jvmciCodeInstaller.cpp

/*
 * Copyright (c) 2011, 2025, Oracle and/or its affiliates. All rights reserved.
 * 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.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
*/

#include"classfile/javaClasses.inline.hpp"
#include"code/compiledIC.hpp"
#include"compiler/compileBroker.hpp"
#include"compiler/compilerThread.hpp"
#include"compiler/oopMap.hpp"
#include"gc/shared/barrierSetNMethod.hpp"
#include"jvmci/jvmciCodeInstaller.hpp"
#include"jvmci/jvmciCompilerToVM.hpp"
#include"jvmci/jvmciRuntime.hpp"
#include"memory/universe.hpp"
#include"oops/compressedKlass.inline.hpp"
#include"oops/klass.inline.hpp"
#include"prims/jvmtiExport.hpp"
#include"prims/methodHandles.hpp"
#include"runtime/arguments.hpp"
#include"runtime/interfaceSupport.inline.hpp"
#include"runtime/jniHandles.inline.hpp"
#include"runtime/os.hpp"
#include"runtime/sharedRuntime.hpp"
#include"utilities/align.hpp"

// frequently used constants
// Allocate them with new so they are never destroyed (otherwise, a
// forced exit could destroy these objects while they are still in
// use).
ConstantOopWriteValue* CodeInstaller::_oop_null_scope_value = new (mtJVMCI) ConstantOopWriteValue(nullptr);
ConstantIntValue* CodeInstaller::_int_m1_scope_value = new (mtJVMCI) ConstantIntValue(-1);
ConstantIntValue* CodeInstaller::_int_0_scope_value = new (mtJVMCI) ConstantIntValue((jint)0);
ConstantIntValue* CodeInstaller::_int_1_scope_value = new (mtJVMCI) ConstantIntValue(1);
ConstantIntValue* CodeInstaller::_int_2_scope_value = new (mtJVMCI) ConstantIntValue(2);
LocationValue* CodeInstaller::_illegal_value = new (mtJVMCI) LocationValue(Location());
MarkerValue* CodeInstaller::_virtual_byte_array_marker = new (mtJVMCI) MarkerValue();

staticboolis_set(u1 flags, u1 bit) {
return flags & bit;
}

oop HotSpotCompiledCodeStream::get_oop(int id, JVMCI_TRAPS) const {
if (_object_pool.is_null()) {
JVMCI_ERROR_NULL("object pool is null%s", context());
 }
if (!_object_pool.is_null() && 0 <= id && id < _object_pool->length()) {
return _object_pool->obj_at(id);
 }
JVMCI_ERROR_NULL("unknown direct object id %d%s", id, context());
}

u4 HotSpotCompiledCodeStream::offset() const {
 u4 res = 0;
for (Chunk* c = _head; c != nullptr; c = c->next()) {
if (c == _chunk) {
 res += _pos - c->data();
break;
 } else {
 res += c->size();
 }
 }
return res;
}

boolHotSpotCompiledCodeStream::available() const {
 u4 rem = _chunk->data_end() - _pos;
for (Chunk* c = _chunk->next(); c != nullptr; c = c->next()) {
 rem += c->size();
 }
return rem;
}

voidHotSpotCompiledCodeStream::dump_buffer(outputStream* st) const {
 st->print_cr("HotSpotCompiledCode stream for %s:", code_desc());
int chunk_index = 0;
for (Chunk* c = _head; c != nullptr; c = c->next()) {
const u1* data = c->data();
const u1* data_end = c->data_end();

int to_dump = data_end - data;
 st->print_cr("# chunk %d, %d bytes", chunk_index, to_dump);
 st->print_data((void*) data, to_dump, true, false);
 chunk_index++;
 }
}

voidHotSpotCompiledCodeStream::dump_buffer_tail(int len, outputStream* st) const {
const u1* start;
int avail = _pos - _chunk->data();
if (len >= avail) {
 len = avail;
 start = _chunk->data();
 } else {
 start = _pos - len;

// Ensure start is 16-byte aligned wrt chunk start
int start_offset = start - _chunk->data();
 start -= (start_offset % 16);
 len = _pos - start;
 }

 st->print_cr("Last %d bytes up to current read position " INTPTR_FORMAT " in HotSpotCompiledCode stream for %s:", len, p2i(_pos), code_desc());
 st->print_data((void*) start, len, true, false);
}

constchar* HotSpotCompiledCodeStream::context() const {
 stringStream st;
 st.cr();
 st.print_cr("at " INTPTR_FORMAT " in HotSpotCompiledCode stream", p2i(_pos));
dump_buffer_tail(100, &st);
return st.as_string();
}

voidHotSpotCompiledCodeStream::before_read(u1 size) {
if (_pos + size > _chunk->data_end()) {
 Chunk* next = _chunk->next();
if (next == nullptr || size > next->size()) {
dump_buffer();
fatal("%s: reading %d bytes overflows buffer at " INTPTR_FORMAT, code_desc(), size, p2i(_pos));
 }
 _chunk = next;
 _pos = _chunk->data();
 }
}

