/*

 * Copyright (c) 2011, 2015, 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 "precompiled.hpp"

#include "code/compiledIC.hpp"

#include "compiler/compileBroker.hpp"

#include "compiler/disassembler.hpp"

#include "oops/oop.inline.hpp"

#include "oops/objArrayOop.inline.hpp"

#include "runtime/javaCalls.hpp"

#include "jvmci/jvmciEnv.hpp"

#include "jvmci/jvmciCompiler.hpp"

#include "jvmci/jvmciCodeInstaller.hpp"

#include "jvmci/jvmciJavaClasses.hpp"

#include "jvmci/jvmciCompilerToVM.hpp"

#include "jvmci/jvmciRuntime.hpp"

#include "asm/register.hpp"

#include "classfile/vmSymbols.hpp"

#include "code/vmreg.hpp"

#ifdef TARGET_ARCH_x86

# include "vmreg_x86.inline.hpp"

#endif

#ifdef TARGET_ARCH_sparc

# include "vmreg_sparc.inline.hpp"

#endif

#ifdef TARGET_ARCH_zero

# include "vmreg_zero.inline.hpp"

#endif

#ifdef TARGET_ARCH_arm

# include "vmreg_arm.inline.hpp"

#endif

#ifdef TARGET_ARCH_ppc

# include "vmreg_ppc.inline.hpp"

#endif

// 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 (ResourceObj::C_HEAP, mtCompiler) ConstantOopWriteValue(NULL);

ConstantIntValue*      CodeInstaller::_int_m1_scope_value = new (ResourceObj::C_HEAP, mtCompiler) ConstantIntValue(-1);

ConstantIntValue*      CodeInstaller::_int_0_scope_value =  new (ResourceObj::C_HEAP, mtCompiler) ConstantIntValue(0);

ConstantIntValue*      CodeInstaller::_int_1_scope_value =  new (ResourceObj::C_HEAP, mtCompiler) ConstantIntValue(1);

ConstantIntValue*      CodeInstaller::_int_2_scope_value =  new (ResourceObj::C_HEAP, mtCompiler) ConstantIntValue(2);

LocationValue*         CodeInstaller::_illegal_value = new (ResourceObj::C_HEAP, mtCompiler) LocationValue(Location());

Method* getMethodFromHotSpotMethod(oop hotspot_method) {

  assert(hotspot_method != NULL && hotspot_method->is_a(HotSpotResolvedJavaMethodImpl::klass()), "sanity");

  return CompilerToVM::asMethod(hotspot_method);

}

VMReg getVMRegFromLocation(oop location, int total_frame_size) {

  oop reg = code_Location::reg(location);

  jint offset = code_Location::offset(location);

  if (reg != NULL) {

    // register

    jint number = code_Register::number(reg);

    VMReg vmReg = CodeInstaller::get_hotspot_reg(number);

    assert(offset % 4 == 0, "must be aligned");

    return vmReg->next(offset / 4);

  } else {

    // stack slot

    assert(offset % 4 == 0, "must be aligned");

    return VMRegImpl::stack2reg(offset / 4);

  }

}

// creates a HotSpot oop map out of the byte arrays provided by DebugInfo

OopMap* CodeInstaller::create_oop_map(oop debug_info) {

  oop reference_map = DebugInfo::referenceMap(debug_info);

  if (HotSpotReferenceMap::maxRegisterSize(reference_map) > 16) {

    _has_wide_vector = true;

  }

  OopMap* map = new OopMap(_total_frame_size, _parameter_count);

  objArrayOop objects = HotSpotReferenceMap::objects(reference_map);

  objArrayOop derivedBase = HotSpotReferenceMap::derivedBase(reference_map);

  typeArrayOop sizeInBytes = HotSpotReferenceMap::sizeInBytes(reference_map);

  for (int i = 0; i < objects->length(); i++) {

    oop location = objects->obj_at(i);

    oop baseLocation = derivedBase->obj_at(i);

    int bytes = sizeInBytes->int_at(i);

