/*

 * Copyright (c) 1999, 2019, 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 "ci/ciField.hpp"

#include "ci/ciInstance.hpp"

#include "ci/ciInstanceKlass.hpp"

#include "ci/ciUtilities.inline.hpp"

#include "classfile/systemDictionary.hpp"

#include "memory/allocation.hpp"

#include "memory/allocation.inline.hpp"

#include "memory/resourceArea.hpp"

#include "oops/oop.inline.hpp"

#include "runtime/fieldDescriptor.inline.hpp"

#include "runtime/handles.inline.hpp"

#include "runtime/jniHandles.inline.hpp"

// ciInstanceKlass

//

// This class represents a Klass* in the HotSpot virtual machine

// whose Klass part in an InstanceKlass.

// ------------------------------------------------------------------

// ciInstanceKlass::ciInstanceKlass

//

// Loaded instance klass.

ciInstanceKlass::ciInstanceKlass(Klass* k) :

  ciKlass(k)

{

  assert(get_Klass()->is_instance_klass(), "wrong type");

  assert(get_instanceKlass()->is_loaded(), "must be at least loaded");

  InstanceKlass* ik = get_instanceKlass();

  AccessFlags access_flags = ik->access_flags();

  _flags = ciFlags(access_flags);

  _has_finalizer = access_flags.has_finalizer();

  _has_subklass = flags().is_final() ? subklass_false : subklass_unknown;

  _init_state = ik->init_state();

  _nonstatic_field_size = ik->nonstatic_field_size();

  _has_nonstatic_fields = ik->has_nonstatic_fields();

  _has_nonstatic_concrete_methods = ik->has_nonstatic_concrete_methods();

  _is_unsafe_anonymous = ik->is_unsafe_anonymous();

  _nonstatic_fields = NULL; // initialized lazily by compute_nonstatic_fields:

  _has_injected_fields = -1;

  _implementor = NULL; // we will fill these lazily

  // Ensure that the metadata wrapped by the ciMetadata is kept alive by GC.

  // This is primarily useful for metadata which is considered as weak roots

  // by the GC but need to be strong roots if reachable from a current compilation.

  // InstanceKlass are created for both weak and strong metadata.  Ensuring this metadata

  // alive covers the cases where there are weak roots without performance cost.

  oop holder = ik->klass_holder();

  if (ik->is_unsafe_anonymous()) {

    // Though ciInstanceKlass records class loader oop, it's not enough to keep

    // VM unsafe anonymous classes alive (loader == NULL). Klass holder should

    // be used instead. It is enough to record a ciObject, since cached elements are never removed

    // during ciObjectFactory lifetime. ciObjectFactory itself is created for

    // every compilation and lives for the whole duration of the compilation.

    assert(holder != NULL, "holder of unsafe anonymous class is the mirror which is never null");

    (void)CURRENT_ENV->get_object(holder);

  }

  Thread *thread = Thread::current();

  if (ciObjectFactory::is_initialized()) {

    _loader = JNIHandles::make_local(thread, ik->class_loader());

    _protection_domain = JNIHandles::make_local(thread,

                                                ik->protection_domain());

    _is_shared = false;

  } else {

    Handle h_loader(thread, ik->class_loader());

    Handle h_protection_domain(thread, ik->protection_domain());

    _loader = JNIHandles::make_global(h_loader);

    _protection_domain = JNIHandles::make_global(h_protection_domain);

    _is_shared = true;

  }

  // Lazy fields get filled in only upon request.

  _super  = NULL;

  _java_mirror = NULL;

  if (is_shared()) {

    if (k != SystemDictionary::Object_klass()) {

      super();

    }

    //compute_nonstatic_fields();  // done outside of constructor

  }

  _field_cache = NULL;

}

// Version for unloaded classes:

ciInstanceKlass::ciInstanceKlass(ciSymbol* name,

                                 jobject loader, jobject protection_domain)

  : ciKlass(name, T_OBJECT)

{

  assert(name->char_at(0) != JVM_SIGNATURE_ARRAY, "not an instance klass");

  _init_state = (InstanceKlass::ClassState)0;

  _nonstatic_field_size = -1;

  _has_nonstatic_fields = false;

  _nonstatic_fields = NULL;

