1 /*
2 * Copyright (c) 1997, 2024, 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 "precompiled.hpp"
26 #include "code/debugInfo.hpp"
27 #include "code/debugInfoRec.hpp"
28 #include "code/nmethod.hpp"
29 #include "gc/shared/collectedHeap.hpp"
30 #include "memory/universe.hpp"
31 #include "oops/oop.inline.hpp"
32 #include "runtime/stackValue.hpp"
33 #include "runtime/handles.inline.hpp"
34 #include "runtime/interfaceSupport.inline.hpp"
35 #include "runtime/javaThread.hpp"
36 #include "runtime/jniHandles.inline.hpp"
37
38 // Constructors
39
40 DebugInfoWriteStream::DebugInfoWriteStream(DebugInformationRecorder* recorder, int initial_size)
41 : CompressedWriteStream(initial_size) {
42 _recorder = recorder;
43 }
44
45 // Serializing oops
46
47 void DebugInfoWriteStream::write_handle(jobject h) {
48 write_int(recorder()->oop_recorder()->find_index(h));
49 }
50
51 void DebugInfoWriteStream::write_metadata(Metadata* h) {
52 write_int(recorder()->oop_recorder()->find_index(h));
53 }
54
55 oop DebugInfoReadStream::read_oop() {
56 // Despite these oops being found inside nmethods that are on-stack,
57 // they are not kept alive by all GCs (e.g. G1 and Shenandoah).
58 oop o = code()->oop_at_phantom(read_int());
59 assert(oopDesc::is_oop_or_null(o), "oop only");
60 return o;
61 }
62
63 ScopeValue* DebugInfoReadStream::read_object_value(bool is_auto_box) {
64 int id = read_int();
65 #ifdef ASSERT
66 assert(_obj_pool != nullptr, "object pool does not exist");
67 for (int i = _obj_pool->length() - 1; i >= 0; i--) {
68 assert(_obj_pool->at(i)->as_ObjectValue()->id() != id, "should not be read twice");
69 }
70 #endif
71 ObjectValue* result = is_auto_box ? new AutoBoxObjectValue(id) : new ObjectValue(id);
72 // Cache the object since an object field could reference it.
73 _obj_pool->push(result);
74 result->read_object(this);
75 return result;
76 }
77
78 ScopeValue* DebugInfoReadStream::read_object_merge_value() {
79 int id = read_int();
80 #ifdef ASSERT
81 assert(_obj_pool != nullptr, "object pool does not exist");
82 for (int i = _obj_pool->length() - 1; i >= 0; i--) {
83 assert(_obj_pool->at(i)->as_ObjectValue()->id() != id, "should not be read twice");
84 }
85 #endif
86 ObjectMergeValue* result = new ObjectMergeValue(id);
87 _obj_pool->push(result);
88 result->read_object(this);
89 return result;
90 }
91
92 ScopeValue* DebugInfoReadStream::get_cached_object() {
93 int id = read_int();
94 assert(_obj_pool != nullptr, "object pool does not exist");
95 for (int i = _obj_pool->length() - 1; i >= 0; i--) {
96 ObjectValue* ov = _obj_pool->at(i)->as_ObjectValue();
97 if (ov->id() == id) {
98 return ov;
99 }
100 }
101 ShouldNotReachHere();
102 return nullptr;
103 }
104
105 // Serializing scope values
106
107 enum { LOCATION_CODE = 0, CONSTANT_INT_CODE = 1, CONSTANT_OOP_CODE = 2,
108 CONSTANT_LONG_CODE = 3, CONSTANT_DOUBLE_CODE = 4,
109 OBJECT_CODE = 5, OBJECT_ID_CODE = 6,
110 AUTO_BOX_OBJECT_CODE = 7, MARKER_CODE = 8,
111 OBJECT_MERGE_CODE = 9 };
112
113 ScopeValue* ScopeValue::read_from(DebugInfoReadStream* stream) {
114 ScopeValue* result = nullptr;
115 switch(stream->read_int()) {
116 case LOCATION_CODE: result = new LocationValue(stream); break;
117 case CONSTANT_INT_CODE: result = new ConstantIntValue(stream); break;
