTANT_DOUBLE_CODE);
342 stream->write_double(value());
343 }
344
345 void ConstantDoubleValue::print_on(outputStream* st) const {
346 st->print("%f", value());
347 }
348
349 // ConstantOopWriteValue
350
351 void ConstantOopWriteValue::write_on(DebugInfoWriteStream* stream) {
352 #ifdef ASSERT
353 {
354 // cannot use ThreadInVMfromNative here since in case of JVMCI compiler,
355 // thread is already in VM state.
356 ThreadInVMfromUnknown tiv;
357 assert(JNIHandles::resolve(value()) == nullptr ||
358 Universe::heap()->is_in(JNIHandles::resolve(value())),
359 "Should be in heap");
360 }
361 #endif
362 stream->write_int(CONSTANT_OOP_CODE);
363 stream->write_handle(value());
364 }
365
366 void ConstantOopWriteValue::print_on(outputStream* st) const {
367 // using ThreadInVMfromUnknown here since in case of JVMCI compiler,
368 // thread is already in VM state.
369 ThreadInVMfromUnknown tiv;
370 JNIHandles::resolve(value())->print_value_on(st);
371 }
372
373
374 // ConstantOopReadValue
375
376 ConstantOopReadValue::ConstantOopReadValue(DebugInfoReadStream* stream) {
377 _value = Handle(Thread::current(), stream->read_oop());
378 assert(_value() == nullptr ||
379 Universe::heap()->is_in(_value()), "Should be in heap");
380 }
381
382 void ConstantOopReadValue::write_on(DebugInfoWriteStream* stream) {
383 ShouldNotReachHere();
384 }
385
386 void ConstantOopReadValue::print_on(outputStream* st) const {
387 if (value()() != nullptr) {
388 value()()->print_value_on(st);
389 } else {
390 st->print("null");
391 }
392 }
393
394
395 // MonitorValue
396
397 MonitorValue::MonitorValue(ScopeValue* owner, Location basic_lock, bool eliminated) {
398 _owner = owner;
399 _basic_lock = basic_lock;
400 _eliminated = eliminated;
401 }
402
403 MonitorValue::MonitorValue(DebugInfoReadStream* stream) {
404 _basic_lock = Location(stream);
405 _owner = ScopeValue::read_from(stream);
406 _eliminated = (stream->read_bool() != 0);
407 }
408
409 void MonitorValue::write_on(DebugInfoWriteStream* stream) {
410 _basic_lock.write_on(stream);
411 _owner->write_on(stream);
412 stream->write_bool(_eliminated);
413 }
414
415 #ifndef PRODUCT
416 void MonitorValue::print_on(outputStream* st) const {
417 st->print("monitor{");
418 owner()->print_on(st);
419 st->print(",");
420 basic_lock().print_on(st);
421 st->print("}");
422 if (_eliminated) {
423 st->print(" (eliminated)");
424 }
425 }
426 #endif