// Reads a size followed by an ascii string from the stream and
// checks that they match `expect_size` and `expect_name` respectively. This
// implements a rudimentary type checking of the stream between the stream producer
// (Java) and the consumer (C++).
voidHotSpotCompiledCodeStream::check_data(u2 expect_size, constchar* expect_name) {
 u2 actual_size = get_u1();
 u2 ascii_len = get_u1();
constchar* actual_name = (constchar*) _pos;
char* end = (char*) _pos + ascii_len;
 _pos = (const u1*) end;
if (strlen(expect_name) != ascii_len || strncmp(expect_name, actual_name, ascii_len) != 0) {
dump_buffer();
fatal("%s: expected \"%s\" at " INTPTR_FORMAT ", got \"%.*s\" (len: %d)",
code_desc(), expect_name, p2i(actual_name), ascii_len, actual_name, ascii_len);
 }
if (actual_size != expect_size) {
dump_buffer();
fatal("%s: expected \"%s\" at " INTPTR_FORMAT " to have size %u, got %u",
code_desc(), expect_name, p2i(actual_name), expect_size, actual_size);
 }
}

constchar* HotSpotCompiledCodeStream::read_utf8(constchar* name, JVMCI_TRAPS) {
 jint utf_len = read_s4(name);
if (utf_len == -1) {
returnnullptr;
 }
guarantee(utf_len >= 0, "bad utf_len: %d", utf_len);

constchar* utf = (constchar*) _pos;
char* end = (char*) _pos + utf_len;
 _pos = (const u1*) (end + 1);
if (*end != '\0') {
JVMCI_ERROR_NULL("UTF8 string at " INTPTR_FORMAT " of length %d missing 0 terminator: \"%.*s\"%s",
p2i(utf), utf_len, utf_len, utf, context());
 }
return utf;
}

Method* HotSpotCompiledCodeStream::read_method(constchar* name) {
return (Method*) read_u8(name);
}

Klass* HotSpotCompiledCodeStream::read_klass(constchar* name) {
return (Klass*) read_u8(name);
}

ScopeValue* HotSpotCompiledCodeStream::virtual_object_at(int id, JVMCI_TRAPS) const {
if (_virtual_objects == nullptr) {
JVMCI_ERROR_NULL("virtual object id %d read outside scope of decoding DebugInfo%s", id, context());
 }
if (id < 0 || id >= _virtual_objects->length()) {
JVMCI_ERROR_NULL("invalid virtual object id %d%s", id, context());
 }
return _virtual_objects->at(id);
}

#ifndef PRODUCT
voidCodeInstaller::verify_bci_constants(JVMCIEnv* env) {
#defineCHECK_IN_SYNC(name) do { \
int expect = env->get_BytecodeFrame_ ## name ##_BCI(); \
int actual = name##_BCI; \
if (expect != actual) fatal("CodeInstaller::" #name "_BCI(%d) != BytecodeFrame." #name "_BCI(%d)", expect, actual); \
} while(0)

CHECK_IN_SYNC(UNWIND);
CHECK_IN_SYNC(BEFORE);
CHECK_IN_SYNC(AFTER);
CHECK_IN_SYNC(AFTER_EXCEPTION);
CHECK_IN_SYNC(UNKNOWN);
CHECK_IN_SYNC(INVALID_FRAMESTATE);
#undef CHECK_IN_SYNC
}
#endif

VMReg CodeInstaller::getVMRegFromLocation(HotSpotCompiledCodeStream* stream, int total_frame_size, JVMCI_TRAPS) {
 u2 reg = stream->read_u2("register");
 u2 offset = stream->read_u2("offset");

if (reg != NO_REGISTER) {
 VMReg vmReg = CodeInstaller::get_hotspot_reg(reg, JVMCI_CHECK_NULL);
if (offset % 4 == 0) {
return vmReg->next(offset / 4);
 } else {
JVMCI_ERROR_NULL("unaligned subregister offset %d in oop map%s", offset, stream->context());
 }
 } else {
if (offset % 4 == 0) {
 VMReg vmReg = VMRegImpl::stack2reg(offset / 4);
if (!OopMapValue::legal_vm_reg_name(vmReg)) {
// This restriction only applies to VMRegs that are used in OopMap but
// since that's the only use of VMRegs it's simplest to put this test
// here. This test should also be equivalent legal_vm_reg_name but JVMCI
// clients can use max_oop_map_stack_stack_offset to detect this problem
// directly. The asserts just ensure that the tests are in agreement.
assert(offset > CompilerToVM::Data::max_oop_map_stack_offset(), "illegal VMReg");
JVMCI_ERROR_NULL("stack offset %d is too large to be encoded in OopMap (max %d)%s",
 offset, CompilerToVM::Data::max_oop_map_stack_offset(), stream->context());
 }
assert(OopMapValue::legal_vm_reg_name(vmReg), "illegal VMReg");
return vmReg;
 } else {
JVMCI_ERROR_NULL("unaligned stack offset %d in oop map%s", offset, stream->context());
 }
 }
}

OopMap* CodeInstaller::create_oop_map(HotSpotCompiledCodeStream* stream, u1 debug_info_flags, JVMCI_TRAPS) {
assert(is_set(debug_info_flags, DI_HAS_REFERENCE_MAP), "must be");
 u2 max_register_size = stream->read_u2("maxRegisterSize");
if (!_has_wide_vector && SharedRuntime::is_wide_vector(max_register_size)) {
if (SharedRuntime::polling_page_vectors_safepoint_handler_blob() == nullptr) {
JVMCI_ERROR_NULL("JVMCI is producing code using vectors larger than the runtime supports%s", stream->context());
 }
 _has_wide_vector = true;
 }
 u2 length = stream->read_u2("referenceMap:length");

