/*

  Copyright (C) 2000,2004 Silicon Graphics, Inc.  All Rights Reserved.
  Portions Copyright 2011-2020 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 <stddef.h> /* NULL */

#include "dwarf.h"
#include "libdwarf.h"
#include "dwarf_base_types.h"
#include "libdwarfp.h"
#include "dwarf_pro_incl.h"
#include "dwarf_pro_opaque.h"
#include "dwarf_pro_error.h"
#include "dwarf_pro_alloc.h"
#include "dwarf_pro_arange.h"
#include "dwarf_pro_section.h"
#include "dwarf_pro_reloc.h"

#define SIZEOFT32 4

/*  This function adds another address range
    to the list of address ranges for the
    given Dwarf_P_Debug.  It returns DW_DLV_ERROR on error,
    and DW_DLV_OK otherwise.  */
int
dwarf_add_arange_c(Dwarf_P_Debug dbg,
    Dwarf_Addr begin_address,
    Dwarf_Unsigned length,
    Dwarf_Unsigned symbol_index,
    Dwarf_Unsigned end_symbol_index,
    Dwarf_Addr offset_from_end_sym,
    Dwarf_Error * error)
{
    Dwarf_P_Arange arange;

    if (dbg == NULL) {
        _dwarf_p_error(NULL, error, DW_DLE_DBG_NULL);
        return DW_DLV_ERROR;
    }

    arange = (Dwarf_P_Arange)
        _dwarf_p_get_alloc(dbg, sizeof(struct Dwarf_P_Arange_s));
    if (arange == NULL) {
        _dwarf_p_error(dbg, error, DW_DLE_ALLOC_FAIL);
        return DW_DLV_ERROR;
    }

    arange->ag_begin_address = begin_address;
    arange->ag_length = length;
    arange->ag_symbol_index = symbol_index;
    arange->ag_end_symbol_index = end_symbol_index;
    arange->ag_end_symbol_offset = offset_from_end_sym;

    if (dbg->de_arange == NULL)
        dbg->de_arange = dbg->de_last_arange = arange;
    else {
        dbg->de_last_arange->ag_next = arange;
        dbg->de_last_arange = arange;
    }
    dbg->de_arange_count++;
    return DW_DLV_OK;
}

int
_dwarf_transform_arange_to_disk(Dwarf_P_Debug dbg,
    Dwarf_Unsigned *nbufs, Dwarf_Error * error)
{
    /* Total num of bytes in .debug_aranges section. */
    Dwarf_Unsigned arange_num_bytes = 0;

    /*  Adjustment to align the start of the actual
        address ranges on a
        boundary aligned with twice the address size. */
    Dwarf_Small remainder = 0;

    /*  Total number of bytes excluding the length field. */
    Dwarf_Unsigned adjusted_length = 0;

    /*  Points to first byte of .debug_aranges buffer. */
    Dwarf_Small *arange = 0;

    /*  Fills in the .debug_aranges buffer. */
    Dwarf_Small *arange_ptr = 0;

    /*  Scans the list of address ranges provided by user. */
    Dwarf_P_Arange given_arange = 0;

    /*  Used to fill in 0. */
    const Dwarf_Signed big_zero = 0;

    int extension_word_size = dbg->de_64bit_extension ? 4 : 0;
    int offset_size = dbg->de_dwarf_offset_size;
    int upointer_size = dbg->de_pointer_size;

    /*  All dwarf versions so far use 2 here. */
    Dwarf_Half version = 2;
    int res = 0;

    /* ***** BEGIN CODE ***** */

    /* Size of the .debug_aranges section header. */
    arange_num_bytes = extension_word_size +
        offset_size +       /* Size of length field.  */
        DWARF_HALF_SIZE +    /* Size of version field. */
        offset_size +            /* Size of .debug_info offset. */
        sizeof(Dwarf_Small) +   /* Size of address size field. */
        sizeof(Dwarf_Small);    /* Size of segment size field. */

    /*  Adjust the size so that the set of aranges
        begins on a boundary
        that aligned with twice the address size.
        This is a Libdwarf requirement. */
    remainder = arange_num_bytes % (2 * upointer_size);
    if (remainder != 0)
        arange_num_bytes += (2 * upointer_size) - remainder;

    /* Add the bytes for the actual address ranges. */
    arange_num_bytes += upointer_size * 2 *
        (dbg->de_arange_count + 1);

    GET_CHUNK(dbg, dbg->de_elf_sects[DEBUG_ARANGES],
        arange, (unsigned long) arange_num_bytes, error);
    arange_ptr = arange;
    if (extension_word_size) {
        DISTINGUISHED_VALUE_ARRAY(v4);
        WRITE_UNALIGNED(dbg, (void *) arange_ptr,
            (const void *)&v4[0] ,
            SIZEOFT32, extension_word_size);
        arange_ptr += extension_word_size;
    }

    /* Write the total length of .debug_aranges section. */
    adjusted_length = arange_num_bytes - offset_size
        - extension_word_size;
    {
        Dwarf_Unsigned du = adjusted_length;

        WRITE_UNALIGNED(dbg, (void *) arange_ptr,
            (const void *) &du, sizeof(du), offset_size);
        arange_ptr += offset_size;
    }