118 case CONSTANT_OOP_CODE: result = new ConstantOopReadValue(stream); break;
119 case CONSTANT_LONG_CODE: result = new ConstantLongValue(stream); break;
120 case CONSTANT_DOUBLE_CODE: result = new ConstantDoubleValue(stream); break;
121 case OBJECT_CODE: result = stream->read_object_value(false /*is_auto_box*/); break;
122 case AUTO_BOX_OBJECT_CODE: result = stream->read_object_value(true /*is_auto_box*/); break;
123 case OBJECT_MERGE_CODE: result = stream->read_object_merge_value(); break;
124 case OBJECT_ID_CODE: result = stream->get_cached_object(); break;
125 case MARKER_CODE: result = new MarkerValue(); break;
126 default: ShouldNotReachHere();
127 }
128 return result;
129 }
130
131 // LocationValue
132
133 LocationValue::LocationValue(DebugInfoReadStream* stream) {
134 _location = Location(stream);
135 }
136
137 void LocationValue::write_on(DebugInfoWriteStream* stream) {
138 stream->write_int(LOCATION_CODE);
139 location().write_on(stream);
140 }
141
142 void LocationValue::print_on(outputStream* st) const {
143 location().print_on(st);
144 }
145
146 // MarkerValue
147
148 void MarkerValue::write_on(DebugInfoWriteStream* stream) {
149 stream->write_int(MARKER_CODE);
150 }
151
152 void MarkerValue::print_on(outputStream* st) const {
153 st->print("marker");
154 }
155
156 // ObjectValue
157
158 void ObjectValue::set_value(oop value) {
159 _value = Handle(Thread::current(), value);
160 }
161
162 void ObjectValue::read_object(DebugInfoReadStream* stream) {
163 _is_root = stream->read_bool();
164 _klass = read_from(stream);
165 _is_init = read_from(stream);
166 assert(_klass->is_constant_oop(), "should be constant java mirror oop");
167 int length = stream->read_int();
168 for (int i = 0; i < length; i++) {
169 ScopeValue* val = read_from(stream);
170 _field_values.append(val);
171 }
172 }
173
174 void ObjectValue::write_on(DebugInfoWriteStream* stream) {
175 if (is_visited()) {
176 stream->write_int(OBJECT_ID_CODE);
177 stream->write_int(_id);
178 } else {
179 set_visited(true);
180 stream->write_int(is_auto_box() ? AUTO_BOX_OBJECT_CODE : OBJECT_CODE);
181 stream->write_int(_id);
182 stream->write_bool(_is_root);
183 _klass->write_on(stream);
184 if (_is_init == nullptr) {
185 // MarkerValue is used for null-free objects
186 _is_init = new MarkerValue();
187 }
188 _is_init->write_on(stream);
189 int length = _field_values.length();
190 stream->write_int(length);
191 for (int i = 0; i < length; i++) {
192 _field_values.at(i)->write_on(stream);
193 }
194 }
195 }
196
197 void ObjectValue::print_on(outputStream* st) const {
198 st->print("%s[%d]", is_auto_box() ? "box_obj" : is_object_merge() ? "merge_obj" : "obj", _id);
199 }
200
201 void ObjectValue::print_fields_on(outputStream* st) const {
202 #ifndef PRODUCT
203 if (is_object_merge()) {
204 ObjectMergeValue* omv = (ObjectMergeValue*)this;
205 st->print("selector=\"");
206 omv->selector()->print_on(st);
207 st->print("\"");
208 ScopeValue* merge_pointer = omv->merge_pointer();
209 if (!(merge_pointer->is_object() && merge_pointer->as_ObjectValue()->value()() == nullptr) &&
210 !(merge_pointer->is_constant_oop() && merge_pointer->as_ConstantOopReadValue()->value()() == nullptr)) {
211 st->print(", merge_pointer=\"");
212 merge_pointer->print_on(st);
213 st->print("\"");
214 }