 OopMap* map = newOopMap(_total_frame_size, _parameter_count);
for (int i = 0; i < length; i++) {
bool has_derived = stream->read_bool("hasDerived");
 u2 bytes = stream->read_u2("sizeInBytes");
 VMReg vmReg = getVMRegFromLocation(stream, _total_frame_size, JVMCI_CHECK_NULL);
if (has_derived) {
// derived oop
if (bytes == LP64_ONLY(8) NOT_LP64(4)) {
 VMReg baseReg = getVMRegFromLocation(stream, _total_frame_size, JVMCI_CHECK_NULL);
 map->set_derived_oop(vmReg, baseReg);
 } else {
JVMCI_ERROR_NULL("invalid derived oop size in ReferenceMap: %d%s", bytes, stream->context());
 }
#ifdef _LP64
 } elseif (bytes == 8) {
// wide oop
 map->set_oop(vmReg);
 } elseif (bytes == 4) {
// narrow oop
 map->set_narrowoop(vmReg);
#else
 } elseif (bytes == 4) {
 map->set_oop(vmReg);
#endif
 } else {
JVMCI_ERROR_NULL("invalid oop size in ReferenceMap: %d%s", bytes, stream->context());
 }
 }

if (is_set(debug_info_flags, DI_HAS_CALLEE_SAVE_INFO)) {
 length = stream->read_u2("calleeSaveInfo:length");
for (jint i = 0; i < length; i++) {
 u2 jvmci_reg_number = stream->read_u2("register");
 VMReg hotspot_reg = CodeInstaller::get_hotspot_reg(jvmci_reg_number, JVMCI_CHECK_NULL);
// HotSpot stack slots are 4 bytes
 u2 jvmci_slot = stream->read_u2("slot");
 jint hotspot_slot = jvmci_slot * VMRegImpl::slots_per_word;
 VMReg hotspot_slot_as_reg = VMRegImpl::stack2reg(hotspot_slot);
 map->set_callee_saved(hotspot_slot_as_reg, hotspot_reg);
#ifdef _LP64
// (copied from generate_oop_map() in c1_Runtime1_x86.cpp)
 VMReg hotspot_slot_hi_as_reg = VMRegImpl::stack2reg(hotspot_slot + 1);
 map->set_callee_saved(hotspot_slot_hi_as_reg, hotspot_reg->next());
#endif
 }
 }
return map;
}

void* CodeInstaller::record_metadata_reference(CodeSection* section, address dest, HotSpotCompiledCodeStream* stream, u1 tag, JVMCI_TRAPS) {
/*
 * This method needs to return a raw (untyped) pointer, since the value of a pointer to the base
 * class is in general not equal to the pointer of the subclass. When patching metaspace pointers,
 * the compiler expects a direct pointer to the subclass (Klass* or Method*), not a pointer to the
 * base class (Metadata* or MetaspaceObj*).
*/
if (tag == PATCH_KLASS) {
 Klass* klass = stream->read_klass("patch:klass");
intindex = _oop_recorder->find_index(klass);
 section->relocate(dest, metadata_Relocation::spec(index));
JVMCI_event_3("metadata[%d of %d] = %s", index, _oop_recorder->metadata_count(), klass->name()->as_C_string());
return klass;
 } elseif (tag == PATCH_METHOD) {
 Method* method = stream->read_method("patch:method");
intindex = _oop_recorder->find_index(method);
 section->relocate(dest, metadata_Relocation::spec(index));
JVMCI_event_3("metadata[%d of %d] = %s", index, _oop_recorder->metadata_count(), method->name()->as_C_string());
return method;
 } else {
JVMCI_ERROR_NULL("unexpected metadata reference tag: %d%s", tag, stream->context());
 }
}

#ifdef _LP64
narrowKlass CodeInstaller::record_narrow_metadata_reference(CodeSection* section, address dest, HotSpotCompiledCodeStream* stream, u1 tag, JVMCI_TRAPS) {
if (tag != PATCH_NARROW_KLASS) {
JVMCI_ERROR_0("unexpected compressed pointer tag %d%s", tag, stream->context());
 }
 Klass* klass = stream->read_klass("patch:klass");
intindex = _oop_recorder->find_index(klass);
 section->relocate(dest, metadata_Relocation::spec(index));
JVMCI_event_3("narrowKlass[%d of %d] = %s", index, _oop_recorder->metadata_count(), klass->name()->as_C_string());
guarantee(CompressedKlassPointers::is_encodable(klass), "klass cannot be compressed: %s", klass->external_name());
returnCompressedKlassPointers::encode(klass);
}
#endif

ScopeValue* CodeInstaller::to_primitive_value(HotSpotCompiledCodeStream* stream, jlong raw, BasicType type, ScopeValue* &second, JVMCI_TRAPS) {
if (type == T_INT || type == T_FLOAT) {
 jint prim = (jint) raw;
switch (prim) {
case -1: return _int_m1_scope_value;
case0: return _int_0_scope_value;
case1: return _int_1_scope_value;
case2: return _int_2_scope_value;
default: returnnewConstantIntValue(prim);
 }
 } elseif (type == T_LONG || type == T_DOUBLE) {
 jlong prim = raw;
 second = _int_1_scope_value;
returnnewConstantLongValue(prim);
 } else {
JVMCI_ERROR_NULL("unexpected primitive constant type %s%s", basictype_to_str(type), stream->context());
 }
}

