/*

  Copyright (C) 2000-2005 Silicon Graphics, Inc.  All Rights Reserved.

  Portions Copyright (C) 2009-2011 David Anderson. All Rights Reserved.

  This program is free software; you can redistribute it and/or modify it

  under the terms of version 2.1 of the GNU Lesser General Public License

  as published by the Free Software Foundation.

  This program is distributed in the hope that it would be useful, but

  WITHOUT ANY WARRANTY; without even the implied warranty of

  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

  Further, this software is distributed without any warranty that it is

  free of the rightful claim of any third person regarding infringement

  or the like.  Any license provided herein, whether implied or

  otherwise, applies only to this software file.  Patent licenses, if

  any, provided herein do not apply to combinations of this program with

  other software, or any other product whatsoever.

  You should have received a copy of the GNU Lesser General Public

  License along with this program; if not, write the Free Software

  Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston MA 02110-1301,

  USA.

*/

#include "config.h"

#include "dwarf_incl.h"

#include <stdio.h>

#include "dwarf_abbrev.h"

/*  This is used to print a .debug_abbrev section without

    knowing about the DIEs that use the abbrevs.

    dwarf_get_abbrev() and,

    in dwarf_util.c,  _dwarf_get_abbrev_for_code()

    When we have a simple .o

    there is at least a hope of iterating through

    the abbrevs meaningfully without knowing

    a CU context.

    This often fails or gets incorrect info

    because there is no guarantee the .debug_abbrev

    section is free of garbage bytes.

    In an object with multiple CU/TUs the

    output is difficult/impossible to usefully interpret.

    In a dwp (Package File)  it is really impossible

    to associate abbrevs with a CU.

*/

int

dwarf_get_abbrev(Dwarf_Debug dbg,

    Dwarf_Unsigned offset,

    Dwarf_Abbrev * returned_abbrev,

    Dwarf_Unsigned * length,

    Dwarf_Unsigned * abbr_count, Dwarf_Error * error)

{

    Dwarf_Small *abbrev_ptr = 0;

    Dwarf_Small *abbrev_section_end = 0;

    Dwarf_Half attr         = 0;

    Dwarf_Half attr_form    = 0;

    Dwarf_Abbrev ret_abbrev = 0;

    Dwarf_Unsigned labbr_count = 0;

    Dwarf_Unsigned utmp     = 0;

    if (!dbg) {

        _dwarf_error(NULL, error, DW_DLE_DBG_NULL);

        return DW_DLV_ERROR;

    }

    if (dbg->de_debug_abbrev.dss_data == 0) {

        /*  Loads abbrev section (and .debug_info as we do those

            together). */

        int res = _dwarf_load_debug_info(dbg, error);

        if (res != DW_DLV_OK) {

            return res;

        }

    }

    if (offset >= dbg->de_debug_abbrev.dss_size) {

        return DW_DLV_NO_ENTRY;

    }

    ret_abbrev = (Dwarf_Abbrev) _dwarf_get_alloc(dbg, DW_DLA_ABBREV, 1);

    if (ret_abbrev == NULL) {

        _dwarf_error(dbg, error, DW_DLE_ALLOC_FAIL);

        return DW_DLV_ERROR;

    }

    ret_abbrev->dab_dbg = dbg;

    if (returned_abbrev == 0 || abbr_count == 0) {

        dwarf_dealloc(dbg, ret_abbrev, DW_DLA_ABBREV);

        _dwarf_error(dbg, error, DW_DLE_DWARF_ABBREV_NULL);

        return DW_DLV_ERROR;

    }

    *abbr_count = 0;

    if (length) {

        *length = 1;

    }

    abbrev_ptr = dbg->de_debug_abbrev.dss_data + offset;

    abbrev_section_end =

        dbg->de_debug_abbrev.dss_data + dbg->de_debug_abbrev.dss_size;

    DECODE_LEB128_UWORD_CK(abbrev_ptr, utmp,

        dbg,error,abbrev_section_end);

    ret_abbrev->dab_code = (Dwarf_Word) utmp;

    if (ret_abbrev->dab_code == 0) {

        *returned_abbrev = ret_abbrev;

        *abbr_count = 0;

        if (length) {

            *length = 1;

        }

        return DW_DLV_OK;

    }

    DECODE_LEB128_UWORD_CK(abbrev_ptr, utmp,

        dbg,error,abbrev_section_end);

    ret_abbrev->dab_tag = utmp;

    if (abbrev_ptr >= abbrev_section_end) {

        _dwarf_error(dbg, error, DW_DLE_ABBREV_DECODE_ERROR);

        return DW_DLV_ERROR;

    }

    ret_abbrev->dab_has_child = *(abbrev_ptr++);

    ret_abbrev->dab_abbrev_ptr = abbrev_ptr;

    do {

        Dwarf_Unsigned utmp2 = 0;

        DECODE_LEB128_UWORD_CK(abbrev_ptr, utmp2,

            dbg,error,abbrev_section_end);

        attr = (Dwarf_Half) utmp2;

        DECODE_LEB128_UWORD_CK(abbrev_ptr, utmp2,

            dbg,error,abbrev_section_end);

        attr_form = (Dwarf_Half) utmp2;

        if (!_dwarf_valid_form_we_know(dbg,attr_form,attr)) {

            _dwarf_error(dbg, error, DW_DLE_UNKNOWN_FORM);

            return (DW_DLV_ERROR);

        }

        if (attr != 0) {

            labbr_count++;

        }

    } while (abbrev_ptr < abbrev_section_end &&

        (attr != 0 || attr_form != 0));