    VMReg vmReg = getVMRegFromLocation(location, _total_frame_size);

    if (baseLocation != NULL) {

      // derived oop

      assert(bytes == 8, "derived oop can't be compressed");

      VMReg baseReg = getVMRegFromLocation(baseLocation, _total_frame_size);

      map->set_derived_oop(vmReg, baseReg);

    } else if (bytes == 8) {

      // wide oop

      map->set_oop(vmReg);

    } else {

      // narrow oop

      assert(bytes == 4, "wrong size");

      map->set_narrowoop(vmReg);

    }

  }

  oop callee_save_info = (oop) DebugInfo::calleeSaveInfo(debug_info);

  if (callee_save_info != NULL) {

    objArrayOop registers = RegisterSaveLayout::registers(callee_save_info);

    typeArrayOop slots = RegisterSaveLayout::slots(callee_save_info);

    for (jint i = 0; i < slots->length(); i++) {

      oop jvmci_reg = registers->obj_at(i);

      jint jvmci_reg_number = code_Register::number(jvmci_reg);

      VMReg hotspot_reg = CodeInstaller::get_hotspot_reg(jvmci_reg_number);

      // HotSpot stack slots are 4 bytes

      jint jvmci_slot = slots->int_at(i);

      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;

}

static void record_metadata_reference(oop obj, jlong prim, jboolean compressed, OopRecorder* oop_recorder) {

  if (obj->is_a(HotSpotResolvedObjectTypeImpl::klass())) {

    Klass* klass = java_lang_Class::as_Klass(HotSpotResolvedObjectTypeImpl::javaClass(obj));

    if (compressed) {

      assert(Klass::decode_klass((narrowKlass) prim) == klass, err_msg("%s @ " INTPTR_FORMAT " != " PTR64_FORMAT, klass->name()->as_C_string(), p2i(klass), prim));

    } else {

      assert((Klass*) prim == klass, err_msg("%s @ " INTPTR_FORMAT " != " PTR64_FORMAT, klass->name()->as_C_string(), p2i(klass), prim));

    }

    int index = oop_recorder->find_index(klass);

    TRACE_jvmci_3("metadata[%d of %d] = %s", index, oop_recorder->metadata_count(), klass->name()->as_C_string());

  } else if (obj->is_a(HotSpotResolvedJavaMethodImpl::klass())) {

    Method* method = (Method*) (address) HotSpotResolvedJavaMethodImpl::metaspaceMethod(obj);

    assert(!compressed, err_msg("unexpected compressed method pointer %s @ " INTPTR_FORMAT " = " PTR64_FORMAT, method->name()->as_C_string(), p2i(method), prim));

    int index = oop_recorder->find_index(method);

    TRACE_jvmci_3("metadata[%d of %d] = %s", index, oop_recorder->metadata_count(), method->name()->as_C_string());

  } else {

    assert(java_lang_String::is_instance(obj),

        err_msg("unexpected metadata reference (%s) for constant " JLONG_FORMAT " (" PTR64_FORMAT ")", obj->klass()->name()->as_C_string(), prim, prim));

  }

}

// Records any Metadata values embedded in a Constant (e.g., the value returned by HotSpotResolvedObjectTypeImpl.klass()).

static void record_metadata_in_constant(oop constant, OopRecorder* oop_recorder) {

  if (constant->is_a(HotSpotMetaspaceConstantImpl::klass())) {

    oop obj = HotSpotMetaspaceConstantImpl::metaspaceObject(constant);

    jlong prim = HotSpotMetaspaceConstantImpl::primitive(constant);

    assert(obj != NULL, "must have an object");

    assert(prim != 0, "must have a primitive value");

    record_metadata_reference(obj, prim, false, oop_recorder);

  }

}

static void record_metadata_in_patch(Handle& constant, OopRecorder* oop_recorder) {

  record_metadata_reference(HotSpotMetaspaceConstantImpl::metaspaceObject(constant), HotSpotMetaspaceConstantImpl::primitive(constant), HotSpotMetaspaceConstantImpl::compressed(constant), oop_recorder);