HandleCodeInstaller::read_oop(HotSpotCompiledCodeStream* stream, u1 tag, JVMCI_TRAPS) {
 oop obj;
if (tag == OBJECT_ID) {
 obj = stream->get_oop(stream->read_u1("id"), JVMCI_CHECK_(Handle()));
 } elseif (tag == OBJECT_ID2) {
 obj = stream->get_oop(stream->read_u2("id:2"), JVMCI_CHECK_(Handle()));
 } elseif (tag == JOBJECT) {
 jlong object_handle = stream->read_u8("jobject");
 obj = jvmci_env()->resolve_oop_handle(object_handle);
 } else {
JVMCI_ERROR_(Handle(), "unexpected oop tag: %d", tag)
 }
if (obj == nullptr) {
JVMCI_THROW_MSG_(InternalError, "Constant was unexpectedly null", Handle());
 } else {
guarantee(oopDesc::is_oop_or_null(obj), "invalid oop: " INTPTR_FORMAT, p2i((oopDesc*) obj));
 }
returnHandle(stream->thread(), obj);
}

ScopeValue* CodeInstaller::get_scope_value(HotSpotCompiledCodeStream* stream, u1 tag, BasicType type, ScopeValue* &second, JVMCI_TRAPS) {
 second = nullptr;
bool stack_slot_is_s2 = true;
switch (tag) {
case ILLEGAL: {
if (type != T_ILLEGAL) {
JVMCI_ERROR_NULL("unexpected illegal value, expected %s%s", basictype_to_str(type), stream->context());
 }
return _illegal_value;
 }
case REGISTER_PRIMITIVE:
case REGISTER_NARROW_OOP:
case REGISTER_OOP:
case REGISTER_VECTOR: {
 u2 number = stream->read_u2("register");
 VMReg hotspotRegister = get_hotspot_reg(number, JVMCI_CHECK_NULL);
if (is_general_purpose_reg(hotspotRegister)) {
 Location::Type locationType;
if (type == T_OBJECT) {
 locationType = tag == REGISTER_NARROW_OOP ? Location::narrowoop : Location::oop;
 } elseif (type == T_LONG) {
 locationType = Location::lng;
 } elseif (type == T_INT || type == T_FLOAT || type == T_SHORT || type == T_CHAR || type == T_BYTE || type == T_BOOLEAN) {
 locationType = Location::int_in_long;
 } else {
JVMCI_ERROR_NULL("unexpected type %s in CPU register%s", basictype_to_str(type), stream->context());
 }
 ScopeValue* value = newLocationValue(Location::new_reg_loc(locationType, hotspotRegister));
if (type == T_LONG) {
 second = value;
 }
return value;
 } else {
 Location::Type locationType;
if (type == T_FLOAT) {
// this seems weird, but the same value is used in c1_LinearScan
 locationType = Location::normal;
 } elseif (type == T_DOUBLE) {
 locationType = Location::dbl;
 } elseif (type == T_OBJECT && tag == REGISTER_VECTOR) {
 locationType = Location::vector;
 } else {
JVMCI_ERROR_NULL("unexpected type %s in floating point register%s", basictype_to_str(type), stream->context());
 }
 ScopeValue* value = newLocationValue(Location::new_reg_loc(locationType, hotspotRegister));
if (type == T_DOUBLE) {
 second = value;
 }
return value;
 }
 }
case STACK_SLOT4_PRIMITIVE:
case STACK_SLOT4_NARROW_OOP:
case STACK_SLOT4_OOP:
case STACK_SLOT4_VECTOR:
 stack_slot_is_s2 = false;
// fall through
case STACK_SLOT_PRIMITIVE:
case STACK_SLOT_NARROW_OOP:
case STACK_SLOT_OOP:
case STACK_SLOT_VECTOR: {
 jint offset = stack_slot_is_s2 ? (jshort) stream->read_s2("offset") : stream->read_s4("offset4");
if (stream->read_bool("addRawFrameSize")) {
 offset += _total_frame_size;
 }
 Location::Type locationType;
if (type == T_OBJECT) {
 locationType = tag == STACK_SLOT_VECTOR ? Location::vector : tag == STACK_SLOT_NARROW_OOP ? Location::narrowoop : Location::oop;
 } elseif (type == T_LONG) {
 locationType = Location::lng;
 } elseif (type == T_DOUBLE) {
 locationType = Location::dbl;
 } elseif (type == T_INT || type == T_FLOAT || type == T_SHORT || type == T_CHAR || type == T_BYTE || type == T_BOOLEAN) {
 locationType = Location::normal;
 } else {
JVMCI_ERROR_NULL("unexpected type %s in stack slot%s", basictype_to_str(type), stream->context());
 }
 ScopeValue* value = newLocationValue(Location::new_stk_loc(locationType, offset));
if (type == T_DOUBLE || type == T_LONG) {
 second = value;
 }
return value;
 }
case NULL_CONSTANT: { return _oop_null_scope_value; }
case RAW_CONSTANT: { returnnewConstantLongValue(stream->read_u8("primitive")); }
case PRIMITIVE_0: { ScopeValue* v = to_primitive_value(stream, 0, type, second, JVMCI_CHECK_NULL); return v; }
case PRIMITIVE4: { ScopeValue* v = to_primitive_value(stream, stream->read_s4("primitive4"), type, second, JVMCI_CHECK_NULL); return v; }
case PRIMITIVE8: { ScopeValue* v = to_primitive_value(stream, stream->read_s8("primitive8"), type, second, JVMCI_CHECK_NULL); return v; }
case VIRTUAL_OBJECT_ID: { ScopeValue* v = stream->virtual_object_at(stream->read_u1("id"), JVMCI_CHECK_NULL); return v; }
case VIRTUAL_OBJECT_ID2: { ScopeValue* v = stream->virtual_object_at(stream->read_u2("id:2"), JVMCI_CHECK_NULL); return v; }

case OBJECT_ID:
case OBJECT_ID2:
case JOBJECT: {
Handle obj = read_oop(stream, tag, JVMCI_CHECK_NULL);
returnnewConstantOopWriteValue(JNIHandles::make_local(obj()));
 }
default: {
JVMCI_ERROR_NULL("unexpected tag in scope: %d%s", tag, stream->context())
 }
 }
}

voidCodeInstaller::record_object_value(ObjectValue* sv, HotSpotCompiledCodeStream* stream, JVMCI_TRAPS) {
 oop javaMirror = JNIHandles::resolve(sv->klass()->as_ConstantOopWriteValue()->value());
 Klass* klass = java_lang_Class::as_Klass(javaMirror);
bool isLongArray = klass == Universe::longArrayKlass();
bool isByteArray = klass == Universe::byteArrayKlass();

 u2 length = stream->read_u2("values:length");
for (jint i = 0; i < length; i++) {
 ScopeValue* cur_second = nullptr;
 BasicType type = (BasicType) stream->read_u1("basicType");
 ScopeValue* value;
 u1 tag = stream->read_u1("tag");
if (tag == ILLEGAL) {
if (isByteArray && type == T_ILLEGAL) {
/*
 * The difference between a virtualized large access and a deferred write is the kind stored in the slotKinds
 * of the virtual object: in the virtualization case, the kind is illegal, in the deferred write case, the kind
 * is access stack kind (an int).
*/
 value = _virtual_byte_array_marker;
 } else {
 value = _illegal_value;
if (type == T_DOUBLE || type == T_LONG) {
 cur_second = _illegal_value;
 }
 }
 } else {
 value = get_scope_value(stream, tag, type, cur_second, JVMCI_CHECK);
 }

if (isLongArray && cur_second == nullptr) {
// we're trying to put ints into a long array... this isn't really valid, but it's used for some optimizations.
// add an int 0 constant
 cur_second = _int_0_scope_value;
 }

if (isByteArray && cur_second != nullptr && (type == T_DOUBLE || type == T_LONG)) {
// we are trying to write a long in a byte Array. We will need to count the illegals to restore the type of
// the thing we put inside.
 cur_second = nullptr;
 }

if (cur_second != nullptr) {
 sv->field_values()->append(cur_second);
 }
assert(value != nullptr, "missing value");
 sv->field_values()->append(value);
 }
}

GrowableArray<ScopeValue*>* CodeInstaller::read_local_or_stack_values(HotSpotCompiledCodeStream* stream, u1 frame_flags, bool is_locals, JVMCI_TRAPS) {
 u2 length;
if (is_locals) {
if (!is_set(frame_flags, DIF_HAS_LOCALS)) {
returnnullptr;
 }
 length = stream->read_u2("numLocals");
 } else {
if (!is_set(frame_flags, DIF_HAS_STACK)) {
returnnullptr;
 }
 length = stream->read_u2("numStack");
 }
 GrowableArray<ScopeValue*>* values = new GrowableArray<ScopeValue*> (length);
for (int i = 0; i < length; i++) {
 ScopeValue* second = nullptr;
 BasicType type = (BasicType) stream->read_u1("basicType");
 u1 tag = stream->read_u1("tag");
 ScopeValue* first = get_scope_value(stream, tag, type, second, JVMCI_CHECK_NULL);
if (second != nullptr) {
if (i == length) {
JVMCI_ERROR_NULL("double-slot value not followed by Value.ILLEGAL%s", stream->context());
 }
 i++;
 stream->read_u1("basicType");
 tag = stream->read_u1("tag");
if (tag != ILLEGAL) {
JVMCI_ERROR_NULL("double-slot value not followed by Value.ILLEGAL%s", stream->context());
 }
 values->append(second);
 }
 values->append(first);
 }
return values;
}

GrowableArray<MonitorValue*>* CodeInstaller::read_monitor_values(HotSpotCompiledCodeStream* stream, u1 frame_flags, JVMCI_TRAPS) {
if (!is_set(frame_flags, DIF_HAS_LOCKS)) {
returnnullptr;
 }
if (!_has_monitors) {
 _has_monitors = true;
 }
 u2 length = stream->read_u2("numLocks");
 GrowableArray<MonitorValue*>* monitors = new GrowableArray<MonitorValue*>(length);
for (int i = 0; i < length; i++) {
bool eliminated = stream->read_bool("isEliminated");
 ScopeValue* second = nullptr;
 ScopeValue* owner_value = get_scope_value(stream, stream->read_u1("tag"), T_OBJECT, second, JVMCI_CHECK_NULL);
assert(second == nullptr, "monitor cannot occupy two stack slots");

 ScopeValue* lock_data_value = get_scope_value(stream, stream->read_u1("tag"), T_LONG, second, JVMCI_CHECK_NULL);
assert(second == lock_data_value, "monitor is LONG value that occupies two stack slots");
assert(lock_data_value->is_location(), "invalid monitor location");
 Location lock_data_loc = ((LocationValue*) lock_data_value)->location();

 monitors->append(newMonitorValue(owner_value, lock_data_loc, eliminated));
 }
return monitors;
}

