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 _properties = 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 _properties->write_on(stream); 184 int length = _field_values.length(); 185 stream->write_int(length); 186 for (int i = 0; i < length; i++) { 187 _field_values.at(i)->write_on(stream); 188 } 189 } 190 } 191 192 void ObjectValue::print_on(outputStream* st) const { 193 st->print("%s[%d]", is_auto_box() ? "box_obj" : is_object_merge() ? "merge_obj" : "obj", _id); 194 } 195 196 void ObjectValue::print_fields_on(outputStream* st) const { 197 #ifndef PRODUCT 198 if (is_object_merge()) { 199 ObjectMergeValue* omv = (ObjectMergeValue*)this; 200 st->print("selector=\""); 201 omv->selector()->print_on(st); 202 st->print("\""); 203 ScopeValue* merge_pointer = omv->merge_pointer(); 204 if (!(merge_pointer->is_object() && merge_pointer->as_ObjectValue()->value()() == nullptr) && 205 !(merge_pointer->is_constant_oop() && merge_pointer->as_ConstantOopReadValue()->value()() == nullptr)) { 206 st->print(", merge_pointer=\""); 207 merge_pointer->print_on(st); 208 st->print("\""); 209 } 210 GrowableArray<ScopeValue*>* possible_objects = omv->possible_objects(); 211 st->print(", candidate_objs=[%d", possible_objects->at(0)->as_ObjectValue()->id()); 212 int ncandidates = possible_objects->length(); 213 for (int i = 1; i < ncandidates; i++) { 214 st->print(", %d", possible_objects->at(i)->as_ObjectValue()->id()); 215 } 216 st->print("]"); 217 } else { 218 st->print("\n Fields: "); 219 if (_field_values.length() > 0) { 220 _field_values.at(0)->print_on(st); 221 } 222 for (int i = 1; i < _field_values.length(); i++) { 223 st->print(", "); 224 _field_values.at(i)->print_on(st); 225 } 226 } 227 #endif 228 } 229 230 231 // ObjectMergeValue 232 233 // Returns the ObjectValue that should be used for the local that this 234 // ObjectMergeValue represents. ObjectMergeValue represents allocation 235 // merges in C2. This method will select which path the allocation merge 236 // took during execution of the Trap that triggered the rematerialization 237 // of the object. 238 ObjectValue* ObjectMergeValue::select(frame& fr, RegisterMap& reg_map) { 239 StackValue* sv_selector = StackValue::create_stack_value(&fr, ®_map, _selector); 240 jint selector = sv_selector->get_jint(); 241 242 // If the selector is '-1' it means that execution followed the path 243 // where no scalar replacement happened. 244 // Otherwise, it is the index in _possible_objects array that holds 245 // the description of the scalar replaced object. 246 if (selector == -1) { 247 StackValue* sv_merge_pointer = StackValue::create_stack_value(&fr, ®_map, _merge_pointer); 248 _selected = new ObjectValue(id(), nullptr, false); 249 250 // Retrieve the pointer to the real object and use it as if we had 251 // allocated it during the deoptimization 252 _selected->set_value(sv_merge_pointer->get_obj()()); 253 254 return _selected; 255 } else { 256 assert(selector < _possible_objects.length(), "sanity"); 257 _selected = (ObjectValue*) _possible_objects.at(selector); 258 return _selected; 259 } 260 } 261 262 Handle ObjectMergeValue::value() const { 263 if (_selected != nullptr) { 264 return _selected->value(); 265 } else { 266 return Handle(); 267 } 268 } 269 270 void ObjectMergeValue::read_object(DebugInfoReadStream* stream) { 271 _selector = read_from(stream); 272 _merge_pointer = read_from(stream); 273 int ncandidates = stream->read_int(); 274 for (int i = 0; i < ncandidates; i++) { 275 ScopeValue* result = read_from(stream); 276 assert(result->is_object(), "Candidate is not an object!"); 277 ObjectValue* obj = result->as_ObjectValue(); 278 _possible_objects.append(obj); 279 } 280 } 281 282 void ObjectMergeValue::write_on(DebugInfoWriteStream* stream) { 283 if (is_visited()) { 284 stream->write_int(OBJECT_ID_CODE); 285 stream->write_int(_id); 