Java example source code file (ciArray.cpp)

This example Java source code file (ciArray.cpp) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

arrayklass, basictype, current_env, guarded_vm_entry, null, t_array, t_boolean, t_byte, t_char, t_double, t_float, t_int, t_object, t_short

The ciArray.cpp Java example source code

/*
 * Copyright (c) 1999, 2013, 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/ciArray.hpp"
#include "ci/ciArrayKlass.hpp"
#include "ci/ciConstant.hpp"
#include "ci/ciKlass.hpp"
#include "ci/ciUtilities.hpp"
#include "oops/objArrayOop.hpp"
#include "oops/typeArrayOop.hpp"

// ciArray
//
// This class represents an arrayOop in the HotSpot virtual
// machine.
static BasicType fixup_element_type(BasicType bt) {
  if (bt == T_ARRAY)    return T_OBJECT;
  if (bt == T_BOOLEAN)  return T_BYTE;
  return bt;
}

ciConstant ciArray::element_value_impl(BasicType elembt,
                                       arrayOop ary,
                                       int index) {
  if (ary == NULL)
    return ciConstant();
  assert(ary->is_array(), "");
  if (index < 0 || index >= ary->length())
    return ciConstant();
  ArrayKlass* ak = (ArrayKlass*) ary->klass();
  BasicType abt = ak->element_type();
  if (fixup_element_type(elembt) !=
      fixup_element_type(abt))
    return ciConstant();
  switch (elembt) {
  case T_ARRAY:
  case T_OBJECT:
    {
      assert(ary->is_objArray(), "");
      objArrayOop objary = (objArrayOop) ary;
      oop elem = objary->obj_at(index);
      ciEnv* env = CURRENT_ENV;
      ciObject* box = env->get_object(elem);
      return ciConstant(T_OBJECT, box);
    }
  }
  assert(ary->is_typeArray(), "");
  typeArrayOop tary = (typeArrayOop) ary;
  jint value = 0;
  switch (elembt) {
  case T_LONG:          return ciConstant(tary->long_at(index));
  case T_FLOAT:         return ciConstant(tary->float_at(index));
  case T_DOUBLE:        return ciConstant(tary->double_at(index));
  default:              return ciConstant();
  case T_BYTE:          value = tary->byte_at(index);           break;
  case T_BOOLEAN:       value = tary->byte_at(index) & 1;       break;
  case T_SHORT:         value = tary->short_at(index);          break;
  case T_CHAR:          value = tary->char_at(index);           break;
  case T_INT:           value = tary->int_at(index);            break;
  }
  return ciConstant(elembt, value);
}

// ------------------------------------------------------------------
// ciArray::element_value
//
// Current value of an element.
// Returns T_ILLEGAL if there is no element at the given index.
ciConstant ciArray::element_value(int index) {
  BasicType elembt = element_basic_type();
  GUARDED_VM_ENTRY(
    return element_value_impl(elembt, get_arrayOop(), index);
  )
}

// ------------------------------------------------------------------
// ciArray::element_value_by_offset
//
// Current value of an element at the specified offset.
// Returns T_ILLEGAL if there is no element at the given offset.
ciConstant ciArray::element_value_by_offset(intptr_t element_offset) {
  BasicType elembt = element_basic_type();
  intptr_t shift  = exact_log2(type2aelembytes(elembt));
  intptr_t header = arrayOopDesc::base_offset_in_bytes(elembt);
  intptr_t index = (element_offset - header) >> shift;
  intptr_t offset = header + ((intptr_t)index << shift);
  if (offset != element_offset || index != (jint)index)
    return ciConstant();
  return element_value((jint) index);
}

// ------------------------------------------------------------------
// ciArray::print_impl
//
// Implementation of the print method.
void ciArray::print_impl(outputStream* st) {
  st->print(" length=%d type=", length());
  klass()->print(st);
}