voidCodeInstaller::initialize_dependencies(HotSpotCompiledCodeStream* stream, u1 code_flags, OopRecorder* oop_recorder, JVMCI_TRAPS) {
 JavaThread* thread = stream->thread();
 CompilerThread* compilerThread = thread->is_Compiler_thread() ? CompilerThread::cast(thread) : nullptr;
 _oop_recorder = oop_recorder;
 _dependencies = newDependencies(&_arena, _oop_recorder, compilerThread != nullptr ? compilerThread->log() : nullptr);
if (is_set(code_flags, HCC_HAS_ASSUMPTIONS)) {
 u2 length = stream->read_u2("assumptions:length");
for (int i = 0; i < length; ++i) {
 u1 tag = stream->read_u1("tag");
switch (tag) {
case NO_FINALIZABLE_SUBCLASS: {
 Klass* receiver_type = stream->read_klass("receiverType");
 _dependencies->assert_has_no_finalizable_subclasses(receiver_type);
break;
 }
case CONCRETE_SUBTYPE: {
 Klass* context = stream->read_klass("context");
 Klass* subtype = stream->read_klass("subtype");
assert(context->is_abstract(), "must be");
 _dependencies->assert_abstract_with_unique_concrete_subtype(context, subtype);
break;
 }
case LEAF_TYPE: {
 Klass* context = stream->read_klass("context");
 _dependencies->assert_leaf_type(context);
break;
 }
case CONCRETE_METHOD: {
 Klass* context = stream->read_klass("context");
 Method* impl = stream->read_method("impl");
 _dependencies->assert_unique_concrete_method(context, impl);
break;
 }
case CALLSITE_TARGET_VALUE: {
 u1 obj_tag = stream->read_u1("tag");
Handle callSite = read_oop(stream, obj_tag, JVMCI_CHECK);
 obj_tag = stream->read_u1("tag");
Handle methodHandle = read_oop(stream, obj_tag, JVMCI_CHECK);
 _dependencies->assert_call_site_target_value(callSite(), methodHandle());
break;
 }
default: {
JVMCI_ERROR("unexpected assumption tag %d%s", tag, stream->context());
 }
 }
 }
 }
if (is_set(code_flags, HCC_HAS_METHODS)) {
 u2 length = stream->read_u2("methods:length");
for (int i = 0; i < length; ++i) {
 Method* method = stream->read_method("method");
if (JvmtiExport::can_hotswap_or_post_breakpoint()) {
 _dependencies->assert_evol_method(method);
 }
 }
 }
}

JVMCI::CodeInstallResult CodeInstaller::install_runtime_stub(CodeBlob*& cb,
constchar* name,
 CodeBuffer* buffer,
int stack_slots,
 JVMCI_TRAPS) {
if (name == nullptr) {
JVMCI_ERROR_OK("stub should have a name");
 }

 name = os::strdup(name);
 GrowableArray<RuntimeStub*> *stubs_to_free = nullptr;
#ifdef ASSERT
constchar* val = Arguments::PropertyList_get_value(Arguments::system_properties(), "test.jvmci.forceRuntimeStubAllocFail");
if (val != nullptr && strstr(name , val) != nullptr) {
 stubs_to_free = new GrowableArray<RuntimeStub*>();
JVMCI_event_1("forcing allocation of %s in code cache to fail", name);
 }
#endif

do {
 RuntimeStub* stub = RuntimeStub::new_runtime_stub(name,
 buffer,
 _offsets.value(CodeOffsets::Frame_Complete),
 stack_slots,
 _debug_recorder->_oopmaps,
/* caller_must_gc_arguments */false,
/* alloc_fail_is_fatal */false);
 cb = stub;
if (stub == nullptr) {
// Allocation failed
#ifdef ASSERT
if (stubs_to_free != nullptr) {
JVMCI_event_1("allocation of %s in code cache failed, freeing %d stubs", name, stubs_to_free->length());
for (GrowableArrayIterator<RuntimeStub*> iter = stubs_to_free->begin(); iter != stubs_to_free->end(); ++iter) {
RuntimeStub::free(*iter);
 }
 }
#endif
return JVMCI::cache_full;
 }
if (stubs_to_free == nullptr) {
return JVMCI::ok;
 }
 stubs_to_free->append(stub);
 } while (true);
}

JVMCI::CodeInstallResult CodeInstaller::install(JVMCICompiler* compiler,
 jlong compiled_code_buffer,
bool with_type_info,
 JVMCIObject compiled_code,
 objArrayHandle object_pool,
 CodeBlob*& cb,
 JVMCINMethodHandle& nmethod_handle,
 JVMCIObject installed_code,
 FailedSpeculation** failed_speculations,
char* speculations,
int speculations_len,
 JVMCI_TRAPS) {

 JavaThread* thread = JavaThread::current();
 HotSpotCompiledCodeStream* stream = newHotSpotCompiledCodeStream(thread, (const u1*) compiled_code_buffer, with_type_info, object_pool);

 u1 code_flags = stream->read_u1("code:flags");
bool is_nmethod = is_set(code_flags, HCC_IS_NMETHOD);
constchar* name = stream->read_utf8("name", JVMCI_CHECK_OK);

 methodHandle method;
 jint entry_bci = -1;
 JVMCICompileState* compile_state = nullptr;
bool has_unsafe_access = false;
bool has_scoped_access = false;
 jint id = -1;

if (is_nmethod) {
 method = methodHandle(thread, stream->read_method("method"));
 entry_bci = is_nmethod ? stream->read_s4("entryBCI") : -1;
 compile_state = (JVMCICompileState*) stream->read_u8("compileState");
 has_unsafe_access = stream->read_bool("hasUnsafeAccess");
 has_scoped_access = stream->read_bool("hasScopedAccess");
 id = stream->read_s4("id");
 }
 stream->set_code_desc(name, method);

 CodeBuffer buffer("JVMCI Compiler CodeBuffer");
 OopRecorder* recorder = newOopRecorder(&_arena, true);
initialize_dependencies(stream, code_flags, recorder, JVMCI_CHECK_OK);

// Get instructions and constants CodeSections early because we need it.
 _instructions = buffer.insts();
 _constants = buffer.consts();

initialize_fields(stream, code_flags, method, buffer, JVMCI_CHECK_OK);
 JVMCI::CodeInstallResult result = initialize_buffer(compiled_code, buffer, stream, code_flags, JVMCI_CHECK_OK);

 u4 available = stream->available();
if (result == JVMCI::ok && available != 0) {
JVMCI_ERROR_OK("%d bytes remaining in stream%s", available, stream->context());
 }

if (result != JVMCI::ok) {
return result;
 }

int stack_slots = _total_frame_size / HeapWordSize; // conversion to words

if (!is_nmethod) {
returninstall_runtime_stub(cb, name, &buffer, stack_slots, JVMCI_CHECK_OK);
 } else {
if (compile_state != nullptr) {
jvmci_env()->set_compile_state(compile_state);
 }

if (id == -1) {
// Make sure a valid compile_id is associated with every compile
 id = CompileBroker::assign_compile_id_unlocked(thread, method, entry_bci);
jvmci_env()->set_HotSpotCompiledNmethod_id(compiled_code, id);
 }
if (!jvmci_env()->isa_HotSpotNmethod(installed_code)) {
JVMCI_THROW_MSG_(IllegalArgumentException, "InstalledCode object must be a HotSpotNmethod when installing a HotSpotCompiledNmethod", JVMCI::ok);
 }

// Enforce that compiled methods have an nmethod barrier.
if (_nmethod_entry_patch_offset == -1) {
JVMCI_THROW_MSG_(IllegalArgumentException, "nmethod entry barrier is missing", JVMCI::ok);
 }

 JVMCIObject mirror = installed_code;
 nmethod* nm = nullptr; // nm is an out parameter of register_method
 result = runtime()->register_method(jvmci_env(),
 method,
 nm,
 entry_bci,
 &_offsets,
 _orig_pc_offset,
 &buffer,
 stack_slots,
 _debug_recorder->_oopmaps,
 &_exception_handler_table,
 &_implicit_exception_table,
 compiler,
 _debug_recorder,
 _dependencies,
 id,
 _has_monitors,
 has_unsafe_access,
 has_scoped_access,
 _has_wide_vector,
 compiled_code,
 mirror,
 failed_speculations,
 speculations,
 speculations_len,
 _nmethod_entry_patch_offset);
if (result == JVMCI::ok) {
guarantee(nm != nullptr, "successful compile must produce an nmethod");
 nmethod_handle.set_nmethod(nm);
 cb = nm;
if (compile_state == nullptr) {
// This compile didn't come through the CompileBroker so perform the printing here
 DirectiveSet* directive = DirectivesStack::getMatchingDirective(method, compiler);
 nm->maybe_print_nmethod(directive);
DirectivesStack::release(directive);

// Since this compilation didn't pass through the broker it wasn't logged yet.
if (PrintCompilation) {
 ttyLocker ttyl;
if (name != nullptr) {
 stringStream st;
 st.print_cr("(hosted JVMCI compilation: %s)", name);
CompileTask::print(tty, nm, st.as_string());
 } else {
CompileTask::print(tty, nm, "(hosted JVMCI compilation)");
 }
 }
 }

 BarrierSetNMethod* bs_nm = BarrierSet::barrier_set()->barrier_set_nmethod();

// an empty error buffer for use by the verify_barrier code
 err_msg msg("");
if (!bs_nm->verify_barrier(nm, msg)) {
JVMCI_THROW_MSG_(IllegalArgumentException, err_msg("nmethod entry barrier is malformed: %s", msg.buffer()), JVMCI::ok);
 }
 }
 }

if (cb != nullptr) {
// Make sure the pre-calculated constants section size was correct.
guarantee((cb->code_begin() - cb->content_begin()) >= _constants_size, "%d < %d", (int)(cb->code_begin() - cb->content_begin()), _constants_size);
 }
return result;
}

voidCodeInstaller::initialize_fields(HotSpotCompiledCodeStream* stream, u1 code_flags, methodHandle& method, CodeBuffer& buffer, JVMCI_TRAPS) {
if (!method.is_null()) {
 _parameter_count = method->size_of_parameters();
JVMCI_event_2("installing code for %s", method->name_and_sig_as_C_string());
 } else {
// Must be a HotSpotCompiledCode for a stub.
// Only used in OopMap constructor for non-product builds
 _parameter_count = 0;
 }
 _sites_count = stream->read_s4("sites:length");
 _code_size = stream->read_s4("targetCodeSize");
 _total_frame_size = stream->read_s4("totalFrameSize");
if (!is_set(code_flags, HCC_HAS_DEOPT_RESCUE_SLOT)) {
 _orig_pc_offset = -1;
 } else {
 _orig_pc_offset = stream->read_s4("offset");
if (stream->read_bool("addRawFrameSize")) {
 _orig_pc_offset += _total_frame_size;
 }
if (_orig_pc_offset < 0) {
JVMCI_ERROR("invalid deopt rescue slot: %d%s", _orig_pc_offset, stream->context());
 }
 }