    /* Global section offset. */

    ret_abbrev->dab_goffset = offset;

    ret_abbrev->dab_count = labbr_count;

    if (abbrev_ptr > abbrev_section_end) {

        dwarf_dealloc(dbg, ret_abbrev, DW_DLA_ABBREV);

        _dwarf_error(dbg, error, DW_DLE_ABBREV_DECODE_ERROR);

        return DW_DLV_ERROR;

    }

    if (length) {

        *length = abbrev_ptr - dbg->de_debug_abbrev.dss_data - offset;

    }

    *returned_abbrev = ret_abbrev;

    *abbr_count = labbr_count;

    return DW_DLV_OK;

}

int

dwarf_get_abbrev_code(Dwarf_Abbrev abbrev,

    Dwarf_Unsigned * returned_code,

    Dwarf_Error * error)

{

    if (abbrev == NULL) {

        _dwarf_error(NULL, error, DW_DLE_DWARF_ABBREV_NULL);

        return (DW_DLV_ERROR);

    }

    *returned_code = abbrev->dab_code;

    return (DW_DLV_OK);

}

/*  DWARF defines DW_TAG_hi_user as 0xffff so no tag should be

    over 16 bits.  */

int

dwarf_get_abbrev_tag(Dwarf_Abbrev abbrev,

    Dwarf_Half * returned_tag, Dwarf_Error * error)

{

    if (abbrev == NULL) {

        _dwarf_error(NULL, error, DW_DLE_DWARF_ABBREV_NULL);

        return (DW_DLV_ERROR);

    }

    *returned_tag = abbrev->dab_tag;

    return (DW_DLV_OK);

}

int

dwarf_get_abbrev_children_flag(Dwarf_Abbrev abbrev,

    Dwarf_Signed * returned_flag,

    Dwarf_Error * error)

{

    if (abbrev == NULL) {

        _dwarf_error(NULL, error, DW_DLE_DWARF_ABBREV_NULL);

        return (DW_DLV_ERROR);

    }

    *returned_flag = abbrev->dab_has_child;

    return (DW_DLV_OK);

}

int

dwarf_get_abbrev_entry(Dwarf_Abbrev abbrev,

    Dwarf_Signed indx,

    Dwarf_Half * returned_attr_num,

    Dwarf_Signed * form,

    Dwarf_Off * offset, Dwarf_Error * error)

{

    Dwarf_Byte_Ptr abbrev_ptr = 0;

    Dwarf_Byte_Ptr abbrev_end = 0;

    Dwarf_Byte_Ptr mark_abbrev_ptr = 0;

    Dwarf_Half attr = 0;

    Dwarf_Half attr_form = 0;

    if (indx < 0)

        return (DW_DLV_NO_ENTRY);

    if (abbrev == NULL) {

        _dwarf_error(NULL, error, DW_DLE_DWARF_ABBREV_NULL);

        return (DW_DLV_ERROR);

    }

    if (abbrev->dab_code == 0) {

        return (DW_DLV_NO_ENTRY);

    }

    if (abbrev->dab_dbg == NULL) {

        _dwarf_error(NULL, error, DW_DLE_DBG_NULL);

        return (DW_DLV_ERROR);

    }

    abbrev_ptr = abbrev->dab_abbrev_ptr;

    abbrev_end =

        abbrev->dab_dbg->de_debug_abbrev.dss_data +

        abbrev->dab_dbg->de_debug_abbrev.dss_size;

    for (attr = 1, attr_form = 1;

        indx >= 0 && abbrev_ptr < abbrev_end && (attr != 0 ||

            attr_form != 0);

        indx--) {

        Dwarf_Unsigned utmp4;

        mark_abbrev_ptr = abbrev_ptr;

        DECODE_LEB128_UWORD_CK(abbrev_ptr, utmp4,abbrev->dab_dbg,

            error,abbrev_end);

        attr = (Dwarf_Half) utmp4;

        DECODE_LEB128_UWORD_CK(abbrev_ptr, utmp4,abbrev->dab_dbg,

            error,abbrev_end);

        attr_form = (Dwarf_Half) utmp4;

    }

    if (abbrev_ptr >= abbrev_end) {

        _dwarf_error(abbrev->dab_dbg, error, DW_DLE_ABBREV_DECODE_ERROR);

        return (DW_DLV_ERROR);

    }

    if (indx >= 0) {

        return (DW_DLV_NO_ENTRY);

    }

    if (form != NULL) {

        *form = attr_form;

    }

    if (offset != NULL) {

        *offset = mark_abbrev_ptr - abbrev->dab_dbg->de_debug_abbrev.dss_data;

    }

    *returned_attr_num = (attr);

    return DW_DLV_OK;

}

/*  This function is not entirely safe to call.

    The problem is that the DWARF[234] specification does not insist

    that bytes in .debug_abbrev that are not referenced by .debug_info

    or .debug_types need to be initialized to anything specific.

    Any garbage bytes may cause trouble.  Not all compilers/linkers

    leave unreferenced garbage bytes in .debug_abbrev, so this may

    work for most objects. */

int

dwarf_get_abbrev_count(Dwarf_Debug dbg)

{

    Dwarf_Abbrev ab;

    Dwarf_Unsigned offset = 0;

    Dwarf_Unsigned length = 0;

    Dwarf_Unsigned attr_count = 0;

    Dwarf_Unsigned abbrev_count = 0;

    int abres = DW_DLV_OK;

    Dwarf_Error err;

    while ((abres = dwarf_get_abbrev(dbg, offset, &ab,

        &length, &attr_count,

        &err)) == DW_DLV_OK) {

        ++abbrev_count;

        offset += length;

        dwarf_dealloc(dbg, ab, DW_DLA_ABBREV);

    }

    return abbrev_count;

}