/*
 * Copyright (C) 2007 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.android.dexgen.dex.file;

/**
 * Constants for the dex debug info state machine format.
 */
public interface DebugInfoConstants {

    /*
     * normal opcodes
     */

    /**
     * Terminates a debug info sequence for a method.<p>
     * Args: none
     *
     */
    static final int DBG_END_SEQUENCE = 0x00;

    /**
     * Advances the program counter/address register without emitting
     * a positions entry.<p>
     *
     * Args:
     * <ol>
     * <li>Unsigned LEB128 &mdash; amount to advance pc by
     * </ol>
     */
    static final int DBG_ADVANCE_PC = 0x01;

    /**
     * Advances the line register without emitting
     * a positions entry.<p>
     *
     * Args:
     * <ol>
     * <li>Signed LEB128 &mdash; amount to change line register by.
     * </ol>
     */
    static final int DBG_ADVANCE_LINE = 0x02;

    /**
     * Introduces a local variable at the current address.<p>
     *
     * Args:
     * <ol>
     * <li>Unsigned LEB128 &mdash; register that will contain local.
     * <li>Unsigned LEB128 &mdash; string index (shifted by 1) of local name.
     * <li>Unsigned LEB128 &mdash; type index (shifted by 1) of type.
     * </ol>
     */
    static final int DBG_START_LOCAL = 0x03;

    /**
     * Introduces a local variable at the current address with a type
     * signature specified.<p>
     *
     * Args:
     * <ol>
     * <li>Unsigned LEB128 &mdash; register that will contain local.
     * <li>Unsigned LEB128 &mdash; string index (shifted by 1) of local name.
     * <li>Unsigned LEB128 &mdash; type index (shifted by 1) of type.
     * <li>Unsigned LEB128 &mdash; string index (shifted by 1) of
     * type signature.
     * </ol>
     */
    static final int DBG_START_LOCAL_EXTENDED = 0x04;

    /**
     * Marks a currently-live local variable as out of scope at the
     * current address.<p>
     *
     * Args:
     * <ol>
     * <li>Unsigned LEB128 &mdash; register that contained local
     * </ol>
     */
    static final int DBG_END_LOCAL = 0x05;

    /**
     * Re-introduces a local variable at the current address. The name
     * and type are the same as the last local that was live in the specified
     * register.<p>
     *
     * Args:
     * <ol>
     * <li>Unsigned LEB128 &mdash; register to re-start.
     * </ol>
     */
    static final int DBG_RESTART_LOCAL = 0x06;


    /**
     * Sets the "prologue_end" state machine register, indicating that the
     * next position entry that is added should be considered the end of
     * a method prologue (an appropriate place for a method breakpoint).<p>
     *
     * The prologue_end register is cleared by any special
     * ({@code >= OPCODE_BASE}) opcode.
     */
    static final int DBG_SET_PROLOGUE_END = 0x07;

    /**
     * Sets the "epilogue_begin" state machine register, indicating that the
     * next position entry that is added should be considered the beginning of
     * a method epilogue (an appropriate place to suspend execution before
     * method exit).<p>
     *
     * The epilogue_begin register is cleared by any special
     * ({@code >= OPCODE_BASE}) opcode.
     */
    static final int DBG_SET_EPILOGUE_BEGIN = 0x08;

    /**
     * Sets the current file that that line numbers refer to. All subsequent
     * line number entries make reference to this source file name, instead
     * of the default name specified in code_item.
     *
     * Args:
     * <ol>
     * <li>Unsigned LEB128 &mdash; string index (shifted by 1) of source
     * file name.
     * </ol>
     */
    static final int DBG_SET_FILE = 0x09;

    /* IF YOU ADD A NEW OPCODE, increase OPCODE_BASE */

    /*
     * "special opcode" configuration, essentially what's found in
     * the line number program header in DWARFv3, Section 6.2.4
     */

    /** the smallest value a special opcode can take */
    static final int DBG_FIRST_SPECIAL = 0x0a;
    static final int DBG_LINE_BASE = -4;
    static final int DBG_LINE_RANGE = 15;
    // MIN_INSN_LENGTH is always 1
}