215 GrowableArray<ScopeValue*>* possible_objects = omv->possible_objects();
216 st->print(", candidate_objs=[%d", possible_objects->at(0)->as_ObjectValue()->id());
217 int ncandidates = possible_objects->length();
218 for (int i = 1; i < ncandidates; i++) {
219 st->print(", %d", possible_objects->at(i)->as_ObjectValue()->id());
220 }
221 st->print("]");
222 } else {
223 st->print("\n Fields: ");
224 if (_field_values.length() > 0) {
225 _field_values.at(0)->print_on(st);
226 }
227 for (int i = 1; i < _field_values.length(); i++) {
228 st->print(", ");
229 _field_values.at(i)->print_on(st);
230 }
231 }
232 #endif
233 }
234
235
236 // ObjectMergeValue
237
238 // Returns the ObjectValue that should be used for the local that this
239 // ObjectMergeValue represents. ObjectMergeValue represents allocation
240 // merges in C2. This method will select which path the allocation merge
241 // took during execution of the Trap that triggered the rematerialization
242 // of the object.
243 ObjectValue* ObjectMergeValue::select(frame& fr, RegisterMap& reg_map) {
244 StackValue* sv_selector = StackValue::create_stack_value(&fr, ®_map, _selector);
245 jint selector = sv_selector->get_jint();
246
247 // If the selector is '-1' it means that execution followed the path
248 // where no scalar replacement happened.
249 // Otherwise, it is the index in _possible_objects array that holds
250 // the description of the scalar replaced object.
251 if (selector == -1) {
252 StackValue* sv_merge_pointer = StackValue::create_stack_value(&fr, ®_map, _merge_pointer);
253 _selected = new ObjectValue(id(), nullptr, false);
254
255 // Retrieve the pointer to the real object and use it as if we had
256 // allocated it during the deoptimization
257 _selected->set_value(sv_merge_pointer->get_obj()());
258
259 return _selected;
260 } else {
261 assert(selector < _possible_objects.length(), "sanity");
262 _selected = (ObjectValue*) _possible_objects.at(selector);
263 return _selected;
264 }
265 }
266
267 Handle ObjectMergeValue::value() const {
268 if (_selected != nullptr) {
269 return _selected->value();
270 } else {
271 return Handle();
272 }
273 }
274
275 void ObjectMergeValue::read_object(DebugInfoReadStream* stream) {
276 _selector = read_from(stream);
277 _merge_pointer = read_from(stream);
278 int ncandidates = stream->read_int();
279 for (int i = 0; i < ncandidates; i++) {
280 ScopeValue* result = read_from(stream);
281 assert(result->is_object(), "Candidate is not an object!");
282 ObjectValue* obj = result->as_ObjectValue();
283 _possible_objects.append(obj);
284 }
285 }
286
287 void ObjectMergeValue::write_on(DebugInfoWriteStream* stream) {
288 if (is_visited()) {
289 stream->write_int(OBJECT_ID_CODE);
290 stream->write_int(_id);
291 } else {
292 set_visited(true);
293 stream->write_int(OBJECT_MERGE_CODE);
294 stream->write_int(_id);
295 _selector->write_on(stream);
296 _merge_pointer->write_on(stream);
297 int ncandidates = _possible_objects.length();
298 stream->write_int(ncandidates);
299 for (int i = 0; i < ncandidates; i++) {
300 _possible_objects.at(i)->as_ObjectValue()->write_on(stream);
301 }
302 }
303 }
304
305 // ConstantIntValue
306
307 ConstantIntValue::ConstantIntValue(DebugInfoReadStream* stream) {
308 _value = stream->read_signed_int();
309 }
310
311 void ConstantIntValue::write_on(DebugInfoWriteStream* stream) {
312 stream->write_int(CONSTANT_INT_CODE);
313 stream->write_signed_int(value());
314 }
315
316 void ConstantIntValue::print_on(outputStream* st) const {
317 st->print("%d", value());
318 }
319
320 // ConstantLongValue
321
322 ConstantLongValue::ConstantLongValue(DebugInfoReadStream* stream) {
323 _value = stream->read_long();
324 }
325
326 void ConstantLongValue::write_on(DebugInfoWriteStream* stream) {
327 stream->write_int(CONSTANT_LONG_CODE);
328 stream->write_long(value());
329 }
330
331 void ConstantLongValue::print_on(outputStream* st) const {
332 st->print(JLONG_FORMAT, value());
333 }
334
335 // ConstantDoubleValue
336
337 ConstantDoubleValue::ConstantDoubleValue(DebugInfoReadStream* stream) {
338 _value = stream->read_double();
339 }
340
341 void ConstantDoubleValue::write_on(DebugInfoWriteStream* stream) {
342 stream->write_int(CONSTANT_DOUBLE_CODE);
343 stream->write_double(value());
344 }
345
346 void ConstantDoubleValue::print_on(outputStream* st) const {
347 st->print("%f", value());
348 }
349
350 // ConstantOopWriteValue
351
352 void ConstantOopWriteValue::write_on(DebugInfoWriteStream* stream) {
353 #ifdef ASSERT
354 {
355 // cannot use ThreadInVMfromNative here since in case of JVMCI compiler,
356 // thread is already in VM state.
357 ThreadInVMfromUnknown tiv;
358 assert(JNIHandles::resolve(value()) == nullptr ||
359 Universe::heap()->is_in(JNIHandles::resolve(value())),
360 "Should be in heap");
361 }
362 #endif
363 stream->write_int(CONSTANT_OOP_CODE);
364 stream->write_handle(value());
365 }
366
367 void ConstantOopWriteValue::print_on(outputStream* st) const {
368 // using ThreadInVMfromUnknown here since in case of JVMCI compiler,
369 // thread is already in VM state.
370 ThreadInVMfromUnknown tiv;
371 JNIHandles::resolve(value())->print_value_on(st);
372 }
373
374
375 // ConstantOopReadValue
376
377 ConstantOopReadValue::ConstantOopReadValue(DebugInfoReadStream* stream) {
378 _value = Handle(Thread::current(), stream->read_oop());
379 assert(_value() == nullptr ||
380 Universe::heap()->is_in(_value()), "Should be in heap");
381 }
382
383 void ConstantOopReadValue::write_on(DebugInfoWriteStream* stream) {
384 ShouldNotReachHere();
385 }
386
387 void ConstantOopReadValue::print_on(outputStream* st) const {
388 if (value()() != nullptr) {
389 value()()->print_value_on(st);
390 } else {
391 st->print("nullptr");
392 }
393 }
394
395
396 // MonitorValue
397
398 MonitorValue::MonitorValue(ScopeValue* owner, Location basic_lock, bool eliminated) {
399 _owner = owner;
400 _basic_lock = basic_lock;
401 _eliminated = eliminated;
402 }
403
404 MonitorValue::MonitorValue(DebugInfoReadStream* stream) {
405 _basic_lock = Location(stream);
406 _owner = ScopeValue::read_from(stream);
407 _eliminated = (stream->read_bool() != 0);
408 }
409
410 void MonitorValue::write_on(DebugInfoWriteStream* stream) {
411 _basic_lock.write_on(stream);
412 _owner->write_on(stream);
413 stream->write_bool(_eliminated);
414 }
415
416 #ifndef PRODUCT
417 void MonitorValue::print_on(outputStream* st) const {
418 st->print("monitor{");
419 owner()->print_on(st);
420 st->print(",");
421 basic_lock().print_on(st);
422 st->print("}");
423 if (_eliminated) {
424 st->print(" (eliminated)");
425 }
426 }
427 #endif