    /* Write the version as 2 bytes. */
    {
        Dwarf_Half verstamp = version;

        WRITE_UNALIGNED(dbg, (void *) arange_ptr,
            (const void *) &verstamp,
            sizeof(verstamp), DWARF_HALF_SIZE);
        arange_ptr += DWARF_HALF_SIZE;
    }

    /* Write the .debug_info offset.  This is always 0. */
    WRITE_UNALIGNED(dbg, (void *) arange_ptr,
        (const void *) &big_zero,
        sizeof(big_zero), offset_size);
    arange_ptr += offset_size;

    {
        unsigned long count = dbg->de_arange_count + 1;
        int res2 = 0;
        Dwarf_P_Per_Reloc_Sect p_reloc =
            &dbg->de_reloc_sect[DEBUG_ARANGES];

        if (dbg->de_relocate_pair_by_symbol) {
            count = (3 * dbg->de_arange_count) + 1;
        }
        /*  The following is a small optimization: not needed for
            correctness.  Does nothing if
            preloc->pr_first_block is non-null */
        res2 = _dwarf_pro_pre_alloc_specific_reloc_slots(dbg,
            p_reloc, count);
        if (res2 != DW_DLV_OK) {
            _dwarf_p_error(dbg, error, DW_DLE_ALLOC_FAIL);
            return DW_DLV_ERROR;
        }
    }

    /* reloc for .debug_info */
    res = dbg->de_relocate_by_name_symbol(dbg,
        DEBUG_ARANGES,
        extension_word_size +
        offset_size + DWARF_HALF_SIZE,
        dbg->de_sect_name_idx[DEBUG_INFO],
        dwarf_drt_data_reloc, offset_size);
    if (res == DW_DLV_NO_ENTRY) {
        return res;
    }
    if (res == DW_DLV_ERROR) {
        _dwarf_p_error(dbg, error,DW_DLE_RELOCS_ERROR);
        return res;
    }

    /* Write the size of addresses. */
    *arange_ptr = dbg->de_pointer_size;
    arange_ptr++;

    /*  Write the size of segment addresses. This is zero for MIPS
        architectures. */
    *arange_ptr = 0;
    arange_ptr++;

    /*  Skip over the padding to align the start of the actual address
        ranges to twice the address size. */
    if (remainder != 0)
        arange_ptr += (2 * upointer_size) - remainder;

    /*  The arange address, length are pointer-size
        fields of the target machine. */
    for (given_arange = dbg->de_arange; given_arange != NULL;
        given_arange = given_arange->ag_next) {

        /* Write relocation record for beginning of address range. */
        res = dbg->de_relocate_by_name_symbol(dbg, DEBUG_ARANGES,
            arange_ptr - arange,       /* r_offset */
            (long) given_arange->ag_symbol_index,
            dwarf_drt_data_reloc, upointer_size);
        if (res != DW_DLV_OK) {
            _dwarf_p_error(dbg, error, DW_DLE_ALLOC_FAIL);
            return DW_DLV_ERROR;
        }

        /* Copy beginning address of range. */
        WRITE_UNALIGNED(dbg, (void *) arange_ptr,
            (const void *) &given_arange->ag_begin_address,
            sizeof(given_arange->ag_begin_address),
            upointer_size);
        arange_ptr += upointer_size;

        if (dbg->de_relocate_pair_by_symbol &&
            given_arange->ag_end_symbol_index != 0 &&
            given_arange->ag_length == 0) {
            /*  Symbolic reloc, need reloc for length
                What if we really
                know the length? If so, should use
                the other part of 'if'. */
            Dwarf_Unsigned val;

            res = dbg->de_relocate_pair_by_symbol(dbg,
                DEBUG_ARANGES,
                arange_ptr - arange,   /* r_offset */
                given_arange->ag_symbol_index,
                given_arange->ag_end_symbol_index,
                dwarf_drt_first_of_length_pair,
                upointer_size);
            if (res != DW_DLV_OK) {
                _dwarf_p_error(dbg, error, DW_DLE_ALLOC_FAIL);
                return DW_DLV_ERROR;
            }

            /*  arange pre-calc so assem text can do .word end - begin
                + val (gets val from stream) */
            val = given_arange->ag_end_symbol_offset -
                given_arange->ag_begin_address;
            WRITE_UNALIGNED(dbg, (void *) arange_ptr,
                (const void *) &val,
                sizeof(val), upointer_size);
            arange_ptr += upointer_size;

        } else {
            /* plain old length to copy, no relocation at all */
            WRITE_UNALIGNED(dbg, (void *) arange_ptr,
                (const void *) &given_arange->ag_length,
                sizeof(given_arange->ag_length),
                upointer_size);
            arange_ptr += upointer_size;
        }
    }

    WRITE_UNALIGNED(dbg, (void *) arange_ptr,
        (const void *) &big_zero,
        sizeof(big_zero), upointer_size);

    arange_ptr += upointer_size;
    WRITE_UNALIGNED(dbg, (void *) arange_ptr,
        (const void *) &big_zero,
        sizeof(big_zero), upointer_size);
    *nbufs =  dbg->de_n_debug_sect;
    return DW_DLV_OK;
}
