/*

 * Copyright (c) 2003, 2010, 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 "oops/constMethodOop.hpp"

#include "oops/methodOop.hpp"

// Static initialization

const u2 constMethodOopDesc::MAX_IDNUM   = 0xFFFE;

const u2 constMethodOopDesc::UNSET_IDNUM = 0xFFFF;

// How big must this constMethodObject be?

int constMethodOopDesc::object_size(int code_size,

                                    int compressed_line_number_size,

                                    int local_variable_table_length,

                                    int checked_exceptions_length) {

  int extra_bytes = code_size;

  if (compressed_line_number_size > 0) {

    extra_bytes += compressed_line_number_size;

  }

  if (checked_exceptions_length > 0) {

    extra_bytes += sizeof(u2);

    extra_bytes += checked_exceptions_length * sizeof(CheckedExceptionElement);

  }

  if (local_variable_table_length > 0) {

    extra_bytes += sizeof(u2);

    extra_bytes +=

              local_variable_table_length * sizeof(LocalVariableTableElement);

  }

  int extra_words = align_size_up(extra_bytes, BytesPerWord) / BytesPerWord;

  return align_object_size(header_size() + extra_words);

}

// linenumber table - note that length is unknown until decompression,

// see class CompressedLineNumberReadStream.

u_char* constMethodOopDesc::compressed_linenumber_table() const {

  // Located immediately following the bytecodes.

  assert(has_linenumber_table(), "called only if table is present");

  return code_end();

}

u2* constMethodOopDesc::checked_exceptions_length_addr() const {

  // Located at the end of the constMethod.

  assert(has_checked_exceptions(), "called only if table is present");

  return last_u2_element();

}

u2* constMethodOopDesc::localvariable_table_length_addr() const {

  assert(has_localvariable_table(), "called only if table is present");

  if (has_checked_exceptions()) {

    // If checked_exception present, locate immediately before them.

    return (u2*) checked_exceptions_start() - 1;

  } else {

    // Else, the linenumber table is at the end of the constMethod.

    return last_u2_element();

  }

}

// Update the flags to indicate the presence of these optional fields.

void constMethodOopDesc::set_inlined_tables_length(

                                              int checked_exceptions_len,

                                              int compressed_line_number_size,

                                              int localvariable_table_len) {

  // Must be done in the order below, otherwise length_addr accessors

  // will not work. Only set bit in header if length is positive.

  assert(_flags == 0, "Error");

  if (compressed_line_number_size > 0) {

    _flags |= _has_linenumber_table;

  }

  if (checked_exceptions_len > 0) {

    _flags |= _has_checked_exceptions;

    *(checked_exceptions_length_addr()) = checked_exceptions_len;

  }

  if (localvariable_table_len > 0) {

    _flags |= _has_localvariable_table;

    *(localvariable_table_length_addr()) = localvariable_table_len;

  }

}

int constMethodOopDesc::checked_exceptions_length() const {

  return has_checked_exceptions() ? *(checked_exceptions_length_addr()) : 0;

}

CheckedExceptionElement* constMethodOopDesc::checked_exceptions_start() const {

  u2* addr = checked_exceptions_length_addr();

  u2 length = *addr;

  assert(length > 0, "should only be called if table is present");

  addr -= length * sizeof(CheckedExceptionElement) / sizeof(u2);

  return (CheckedExceptionElement*) addr;

}

int constMethodOopDesc::localvariable_table_length() const {

  return has_localvariable_table() ? *(localvariable_table_length_addr()) : 0;

}

LocalVariableTableElement* constMethodOopDesc::localvariable_table_start() const {

  u2* addr = localvariable_table_length_addr();

  u2 length = *addr;

  assert(length > 0, "should only be called if table is present");

  addr -= length * sizeof(LocalVariableTableElement) / sizeof(u2);

  return (LocalVariableTableElement*) addr;

}