}

Location::Type CodeInstaller::get_oop_type(oop value) {

  oop lirKind = Value::lirKind(value);

  oop platformKind = LIRKind::platformKind(lirKind);

  assert(LIRKind::referenceMask(lirKind) == 1, "unexpected referenceMask");

  if (platformKind == word_kind()) {

    return Location::oop;

  } else {

    return Location::narrowoop;

  }

}

ScopeValue* CodeInstaller::get_scope_value(oop value, BasicType type, GrowableArray<ScopeValue*>* objects, ScopeValue* &second) {

  second = NULL;

  if (value == Value::ILLEGAL()) {

    assert(type == T_ILLEGAL, "expected legal value");

    return _illegal_value;

  } else if (value->is_a(RegisterValue::klass())) {

    oop reg = RegisterValue::reg(value);

    jint number = code_Register::number(reg);

    VMReg hotspotRegister = get_hotspot_reg(number);

    if (is_general_purpose_reg(hotspotRegister)) {

      Location::Type locationType;

      if (type == T_OBJECT) {

        locationType = get_oop_type(value);

      } else if (type == T_LONG) {

        locationType = Location::lng;

      } else {

        assert(type == T_INT || type == T_FLOAT || type == T_SHORT || type == T_CHAR || type == T_BYTE || type == T_BOOLEAN, "unexpected type in cpu register");

        locationType = Location::int_in_long;

      }

      ScopeValue* value = new LocationValue(Location::new_reg_loc(locationType, hotspotRegister));

      if (type == T_LONG) {

        second = value;

      }

      return value;

    } else {

      assert(type == T_FLOAT || type == T_DOUBLE, "only float and double expected in xmm register");

      Location::Type locationType;

      if (type == T_FLOAT) {

        // this seems weird, but the same value is used in c1_LinearScan

        locationType = Location::normal;

      } else {

        locationType = Location::dbl;

      }

      ScopeValue* value = new LocationValue(Location::new_reg_loc(locationType, hotspotRegister));

      if (type == T_DOUBLE) {

        second = value;

      }

      return value;

    }

  } else if (value->is_a(StackSlot::klass())) {

    jint offset = StackSlot::offset(value);

    if (StackSlot::addFrameSize(value)) {

      offset += _total_frame_size;

    }

    Location::Type locationType;

    if (type == T_OBJECT) {

      locationType = get_oop_type(value);

    } else if (type == T_LONG) {

      locationType = Location::lng;

    } else if (type == T_DOUBLE) {

      locationType = Location::dbl;

    } else {

      assert(type == T_INT || type == T_FLOAT || type == T_SHORT || type == T_CHAR || type == T_BYTE || type == T_BOOLEAN, "unexpected type in stack slot");

      locationType = Location::normal;

    }

    ScopeValue* value = new LocationValue(Location::new_stk_loc(locationType, offset));

    if (type == T_DOUBLE || type == T_LONG) {

      second = value;

    }

    return value;

  } else if (value->is_a(JavaConstant::klass())) {

    record_metadata_in_constant(value, _oop_recorder);

    if (value->is_a(PrimitiveConstant::klass())) {

      if (value->is_a(RawConstant::klass())) {

        jlong prim = PrimitiveConstant::primitive(value);

        return new ConstantLongValue(prim);

      } else {

        assert(type == JVMCIRuntime::kindToBasicType(JavaKind::typeChar(PrimitiveConstant::kind(value))), "primitive constant type doesn't match");

        if (type == T_INT || type == T_FLOAT) {

          jint prim = (jint)PrimitiveConstant::primitive(value);

          switch (prim) {

            case -1: return _int_m1_scope_value;

            case  0: return _int_0_scope_value;

            case  1: return _int_1_scope_value;

            case  2: return _int_2_scope_value;

            default: return new ConstantIntValue(prim);

