/*

 * Copyright (c) 1999, 2017, 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/ciConstant.hpp"

#include "ci/ciField.hpp"

#include "ci/ciInstance.hpp"

#include "ci/ciInstanceKlass.hpp"

#include "classfile/systemDictionary.hpp"

#include "oops/oop.inline.hpp"

// ciInstance

//

// This class represents an instanceOop in the HotSpot virtual

// machine.

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

// ciObject::java_mirror_type

ciType* ciInstance::java_mirror_type() {

  VM_ENTRY_MARK;

  oop m = get_oop();

  // Return NULL if it is not java.lang.Class.

  if (m == NULL || m->klass() != SystemDictionary::Class_klass()) {

    return NULL;

  }

  // Return either a primitive type or a klass.

  if (java_lang_Class::is_primitive(m)) {

    return ciType::make(java_lang_Class::primitive_type(m));

  } else {

    Klass* k = java_lang_Class::as_Klass(m);

    assert(k != NULL, "");

    return CURRENT_THREAD_ENV->get_klass(k);

  }

}

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

// ciInstance::field_value_impl

ciConstant ciInstance::field_value_impl(BasicType field_btype, int offset) {

  oop obj = get_oop();

  assert(obj != NULL, "bad oop");

  switch(field_btype) {

    case T_BYTE:    return ciConstant(field_btype, obj->byte_field(offset));

    case T_CHAR:    return ciConstant(field_btype, obj->char_field(offset));

    case T_SHORT:   return ciConstant(field_btype, obj->short_field(offset));

    case T_BOOLEAN: return ciConstant(field_btype, obj->bool_field(offset));

    case T_INT:     return ciConstant(field_btype, obj->int_field(offset));

    case T_FLOAT:   return ciConstant(obj->float_field(offset));

    case T_DOUBLE:  return ciConstant(obj->double_field(offset));

    case T_LONG:    return ciConstant(obj->long_field(offset));

    case T_OBJECT:  // fall through

    case T_ARRAY: {

      oop o = obj->obj_field(offset);

      // A field will be "constant" if it is known always to be

      // a non-null reference to an instance of a particular class,

      // or to a particular array.  This can happen even if the instance

      // or array is not perm.  In such a case, an "unloaded" ciArray

      // or ciInstance is created.  The compiler may be able to use

      // information about the object's class (which is exact) or length.

      if (o == NULL) {

        return ciConstant(field_btype, ciNullObject::make());

      } else {

        return ciConstant(field_btype, CURRENT_ENV->get_object(o));

      }

    }

    default:

      fatal("no field value: %s", type2name(field_btype));

      return ciConstant();

  }

}

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

// ciInstance::field_value

//

// Constant value of a field.

ciConstant ciInstance::field_value(ciField* field) {

  assert(is_loaded(), "invalid access - must be loaded");

  assert(field->holder()->is_loaded(), "invalid access - holder must be loaded");

  assert(field->is_static() || klass()->is_subclass_of(field->holder()), "invalid access - must be subclass");

  GUARDED_VM_ENTRY(return field_value_impl(field->type()->basic_type(), field->offset());)

}

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

// ciInstance::field_value_by_offset

//

// Constant value of a field at the specified offset.

ciConstant ciInstance::field_value_by_offset(int field_offset) {

  ciInstanceKlass* ik = klass()->as_instance_klass();

  ciField* field = ik->get_field_by_offset(field_offset, false);

  if (field == NULL)

    return ciConstant();  // T_ILLEGAL

  return field_value(field);

}

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

// ciInstance::print_impl

//

// Implementation of the print method.

void ciInstance::print_impl(outputStream* st) {

  st->print(" type=");

  klass()->print(st);

}

ciKlass* ciInstance::java_lang_Class_klass() {

  VM_ENTRY_MARK;

  return CURRENT_ENV->get_metadata(java_lang_Class::as_Klass(get_oop()))->as_klass();

}