/*
 * Copyright (c) 2020, 2020, Oracle and/or its affiliates. All rights reserved.
 * Copyright (c) 2020, Red Hat Inc. 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.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * 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 com.oracle.objectfile.elf.dwarf;

import java.nio.ByteOrder;

import com.oracle.objectfile.debugentry.DebugInfoBase;

import com.oracle.objectfile.elf.ELFMachine;

A class that models the debug info in an organization that facilitates generation of the required
DWARF sections. It groups common data and behaviours for use by the various subclasses of class
DwarfSectionImpl that take responsibility for generating content for a specific section type.
/**
 * A class that models the debug info in an organization that facilitates generation of the required
 * DWARF sections. It groups common data and behaviours for use by the various subclasses of class
 * DwarfSectionImpl that take responsibility for generating content for a specific section type.
 */
public class DwarfDebugInfo extends DebugInfoBase {

    /*
     * Names of the different ELF sections we create or reference in reverse dependency order.
     */
    public static final String TEXT_SECTION_NAME = ".text";
    public static final String DW_STR_SECTION_NAME = ".debug_str";
    public static final String DW_LINE_SECTION_NAME = ".debug_line";
    public static final String DW_FRAME_SECTION_NAME = ".debug_frame";
    public static final String DW_ABBREV_SECTION_NAME = ".debug_abbrev";
    public static final String DW_INFO_SECTION_NAME = ".debug_info";
    public static final String DW_ARANGES_SECTION_NAME = ".debug_aranges";

    
Currently generated debug info relies on DWARF spec vesion 2.
/**
     * Currently generated debug info relies on DWARF spec vesion 2.
     */
    public static final short DW_VERSION_2 = 2;

    /*
     * Define all the abbrev section codes we need for our DIEs.
     */
    @SuppressWarnings("unused") public static final int DW_ABBREV_CODE_null = 0;
    public static final int DW_ABBREV_CODE_compile_unit_1 = 1;
    public static final int DW_ABBREV_CODE_compile_unit_2 = 2;
    public static final int DW_ABBREV_CODE_subprogram = 3;

    /*
     * Define all the Dwarf tags we need for our DIEs.
     */
    public static final int DW_TAG_compile_unit = 0x11;
    public static final int DW_TAG_subprogram = 0x2e;
    /*
     * Define all the Dwarf attributes we need for our DIEs.
     */
    public static final int DW_AT_null = 0x0;
    public static final int DW_AT_name = 0x3;
    public static final int DW_AT_comp_dir = 0x1b;
    public static final int DW_AT_stmt_list = 0x10;
    public static final int DW_AT_low_pc = 0x11;
    public static final int DW_AT_hi_pc = 0x12;
    public static final int DW_AT_language = 0x13;
    public static final int DW_AT_external = 0x3f;
    @SuppressWarnings("unused") public static final int DW_AT_return_addr = 0x2a;
    @SuppressWarnings("unused") public static final int DW_AT_frame_base = 0x40;
    /*
     * Define all the Dwarf attribute forms we need for our DIEs.
     */
    public static final int DW_FORM_null = 0x0;
    @SuppressWarnings("unused") private static final int DW_FORM_string = 0x8;
    public static final int DW_FORM_strp = 0xe;
    public static final int DW_FORM_addr = 0x1;
    public static final int DW_FORM_data1 = 0x0b;
    public static final int DW_FORM_data4 = 0x6;
    @SuppressWarnings("unused") public static final int DW_FORM_data8 = 0x7;
    @SuppressWarnings("unused") public static final int DW_FORM_block1 = 0x0a;
    public static final int DW_FORM_flag = 0xc;

    /*
     * Define specific attribute values for given attribute or form types.
     */
    /*
     * DIE header has_children attribute values.
     */
    public static final byte DW_CHILDREN_no = 0;
    public static final byte DW_CHILDREN_yes = 1;
    /*
     * DW_FORM_flag attribute values.
     */
    @SuppressWarnings("unused") public static final byte DW_FLAG_false = 0;
    public static final byte DW_FLAG_true = 1;
    /*
     * Value for DW_AT_language attribute with form DATA1.
     */
    public static final byte DW_LANG_Java = 0xb;

