1 /*
2 * Copyright (c) 1997, 2023, 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 nmethod* nm = const_cast<CompiledMethod*>(code())->as_nmethod_or_null();
57 oop o;
58 if (nm != nullptr) {
59 // Despite these oops being found inside nmethods that are on-stack,
60 // they are not kept alive by all GCs (e.g. G1 and Shenandoah).
61 o = nm->oop_at_phantom(read_int());
62 } else {
63 o = code()->oop_at(read_int());
64 }
65 assert(oopDesc::is_oop_or_null(o), "oop only");
66 return o;
67 }
68
69 ScopeValue* DebugInfoReadStream::read_object_value(bool is_auto_box) {
70 int id = read_int();
71 #ifdef ASSERT
72 assert(_obj_pool != nullptr, "object pool does not exist");
73 for (int i = _obj_pool->length() - 1; i >= 0; i--) {
74 assert(_obj_pool->at(i)->as_ObjectValue()->id() != id, "should not be read twice");
75 }
76 #endif
77 ObjectValue* result = is_auto_box ? new AutoBoxObjectValue(id) : new ObjectValue(id);
78 // Cache the object since an object field could reference it.
79 _obj_pool->push(result);
80 result->read_object(this);
81 return result;
82 }
83
84 ScopeValue* DebugInfoReadStream::read_object_merge_value() {
85 int id = read_int();
86 #ifdef ASSERT
87 assert(_obj_pool != nullptr, "object pool does not exist");
88 for (int i = _obj_pool->length() - 1; i >= 0; i--) {
89 assert(_obj_pool->at(i)->as_ObjectValue()->id() != id, "should not be read twice");
90 }
91 #endif
92 ObjectMergeValue* result = new ObjectMergeValue(id);
93 _obj_pool->push(result);
94 result->read_object(this);
95 return result;
96 }
97
98 ScopeValue* DebugInfoReadStream::get_cached_object() {
99 int id = read_int();
100 assert(_obj_pool != nullptr, "object pool does not exist");
101 for (int i = _obj_pool->length() - 1; i >= 0; i--) {
102 ObjectValue* ov = _obj_pool->at(i)->as_ObjectValue();
103 if (ov->id() == id) {
104 return ov;
105 }
106 }
107 ShouldNotReachHere();
108 return nullptr;
109 }
110
111 // Serializing scope values
112
113 enum { LOCATION_CODE = 0, CONSTANT_INT_CODE = 1, CONSTANT_OOP_CODE = 2,
114 CONSTANT_LONG_CODE = 3, CONSTANT_DOUBLE_CODE = 4,
115 OBJECT_CODE = 5, OBJECT_ID_CODE = 6,
116 AUTO_BOX_OBJECT_CODE = 7, MARKER_CODE = 8,
117 OBJECT_MERGE_CODE = 9 };
118
119 ScopeValue* ScopeValue::read_from(DebugInfoReadStream* stream) {
120 ScopeValue* result = nullptr;
121 switch(stream->read_int()) {
122 case LOCATION_CODE: result = new LocationValue(stream); break;
123 case CONSTANT_INT_CODE: result = new ConstantIntValue(stream); break;
124 case CONSTANT_OOP_CODE: result = new ConstantOopReadValue(stream); break;
125 case CONSTANT_LONG_CODE: result = new ConstantLongValue(stream); break;
126 case CONSTANT_DOUBLE_CODE: result = new ConstantDoubleValue(stream); break;
127 case OBJECT_CODE: result = stream->read_object_value(false /*is_auto_box*/); break;
128 case AUTO_BOX_OBJECT_CODE: result = stream->read_object_value(true /*is_auto_box*/); break;
129 case OBJECT_MERGE_CODE: result = stream->read_object_merge_value(); break;
130 case OBJECT_ID_CODE: result = stream->get_cached_object(); break;
131 case MARKER_CODE: result = new MarkerValue(); break;
132 default: ShouldNotReachHere();
133 }
134 return result;
135 }
136
137 // LocationValue
138
139 LocationValue::LocationValue(DebugInfoReadStream* stream) {
140 _location = Location(stream);
141 }
142
143 void LocationValue::write_on(DebugInfoWriteStream* stream) {
144 stream->write_int(LOCATION_CODE);
145 location().write_on(stream);
146 }
147
148 void LocationValue::print_on(outputStream* st) const {
149 location().print_on(st);
150 }
151
152 // MarkerValue
153
154 void MarkerValue::write_on(DebugInfoWriteStream* stream) {
155 stream->write_int(MARKER_CODE);
156 }
157
158 void MarkerValue::print_on(outputStream* st) const {
159 st->print("marker");
160 }
161
162 // ObjectValue
163
164 void ObjectValue::set_value(oop value) {
165 _value = Handle(Thread::current(), value);
166 }
167
168 void ObjectValue::read_object(DebugInfoReadStream* stream) {
169 _is_root = stream->read_bool();
170 _klass = read_from(stream);
171 _is_init = read_from(stream);
172 assert(_klass->is_constant_oop(), "should be constant java mirror oop");
173 int length = stream->read_int();
174 for (int i = 0; i < length; i++) {
175 ScopeValue* val = read_from(stream);
176 _field_values.append(val);
177 }
178 }
179
180 void ObjectValue::write_on(DebugInfoWriteStream* stream) {
181 if (is_visited()) {
182 stream->write_int(OBJECT_ID_CODE);
183 stream->write_int(_id);
184 } else {
185 set_visited(true);
186 stream->write_int(is_auto_box() ? AUTO_BOX_OBJECT_CODE : OBJECT_CODE);
187 stream->write_int(_id);
188 stream->write_bool(_is_root);
189 _klass->write_on(stream);
190 if (_is_init == nullptr) {
191 // MarkerValue is used for null-free objects
192 _is_init = new MarkerValue();
193 }
194 _is_init->write_on(stream);
195 int length = _field_values.length();
196 stream->write_int(length);
197 for (int i = 0; i < length; i++) {
198 _field_values.at(i)->write_on(stream);
199 }
200 }
201 }
202
203 void ObjectValue::print_on(outputStream* st) const {
204 st->print("%s[%d]", is_auto_box() ? "box_obj" : is_object_merge() ? "merge_obj" : "obj", _id);
205 }
206
207 void ObjectValue::print_fields_on(outputStream* st) const {
208 #ifndef PRODUCT
209 if (is_object_merge()) {
210 ObjectMergeValue* omv = (ObjectMergeValue*)this;
211 st->print("selector=\"");
212 omv->selector()->print_on(st);
213 st->print("\"");
214 ScopeValue* merge_pointer = omv->merge_pointer();
215 if (!(merge_pointer->is_object() && merge_pointer->as_ObjectValue()->value()() == nullptr) &&
216 !(merge_pointer->is_constant_oop() && merge_pointer->as_ConstantOopReadValue()->value()() == nullptr)) {
217 st->print(", merge_pointer=\"");
218 merge_pointer->print_on(st);
219 st->print("\"");
220 }
221 GrowableArray<ScopeValue*>* possible_objects = omv->possible_objects();
222 st->print(", candidate_objs=[%d", possible_objects->at(0)->as_ObjectValue()->id());
223 int ncandidates = possible_objects->length();
224 for (int i = 1; i < ncandidates; i++) {
225 st->print(", %d", possible_objects->at(i)->as_ObjectValue()->id());
226 }
227 st->print("]");
228 } else {
229 st->print("\n Fields: ");
230 if (_field_values.length() > 0) {
231 _field_values.at(0)->print_on(st);
232 }
233 for (int i = 1; i < _field_values.length(); i++) {
234 st->print(", ");
235 _field_values.at(i)->print_on(st);
236 }
237 }
238 #endif
239 }
240
241
242 // ObjectMergeValue
243
244 // Returns the ObjectValue that should be used for the local that this
245 // ObjectMergeValue represents. ObjectMergeValue represents allocation
246 // merges in C2. This method will select which path the allocation merge
247 // took during execution of the Trap that triggered the rematerialization
248 // of the object.
249 ObjectValue* ObjectMergeValue::select(frame& fr, RegisterMap& reg_map) {
250 StackValue* sv_selector = StackValue::create_stack_value(&fr, ®_map, _selector);
251 jint selector = sv_selector->get_jint();
252
253 // If the selector is '-1' it means that execution followed the path
254 // where no scalar replacement happened.
255 // Otherwise, it is the index in _possible_objects array that holds
256 // the description of the scalar replaced object.
257 if (selector == -1) {
258 StackValue* sv_merge_pointer = StackValue::create_stack_value(&fr, ®_map, _merge_pointer);
259 _selected = new ObjectValue(id());
260
261 // Retrieve the pointer to the real object and use it as if we had
262 // allocated it during the deoptimization
263 _selected->set_value(sv_merge_pointer->get_obj()());
264
265 // No need to rematerialize
266 return nullptr;
267 } else {
268 assert(selector < _possible_objects.length(), "sanity");
269 _selected = (ObjectValue*) _possible_objects.at(selector);
270 return _selected;
271 }
272 }
273
274 Handle ObjectMergeValue::value() const {
275 if (_selected != nullptr) {
276 return _selected->value();
277 } else {
278 return Handle();
279 }
280 }
281
282 void ObjectMergeValue::read_object(DebugInfoReadStream* stream) {
283 _selector = read_from(stream);
284 _merge_pointer = read_from(stream);
285 int ncandidates = stream->read_int();
286 for (int i = 0; i < ncandidates; i++) {
287 ScopeValue* result = read_from(stream);
288 assert(result->is_object(), "Candidate is not an object!");
289 ObjectValue* obj = result->as_ObjectValue();
290 _possible_objects.append(obj);
291 }
292 }
293
294 void ObjectMergeValue::write_on(DebugInfoWriteStream* stream) {
295 if (is_visited()) {
296 stream->write_int(OBJECT_ID_CODE);
297 stream->write_int(_id);
298 } else {
299 set_visited(true);
300 stream->write_int(OBJECT_MERGE_CODE);
301 stream->write_int(_id);
302 _selector->write_on(stream);
303 _merge_pointer->write_on(stream);
304 int ncandidates = _possible_objects.length();
305 stream->write_int(ncandidates);
306 for (int i = 0; i < ncandidates; i++) {
307 _possible_objects.at(i)->as_ObjectValue()->write_on(stream);
308 }
309 }
310 }
311
312 // ConstantIntValue
313
314 ConstantIntValue::ConstantIntValue(DebugInfoReadStream* stream) {
315 _value = stream->read_signed_int();
316 }
317
318 void ConstantIntValue::write_on(DebugInfoWriteStream* stream) {
319 stream->write_int(CONSTANT_INT_CODE);
320 stream->write_signed_int(value());
321 }
322
323 void ConstantIntValue::print_on(outputStream* st) const {
324 st->print("%d", value());
325 }
326
327 // ConstantLongValue
328
329 ConstantLongValue::ConstantLongValue(DebugInfoReadStream* stream) {
330 _value = stream->read_long();
331 }
332
333 void ConstantLongValue::write_on(DebugInfoWriteStream* stream) {
334 stream->write_int(CONSTANT_LONG_CODE);
335 stream->write_long(value());
336 }
337
338 void ConstantLongValue::print_on(outputStream* st) const {
339 st->print(JLONG_FORMAT, value());
340 }
341
342 // ConstantDoubleValue
343
344 ConstantDoubleValue::ConstantDoubleValue(DebugInfoReadStream* stream) {
345 _value = stream->read_double();
346 }
347
348 void ConstantDoubleValue::write_on(DebugInfoWriteStream* stream) {
349 stream->write_int(CONSTANT_DOUBLE_CODE);
350 stream->write_double(value());
351 }
352
353 void ConstantDoubleValue::print_on(outputStream* st) const {
354 st->print("%f", value());
355 }
356
357 // ConstantOopWriteValue
358
359 void ConstantOopWriteValue::write_on(DebugInfoWriteStream* stream) {
360 #ifdef ASSERT
361 {
362 // cannot use ThreadInVMfromNative here since in case of JVMCI compiler,
363 // thread is already in VM state.
364 ThreadInVMfromUnknown tiv;
365 assert(JNIHandles::resolve(value()) == nullptr ||
366 Universe::heap()->is_in(JNIHandles::resolve(value())),
367 "Should be in heap");
368 }
369 #endif
370 stream->write_int(CONSTANT_OOP_CODE);
371 stream->write_handle(value());
372 }
373
374 void ConstantOopWriteValue::print_on(outputStream* st) const {
375 // using ThreadInVMfromUnknown here since in case of JVMCI compiler,
376 // thread is already in VM state.
377 ThreadInVMfromUnknown tiv;
378 JNIHandles::resolve(value())->print_value_on(st);
379 }
380
381
382 // ConstantOopReadValue
383
384 ConstantOopReadValue::ConstantOopReadValue(DebugInfoReadStream* stream) {
385 _value = Handle(Thread::current(), stream->read_oop());
386 assert(_value() == nullptr ||
387 Universe::heap()->is_in(_value()), "Should be in heap");
388 }
389
390 void ConstantOopReadValue::write_on(DebugInfoWriteStream* stream) {
391 ShouldNotReachHere();
392 }
393
394 void ConstantOopReadValue::print_on(outputStream* st) const {
395 if (value()() != nullptr) {
396 value()()->print_value_on(st);
397 } else {
398 st->print("nullptr");
399 }
400 }
401
402
403 // MonitorValue
404
405 MonitorValue::MonitorValue(ScopeValue* owner, Location basic_lock, bool eliminated) {
406 _owner = owner;
407 _basic_lock = basic_lock;
408 _eliminated = eliminated;
409 }
410
411 MonitorValue::MonitorValue(DebugInfoReadStream* stream) {
412 _basic_lock = Location(stream);
413 _owner = ScopeValue::read_from(stream);
414 _eliminated = (stream->read_bool() != 0);
415 }
416
417 void MonitorValue::write_on(DebugInfoWriteStream* stream) {
418 _basic_lock.write_on(stream);
419 _owner->write_on(stream);
420 stream->write_bool(_eliminated);
421 }
422
423 #ifndef PRODUCT
424 void MonitorValue::print_on(outputStream* st) const {
425 st->print("monitor{");
426 owner()->print_on(st);
427 st->print(",");
428 basic_lock().print_on(st);
429 st->print("}");
430 if (_eliminated) {
431 st->print(" (eliminated)");
432 }
433 }
434 #endif