// Pre-calculate the constants section size. This is required for PC-relative addressing.
 u4 data_section_size = stream->read_u4("dataSectionSize");
 u1 data_section_alignment = stream->read_u1("dataSectionAlignment");
 buffer.set_const_section_alignment(data_section_alignment);
if ((_constants->alignment() % data_section_alignment) != 0) {
JVMCI_ERROR("invalid data section alignment: %d [constants alignment: %d]%s",
 data_section_alignment, _constants->alignment(), stream->context());
 }
 _constants_size = data_section_size;
 _next_call_type = INVOKE_INVALID;
 _has_monitors = false;
 _has_wide_vector = false;
 _nmethod_entry_patch_offset = -1;
}

u1 CodeInstaller::as_read_oop_tag(HotSpotCompiledCodeStream* stream, u1 patch_object_tag, JVMCI_TRAPS) {
switch (patch_object_tag) {
case PATCH_OBJECT_ID:
case PATCH_NARROW_OBJECT_ID: {
return OBJECT_ID;
 }
case PATCH_OBJECT_ID2:
case PATCH_NARROW_OBJECT_ID2: {
return OBJECT_ID2;
 }
case PATCH_NARROW_JOBJECT:
case PATCH_JOBJECT: {
return JOBJECT;
 }
default: {
JVMCI_ERROR_0("unknown object patch tag: %d%s", patch_object_tag, stream->context());
 }
 }
}

intCodeInstaller::estimate_stubs_size(HotSpotCompiledCodeStream* stream, JVMCI_TRAPS) {
// Estimate the number of static call stubs that might be emitted.
 u2 static_call_stubs = stream->read_u2("numStaticCallStubs");
 u2 trampoline_stubs = stream->read_u2("numTrampolineStubs");
int size = static_call_stubs * CompiledDirectCall::to_interp_stub_size();
 size += trampoline_stubs * CompiledDirectCall::to_trampoline_stub_size();
return size;
}

// perform data and call relocation on the CodeBuffer
JVMCI::CodeInstallResult CodeInstaller::initialize_buffer(JVMCIObject compiled_code, CodeBuffer& buffer, HotSpotCompiledCodeStream* stream, u1 code_flags, JVMCI_TRAPS) {
 JavaThread* thread = stream->thread();
 HandleMark hm(thread);
int locs_buffer_size = _sites_count * (relocInfo::length_limit + sizeof(relocInfo));


// Allocate enough space in the stub section for the static call
// stubs. Stubs have extra relocs but they are managed by the stub
// section itself so they don't need to be accounted for in the
// locs_buffer above.
int stubs_size = estimate_stubs_size(stream, JVMCI_CHECK_OK);

assert((CodeBuffer::SECT_INSTS == CodeBuffer::SECT_STUBS - 1) &&
 (CodeBuffer::SECT_CONSTS == CodeBuffer::SECT_INSTS - 1), "sections order: consts, insts, stubs");
// buffer content: [constants + code_align] + [code + stubs_align] + [stubs]
int total_size = align_up(_constants_size, buffer.insts()->alignment()) +
align_up(_code_size, buffer.stubs()->alignment()) +
 stubs_size;

if (total_size > JVMCINMethodSizeLimit) {
return JVMCI::code_too_large;
 }

 buffer.initialize(total_size, locs_buffer_size);
if (buffer.blob() == nullptr) {
return JVMCI::cache_full;
 }
 buffer.initialize_stubs_size(stubs_size);
 buffer.initialize_consts_size(_constants_size);

 _debug_recorder = newDebugInformationRecorder(_oop_recorder);
 _debug_recorder->set_oopmaps(newOopMapSet());

 buffer.initialize_oop_recorder(_oop_recorder);

// copy the constant data into the newly created CodeBuffer
 address end_data = _constants->start() + _constants_size;
 JVMCIObject data_section = jvmci_env()->get_HotSpotCompiledCode_dataSection(compiled_code);
 JVMCIENV->copy_bytes_to(data_section, (jbyte*) _constants->start(), 0, _constants_size);
 _constants->set_end(end_data);

// copy the code into the newly created CodeBuffer
 address end_pc = _instructions->start() + _code_size;
guarantee(_instructions->allocates2(end_pc), "initialize should have reserved enough space for all the code");

 JVMCIPrimitiveArray code = jvmci_env()->get_HotSpotCompiledCode_targetCode(compiled_code);
 JVMCIENV->copy_bytes_to(code, (jbyte*) _instructions->start(), 0, _code_size);
 _instructions->set_end(end_pc);


 u2 length = stream->read_u2("dataSectionPatches:length");
for (int i = 0; i < length; i++) {
 address dest = _constants->start() + stream->read_u4("patch:pcOffset");
 u1 tag = stream->read_u1("tag");

switch (tag) {
case PATCH_METHOD:
case PATCH_KLASS: {
 *((void**) dest) = record_metadata_reference(_constants, dest, stream, tag, JVMCI_CHECK_OK);
break;
 }
case PATCH_NARROW_KLASS: {
#ifdef _LP64
 *((narrowKlass*) dest) = record_narrow_metadata_reference(_constants, dest, stream, tag, JVMCI_CHECK_OK);
#else
JVMCI_ERROR_OK("unexpected compressed Klass* in 32-bit mode");
#endif
break;
 }
case PATCH_OBJECT_ID:
case PATCH_OBJECT_ID2:
case PATCH_NARROW_OBJECT_ID:
case PATCH_NARROW_OBJECT_ID2:
case PATCH_JOBJECT:
case PATCH_NARROW_JOBJECT: {
bool narrow = tag == PATCH_NARROW_OBJECT_ID || tag == PATCH_NARROW_OBJECT_ID2 || tag == PATCH_NARROW_JOBJECT;
 u1 read_tag = as_read_oop_tag(stream, tag, JVMCI_CHECK_OK);