    /*
     * DW_AT_Accessibility attribute values.
     *
     * These are not needed until we make functions members.
     */
    @SuppressWarnings("unused") public static final byte DW_ACCESS_public = 1;
    @SuppressWarnings("unused") public static final byte DW_ACCESS_protected = 2;
    @SuppressWarnings("unused") public static final byte DW_ACCESS_private = 3;

    /*
     * Others that are not yet needed.
     */
    @SuppressWarnings("unused") public static final int DW_AT_type = 0; // only present for non-void
    // functions
    @SuppressWarnings("unused") public static final int DW_AT_accessibility = 0;

    /*
     * CIE and FDE entries.
     */

    /* Full byte/word values. */
    public static final int DW_CFA_CIE_id = -1;
    @SuppressWarnings("unused") public static final int DW_CFA_FDE_id = 0;

    public static final byte DW_CFA_CIE_version = 1;

    /* Values encoded in high 2 bits. */
    public static final byte DW_CFA_advance_loc = 0x1;
    public static final byte DW_CFA_offset = 0x2;
    public static final byte DW_CFA_restore = 0x3;

    /* Values encoded in low 6 bits. */
    public static final byte DW_CFA_nop = 0x0;
    @SuppressWarnings("unused") public static final byte DW_CFA_set_loc1 = 0x1;
    public static final byte DW_CFA_advance_loc1 = 0x2;
    public static final byte DW_CFA_advance_loc2 = 0x3;
    public static final byte DW_CFA_advance_loc4 = 0x4;
    @SuppressWarnings("unused") public static final byte DW_CFA_offset_extended = 0x5;
    @SuppressWarnings("unused") public static final byte DW_CFA_restore_extended = 0x6;
    @SuppressWarnings("unused") public static final byte DW_CFA_undefined = 0x7;
    @SuppressWarnings("unused") public static final byte DW_CFA_same_value = 0x8;
    public static final byte DW_CFA_register = 0x9;
    public static final byte DW_CFA_def_cfa = 0xc;
    @SuppressWarnings("unused") public static final byte DW_CFA_def_cfa_register = 0xd;
    public static final byte DW_CFA_def_cfa_offset = 0xe;

    private DwarfStrSectionImpl dwarfStrSection;
    private DwarfAbbrevSectionImpl dwarfAbbrevSection;
    private DwarfInfoSectionImpl dwarfInfoSection;
    private DwarfARangesSectionImpl dwarfARangesSection;
    private DwarfLineSectionImpl dwarfLineSection;
    private DwarfFrameSectionImpl dwarfFameSection;
    public final ELFMachine elfMachine;

    public DwarfDebugInfo(ELFMachine elfMachine, ByteOrder byteOrder) {
        super(byteOrder);
        this.elfMachine = elfMachine;
        dwarfStrSection = new DwarfStrSectionImpl(this);
        dwarfAbbrevSection = new DwarfAbbrevSectionImpl(this);
        dwarfInfoSection = new DwarfInfoSectionImpl(this);
        dwarfARangesSection = new DwarfARangesSectionImpl(this);
        dwarfLineSection = new DwarfLineSectionImpl(this);
        if (elfMachine == ELFMachine.AArch64) {
            dwarfFameSection = new DwarfFrameSectionImplAArch64(this);
        } else {
            dwarfFameSection = new DwarfFrameSectionImplX86_64(this);
        }
    }

    public DwarfStrSectionImpl getStrSectionImpl() {
        return dwarfStrSection;
    }

    public DwarfAbbrevSectionImpl getAbbrevSectionImpl() {
        return dwarfAbbrevSection;
    }

    public DwarfFrameSectionImpl getFrameSectionImpl() {
        return dwarfFameSection;
    }

    public DwarfInfoSectionImpl getInfoSectionImpl() {
        return dwarfInfoSection;
    }

    public DwarfARangesSectionImpl getARangesSectionImpl() {
        return dwarfARangesSection;
    }

    public DwarfLineSectionImpl getLineSectionImpl() {
        return dwarfLineSection;
    }
}