  _has_injected_fields = -1;

  _is_unsafe_anonymous = false;

  _loader = loader;

  _protection_domain = protection_domain;

  _is_shared = false;

  _super = NULL;

  _java_mirror = NULL;

  _field_cache = NULL;

}

// ------------------------------------------------------------------

// ciInstanceKlass::compute_shared_is_initialized

void ciInstanceKlass::compute_shared_init_state() {

  GUARDED_VM_ENTRY(

    InstanceKlass* ik = get_instanceKlass();

    _init_state = ik->init_state();

  )

}

// ------------------------------------------------------------------

// ciInstanceKlass::compute_shared_has_subklass

bool ciInstanceKlass::compute_shared_has_subklass() {

  GUARDED_VM_ENTRY(

    InstanceKlass* ik = get_instanceKlass();

    _has_subklass = ik->subklass() != NULL ? subklass_true : subklass_false;

    return _has_subklass == subklass_true;

  )

}

// ------------------------------------------------------------------

// ciInstanceKlass::loader

oop ciInstanceKlass::loader() {

  ASSERT_IN_VM;

  return JNIHandles::resolve(_loader);

}

// ------------------------------------------------------------------

// ciInstanceKlass::loader_handle

jobject ciInstanceKlass::loader_handle() {

  return _loader;

}

// ------------------------------------------------------------------

// ciInstanceKlass::protection_domain

oop ciInstanceKlass::protection_domain() {

  ASSERT_IN_VM;

  return JNIHandles::resolve(_protection_domain);

}

// ------------------------------------------------------------------

// ciInstanceKlass::protection_domain_handle

jobject ciInstanceKlass::protection_domain_handle() {

  return _protection_domain;

}

// ------------------------------------------------------------------

// ciInstanceKlass::field_cache

//

// Get the field cache associated with this klass.

ciConstantPoolCache* ciInstanceKlass::field_cache() {

  if (is_shared()) {

    return NULL;

  }

  if (_field_cache == NULL) {

    assert(!is_java_lang_Object(), "Object has no fields");

    Arena* arena = CURRENT_ENV->arena();

    _field_cache = new (arena) ciConstantPoolCache(arena, 5);

  }

  return _field_cache;

}

// ------------------------------------------------------------------

// ciInstanceKlass::get_canonical_holder

//

ciInstanceKlass* ciInstanceKlass::get_canonical_holder(int offset) {

  #ifdef ASSERT

  if (!(offset >= 0 && offset < layout_helper())) {

    tty->print("*** get_canonical_holder(%d) on ", offset);

    this->print();

    tty->print_cr(" ***");

  };

  assert(offset >= 0 && offset < layout_helper(), "offset must be tame");

  #endif

  if (offset < instanceOopDesc::base_offset_in_bytes()) {

    // All header offsets belong properly to java/lang/Object.

    return CURRENT_ENV->Object_klass();

  }

  ciInstanceKlass* self = this;

  for (;;) {

    assert(self->is_loaded(), "must be loaded to have size");

    ciInstanceKlass* super = self->super();

    if (super == NULL || super->nof_nonstatic_fields() == 0 ||

        !super->contains_field_offset(offset)) {

      return self;

    } else {

      self = super;  // return super->get_canonical_holder(offset)

    }

  }

}

// ------------------------------------------------------------------

// ciInstanceKlass::is_java_lang_Object

//

// Is this klass java.lang.Object?

bool ciInstanceKlass::is_java_lang_Object() const {

  return equals(CURRENT_ENV->Object_klass());

}

// ------------------------------------------------------------------

// ciInstanceKlass::uses_default_loader

bool ciInstanceKlass::uses_default_loader() const {

  // Note:  We do not need to resolve the handle or enter the VM

  // in order to test null-ness.

  return _loader == NULL;

}

// ------------------------------------------------------------------

/**

 * Return basic type of boxed value for box klass or T_OBJECT if not.

 */

BasicType ciInstanceKlass::box_klass_type() const {

  if (uses_default_loader() && is_loaded()) {

    return SystemDictionary::box_klass_type(get_Klass());

  } else {

    return T_OBJECT;

  }

}

/**

 * Is this boxing klass?

