/*

 * Copyright (c) 2001, 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.

 *

 */

package sun.jvm.hotspot.runtime;

import sun.jvm.hotspot.oops.*;

/** Specialized SignatureIterator: Used for native call purposes */

public abstract class NativeSignatureIterator extends SignatureIterator {

  private Method method;

// [RGV] We need seperate JNI and Java offset values because in 64 bit mode, the argument offsets

//       are not in sync with the Java stack.  For example a long takes up 1 "C" stack entry

//       but 2 Java stack entries.

  private int offset;     // The java stack offset

  private int prepended;  // number of prepended JNI parameters (1 JNIEnv, plus 1 mirror if static)

  private int jni_offset; // the current parameter offset, starting with 0

  public void doBool  ()                     { passInt();    jni_offset++; offset++;       }

  public void doChar  ()                     { passInt();    jni_offset++; offset++;       }

  public void doFloat () {

    if (VM.getVM().isLP64()) {

      passFloat();

    } else {

      passInt();

    }

    jni_offset++; offset++;

  }

  public void doDouble() {

    if (VM.getVM().isLP64()) {

      passDouble(); jni_offset++; offset += 2;

    } else {

      passDouble(); jni_offset += 2; offset += 2;

    }

  }

  public void doByte  ()                     { passInt();    jni_offset++; offset++;       }

  public void doShort ()                     { passInt();    jni_offset++; offset++;       }

  public void doInt   ()                     { passInt();    jni_offset++; offset++;       }

  public void doLong  () {

    if (VM.getVM().isLP64()) {

      passLong(); jni_offset++; offset += 2;

    } else {

      passLong(); jni_offset += 2; offset += 2;

    }

  }

  public void doVoid  ()                     { throw new RuntimeException("should not reach here"); }

  public void doObject(int begin, int end)   { passObject(); jni_offset++; offset++;        }

  public void doArray (int begin, int end)   { passObject(); jni_offset++; offset++;        }

  public Method       method()               { return method; }

  public int          offset()               { return offset; }

  public int       jniOffset()               { return jni_offset + prepended; }

  public boolean    isStatic()               { return method.isStatic(); }

  public abstract void passInt();

  public abstract void passLong();

  public abstract void passObject();

  public abstract void passFloat();

  public abstract void passDouble();

  public NativeSignatureIterator(Method method) {

    super(method.getSignature());

    this.method = method;

    offset = 0;

    jni_offset = 0;

    int JNIEnv_words = 1;

    int mirror_words = 1;

    prepended = !isStatic() ? JNIEnv_words : JNIEnv_words + mirror_words;

  }

  // iterate() calles the 2 virtual methods according to the following invocation syntax:

  //

  // {pass_int | pass_long | pass_object}

  //

  // Arguments are handled from left to right (receiver first, if any).

  // The offset() values refer to the Java stack offsets but are 0 based and increasing.

  // The java_offset() values count down to 0, and refer to the Java TOS.

  // The jni_offset() values increase from 1 or 2, and refer to C arguments.

  public void iterate() {

    if (!isStatic()) {

      // handle receiver (not handled by iterate because not in signature)

      passObject(); jni_offset++; offset++;

    }

    iterateParameters();

  }

}