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 assert(_klass->is_constant_oop(), "should be constant java mirror oop");
172 int length = stream->read_int();
173 for (int i = 0; i < length; i++) {
174 ScopeValue* val = read_from(stream);
175 _field_values.append(val);
176 }
177 }
178
179 void ObjectValue::write_on(DebugInfoWriteStream* stream) {
180 if (is_visited()) {
181 stream->write_int(OBJECT_ID_CODE);
182 stream->write_int(_id);
183 } else {
184 set_visited(true);
185 stream->write_int(is_auto_box() ? AUTO_BOX_OBJECT_CODE : OBJECT_CODE);
186 stream->write_int(_id);
187 stream->write_bool(_is_root);
188 _klass->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());
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 // No need to rematerialize
260 return nullptr;
261 } else {
262 assert(selector < _possible_objects.length(), "sanity");
263 _selected = (ObjectValue*) _possible_objects.at(selector);
264 return _selected;
265 }
266 }
267
268 Handle ObjectMergeValue::value() const {
269 if (_selected != nullptr) {
270 return _selected->value();
271 } else {
272 return Handle();
273 }
274 }
275
276 void ObjectMergeValue::read_object(DebugInfoReadStream* stream) {
277 _selector = read_from(stream);
278 _merge_pointer = read_from(stream);
279 int ncandidates = stream->read_int();
280 for (int i = 0; i < ncandidates; i++) {
281 ScopeValue* result = read_from(stream);
282 assert(result->is_object(), "Candidate is not an object!");
283 ObjectValue* obj = result->as_ObjectValue();
284 _possible_objects.append(obj);
285 }
286 }
287
288 void ObjectMergeValue::write_on(DebugInfoWriteStream* stream) {
289 if (is_visited()) {
290 stream->write_int(OBJECT_ID_CODE);
291 stream->write_int(_id);
292 } else {
293 set_visited(true);
294 stream->write_int(OBJECT_MERGE_CODE);
295 stream->write_int(_id);
296 _selector->write_on(stream);
297 _merge_pointer->write_on(stream);
298 int ncandidates = _possible_objects.length();
299 stream->write_int(ncandidates);
300 for (int i = 0; i < ncandidates; i++) {
301 _possible_objects.at(i)->as_ObjectValue()->write_on(stream);
302 }
303 }
304 }
305
306 // ConstantIntValue
307
308 ConstantIntValue::ConstantIntValue(DebugInfoReadStream* stream) {
309 _value = stream->read_signed_int();
310 }
311
312 void ConstantIntValue::write_on(DebugInfoWriteStream* stream) {
313 stream->write_int(CONSTANT_INT_CODE);
314 stream->write_signed_int(value());
315 }
316
317 void ConstantIntValue::print_on(outputStream* st) const {
318 st->print("%d", value());
319 }
320
321 // ConstantLongValue
322
323 ConstantLongValue::ConstantLongValue(DebugInfoReadStream* stream) {
324 _value = stream->read_long();
325 }
326
327 void ConstantLongValue::write_on(DebugInfoWriteStream* stream) {
328 stream->write_int(CONSTANT_LONG_CODE);
329 stream->write_long(value());
330 }
331
332 void ConstantLongValue::print_on(outputStream* st) const {
333 st->print(JLONG_FORMAT, value());
334 }
335
336 // ConstantDoubleValue
337
338 ConstantDoubleValue::ConstantDoubleValue(DebugInfoReadStream* stream) {
339 _value = stream->read_double();
340 }
341
342 void ConstantDoubleValue::write_on(DebugInfoWriteStream* stream) {
343 stream->write_int(CONSTANT_DOUBLE_CODE);
344 stream->write_double(value());
345 }
346
347 void ConstantDoubleValue::print_on(outputStream* st) const {
348 st->print("%f", value());
349 }
350
351 // ConstantOopWriteValue
352
353 void ConstantOopWriteValue::write_on(DebugInfoWriteStream* stream) {
354 #ifdef ASSERT
355 {
356 // cannot use ThreadInVMfromNative here since in case of JVMCI compiler,
357 // thread is already in VM state.
358 ThreadInVMfromUnknown tiv;
359 assert(JNIHandles::resolve(value()) == nullptr ||
360 Universe::heap()->is_in(JNIHandles::resolve(value())),
361 "Should be in heap");
362 }
363 #endif
364 stream->write_int(CONSTANT_OOP_CODE);
365 stream->write_handle(value());
366 }
367
368 void ConstantOopWriteValue::print_on(outputStream* st) const {
369 // using ThreadInVMfromUnknown here since in case of JVMCI compiler,
370 // thread is already in VM state.
371 ThreadInVMfromUnknown tiv;
372 JNIHandles::resolve(value())->print_value_on(st);
373 }
374
375
376 // ConstantOopReadValue
377
378 ConstantOopReadValue::ConstantOopReadValue(DebugInfoReadStream* stream) {
379 _value = Handle(Thread::current(), stream->read_oop());
380 assert(_value() == nullptr ||
381 Universe::heap()->is_in(_value()), "Should be in heap");
382 }
383
384 void ConstantOopReadValue::write_on(DebugInfoWriteStream* stream) {
385 ShouldNotReachHere();
386 }
387
388 void ConstantOopReadValue::print_on(outputStream* st) const {
389 if (value()() != nullptr) {
390 value()()->print_value_on(st);
391 } else {
392 st->print("nullptr");
393 }
394 }
395
396
397 // MonitorValue
398
399 MonitorValue::MonitorValue(ScopeValue* owner, Location basic_lock, bool eliminated) {
400 _owner = owner;
401 _basic_lock = basic_lock;
402 _eliminated = eliminated;
403 }
404
405 MonitorValue::MonitorValue(DebugInfoReadStream* stream) {
406 _basic_lock = Location(stream);
407 _owner = ScopeValue::read_from(stream);
408 _eliminated = (stream->read_bool() != 0);
409 }
410
411 void MonitorValue::write_on(DebugInfoWriteStream* stream) {
412 _basic_lock.write_on(stream);
413 _owner->write_on(stream);
414 stream->write_bool(_eliminated);
415 }
416
417 #ifndef PRODUCT
418 void MonitorValue::print_on(outputStream* st) const {
419 st->print("monitor{");
420 owner()->print_on(st);
421 st->print(",");
422 basic_lock().print_on(st);
423 st->print("}");
424 if (_eliminated) {
425 st->print(" (eliminated)");
426 }
427 }
428 #endif