          }

        } else {

          assert(type == T_LONG || type == T_DOUBLE, "unexpected primitive constant type");

          jlong prim = PrimitiveConstant::primitive(value);

          second = _int_1_scope_value;

          return new ConstantLongValue(prim);

        }

      }

    } else {

      assert(type == T_OBJECT, "unexpected object constant");

      if (value->is_a(NullConstant::klass()) || value->is_a(HotSpotCompressedNullConstant::klass())) {

        return _oop_null_scope_value;

      } else {

        assert(value->is_a(HotSpotObjectConstantImpl::klass()), "unexpected constant type");

        oop obj = HotSpotObjectConstantImpl::object(value);

        assert(obj != NULL, "null value must be in NullConstant");

        return new ConstantOopWriteValue(JNIHandles::make_local(obj));

      }

    }

  } else if (value->is_a(VirtualObject::klass())) {

    assert(type == T_OBJECT, "unexpected virtual object");

    int id = VirtualObject::id(value);

    ScopeValue* object = objects->at(id);

    assert(object != NULL, "missing value");

    return object;

  } else {

    value->klass()->print();

    value->print();

  }

  ShouldNotReachHere();

  return NULL;

}

void CodeInstaller::record_object_value(ObjectValue* sv, oop value, GrowableArray<ScopeValue*>* objects) {

  oop type = VirtualObject::type(value);

  int id = VirtualObject::id(value);

  oop javaMirror = HotSpotResolvedObjectTypeImpl::javaClass(type);

  Klass* klass = java_lang_Class::as_Klass(javaMirror);

  bool isLongArray = klass == Universe::longArrayKlassObj();

  objArrayOop values = VirtualObject::values(value);

  objArrayOop slotKinds = VirtualObject::slotKinds(value);

  for (jint i = 0; i < values->length(); i++) {

    ScopeValue* cur_second = NULL;

    oop object = values->obj_at(i);

    oop kind = slotKinds->obj_at(i);

    BasicType type = JVMCIRuntime::kindToBasicType(JavaKind::typeChar(kind));

    ScopeValue* value = get_scope_value(object, type, objects, cur_second);

    if (isLongArray && cur_second == NULL) {

      // 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 (cur_second != NULL) {

      sv->field_values()->append(cur_second);

    }

    assert(value != NULL, "missing value");

    sv->field_values()->append(value);

  }

}

MonitorValue* CodeInstaller::get_monitor_value(oop value, GrowableArray<ScopeValue*>* objects) {

  guarantee(value->is_a(StackLockValue::klass()), "Monitors must be of type StackLockValue");

  ScopeValue* second = NULL;

  ScopeValue* owner_value = get_scope_value(StackLockValue::owner(value), T_OBJECT, objects, second);

  assert(second == NULL, "monitor cannot occupy two stack slots");

  ScopeValue* lock_data_value = get_scope_value(StackLockValue::slot(value), T_LONG, objects, second);

  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();

  bool eliminated = false;

  if (StackLockValue::eliminated(value)) {

    eliminated = true;

  }

  return new MonitorValue(owner_value, lock_data_loc, eliminated);

}

void CodeInstaller::initialize_dependencies(oop compiled_code, OopRecorder* recorder) {

  JavaThread* thread = JavaThread::current();

  CompilerThread* compilerThread = thread->is_Compiler_thread() ? thread->as_CompilerThread() : NULL;

  _oop_recorder = recorder;

  _dependencies = new Dependencies(&_arena, _oop_recorder, compilerThread != NULL ? compilerThread->log() : NULL);

  objArrayHandle assumptions = HotSpotCompiledCode::assumptions(compiled_code);

  if (!assumptions.is_null()) {

    int length = assumptions->length();

    for (int i = 0; i < length; ++i) {

      Handle assumption = assumptions->obj_at(i);

      if (!assumption.is_null()) {

        if (assumption->klass() == Assumptions_NoFinalizableSubclass::klass()) {

          assumption_NoFinalizableSubclass(assumption);

