jdk

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/*
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 * Copyright (c) 1997, 2024, Oracle and/or its affiliates. All rights reserved.
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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 *
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 * This code is free software; you can redistribute it and/or modify it
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 * under the terms of the GNU General Public License version 2 only, as
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 * published by the Free Software Foundation.
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 *
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 * This code is distributed in the hope that it will be useful, but WITHOUT
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 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
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 * version 2 for more details (a copy is included in the LICENSE file that
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 * accompanied this code).
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 *
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 * You should have received a copy of the GNU General Public License version
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 * 2 along with this work; if not, write to the Free Software Foundation,
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 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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 *
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 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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 * or visit www.oracle.com if you need additional information or have any
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 * questions.
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 *
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 */
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#include "precompiled.hpp"
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#include "code/debugInfo.hpp"
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#include "code/debugInfoRec.hpp"
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#include "code/nmethod.hpp"
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#include "gc/shared/collectedHeap.hpp"
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#include "memory/universe.hpp"
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#include "oops/oop.inline.hpp"
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#include "runtime/stackValue.hpp"
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#include "runtime/handles.inline.hpp"
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#include "runtime/interfaceSupport.inline.hpp"
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#include "runtime/javaThread.hpp"
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#include "runtime/jniHandles.inline.hpp"
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// Constructors
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DebugInfoWriteStream::DebugInfoWriteStream(DebugInformationRecorder* recorder, int initial_size)
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: CompressedWriteStream(initial_size) {
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  _recorder = recorder;
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}
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// Serializing oops
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void DebugInfoWriteStream::write_handle(jobject h) {
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  write_int(recorder()->oop_recorder()->find_index(h));
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}
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void DebugInfoWriteStream::write_metadata(Metadata* h) {
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  write_int(recorder()->oop_recorder()->find_index(h));
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}
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oop DebugInfoReadStream::read_oop() {
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  // Despite these oops being found inside nmethods that are on-stack,
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  // they are not kept alive by all GCs (e.g. G1 and Shenandoah).
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  oop o = code()->oop_at_phantom(read_int());
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  assert(oopDesc::is_oop_or_null(o), "oop only");
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  return o;
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}
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ScopeValue* DebugInfoReadStream::read_object_value(bool is_auto_box) {
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  int id = read_int();
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#ifdef ASSERT
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  assert(_obj_pool != nullptr, "object pool does not exist");
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  for (int i = _obj_pool->length() - 1; i >= 0; i--) {
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    assert(_obj_pool->at(i)->as_ObjectValue()->id() != id, "should not be read twice");
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  }
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#endif
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  ObjectValue* result = is_auto_box ? new AutoBoxObjectValue(id) : new ObjectValue(id);
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  // Cache the object since an object field could reference it.
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  _obj_pool->push(result);
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  result->read_object(this);
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  return result;
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}
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ScopeValue* DebugInfoReadStream::read_object_merge_value() {
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  int id = read_int();
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#ifdef ASSERT
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  assert(_obj_pool != nullptr, "object pool does not exist");
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  for (int i = _obj_pool->length() - 1; i >= 0; i--) {
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    assert(_obj_pool->at(i)->as_ObjectValue()->id() != id, "should not be read twice");
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  }
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#endif
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  ObjectMergeValue* result = new ObjectMergeValue(id);
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  _obj_pool->push(result);
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  result->read_object(this);
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  return result;
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}
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ScopeValue* DebugInfoReadStream::get_cached_object() {
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  int id = read_int();
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  assert(_obj_pool != nullptr, "object pool does not exist");
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  for (int i = _obj_pool->length() - 1; i >= 0; i--) {
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    ObjectValue* ov = _obj_pool->at(i)->as_ObjectValue();
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    if (ov->id() == id) {
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      return ov;
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    }
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  }
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  ShouldNotReachHere();