286 } else { 287 set_visited(true); 288 stream->write_int(OBJECT_MERGE_CODE); 289 stream->write_int(_id); 290 _selector->write_on(stream); 291 _merge_pointer->write_on(stream); 292 int ncandidates = _possible_objects.length(); 293 stream->write_int(ncandidates); 294 for (int i = 0; i < ncandidates; i++) { 295 _possible_objects.at(i)->as_ObjectValue()->write_on(stream); 296 } 297 } 298 } 299 300 // ConstantIntValue 301 302 ConstantIntValue::ConstantIntValue(DebugInfoReadStream* stream) { 303 _value = stream->read_signed_int(); 304 } 305 306 void ConstantIntValue::write_on(DebugInfoWriteStream* stream) { 307 stream->write_int(CONSTANT_INT_CODE); 308 stream->write_signed_int(value()); 309 } 310 311 void ConstantIntValue::print_on(outputStream* st) const { 312 st->print("%d", value()); 313 } 314 315 // ConstantLongValue 316 317 ConstantLongValue::ConstantLongValue(DebugInfoReadStream* stream) { 318 _value = stream->read_long(); 319 } 320 321 void ConstantLongValue::write_on(DebugInfoWriteStream* stream) { 322 stream->write_int(CONSTANT_LONG_CODE); 323 stream->write_long(value()); 324 } 325 326 void ConstantLongValue::print_on(outputStream* st) const { 327 st->print(JLONG_FORMAT, value()); 328 } 329 330 // ConstantDoubleValue 331 332 ConstantDoubleValue::ConstantDoubleValue(DebugInfoReadStream* stream) { 333 _value = stream->read_double(); 334 } 335 336 void ConstantDoubleValue::write_on(DebugInfoWriteStream* stream) { 337 stream->write_int(CONSTANT_DOUBLE_CODE); 338 stream->write_double(value()); 339 } 340 341 void ConstantDoubleValue::print_on(outputStream* st) const { 342 st->print("%f", value()); 343 } 344 345 // ConstantOopWriteValue 346 347 void ConstantOopWriteValue::write_on(DebugInfoWriteStream* stream) { 348 #ifdef ASSERT 349 { 350 // cannot use ThreadInVMfromNative here since in case of JVMCI compiler, 351 // thread is already in VM state. 352 ThreadInVMfromUnknown tiv; 353 assert(JNIHandles::resolve(value()) == nullptr || 354 Universe::heap()->is_in(JNIHandles::resolve(value())), 355 "Should be in heap"); 356 } 357 #endif 358 stream->write_int(CONSTANT_OOP_CODE); 359 stream->write_handle(value()); 360 } 361 362 void ConstantOopWriteValue::print_on(outputStream* st) const { 363 // using ThreadInVMfromUnknown here since in case of JVMCI compiler, 364 // thread is already in VM state. 365 ThreadInVMfromUnknown tiv; 366 JNIHandles::resolve(value())->print_value_on(st); 367 } 368 369 370 // ConstantOopReadValue 371 372 ConstantOopReadValue::ConstantOopReadValue(DebugInfoReadStream* stream) { 373 _value = Handle(Thread::current(), stream->read_oop()); 374 assert(_value() == nullptr || 375 Universe::heap()->is_in(_value()), "Should be in heap"); 376 } 377 378 void ConstantOopReadValue::write_on(DebugInfoWriteStream* stream) { 379 ShouldNotReachHere(); 380 } 381 382 void ConstantOopReadValue::print_on(outputStream* st) const { 383 if (value()() != nullptr) { 384 value()()->print_value_on(st); 385 } else { 386 st->print("null"); 387 } 388 } 389 390 391 // MonitorValue 392 393 MonitorValue::MonitorValue(ScopeValue* owner, Location basic_lock, bool eliminated) { 394 _owner = owner; 395 _basic_lock = basic_lock; 396 _eliminated = eliminated; 397 } 398 399 MonitorValue::MonitorValue(DebugInfoReadStream* stream) { 400 _basic_lock = Location(stream); 401 _owner = ScopeValue::read_from(stream); 402 _eliminated = (stream->read_bool() != 0); 403 } 404 405 void MonitorValue::write_on(DebugInfoWriteStream* stream) { 406 _basic_lock.write_on(stream); 407 _owner->write_on(stream); 408 stream->write_bool(_eliminated); 409 } 410 411 #ifndef PRODUCT 412 void MonitorValue::print_on(outputStream* st) const { 413 st->print("monitor{"); 414 owner()->print_on(st); 415 st->print(","); 416 basic_lock().print_on(st); 417 st->print("}"); 418 if (_eliminated) { 419 st->print(" (eliminated)"); 420 } 421 } 422 #endif