        } else if (assumption->klass() == Assumptions_ConcreteSubtype::klass()) {

          assumption_ConcreteSubtype(assumption);

        } else if (assumption->klass() == Assumptions_LeafType::klass()) {

          assumption_LeafType(assumption);

        } else if (assumption->klass() == Assumptions_ConcreteMethod::klass()) {

          assumption_ConcreteMethod(assumption);

        } else if (assumption->klass() == Assumptions_CallSiteTargetValue::klass()) {

          assumption_CallSiteTargetValue(assumption);

        } else {

          assumption->print();

          fatal("unexpected Assumption subclass");

        }

      }

    }

  }

  objArrayHandle methods = HotSpotCompiledCode::methods(compiled_code);

  if (!methods.is_null()) {

    int length = methods->length();

    for (int i = 0; i < length; ++i) {

      Handle method_handle = methods->obj_at(i);

      methodHandle method = getMethodFromHotSpotMethod(method_handle());

      _dependencies->assert_evol_method(method());

    }

  }

}

RelocBuffer::~RelocBuffer() {

  if (_buffer != NULL) {

    FREE_C_HEAP_ARRAY(char, _buffer);

  }

}

address RelocBuffer::begin() const {

  if (_buffer != NULL) {

    return (address) _buffer;

  }

  return (address) _static_buffer;

}

void RelocBuffer::set_size(size_t bytes) {

  assert(bytes <= _size, "can't grow in size!");

  _size = bytes;

}

void RelocBuffer::ensure_size(size_t bytes) {

  assert(_buffer == NULL, "can only be used once");

  assert(_size == 0, "can only be used once");

  if (bytes >= RelocBuffer::stack_size) {

    _buffer = NEW_C_HEAP_ARRAY(char, bytes, mtInternal);

  }

  _size = bytes;

}

JVMCIEnv::CodeInstallResult CodeInstaller::gather_metadata(Handle target, Handle& compiled_code, CodeMetadata& metadata) {

  CodeBuffer buffer("JVMCI Compiler CodeBuffer for Metadata");

  jobject compiled_code_obj = JNIHandles::make_local(compiled_code());

  initialize_dependencies(JNIHandles::resolve(compiled_code_obj), NULL);

  // Get instructions and constants CodeSections early because we need it.

  _instructions = buffer.insts();

  _constants = buffer.consts();

  initialize_fields(target(), JNIHandles::resolve(compiled_code_obj));

  if (!initialize_buffer(buffer)) {

    return JVMCIEnv::code_too_large;

  }

  process_exception_handlers();

  _debug_recorder->pcs_size(); // ehm, create the sentinel record

  assert(_debug_recorder->pcs_length() >= 2, "must be at least 2");

  metadata.set_pc_desc(_debug_recorder->pcs(), _debug_recorder->pcs_length());

  metadata.set_scopes(_debug_recorder->stream()->buffer(), _debug_recorder->data_size());

  metadata.set_exception_table(&_exception_handler_table);

  RelocBuffer* reloc_buffer = metadata.get_reloc_buffer();

  reloc_buffer->ensure_size(buffer.total_relocation_size());

  size_t size = (size_t) buffer.copy_relocations_to(reloc_buffer->begin(), (CodeBuffer::csize_t) reloc_buffer->size(), true);

  reloc_buffer->set_size(size);

  return JVMCIEnv::ok;

}

// constructor used to create a method

JVMCIEnv::CodeInstallResult CodeInstaller::install(JVMCICompiler* compiler, Handle target, Handle& compiled_code, CodeBlob*& cb, Handle installed_code, Handle speculation_log) {

  CodeBuffer buffer("JVMCI Compiler CodeBuffer");

  jobject compiled_code_obj = JNIHandles::make_local(compiled_code());

  OopRecorder* recorder = new OopRecorder(&_arena, true);

  initialize_dependencies(JNIHandles::resolve(compiled_code_obj), recorder);

  // Get instructions and constants CodeSections early because we need it.

  _instructions = buffer.insts();

  _constants = buffer.consts();

  initialize_fields(target(), JNIHandles::resolve(compiled_code_obj));

  JVMCIEnv::CodeInstallResult result = initialize_buffer(buffer);

  if (result != JVMCIEnv::ok) {

    return result;

  }

  process_exception_handlers();

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

  if (!compiled_code->is_a(HotSpotCompiledNmethod::klass())) {

    oop stubName = HotSpotCompiledCode::name(compiled_code_obj);

    char* name = strdup(java_lang_String::as_utf8_string(stubName));

    cb = RuntimeStub::new_runtime_stub(name,

                                       &buffer,

                                       CodeOffsets::frame_never_safe,

                                       stack_slots,

                                       _debug_recorder->_oopmaps,

                                       false);

    result = JVMCIEnv::ok;

  } else {

    nmethod* nm = NULL;

    methodHandle method = getMethodFromHotSpotMethod(HotSpotCompiledNmethod::method(compiled_code));

    jint entry_bci = HotSpotCompiledNmethod::entryBCI(compiled_code);

    jint id = HotSpotCompiledNmethod::id(compiled_code);

    bool has_unsafe_access = HotSpotCompiledNmethod::hasUnsafeAccess(compiled_code) == JNI_TRUE;

    JVMCIEnv* env = (JVMCIEnv*) (address) HotSpotCompiledNmethod::jvmciEnv(compiled_code);

    if (id == -1) {

      // Make sure a valid compile_id is associated with every compile

      id = CompileBroker::assign_compile_id_unlocked(Thread::current(), method, entry_bci);

    }

    result = JVMCIEnv::register_method(method, nm, entry_bci, &_offsets, _custom_stack_area_offset, &buffer,

                                       stack_slots, _debug_recorder->_oopmaps, &_exception_handler_table,

                                       compiler, _debug_recorder, _dependencies, env, id,

                                       has_unsafe_access, _has_wide_vector, installed_code, compiled_code, speculation_log);

    cb = nm;

  }

  if (cb != NULL) {

    // Make sure the pre-calculated constants section size was correct.

    guarantee((cb->code_begin() - cb->content_begin()) >= _constants_size, err_msg("%d < %d", (int)(cb->code_begin() - cb->content_begin()), _constants_size));

  }

  return result;

}

void CodeInstaller::initialize_fields(oop target, oop compiled_code) {

  if (compiled_code->is_a(HotSpotCompiledNmethod::klass())) {

    Handle hotspotJavaMethod = HotSpotCompiledNmethod::method(compiled_code);

    methodHandle method = getMethodFromHotSpotMethod(hotspotJavaMethod());

    _parameter_count = method->size_of_parameters();

    TRACE_jvmci_2("installing code for %s", method->name_and_sig_as_C_string());

  } else {

    // Must be a HotSpotCompiledRuntimeStub.

    // Only used in OopMap constructor for non-product builds

    _parameter_count = 0;

  }

  _sites_handle = JNIHandles::make_local(HotSpotCompiledCode::sites(compiled_code));

  _exception_handlers_handle = JNIHandles::make_local(HotSpotCompiledCode::exceptionHandlers(compiled_code));

  _code_handle = JNIHandles::make_local(HotSpotCompiledCode::targetCode(compiled_code));

  _code_size = HotSpotCompiledCode::targetCodeSize(compiled_code);

  _total_frame_size = HotSpotCompiledCode::totalFrameSize(compiled_code);

  _custom_stack_area_offset = HotSpotCompiledCode::customStackAreaOffset(compiled_code);

  // Pre-calculate the constants section size.  This is required for PC-relative addressing.

  _data_section_handle = JNIHandles::make_local(HotSpotCompiledCode::dataSection(compiled_code));

  guarantee(HotSpotCompiledCode::dataSectionAlignment(compiled_code) <= _constants->alignment(), "Alignment inside constants section is restricted by alignment of section begin");

  _constants_size = data_section()->length();