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  return nullptr;
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}
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// Serializing scope values
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enum { LOCATION_CODE = 0, CONSTANT_INT_CODE = 1,  CONSTANT_OOP_CODE = 2,
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                          CONSTANT_LONG_CODE = 3, CONSTANT_DOUBLE_CODE = 4,
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                          OBJECT_CODE = 5,        OBJECT_ID_CODE = 6,
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                          AUTO_BOX_OBJECT_CODE = 7, MARKER_CODE = 8,
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                          OBJECT_MERGE_CODE = 9 };
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ScopeValue* ScopeValue::read_from(DebugInfoReadStream* stream) {
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  ScopeValue* result = nullptr;
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  switch(stream->read_int()) {
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   case LOCATION_CODE:        result = new LocationValue(stream);                        break;
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   case CONSTANT_INT_CODE:    result = new ConstantIntValue(stream);                     break;
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   case CONSTANT_OOP_CODE:    result = new ConstantOopReadValue(stream);                 break;
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   case CONSTANT_LONG_CODE:   result = new ConstantLongValue(stream);                    break;
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   case CONSTANT_DOUBLE_CODE: result = new ConstantDoubleValue(stream);                  break;
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   case OBJECT_CODE:          result = stream->read_object_value(false /*is_auto_box*/); break;
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   case AUTO_BOX_OBJECT_CODE: result = stream->read_object_value(true /*is_auto_box*/);  break;
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   case OBJECT_MERGE_CODE:    result = stream->read_object_merge_value();                break;
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   case OBJECT_ID_CODE:       result = stream->get_cached_object();                      break;
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   case MARKER_CODE:          result = new MarkerValue();                                break;
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   default: ShouldNotReachHere();
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  }
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  return result;
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}
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// LocationValue
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LocationValue::LocationValue(DebugInfoReadStream* stream) {
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  _location = Location(stream);
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}
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void LocationValue::write_on(DebugInfoWriteStream* stream) {
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  stream->write_int(LOCATION_CODE);
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  location().write_on(stream);
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}
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void LocationValue::print_on(outputStream* st) const {
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  location().print_on(st);
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}
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// MarkerValue
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void MarkerValue::write_on(DebugInfoWriteStream* stream) {
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  stream->write_int(MARKER_CODE);
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}
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void MarkerValue::print_on(outputStream* st) const {
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    st->print("marker");
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}
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// ObjectValue
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void ObjectValue::set_value(oop value) {
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  _value = Handle(Thread::current(), value);
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}
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void ObjectValue::read_object(DebugInfoReadStream* stream) {
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  _is_root = stream->read_bool();
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  _klass = read_from(stream);
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  assert(_klass->is_constant_oop(), "should be constant java mirror oop");
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  int length = stream->read_int();
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  for (int i = 0; i < length; i++) {
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    ScopeValue* val = read_from(stream);
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    _field_values.append(val);
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  }
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}
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void ObjectValue::write_on(DebugInfoWriteStream* stream) {
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  if (is_visited()) {
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    stream->write_int(OBJECT_ID_CODE);
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    stream->write_int(_id);
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  } else {
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    set_visited(true);
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    stream->write_int(is_auto_box() ? AUTO_BOX_OBJECT_CODE : OBJECT_CODE);
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    stream->write_int(_id);
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    stream->write_bool(_is_root);
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    _klass->write_on(stream);
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    int length = _field_values.length();
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    stream->write_int(length);
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    for (int i = 0; i < length; i++) {
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      _field_values.at(i)->write_on(stream);
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    }
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  }
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}
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void ObjectValue::print_on(outputStream* st) const {
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  st->print("%s[%d]", is_auto_box() ? "box_obj" : is_object_merge() ? "merge_obj" : "obj", _id);
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}
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void ObjectValue::print_fields_on(outputStream* st) const {
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#ifndef PRODUCT
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  if (is_object_merge()) {
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    ObjectMergeValue* omv = (ObjectMergeValue*)this;
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    st->print("selector=\"");
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    omv->selector()->print_on(st);
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    st->print("\"");
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    ScopeValue* merge_pointer = omv->merge_pointer();
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    if (!(merge_pointer->is_object() && merge_pointer->as_ObjectValue()->value()() == nullptr) &&
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        !(merge_pointer->is_constant_oop() && merge_pointer->as_ConstantOopReadValue()->value()() == nullptr)) {
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      st->print(", merge_pointer=\"");
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      merge_pointer->print_on(st);
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      st->print("\"");
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    }
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    GrowableArray<ScopeValue*>* possible_objects = omv->possible_objects();
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    st->print(", candidate_objs=[%d", possible_objects->at(0)->as_ObjectValue()->id());
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    int ncandidates = possible_objects->length();
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    for (int i = 1; i < ncandidates; i++) {
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      st->print(", %d", possible_objects->at(i)->as_ObjectValue()->id());
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    }
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    st->print("]");
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  } else {
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    st->print("\n        Fields: ");
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    if (_field_values.length() > 0) {
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      _field_values.at(0)->print_on(st);
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    }
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    for (int i = 1; i < _field_values.length(); i++) {
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      st->print(", ");
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      _field_values.at(i)->print_on(st);
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    }
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  }
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#endif
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}
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// ObjectMergeValue
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// Returns the ObjectValue that should be used for the local that this
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// ObjectMergeValue represents. ObjectMergeValue represents allocation
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// merges in C2. This method will select which path the allocation merge
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// took during execution of the Trap that triggered the rematerialization
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// of the object.
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ObjectValue* ObjectMergeValue::select(frame& fr, RegisterMap& reg_map) {
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  StackValue* sv_selector = StackValue::create_stack_value(&fr, &reg_map, _selector);
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  jint selector = sv_selector->get_jint();
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  // If the selector is '-1' it means that execution followed the path
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  // where no scalar replacement happened.
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  // Otherwise, it is the index in _possible_objects array that holds
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  // the description of the scalar replaced object.
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  if (selector == -1) {
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    StackValue* sv_merge_pointer = StackValue::create_stack_value(&fr, &reg_map, _merge_pointer);
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    _selected = new ObjectValue(id(), nullptr, false);
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    // Retrieve the pointer to the real object and use it as if we had
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    // allocated it during the deoptimization
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    _selected->set_value(sv_merge_pointer->get_obj()());
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    return _selected;
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  } else {
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    assert(selector < _possible_objects.length(), "sanity");
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    _selected = (ObjectValue*) _possible_objects.at(selector);
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    return _selected;
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  }
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}
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Handle ObjectMergeValue::value() const {
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  if (_selected != nullptr) {
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    return _selected->value();
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  } else {
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    return Handle();
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  }
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}
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void ObjectMergeValue::read_object(DebugInfoReadStream* stream) {
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  _selector = read_from(stream);
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  _merge_pointer = read_from(stream);
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  int ncandidates = stream->read_int();
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  for (int i = 0; i < ncandidates; i++) {
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    ScopeValue* result = read_from(stream);
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    assert(result->is_object(), "Candidate is not an object!");
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    ObjectValue* obj = result->as_ObjectValue();
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    _possible_objects.append(obj);
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  }
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}
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void ObjectMergeValue::write_on(DebugInfoWriteStream* stream) {
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  if (is_visited()) {
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    stream->write_int(OBJECT_ID_CODE);
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    stream->write_int(_id);
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  } else {
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    set_visited(true);
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    stream->write_int(OBJECT_MERGE_CODE);
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    stream->write_int(_id);
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    _selector->write_on(stream);
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    _merge_pointer->write_on(stream);
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    int ncandidates = _possible_objects.length();
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    stream->write_int(ncandidates);
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    for (int i = 0; i < ncandidates; i++) {
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      _possible_objects.at(i)->as_ObjectValue()->write_on(stream);
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    }
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  }
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}
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// ConstantIntValue
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ConstantIntValue::ConstantIntValue(DebugInfoReadStream* stream) {
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  _value = stream->read_signed_int();