 */

bool ciInstanceKlass::is_box_klass() const {

  return is_java_primitive(box_klass_type());

}

/**

 *  Is this boxed value offset?

 */

bool ciInstanceKlass::is_boxed_value_offset(int offset) const {

  BasicType bt = box_klass_type();

  return is_java_primitive(bt) &&

         (offset == java_lang_boxing_object::value_offset_in_bytes(bt));

}

// ------------------------------------------------------------------

// ciInstanceKlass::is_in_package

//

// Is this klass in the given package?

bool ciInstanceKlass::is_in_package(const char* packagename, int len) {

  // To avoid class loader mischief, this test always rejects application classes.

  if (!uses_default_loader())

    return false;

  GUARDED_VM_ENTRY(

    return is_in_package_impl(packagename, len);

  )

}

bool ciInstanceKlass::is_in_package_impl(const char* packagename, int len) {

  ASSERT_IN_VM;

  // If packagename contains trailing '/' exclude it from the

  // prefix-test since we test for it explicitly.

  if (packagename[len - 1] == '/')

    len--;

  if (!name()->starts_with(packagename, len))

    return false;

  // Test if the class name is something like "java/lang".

  if ((len + 1) > name()->utf8_length())

    return false;

  // Test for trailing '/'

  if (name()->char_at(len) != '/')

    return false;

  // Make sure it's not actually in a subpackage:

  if (name()->index_of_at(len+1, "/", 1) >= 0)

    return false;

  return true;

}

// ------------------------------------------------------------------

// ciInstanceKlass::print_impl

//

// Implementation of the print method.

void ciInstanceKlass::print_impl(outputStream* st) {

  ciKlass::print_impl(st);

  GUARDED_VM_ENTRY(st->print(" loader=" INTPTR_FORMAT, p2i((address)loader()));)

  if (is_loaded()) {

    st->print(" loaded=true initialized=%s finalized=%s subklass=%s size=%d flags=",

              bool_to_str(is_initialized()),

              bool_to_str(has_finalizer()),

              bool_to_str(has_subklass()),

              layout_helper());

    _flags.print_klass_flags();

    if (_super) {

      st->print(" super=");

      _super->print_name();

    }

    if (_java_mirror) {

      st->print(" mirror=PRESENT");

    }

  } else {

    st->print(" loaded=false");

  }

}

// ------------------------------------------------------------------

// ciInstanceKlass::super

//

// Get the superklass of this klass.

ciInstanceKlass* ciInstanceKlass::super() {

  assert(is_loaded(), "must be loaded");

  if (_super == NULL && !is_java_lang_Object()) {

    GUARDED_VM_ENTRY(

      Klass* super_klass = get_instanceKlass()->super();

      _super = CURRENT_ENV->get_instance_klass(super_klass);

    )

  }

  return _super;

}

// ------------------------------------------------------------------

// ciInstanceKlass::java_mirror

//

// Get the instance of java.lang.Class corresponding to this klass.

// Cache it on this->_java_mirror.

ciInstance* ciInstanceKlass::java_mirror() {

  if (is_shared()) {

    return ciKlass::java_mirror();

  }

  if (_java_mirror == NULL) {

    _java_mirror = ciKlass::java_mirror();

  }

  return _java_mirror;

}

// ------------------------------------------------------------------

// ciInstanceKlass::unique_concrete_subklass

ciInstanceKlass* ciInstanceKlass::unique_concrete_subklass() {

  if (!is_loaded())     return NULL; // No change if class is not loaded

  if (!is_abstract())   return NULL; // Only applies to abstract classes.

  if (!has_subklass())  return NULL; // Must have at least one subklass.

