debugInfo.cpp

/*
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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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*/

#include"code/debugInfo.hpp"
#include"code/debugInfoRec.hpp"
#include"code/nmethod.hpp"
#include"gc/shared/collectedHeap.hpp"
#include"memory/universe.hpp"
#include"oops/oop.inline.hpp"
#include"runtime/stackValue.hpp"
#include"runtime/handles.inline.hpp"
#include"runtime/interfaceSupport.inline.hpp"
#include"runtime/javaThread.hpp"
#include"runtime/jniHandles.inline.hpp"

// Constructors

DebugInfoWriteStream::DebugInfoWriteStream(DebugInformationRecorder* recorder, int initial_size)
: CompressedWriteStream(initial_size) {
 _recorder = recorder;
}

// Serializing oops

voidDebugInfoWriteStream::write_handle(jobject h) {
write_int(recorder()->oop_recorder()->find_index(h));
}

voidDebugInfoWriteStream::write_metadata(Metadata* h) {
write_int(recorder()->oop_recorder()->find_index(h));
}

oop DebugInfoReadStream::read_oop() {
// Despite these oops being found inside nmethods that are on-stack,
// they are not kept alive by all GCs (e.g. G1 and Shenandoah).
 oop o = code()->oop_at_phantom(read_int());
assert(oopDesc::is_oop_or_null(o), "oop only");
return o;
}

ScopeValue* DebugInfoReadStream::read_object_value(bool is_auto_box) {
int id = read_int();
#ifdef ASSERT
assert(_obj_pool != nullptr, "object pool does not exist");
for (int i = _obj_pool->length() - 1; i >= 0; i--) {
assert(_obj_pool->at(i)->as_ObjectValue()->id() != id, "should not be read twice");
 }
#endif
 ObjectValue* result = is_auto_box ? newAutoBoxObjectValue(id) : newObjectValue(id);
// Cache the object since an object field could reference it.
 _obj_pool->push(result);
 result->read_object(this);
return result;
}

ScopeValue* DebugInfoReadStream::read_object_merge_value() {
int id = read_int();
#ifdef ASSERT
assert(_obj_pool != nullptr, "object pool does not exist");
for (int i = _obj_pool->length() - 1; i >= 0; i--) {
assert(_obj_pool->at(i)->as_ObjectValue()->id() != id, "should not be read twice");
 }
#endif
 ObjectMergeValue* result = newObjectMergeValue(id);
 _obj_pool->push(result);
 result->read_object(this);
return result;
}

ScopeValue* DebugInfoReadStream::get_cached_object() {
int id = read_int();
assert(_obj_pool != nullptr, "object pool does not exist");
for (int i = _obj_pool->length() - 1; i >= 0; i--) {
 ObjectValue* ov = _obj_pool->at(i)->as_ObjectValue();
if (ov->id() == id) {
return ov;
 }
 }
ShouldNotReachHere();
returnnullptr;
}

// Serializing scope values

enum { LOCATION_CODE = 0, CONSTANT_INT_CODE = 1, CONSTANT_OOP_CODE = 2,
 CONSTANT_LONG_CODE = 3, CONSTANT_DOUBLE_CODE = 4,
 OBJECT_CODE = 5, OBJECT_ID_CODE = 6,
 AUTO_BOX_OBJECT_CODE = 7, MARKER_CODE = 8,
 OBJECT_MERGE_CODE = 9 };

ScopeValue* ScopeValue::read_from(DebugInfoReadStream* stream) {
 ScopeValue* result = nullptr;
switch(stream->read_int()) {
case LOCATION_CODE: result = newLocationValue(stream); break;
case CONSTANT_INT_CODE: result = newConstantIntValue(stream); break;
case CONSTANT_OOP_CODE: result = newConstantOopReadValue(stream); break;
case CONSTANT_LONG_CODE: result = newConstantLongValue(stream); break;
case CONSTANT_DOUBLE_CODE: result = newConstantDoubleValue(stream); break;
case OBJECT_CODE: result = stream->read_object_value(false/*is_auto_box*/); break;
case AUTO_BOX_OBJECT_CODE: result = stream->read_object_value(true/*is_auto_box*/); break;
case OBJECT_MERGE_CODE: result = stream->read_object_merge_value(); break;
case OBJECT_ID_CODE: result = stream->get_cached_object(); break;
case MARKER_CODE: result = newMarkerValue(); break;
default: ShouldNotReachHere();
 }
return result;
}

// LocationValue

LocationValue::LocationValue(DebugInfoReadStream* stream) {
 _location = Location(stream);
}

voidLocationValue::write_on(DebugInfoWriteStream* stream) {
 stream->write_int(LOCATION_CODE);
location().write_on(stream);
}

voidLocationValue::print_on(outputStream* st) const {
location().print_on(st);
}

// MarkerValue

voidMarkerValue::write_on(DebugInfoWriteStream* stream) {
 stream->write_int(MARKER_CODE);
}

voidMarkerValue::print_on(outputStream* st) const {
 st->print("marker");
}

// ObjectValue

voidObjectValue::set_value(oop value) {
 _value = Handle(Thread::current(), value);
}

voidObjectValue::read_object(DebugInfoReadStream* stream) {
 _is_root = stream->read_bool();
 _klass = read_from(stream);
assert(_klass->is_constant_oop(), "should be constant java mirror oop");
int length = stream->read_int();
for (int i = 0; i < length; i++) {
 ScopeValue* val = read_from(stream);
 _field_values.append(val);
 }
}

voidObjectValue::write_on(DebugInfoWriteStream* stream) {
if (is_visited()) {
 stream->write_int(OBJECT_ID_CODE);
 stream->write_int(_id);
 } else {
set_visited(true);
 stream->write_int(is_auto_box() ? AUTO_BOX_OBJECT_CODE : OBJECT_CODE);
 stream->write_int(_id);
 stream->write_bool(_is_root);
 _klass->write_on(stream);
int length = _field_values.length();
 stream->write_int(length);
for (int i = 0; i < length; i++) {
 _field_values.at(i)->write_on(stream);
 }
 }
}

voidObjectValue::print_on(outputStream* st) const {
 st->print("%s[%d]", is_auto_box() ? "box_obj" : is_object_merge() ? "merge_obj" : "obj", _id);
}

voidObjectValue::print_fields_on(outputStream* st) const {
#ifndef PRODUCT
if (is_object_merge()) {
 ObjectMergeValue* omv = (ObjectMergeValue*)this;
 st->print("selector=\"");
 omv->selector()->print_on(st);
 st->print("\"");
 ScopeValue* merge_pointer = omv->merge_pointer();
if (!(merge_pointer->is_object() && merge_pointer->as_ObjectValue()->value()() == nullptr) &&
 !(merge_pointer->is_constant_oop() && merge_pointer->as_ConstantOopReadValue()->value()() == nullptr)) {
 st->print(", merge_pointer=\"");
 merge_pointer->print_on(st);
 st->print("\"");
 }
 GrowableArray<ScopeValue*>* possible_objects = omv->possible_objects();
 st->print(", candidate_objs=[%d", possible_objects->at(0)->as_ObjectValue()->id());
int ncandidates = possible_objects->length();
for (int i = 1; i < ncandidates; i++) {
 st->print(", %d", possible_objects->at(i)->as_ObjectValue()->id());
 }
 st->print("]");
 } else {
 st->print("\n Fields: ");
if (_field_values.length() > 0) {
 _field_values.at(0)->print_on(st);
 }
for (int i = 1; i < _field_values.length(); i++) {
 st->print(", ");
 _field_values.at(i)->print_on(st);
 }
 }
#endif
}


// ObjectMergeValue

// Returns the ObjectValue that should be used for the local that this
// ObjectMergeValue represents. ObjectMergeValue represents allocation
// merges in C2. This method will select which path the allocation merge
// took during execution of the Trap that triggered the rematerialization
// of the object.
ObjectValue* ObjectMergeValue::select(frame& fr, RegisterMap& reg_map) {
 StackValue* sv_selector = StackValue::create_stack_value(&fr, &reg_map, _selector);
 jint selector = sv_selector->get_jint();

// If the selector is '-1' it means that execution followed the path
// where no scalar replacement happened.
// Otherwise, it is the index in _possible_objects array that holds
// the description of the scalar replaced object.
if (selector == -1) {
 StackValue* sv_merge_pointer = StackValue::create_stack_value(&fr, &reg_map, _merge_pointer);
 _selected = newObjectValue(id(), nullptr, false);

// Retrieve the pointer to the real object and use it as if we had
// allocated it during the deoptimization
 _selected->set_value(sv_merge_pointer->get_obj()());

return _selected;
 } else {
assert(selector < _possible_objects.length(), "sanity");
 _selected = (ObjectValue*) _possible_objects.at(selector);
return _selected;
 }
}

HandleObjectMergeValue::value() const {
if (_selected != nullptr) {
return _selected->value();
 } else {
returnHandle();
 }
}

voidObjectMergeValue::read_object(DebugInfoReadStream* stream) {
 _selector = read_from(stream);
 _merge_pointer = read_from(stream);
int ncandidates = stream->read_int();
for (int i = 0; i < ncandidates; i++) {
 ScopeValue* result = read_from(stream);
assert(result->is_object(), "Candidate is not an object!");
 ObjectValue* obj = result->as_ObjectValue();
 _possible_objects.append(obj);
 }
}

voidObjectMergeValue::write_on(DebugInfoWriteStream* stream) {
if (is_visited()) {
 stream->write_int(OBJECT_ID_CODE);
 stream->write_int(_id);
 } else {
set_visited(true);
 stream->write_int(OBJECT_MERGE_CODE);
 stream->write_int(_id);
 _selector->write_on(stream);
 _merge_pointer->write_on(stream);
int ncandidates = _possible_objects.length();
 stream->write_int(ncandidates);
for (int i = 0; i < ncandidates; i++) {
 _possible_objects.at(i)->as_ObjectValue()->write_on(stream);
 }
 }
}

// ConstantIntValue

ConstantIntValue::ConstantIntValue(DebugInfoReadStream* stream) {
 _value = stream->read_signed_int();
}

voidConstantIntValue::write_on(DebugInfoWriteStream* stream) {
 stream->write_int(CONSTANT_INT_CODE);
 stream->write_signed_int(value());
}

voidConstantIntValue::print_on(outputStream* st) const {
 st->print("%d", value());
}

// ConstantLongValue

ConstantLongValue::ConstantLongValue(DebugInfoReadStream* stream) {
 _value = stream->read_long();
}

voidConstantLongValue::write_on(DebugInfoWriteStream* stream) {
 stream->write_int(CONSTANT_LONG_CODE);
 stream->write_long(value());
}

voidConstantLongValue::print_on(outputStream* st) const {
 st->print(JLONG_FORMAT, value());
}

// ConstantDoubleValue

ConstantDoubleValue::ConstantDoubleValue(DebugInfoReadStream* stream) {
 _value = stream->read_double();
}

voidConstantDoubleValue::write_on(DebugInfoWriteStream* stream) {
 stream->write_int(CONSTANT_DOUBLE_CODE);
 stream->write_double(value());
}

voidConstantDoubleValue::print_on(outputStream* st) const {
 st->print("%f", value());
}

// ConstantOopWriteValue

voidConstantOopWriteValue::write_on(DebugInfoWriteStream* stream) {
#ifdef ASSERT
 {
// cannot use ThreadInVMfromNative here since in case of JVMCI compiler,
// thread is already in VM state.
 ThreadInVMfromUnknown tiv;
assert(JNIHandles::resolve(value()) == nullptr ||
Universe::heap()->is_in(JNIHandles::resolve(value())),
"Should be in heap");
 }
#endif
 stream->write_int(CONSTANT_OOP_CODE);
 stream->write_handle(value());
}

voidConstantOopWriteValue::print_on(outputStream* st) const {
// using ThreadInVMfromUnknown here since in case of JVMCI compiler,
// thread is already in VM state.
 ThreadInVMfromUnknown tiv;
JNIHandles::resolve(value())->print_value_on(st);
}


// ConstantOopReadValue

ConstantOopReadValue::ConstantOopReadValue(DebugInfoReadStream* stream) {
 _value = Handle(Thread::current(), stream->read_oop());
assert(_value() == nullptr ||
Universe::heap()->is_in(_value()), "Should be in heap");
}

voidConstantOopReadValue::write_on(DebugInfoWriteStream* stream) {
ShouldNotReachHere();
}

voidConstantOopReadValue::print_on(outputStream* st) const {
if (value()() != nullptr) {
value()()->print_value_on(st);
 } else {
 st->print("null");
 }
}


// MonitorValue

MonitorValue::MonitorValue(ScopeValue* owner, Location basic_lock, bool eliminated) {
 _owner = owner;
 _basic_lock = basic_lock;
 _eliminated = eliminated;
}

MonitorValue::MonitorValue(DebugInfoReadStream* stream) {
 _basic_lock = Location(stream);
 _owner = ScopeValue::read_from(stream);
 _eliminated = (stream->read_bool() != 0);
}

voidMonitorValue::write_on(DebugInfoWriteStream* stream) {
 _basic_lock.write_on(stream);
 _owner->write_on(stream);
 stream->write_bool(_eliminated);
}

#ifndef PRODUCT
voidMonitorValue::print_on(outputStream* st) const {
 st->print("monitor{");
owner()->print_on(st);
 st->print(",");
basic_lock().print_on(st);
 st->print("}");
if (_eliminated) {
 st->print(" (eliminated)");
 }
}
#endif