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}
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void ConstantIntValue::write_on(DebugInfoWriteStream* stream) {
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  stream->write_int(CONSTANT_INT_CODE);
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  stream->write_signed_int(value());
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}
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void ConstantIntValue::print_on(outputStream* st) const {
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  st->print("%d", value());
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}
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// ConstantLongValue
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ConstantLongValue::ConstantLongValue(DebugInfoReadStream* stream) {
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  _value = stream->read_long();
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}
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void ConstantLongValue::write_on(DebugInfoWriteStream* stream) {
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  stream->write_int(CONSTANT_LONG_CODE);
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  stream->write_long(value());
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}
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void ConstantLongValue::print_on(outputStream* st) const {
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  st->print(JLONG_FORMAT, value());
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}
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// ConstantDoubleValue
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ConstantDoubleValue::ConstantDoubleValue(DebugInfoReadStream* stream) {
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  _value = stream->read_double();
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}
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void ConstantDoubleValue::write_on(DebugInfoWriteStream* stream) {
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  stream->write_int(CONSTANT_DOUBLE_CODE);
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  stream->write_double(value());
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}
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void ConstantDoubleValue::print_on(outputStream* st) const {
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  st->print("%f", value());
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}
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// ConstantOopWriteValue
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void ConstantOopWriteValue::write_on(DebugInfoWriteStream* stream) {
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#ifdef ASSERT
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  {
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    // cannot use ThreadInVMfromNative here since in case of JVMCI compiler,
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    // thread is already in VM state.
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    ThreadInVMfromUnknown tiv;
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    assert(JNIHandles::resolve(value()) == nullptr ||
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           Universe::heap()->is_in(JNIHandles::resolve(value())),
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           "Should be in heap");
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 }
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#endif
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  stream->write_int(CONSTANT_OOP_CODE);
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  stream->write_handle(value());
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}
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void ConstantOopWriteValue::print_on(outputStream* st) const {
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  // using ThreadInVMfromUnknown here since in case of JVMCI compiler,
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  // thread is already in VM state.
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  ThreadInVMfromUnknown tiv;
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  JNIHandles::resolve(value())->print_value_on(st);
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}
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// ConstantOopReadValue
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ConstantOopReadValue::ConstantOopReadValue(DebugInfoReadStream* stream) {
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  _value = Handle(Thread::current(), stream->read_oop());
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  assert(_value() == nullptr ||
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         Universe::heap()->is_in(_value()), "Should be in heap");
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}
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void ConstantOopReadValue::write_on(DebugInfoWriteStream* stream) {
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  ShouldNotReachHere();
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}
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void ConstantOopReadValue::print_on(outputStream* st) const {
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  if (value()() != nullptr) {
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    value()()->print_value_on(st);
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  } else {
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    st->print("nullptr");
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  }
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}
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// MonitorValue
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MonitorValue::MonitorValue(ScopeValue* owner, Location basic_lock, bool eliminated) {
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  _owner       = owner;
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  _basic_lock  = basic_lock;
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  _eliminated  = eliminated;
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}
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MonitorValue::MonitorValue(DebugInfoReadStream* stream) {
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  _basic_lock  = Location(stream);
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  _owner       = ScopeValue::read_from(stream);
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  _eliminated  = (stream->read_bool() != 0);
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}
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void MonitorValue::write_on(DebugInfoWriteStream* stream) {
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  _basic_lock.write_on(stream);
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  _owner->write_on(stream);
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  stream->write_bool(_eliminated);
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}
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#ifndef PRODUCT
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void MonitorValue::print_on(outputStream* st) const {
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  st->print("monitor{");
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  owner()->print_on(st);
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  st->print(",");
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  basic_lock().print_on(st);
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  st->print("}");
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  if (_eliminated) {
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    st->print(" (eliminated)");
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  }
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}
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#endif
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