  VM_ENTRY_MARK;

  InstanceKlass* ik = get_instanceKlass();

  Klass* up = ik->up_cast_abstract();

  assert(up->is_instance_klass(), "must be InstanceKlass");

  if (ik == up) {

    return NULL;

  }

  return CURRENT_THREAD_ENV->get_instance_klass(up);

}

// ------------------------------------------------------------------

// ciInstanceKlass::has_finalizable_subclass

bool ciInstanceKlass::has_finalizable_subclass() {

  if (!is_loaded())     return true;

  VM_ENTRY_MARK;

  return Dependencies::find_finalizable_subclass(get_instanceKlass()) != NULL;

}

// ------------------------------------------------------------------

// ciInstanceKlass::get_field_by_offset

ciField* ciInstanceKlass::get_field_by_offset(int field_offset, bool is_static) {

  if (!is_static) {

    for (int i = 0, len = nof_nonstatic_fields(); i < len; i++) {

      ciField* field = _nonstatic_fields->at(i);

      int  field_off = field->offset_in_bytes();

      if (field_off == field_offset)

        return field;

      if (field_off > field_offset)

        break;

      // could do binary search or check bins, but probably not worth it

    }

    return NULL;

  }

  VM_ENTRY_MARK;

  InstanceKlass* k = get_instanceKlass();

  fieldDescriptor fd;

  if (!k->find_field_from_offset(field_offset, is_static, &fd)) {

    return NULL;

  }

  ciField* field = new (CURRENT_THREAD_ENV->arena()) ciField(&fd);

  return field;

}

// ------------------------------------------------------------------

// ciInstanceKlass::get_field_by_name

ciField* ciInstanceKlass::get_field_by_name(ciSymbol* name, ciSymbol* signature, bool is_static) {

  VM_ENTRY_MARK;

  InstanceKlass* k = get_instanceKlass();

  fieldDescriptor fd;

  Klass* def = k->find_field(name->get_symbol(), signature->get_symbol(), is_static, &fd);

  if (def == NULL) {

    return NULL;

  }

  ciField* field = new (CURRENT_THREAD_ENV->arena()) ciField(&fd);

  return field;

}

static int sort_field_by_offset(ciField** a, ciField** b) {

  return (*a)->offset_in_bytes() - (*b)->offset_in_bytes();

  // (no worries about 32-bit overflow...)

}

// ------------------------------------------------------------------

// ciInstanceKlass::compute_nonstatic_fields

int ciInstanceKlass::compute_nonstatic_fields() {

  assert(is_loaded(), "must be loaded");

  if (_nonstatic_fields != NULL)

    return _nonstatic_fields->length();

  if (!has_nonstatic_fields()) {

    Arena* arena = CURRENT_ENV->arena();

    _nonstatic_fields = new (arena) GrowableArray<ciField*>(arena, 0, 0, NULL);

    return 0;

  }

  assert(!is_java_lang_Object(), "bootstrap OK");

  // Size in bytes of my fields, including inherited fields.

  int fsize = nonstatic_field_size() * heapOopSize;

  ciInstanceKlass* super = this->super();

  GrowableArray<ciField*>* super_fields = NULL;

  if (super != NULL && super->has_nonstatic_fields()) {

    int super_fsize  = super->nonstatic_field_size() * heapOopSize;

    int super_flen   = super->nof_nonstatic_fields();

    super_fields = super->_nonstatic_fields;

    assert(super_flen == 0 || super_fields != NULL, "first get nof_fields");

    // See if I am no larger than my super; if so, I can use his fields.

    if (fsize == super_fsize) {

      _nonstatic_fields = super_fields;

      return super_fields->length();

    }

  }

  GrowableArray<ciField*>* fields = NULL;

  GUARDED_VM_ENTRY({

      fields = compute_nonstatic_fields_impl(super_fields);

    });

  if (fields == NULL) {

    // This can happen if this class (java.lang.Class) has invisible fields.

    if (super_fields != NULL) {

      _nonstatic_fields = super_fields;

      return super_fields->length();

    } else {

      return 0;

    }

  }

  int flen = fields->length();

  // Now sort them by offset, ascending.

  // (In principle, they could mix with superclass fields.)

  fields->sort(sort_field_by_offset);

  _nonstatic_fields = fields;

  return flen;

}

GrowableArray<ciField*>*

ciInstanceKlass::compute_nonstatic_fields_impl(GrowableArray<ciField*>*

                                               super_fields) {

  ASSERT_IN_VM;

  Arena* arena = CURRENT_ENV->arena();

  int flen = 0;

  GrowableArray<ciField*>* fields = NULL;

  InstanceKlass* k = get_instanceKlass();

  for (JavaFieldStream fs(k); !fs.done(); fs.next()) {

    if (fs.access_flags().is_static())  continue;

    flen += 1;

  }

  // allocate the array: