xref: /titanic_44/usr/src/tools/ctf/dwarf/common/dwarf_frame.c (revision 07dc1947c362e187fb955d283b692f8769dd5def)

/*

  Copyright (C) 2000-2006 Silicon Graphics, Inc.  All Rights Reserved.
  Portions Copyright (C) 2007-2010 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.

  Contact information:  Silicon Graphics, Inc., 1500 Crittenden Lane,
  Mountain View, CA 94043, or:

  http://www.sgi.com

  For further information regarding this notice, see:

  http://oss.sgi.com/projects/GenInfo/NoticeExplan

*/
/* The address of the Free Software Foundation is
   Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
   Boston, MA 02110-1301, USA.
   SGI has moved from the Crittenden Lane address.
*/





#include "config.h"
#include "dwarf_incl.h"
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include "dwarf_frame.h"
#include "dwarf_arange.h"       /* Using Arange as a way to build a
                                   list */

#define FDE_NULL_CHECKS_AND_SET_DBG(fde,dbg )          \
    do {                                               \
     if ((fde) == NULL) {                              \
        _dwarf_error(NULL, error, DW_DLE_FDE_NULL);    \
        return (DW_DLV_ERROR);                         \
    }                                                  \
    (dbg)= (fde)->fd_dbg;                              \
    if ((dbg) == NULL) {                               \
        _dwarf_error(NULL, error, DW_DLE_FDE_DBG_NULL);\
        return (DW_DLV_ERROR);                         \
    } } while (0)


#define MIN(a,b)  (((a) < (b))? a:b)

static void _dwarf_init_regrule_table(struct Dwarf_Reg_Rule_s *t1reg,
                                      int last_reg_num,
                                      int initial_value);
static int dwarf_initialize_fde_table(Dwarf_Debug dbg,
                                      struct Dwarf_Frame_s *fde_table,
                                      unsigned table_real_data_size,
                                      Dwarf_Error * error);
static void dwarf_free_fde_table(struct Dwarf_Frame_s *fde_table);

#if 0
/* Only used for debugging libdwarf. */
static void dump_frame_rule(char *msg,
                            struct Dwarf_Reg_Rule_s *reg_rule);
#endif



/*
    This function is the heart of the debug_frame stuff.  Don't even
    think of reading this without reading both the Libdwarf and
    consumer API carefully first.  This function basically executes
    frame instructions contained in a Cie or an Fde, but does in a
    number of different ways depending on the information sought.
    Start_instr_ptr points to the first byte of the frame instruction
    stream, and final_instr_ptr to the to the first byte after the
    last.

    The offsets returned in the frame instructions are factored.  That
    is they need to be multiplied by either the code_alignment_factor
    or the data_alignment_factor, as appropriate to obtain the actual
    offset.  This makes it possible to expand an instruction stream
    without the corresponding Cie.  However, when an Fde frame instr
    sequence is being expanded there must be a valid Cie with a pointer
    to an initial table row.


    If successful, returns DW_DLV_OK
                And sets returned_count thru the pointer
                 if make_instr is true.
                If make_instr is false returned_count
                 should NOT be used by the caller (returned_count
                 is set to 0 thru the pointer by this routine...)
    If unsuccessful, returns DW_DLV_ERROR
                and sets returned_error to the error code

    It does not do a whole lot of input validation being a private
    function.  Please make sure inputs are valid.

    (1) If make_instr is true, it makes a list of pointers to
    Dwarf_Frame_Op structures containing the frame instructions
    executed.  A pointer to this list is returned in ret_frame_instr.
    Make_instr is true only when a list of frame instructions is to be
    returned.  In this case since we are not interested in the contents
    of the table, the input Cie can be NULL.  This is the only case
    where the inpute Cie can be NULL.

    (2) If search_pc is true, frame instructions are executed till
    either a location is reached that is greater than the search_pc_val
    provided, or all instructions are executed.  At this point the
    last row of the table generated is returned in a structure.
    A pointer to this structure is supplied in table.

    (3) This function is also used to create the initial table row
    defined by a Cie.  In this case, the Dwarf_Cie pointer cie, is
    NULL.  For an FDE, however, cie points to the associated Cie.

    make_instr - make list of frame instr? 0/1
    ret_frame_instr -  Ptr to list of ptrs to frame instrs
    search_pc  - Search for a pc value?  0/1
     search_pc_val -  Search for this pc value
    initial_loc - Initial code location value.
    start_instr_ptr -   Ptr to start of frame instrs.
    final_instr_ptr -   Ptr just past frame instrs.
    table       -     Ptr to struct with last row.
    cie     -   Ptr to Cie used by the Fde.
       Different cies may have distinct address-sizes, so the cie
       is used, not de_pointer_size.

*/

int
_dwarf_exec_frame_instr(Dwarf_Bool make_instr,
    Dwarf_Frame_Op ** ret_frame_instr,
    Dwarf_Bool search_pc,
    Dwarf_Addr search_pc_val,
    Dwarf_Addr initial_loc,
    Dwarf_Small * start_instr_ptr,
    Dwarf_Small * final_instr_ptr,
    Dwarf_Frame table,
    Dwarf_Cie cie,
    Dwarf_Debug dbg,
    Dwarf_Half reg_num_of_cfa,
    Dwarf_Sword * returned_count,
    int *returned_error)
{
#define ERROR_IF_REG_NUM_TOO_HIGH(macreg,machigh_reg)               \
     do {                                             \
       if ((macreg) >= (machigh_reg) || (macreg) < 0) {            \
        SIMPLE_ERROR_RETURN(DW_DLE_DF_REG_NUM_TOO_HIGH); \
       }                                              \
     } /*CONSTCOND */ while(0)
#define SIMPLE_ERROR_RETURN(code) \
        free(localregtab); \
        *returned_error = code; \
        return DW_DLV_ERROR

    /* Sweeps the frame instructions. */
    Dwarf_Small *instr_ptr;

    /* Register numbers not limited to just 255, thus not using
       Dwarf_Small. */
    typedef int reg_num_type;

    Dwarf_Unsigned factored_N_value;
    Dwarf_Signed signed_factored_N_value;
    Dwarf_Addr current_loc = initial_loc;       /* code location/
                                                   pc-value
                                                   corresponding to the
                                                   frame instructions.
                                                   Starts at zero when
                                                   the caller has no
                                                   value to pass in. */

    /* Must be min de_pointer_size bytes and must be at least sizeof
       Dwarf_ufixed */
    Dwarf_Unsigned adv_loc = 0;

    int reg_count = dbg->de_frame_reg_rules_entry_count;
    struct Dwarf_Reg_Rule_s *localregtab = calloc(reg_count,
                                          sizeof(struct
                                                 Dwarf_Reg_Rule_s));

    struct Dwarf_Reg_Rule_s cfa_reg;


    /* This is used to end executing frame instructions.  */
    /* Becomes true when search_pc is true and current_loc */
    /* is greater than search_pc_val.  */
    Dwarf_Bool search_over = false;

    /* Used by the DW_FRAME_advance_loc instr */
    /* to hold the increment in pc value.  */
    Dwarf_Addr adv_pc;

    /* Contains the length in bytes of */
    /* an leb128 encoded number.  */
    Dwarf_Word leb128_length;

    Dwarf_Half address_size = (cie)? cie->ci_address_size:
        dbg->de_pointer_size;

    /* Counts the number of frame instructions executed.  */
    Dwarf_Word instr_count = 0;

    /*
       These contain the current fields of the current frame
       instruction. */
    Dwarf_Small fp_base_op = 0;
    Dwarf_Small fp_extended_op;
    reg_num_type fp_register;

    /* The value in fp_offset may be signed, though we call it
       unsigned. This works ok for 2-s complement arithmetic. */
    Dwarf_Unsigned fp_offset;
    Dwarf_Off fp_instr_offset;

    /*
       Stack_table points to the row (Dwarf_Frame ie) being pushed or
       popped by a remember or restore instruction. Top_stack points to
       the top of the stack of rows. */
    Dwarf_Frame stack_table = NULL;
    Dwarf_Frame top_stack = NULL;

    /*
       These are used only when make_instr is true. Curr_instr is a
       pointer to the current frame instruction executed.
       Curr_instr_ptr, head_instr_list, and curr_instr_list are used to
       form a chain of Dwarf_Frame_Op structs. Dealloc_instr_ptr is
       used to deallocate the structs used to form the chain.
       Head_instr_block points to a contiguous list of pointers to the
       Dwarf_Frame_Op structs executed. */
    Dwarf_Frame_Op *curr_instr;
    Dwarf_Chain curr_instr_item, dealloc_instr_item;
    Dwarf_Chain head_instr_chain = NULL;
    Dwarf_Chain tail_instr_chain = NULL;
    Dwarf_Frame_Op *head_instr_block;

    /*
       These are the alignment_factors taken from the Cie provided.
       When no input Cie is provided they are set to 1, because only
       factored offsets are required. */
    Dwarf_Sword code_alignment_factor = 1;
    Dwarf_Sword data_alignment_factor = 1;

    /*
       This flag indicates when an actual alignment factor is needed.
       So if a frame instruction that computes an offset using an
       alignment factor is encountered when this flag is set, an error
       is returned because the Cie did not have a valid augmentation. */
    Dwarf_Bool need_augmentation = false;

    Dwarf_Word i;

    /* Initialize first row from associated Cie. Using temp regs
       explicity */

    if (localregtab == 0) {
        SIMPLE_ERROR_RETURN(DW_DLE_ALLOC_FAIL);
    }
    {
        struct Dwarf_Reg_Rule_s *t1reg = localregtab;
        struct Dwarf_Reg_Rule_s *t1end = t1reg + reg_count;

        if (cie != NULL && cie->ci_initial_table != NULL) {
            struct Dwarf_Reg_Rule_s *t2reg =
                cie->ci_initial_table->fr_reg;

            if (reg_count != cie->ci_initial_table->fr_reg_count) {
                /* Should never happen, it makes no sense to have the
                   table sizes change. There is no real allowance for
                   the set of registers to change dynamically in a
                   single Dwarf_Debug (except the size can be set near
                   initial Dwarf_Debug creation time). */
                SIMPLE_ERROR_RETURN
                    (DW_DLE_FRAME_REGISTER_COUNT_MISMATCH);
            }

            for (; t1reg < t1end; t1reg++, t2reg++) {
                *t1reg = *t2reg;
            }
            cfa_reg = cie->ci_initial_table->fr_cfa_rule;
        } else {
            _dwarf_init_regrule_table(t1reg,
                                      reg_count,
                                      dbg->de_frame_rule_initial_value);
            _dwarf_init_regrule_table(&cfa_reg, 1,
                                      dbg->de_frame_rule_initial_value);
        }
    }

    /*
       The idea here is that the code_alignment_factor and
       data_alignment_factor which are needed for certain instructions
       are valid only when the Cie has a proper augmentation string. So
       if the augmentation is not right, only Frame instruction can be
       read. */
    if (cie != NULL && cie->ci_augmentation != NULL) {
        code_alignment_factor = cie->ci_code_alignment_factor;
        data_alignment_factor = cie->ci_data_alignment_factor;
    } else {
        need_augmentation = !make_instr;
    }

    instr_ptr = start_instr_ptr;
    while ((instr_ptr < final_instr_ptr) && (!search_over)) {
        Dwarf_Small instr = 0;
        Dwarf_Small opcode = 0;
        reg_num_type reg_no = 0;

        fp_instr_offset = instr_ptr - start_instr_ptr;
        instr = *(Dwarf_Small *) instr_ptr;
        instr_ptr += sizeof(Dwarf_Small);

        fp_base_op = (instr & 0xc0) >> 6;
        if ((instr & 0xc0) == 0x00) {
            opcode = instr;     /* is really extended op */
            fp_extended_op = (instr & (~(0xc0))) & 0xff;
        } else {
            opcode = instr & 0xc0;      /* is base op */
            fp_extended_op = 0;
        }

        fp_register = 0;
        fp_offset = 0;
        switch (opcode) {
        case DW_CFA_advance_loc:
            {
                /* base op */
                fp_offset = adv_pc = instr & DW_FRAME_INSTR_OFFSET_MASK;

                if (need_augmentation) {
                    SIMPLE_ERROR_RETURN(DW_DLE_DF_NO_CIE_AUGMENTATION);
                }
                adv_pc = adv_pc * code_alignment_factor;

                search_over = search_pc &&
                    (current_loc + adv_pc > search_pc_val);
                /* If gone past pc needed, retain old pc.  */
                if (!search_over) {
                    current_loc = current_loc + adv_pc;
                }
                break;
            }

        case DW_CFA_offset:
            {                   /* base op */
                reg_no =
                    (reg_num_type) (instr & DW_FRAME_INSTR_OFFSET_MASK);
                ERROR_IF_REG_NUM_TOO_HIGH(reg_no, reg_count);

                factored_N_value =
                    _dwarf_decode_u_leb128(instr_ptr, &leb128_length);
                instr_ptr = instr_ptr + leb128_length;

                fp_register = reg_no;
                fp_offset = factored_N_value;

                if (need_augmentation) {
                    SIMPLE_ERROR_RETURN(DW_DLE_DF_NO_CIE_AUGMENTATION);
                }

                localregtab[reg_no].ru_is_off = 1;
                localregtab[reg_no].ru_value_type = DW_EXPR_OFFSET;
                localregtab[reg_no].ru_register = reg_num_of_cfa;
                localregtab[reg_no].ru_offset_or_block_len =
                    factored_N_value * data_alignment_factor;

                break;
            }

        case DW_CFA_restore:
            {                   /* base op */
                reg_no = (instr & DW_FRAME_INSTR_OFFSET_MASK);
                ERROR_IF_REG_NUM_TOO_HIGH(reg_no, reg_count);

                fp_register = reg_no;

                if (cie != NULL && cie->ci_initial_table != NULL)
                    localregtab[reg_no] =
                       cie->ci_initial_table->fr_reg[reg_no];
                else if (!make_instr) {
                    SIMPLE_ERROR_RETURN(DW_DLE_DF_MAKE_INSTR_NO_INIT);
                }

                break;
            }
        case DW_CFA_set_loc:
            {
                Dwarf_Addr new_loc = 0;

                READ_UNALIGNED(dbg, new_loc, Dwarf_Addr,
                               instr_ptr, address_size);
                instr_ptr += address_size;
                if (new_loc != 0 && current_loc != 0) {
                    /* Pre-relocation or before current_loc is set the
                       test comparing new_loc and current_loc makes no
                       sense. Testing for non-zero (above) is a way
                       (fallible) to check that current_loc, new_loc
                       are already relocated.  */
                    if (new_loc <= current_loc) {
                        /* Within a frame, address must increase.
                           Seemingly it has not. Seems to be an error. */

                        SIMPLE_ERROR_RETURN
                            (DW_DLE_DF_NEW_LOC_LESS_OLD_LOC);
                    }
                }

                search_over = search_pc && (new_loc > search_pc_val);

                /* If gone past pc needed, retain old pc.  */
                if (!search_over) {
                    current_loc = new_loc;
                }
                fp_offset = new_loc;
                break;
            }

        case DW_CFA_advance_loc1:
            {
                fp_offset = adv_loc = *(Dwarf_Small *) instr_ptr;
                instr_ptr += sizeof(Dwarf_Small);

                if (need_augmentation) {
                    SIMPLE_ERROR_RETURN(DW_DLE_DF_NO_CIE_AUGMENTATION);
                }
                adv_loc *= code_alignment_factor;

                search_over = search_pc &&
                    (current_loc + adv_loc > search_pc_val);

                /* If gone past pc needed, retain old pc.  */
                if (!search_over) {
                    current_loc = current_loc + adv_loc;
                }
                break;
            }

        case DW_CFA_advance_loc2:
            {
                READ_UNALIGNED(dbg, adv_loc, Dwarf_Unsigned,
                               instr_ptr, sizeof(Dwarf_Half));
                instr_ptr += sizeof(Dwarf_Half);
                fp_offset = adv_loc;

                if (need_augmentation) {
                    SIMPLE_ERROR_RETURN(DW_DLE_DF_NO_CIE_AUGMENTATION);
                }
                adv_loc *= code_alignment_factor;

                search_over = search_pc &&
                    (current_loc + adv_loc > search_pc_val);

                /* If gone past pc needed, retain old pc.  */
                if (!search_over) {
                    current_loc = current_loc + adv_loc;
                }
                break;
            }

        case DW_CFA_advance_loc4:
            {
                READ_UNALIGNED(dbg, adv_loc, Dwarf_Unsigned,
                               instr_ptr, sizeof(Dwarf_ufixed));
                instr_ptr += sizeof(Dwarf_ufixed);
                fp_offset = adv_loc;

                if (need_augmentation) {
                    SIMPLE_ERROR_RETURN(DW_DLE_DF_NO_CIE_AUGMENTATION);
                }
                adv_loc *= code_alignment_factor;

                search_over = search_pc &&
                    (current_loc + adv_loc > search_pc_val);

                /* If gone past pc needed, retain old pc.  */
                if (!search_over) {
                    current_loc = current_loc + adv_loc;
                }
                break;
            }

        case DW_CFA_offset_extended:
            {
                Dwarf_Unsigned lreg;

                DECODE_LEB128_UWORD(instr_ptr, lreg);
                reg_no = (reg_num_type) lreg;
                ERROR_IF_REG_NUM_TOO_HIGH(reg_no, reg_count);;
                factored_N_value =
                    _dwarf_decode_u_leb128(instr_ptr, &leb128_length);
                instr_ptr += leb128_length;

                if (need_augmentation) {
                    SIMPLE_ERROR_RETURN(DW_DLE_DF_NO_CIE_AUGMENTATION);
                }
                localregtab[reg_no].ru_is_off = 1;
                localregtab[reg_no].ru_value_type = DW_EXPR_OFFSET;
                localregtab[reg_no].ru_register = reg_num_of_cfa;
                localregtab[reg_no].ru_offset_or_block_len = factored_N_value *
                    data_alignment_factor;

                fp_register = reg_no;
                fp_offset = factored_N_value;
                break;
            }

        case DW_CFA_restore_extended:
            {
                Dwarf_Unsigned lreg;

                DECODE_LEB128_UWORD(instr_ptr, lreg);
                reg_no = (reg_num_type) lreg;

                ERROR_IF_REG_NUM_TOO_HIGH(reg_no, reg_count);

                if (cie != NULL && cie->ci_initial_table != NULL) {
                    localregtab[reg_no] = cie->ci_initial_table->fr_reg[reg_no];
                } else {
                    if (!make_instr) {
                        SIMPLE_ERROR_RETURN
                            (DW_DLE_DF_MAKE_INSTR_NO_INIT);
                    }
                }

                fp_register = reg_no;
                break;
            }

        case DW_CFA_undefined:
            {
                Dwarf_Unsigned lreg;

                DECODE_LEB128_UWORD(instr_ptr, lreg);
                reg_no = (reg_num_type) lreg;
                ERROR_IF_REG_NUM_TOO_HIGH(reg_no, reg_count);

                localregtab[reg_no].ru_is_off = 0;
                localregtab[reg_no].ru_value_type = DW_EXPR_OFFSET;
                localregtab[reg_no].ru_register =
                    dbg->de_frame_undefined_value_number;
                localregtab[reg_no].ru_offset_or_block_len = 0;

                fp_register = reg_no;
                break;
            }

        case DW_CFA_same_value:
            {
                Dwarf_Unsigned lreg;

                DECODE_LEB128_UWORD(instr_ptr, lreg);
                reg_no = (reg_num_type) lreg;
                ERROR_IF_REG_NUM_TOO_HIGH(reg_no, reg_count);

                localregtab[reg_no].ru_is_off = 0;
                localregtab[reg_no].ru_value_type = DW_EXPR_OFFSET;
                localregtab[reg_no].ru_register =
                    dbg->de_frame_same_value_number;
                localregtab[reg_no].ru_offset_or_block_len = 0;
                fp_register = reg_no;
                break;
            }

        case DW_CFA_register:
            {
                Dwarf_Unsigned lreg;
                reg_num_type reg_noA = 0;
                reg_num_type reg_noB = 0;

                DECODE_LEB128_UWORD(instr_ptr, lreg);
                reg_noA = (reg_num_type) lreg;

                ERROR_IF_REG_NUM_TOO_HIGH(reg_noA, reg_count);

                DECODE_LEB128_UWORD(instr_ptr, lreg);
                reg_noB = (reg_num_type) lreg;

                if (reg_noB > reg_count) {
                    SIMPLE_ERROR_RETURN(DW_DLE_DF_REG_NUM_TOO_HIGH);
                }


                localregtab[reg_noA].ru_is_off = 0;
                localregtab[reg_noA].ru_value_type = DW_EXPR_OFFSET;
                localregtab[reg_noA].ru_register = reg_noB;
                localregtab[reg_noA].ru_offset_or_block_len = 0;

                fp_register = reg_noA;
                fp_offset = reg_noB;
                break;
            }

        case DW_CFA_remember_state:
            {
                stack_table = (Dwarf_Frame)
                    _dwarf_get_alloc(dbg, DW_DLA_FRAME, 1);
                if (stack_table == NULL) {
                    SIMPLE_ERROR_RETURN(DW_DLE_DF_ALLOC_FAIL);
                }

                for (i = 0; i < reg_count; i++)
                    stack_table->fr_reg[i] = localregtab[i];
                stack_table->fr_cfa_rule = cfa_reg;

                if (top_stack != NULL)
                    stack_table->fr_next = top_stack;
                top_stack = stack_table;

                break;
            }

        case DW_CFA_restore_state:
            {
                if (top_stack == NULL) {
                    SIMPLE_ERROR_RETURN(DW_DLE_DF_POP_EMPTY_STACK);
                }
                stack_table = top_stack;
                top_stack = stack_table->fr_next;

                for (i = 0; i < reg_count; i++)
                    localregtab[i] = stack_table->fr_reg[i];
                cfa_reg = stack_table->fr_cfa_rule;

                dwarf_dealloc(dbg, stack_table, DW_DLA_FRAME);
                break;
            }

        case DW_CFA_def_cfa:
            {
                Dwarf_Unsigned lreg;

                DECODE_LEB128_UWORD(instr_ptr, lreg);
                reg_no = (reg_num_type) lreg;

                ERROR_IF_REG_NUM_TOO_HIGH(reg_no, reg_count);

                factored_N_value =
                    _dwarf_decode_u_leb128(instr_ptr, &leb128_length);
                instr_ptr += leb128_length;

                if (need_augmentation) {
                    SIMPLE_ERROR_RETURN(DW_DLE_DF_NO_CIE_AUGMENTATION);
                }
                cfa_reg.ru_is_off = 1;
                cfa_reg.ru_value_type = DW_EXPR_OFFSET;
                cfa_reg.ru_register = reg_no;
                cfa_reg.ru_offset_or_block_len = factored_N_value;

                fp_register = reg_no;
                fp_offset = factored_N_value;
                break;
            }

        case DW_CFA_def_cfa_register:
            {
                Dwarf_Unsigned lreg;

                DECODE_LEB128_UWORD(instr_ptr, lreg);
                reg_no = (reg_num_type) lreg;
                ERROR_IF_REG_NUM_TOO_HIGH(reg_no, reg_count);

                cfa_reg.ru_register = reg_no;
                /* Do NOT set ru_offset_or_block_len or ru_is_off here.
                   See dwarf2/3 spec.  */
                fp_register = reg_no;
                break;
            }

        case DW_CFA_def_cfa_offset:
            {
                factored_N_value =
                    _dwarf_decode_u_leb128(instr_ptr, &leb128_length);
                instr_ptr += leb128_length;

                if (need_augmentation) {
                    SIMPLE_ERROR_RETURN(DW_DLE_DF_NO_CIE_AUGMENTATION);
                }
                /* Do set ru_is_off here, as here factored_N_value
                   counts.  */
                cfa_reg.ru_is_off = 1;
                cfa_reg.ru_value_type = DW_EXPR_OFFSET;
                cfa_reg.ru_offset_or_block_len = factored_N_value;

                fp_offset = factored_N_value;
                break;
            }
        case DW_CFA_nop:
            {
                break;
            }
            /* DWARF3 ops begin here. */
        case DW_CFA_def_cfa_expression:
            {
                /* A single DW_FORM_block representing a dwarf
                   expression. The form block establishes the way to
                   compute the CFA. */
                Dwarf_Unsigned block_len = 0;

                DECODE_LEB128_UWORD(instr_ptr, block_len);
                cfa_reg.ru_is_off = 0;  /* arbitrary */
                cfa_reg.ru_value_type = DW_EXPR_EXPRESSION;
                cfa_reg.ru_offset_or_block_len = block_len;
                cfa_reg.ru_block = instr_ptr;
                fp_offset = (Dwarf_Unsigned)(uintptr_t)instr_ptr;
                instr_ptr += block_len;
            }
            break;
        case DW_CFA_expression:
            {
                /* An unsigned leb128 value is the first operand (a
                   register number). The second operand is single
                   DW_FORM_block representing a dwarf expression. The
                   evaluator pushes the CFA on the evaluation stack
                   then evaluates the expression to compute the value
                   of the register contents. */
                Dwarf_Unsigned lreg = 0;
                Dwarf_Unsigned block_len = 0;

                DECODE_LEB128_UWORD(instr_ptr, lreg);
                reg_no = (reg_num_type) lreg;
                ERROR_IF_REG_NUM_TOO_HIGH(reg_no, reg_count);
                DECODE_LEB128_UWORD(instr_ptr, block_len);
                localregtab[lreg].ru_is_off = 0;        /* arbitrary */
                localregtab[lreg].ru_value_type = DW_EXPR_EXPRESSION;
                localregtab[lreg].ru_offset_or_block_len = block_len;
                localregtab[lreg].ru_block = instr_ptr;
                fp_offset = (Dwarf_Unsigned)(uintptr_t)instr_ptr;
                fp_register = reg_no;
                instr_ptr += block_len;
            }
            break;
        case DW_CFA_offset_extended_sf:
            {
                /* The first operand is an unsigned leb128 register
                   number. The second is a signed factored offset.
                   Identical to DW_CFA_offset_extended except the
                   secondoperand is signed */
                Dwarf_Unsigned lreg;

                DECODE_LEB128_UWORD(instr_ptr, lreg);
                reg_no = (reg_num_type) lreg;
                ERROR_IF_REG_NUM_TOO_HIGH(reg_no, reg_count);
                signed_factored_N_value =
                    _dwarf_decode_s_leb128(instr_ptr, &leb128_length);
                instr_ptr += leb128_length;

                if (need_augmentation) {
                    SIMPLE_ERROR_RETURN(DW_DLE_DF_NO_CIE_AUGMENTATION);
                }
                localregtab[reg_no].ru_is_off = 1;
                localregtab[reg_no].ru_value_type = DW_EXPR_OFFSET;
                localregtab[reg_no].ru_register = reg_num_of_cfa;
                localregtab[reg_no].ru_offset_or_block_len =
                    signed_factored_N_value * data_alignment_factor;

                fp_register = reg_no;
                fp_offset = signed_factored_N_value;
            }
            break;
        case DW_CFA_def_cfa_sf:
            {
                /* The first operand is an unsigned leb128 register
                   number. The second is a signed leb128 factored
                   offset. Identical to DW_CFA_def_cfa except that the
                   second operand is signed and factored. */
                Dwarf_Unsigned lreg;

                DECODE_LEB128_UWORD(instr_ptr, lreg);
                reg_no = (reg_num_type) lreg;
                ERROR_IF_REG_NUM_TOO_HIGH(reg_no, reg_count);

                signed_factored_N_value =
                    _dwarf_decode_s_leb128(instr_ptr, &leb128_length);
                instr_ptr += leb128_length;

                if (need_augmentation) {
                    SIMPLE_ERROR_RETURN(DW_DLE_DF_NO_CIE_AUGMENTATION);
                }
                cfa_reg.ru_is_off = 1;
                cfa_reg.ru_value_type = DW_EXPR_OFFSET;
                cfa_reg.ru_register = reg_no;
                cfa_reg.ru_offset_or_block_len =
                    signed_factored_N_value * data_alignment_factor;

                fp_register = reg_no;
                fp_offset = signed_factored_N_value;
            }
            break;
        case DW_CFA_def_cfa_offset_sf:
            {
                /* The operand is a signed leb128 operand representing
                   a factored offset.  Identical to
                   DW_CFA_def_cfa_offset excep the operand is signed
                   and factored. */

                signed_factored_N_value =
                    _dwarf_decode_s_leb128(instr_ptr, &leb128_length);
                instr_ptr += leb128_length;

                if (need_augmentation) {
                    SIMPLE_ERROR_RETURN(DW_DLE_DF_NO_CIE_AUGMENTATION);
                }
                /* Do set ru_is_off here, as here factored_N_value
                   counts.  */
                cfa_reg.ru_is_off = 1;
                cfa_reg.ru_value_type = DW_EXPR_OFFSET;
                cfa_reg.ru_offset_or_block_len =
                    signed_factored_N_value * data_alignment_factor;

                fp_offset = signed_factored_N_value;
            }
            break;
        case DW_CFA_val_offset:
            {
                /* The first operand is an unsigned leb128 register
                   number. The second is a factored unsigned offset.
                   Makes the register be a val_offset(N) rule with N =
                   factored_offset*data_alignment_factor. */

                Dwarf_Unsigned lreg;

                DECODE_LEB128_UWORD(instr_ptr, lreg);
                reg_no = (reg_num_type) lreg;

                ERROR_IF_REG_NUM_TOO_HIGH(reg_no, reg_count);

                factored_N_value =
                    _dwarf_decode_u_leb128(instr_ptr, &leb128_length);
                instr_ptr += leb128_length;

                if (need_augmentation) {
                    SIMPLE_ERROR_RETURN(DW_DLE_DF_NO_CIE_AUGMENTATION);
                }
                /* Do set ru_is_off here, as here factored_N_value
                   counts.  */
                localregtab[reg_no].ru_is_off = 1;
                localregtab[reg_no].ru_register = reg_num_of_cfa;
                localregtab[reg_no].ru_value_type = DW_EXPR_VAL_OFFSET;
                localregtab[reg_no].ru_offset_or_block_len =
                    factored_N_value * data_alignment_factor;

                fp_offset = factored_N_value;
                break;
            }
        case DW_CFA_val_offset_sf:
            {
                /* The first operand is an unsigned leb128 register
                   number. The second is a factored signed offset.
                   Makes the register be a val_offset(N) rule with N =
                   factored_offset*data_alignment_factor. */
                Dwarf_Unsigned lreg;

                DECODE_LEB128_UWORD(instr_ptr, lreg);
                reg_no = (reg_num_type) lreg;

                ERROR_IF_REG_NUM_TOO_HIGH(reg_no, reg_count);
                signed_factored_N_value =
                    _dwarf_decode_s_leb128(instr_ptr, &leb128_length);
                instr_ptr += leb128_length;

                if (need_augmentation) {
                    SIMPLE_ERROR_RETURN(DW_DLE_DF_NO_CIE_AUGMENTATION);
                }
                /* Do set ru_is_off here, as here factored_N_value
                   counts.  */
                localregtab[reg_no].ru_is_off = 1;
                localregtab[reg_no].ru_value_type = DW_EXPR_VAL_OFFSET;
                localregtab[reg_no].ru_offset_or_block_len =
                    signed_factored_N_value * data_alignment_factor;

                fp_offset = signed_factored_N_value;

            }
            break;
        case DW_CFA_val_expression:
            {
                /* The first operand is an unsigned leb128 register
                   number. The second is a DW_FORM_block representing a
                   DWARF expression. The rule for the register number
                   becomes a val_expression(E) rule. */
                Dwarf_Unsigned lreg = 0;
                Dwarf_Unsigned block_len = 0;

                DECODE_LEB128_UWORD(instr_ptr, lreg);
                reg_no = (reg_num_type) lreg;
                ERROR_IF_REG_NUM_TOO_HIGH(reg_no, reg_count);
                DECODE_LEB128_UWORD(instr_ptr, block_len);
                localregtab[lreg].ru_is_off = 0;        /* arbitrary */
                localregtab[lreg].ru_value_type = DW_EXPR_VAL_EXPRESSION;
                localregtab[lreg].ru_offset_or_block_len = block_len;
                localregtab[lreg].ru_block = instr_ptr;
                fp_offset = (Dwarf_Unsigned)(uintptr_t)instr_ptr;

                instr_ptr += block_len;
                fp_register = reg_no;

            }
            break;

            /* END DWARF3 new ops. */


#ifdef DW_CFA_GNU_window_save
        case DW_CFA_GNU_window_save:
            {
                /* no information: this just tells unwinder to restore
                   the window registers from the previous frame's
                   window save area */
                break;
            }
#endif
#ifdef  DW_CFA_GNU_args_size
            /* single uleb128 is the current arg area size in bytes. No
               register exists yet to save this in */
        case DW_CFA_GNU_args_size:
            {
                Dwarf_Unsigned lreg;

                DECODE_LEB128_UWORD(instr_ptr, lreg);
                reg_no = (reg_num_type) lreg;

                break;
            }
#endif
        default:
            /* ERROR, we have an opcode we know nothing about. Memory
               leak here, but an error like this is not supposed to
               happen so we ignore the leak. These used to be ignored,
               now we notice and report. */
            SIMPLE_ERROR_RETURN(DW_DLE_DF_FRAME_DECODING_ERROR);

        }

        if (make_instr) {
            instr_count++;

            curr_instr = (Dwarf_Frame_Op *)
                _dwarf_get_alloc(dbg, DW_DLA_FRAME_OP, 1);
            if (curr_instr == NULL) {
                SIMPLE_ERROR_RETURN(DW_DLE_DF_ALLOC_FAIL);
            }

            curr_instr->fp_base_op = fp_base_op;
            curr_instr->fp_extended_op = fp_extended_op;
            curr_instr->fp_register = fp_register;
            curr_instr->fp_offset = fp_offset;
            curr_instr->fp_instr_offset = fp_instr_offset;

            curr_instr_item = (Dwarf_Chain)
                _dwarf_get_alloc(dbg, DW_DLA_CHAIN, 1);
            if (curr_instr_item == NULL) {
                SIMPLE_ERROR_RETURN(DW_DLE_DF_ALLOC_FAIL);
            }

            curr_instr_item->ch_item = curr_instr;
            if (head_instr_chain == NULL)
                head_instr_chain = tail_instr_chain = curr_instr_item;
            else {
                tail_instr_chain->ch_next = curr_instr_item;
                tail_instr_chain = curr_instr_item;
            }
        }
    }

    /*
       If frame instruction decoding was right we would stop exactly at
       final_instr_ptr. */
    if (instr_ptr > final_instr_ptr) {
        SIMPLE_ERROR_RETURN(DW_DLE_DF_FRAME_DECODING_ERROR);
    }

    /* Fill in the actual output table, the space the caller passed in. */
    if (table != NULL) {

        struct Dwarf_Reg_Rule_s *t2reg = table->fr_reg;
        struct Dwarf_Reg_Rule_s *t3reg = localregtab;
        struct Dwarf_Reg_Rule_s *t3end = t3reg + reg_count;

        table->fr_loc = current_loc;
        for (; t3reg < t3end; t3reg++, t2reg++) {
            *t2reg = *t3reg;
        }

        /* CONSTCOND */
        /* Do not update the main table with the cfa_reg.
           Just leave cfa_reg as cfa_reg. */
        table->fr_cfa_rule = cfa_reg;
    }

    /* Dealloc anything remaining on stack. */
    for (; top_stack != NULL;) {
        stack_table = top_stack;
        top_stack = top_stack->fr_next;
        dwarf_dealloc(dbg, stack_table, DW_DLA_FRAME);
    }

    if (make_instr) {
        /* Allocate list of pointers to Dwarf_Frame_Op's.  */
        head_instr_block = (Dwarf_Frame_Op *)
            _dwarf_get_alloc(dbg, DW_DLA_FRAME_BLOCK, instr_count);
        if (head_instr_block == NULL) {
            SIMPLE_ERROR_RETURN(DW_DLE_DF_ALLOC_FAIL);
        }

        /*
           Store pointers to Dwarf_Frame_Op's in this list and
           deallocate the structs that chain the Dwarf_Frame_Op's. */
        curr_instr_item = head_instr_chain;
        for (i = 0; i < instr_count; i++) {
            *(head_instr_block + i) =
                *(Dwarf_Frame_Op *) curr_instr_item->ch_item;
            dealloc_instr_item = curr_instr_item;
            curr_instr_item = curr_instr_item->ch_next;
            dwarf_dealloc(dbg, dealloc_instr_item->ch_item,
                          DW_DLA_FRAME_OP);
            dwarf_dealloc(dbg, dealloc_instr_item, DW_DLA_CHAIN);
        }
        *ret_frame_instr = head_instr_block;

        *returned_count = (Dwarf_Sword) instr_count;
    } else {
        *returned_count = 0;
    }
    free(localregtab);
    return DW_DLV_OK;
#undef ERROR_IF_REG_NUM_TOO_HIGH
#undef SIMPLE_ERROR_RETURN
}

/*  Depending on version, either read the return address register
    as a ubyte or as an leb number.
    The form of this value changed for DWARF3.
*/
Dwarf_Unsigned
_dwarf_get_return_address_reg(Dwarf_Small * frame_ptr,
    int version, unsigned long *size)
{
    Dwarf_Unsigned uvalue = 0;
    Dwarf_Word leb128_length = 0;

    if (version == 1) {
        *size = 1;
        uvalue = *(unsigned char *) frame_ptr;
        return uvalue;
    }
    uvalue = _dwarf_decode_u_leb128(frame_ptr, &leb128_length);
    *size = leb128_length;
    return uvalue;
}


/* Trivial consumer function.
*/
int
dwarf_get_cie_of_fde(Dwarf_Fde fde,
    Dwarf_Cie * cie_returned, Dwarf_Error * error)
{
    if (fde == NULL) {
        _dwarf_error(NULL, error, DW_DLE_FDE_NULL);
        return (DW_DLV_ERROR);
    }

    *cie_returned = fde->fd_cie;
    return DW_DLV_OK;

}

int dwarf_get_cie_index(
    Dwarf_Cie cie,
    Dwarf_Signed* index,
    Dwarf_Error* error )
{
    if( cie == NULL )
    {
        _dwarf_error(NULL, error, DW_DLE_CIE_NULL);
        return (DW_DLV_ERROR);
    }

    *index = cie->ci_index;
    return (DW_DLV_OK);
}


/*
  For g++ .eh_frame fde and cie.
  the cie id is different as the
  definition of the cie_id in an fde
        is the distance back from the address of the
        value to the cie.
  Or 0 if this is a true cie.
  Non standard dwarf, designed this way to be
  convenient at run time for an allocated
  (mapped into memory as part of the running image) section.
*/
int
dwarf_get_fde_list_eh(Dwarf_Debug dbg,
    Dwarf_Cie ** cie_data,
    Dwarf_Signed * cie_element_count,
    Dwarf_Fde ** fde_data,
    Dwarf_Signed * fde_element_count,
    Dwarf_Error * error)
{
    int res = _dwarf_load_section(dbg, &dbg->de_debug_frame_eh_gnu,error);
    if (res != DW_DLV_OK) {
        return res;
    }

    res = _dwarf_get_fde_list_internal(dbg,
        cie_data,
        cie_element_count,
        fde_data,
        fde_element_count,
        dbg->de_debug_frame_eh_gnu.dss_data,
        dbg->de_debug_frame_eh_gnu.dss_index,
        dbg->de_debug_frame_eh_gnu.dss_size,
        /* cie_id_value */ 0,
        /* use_gnu_cie_calc= */ 1,
        error);
    return res;
}



/*
  For standard dwarf .debug_frame
  cie_id is -1  in a cie, and
  is the section offset in the .debug_frame section
  of the cie otherwise.  Standard dwarf
*/
int
dwarf_get_fde_list(Dwarf_Debug dbg,
    Dwarf_Cie ** cie_data,
    Dwarf_Signed * cie_element_count,
    Dwarf_Fde ** fde_data,
    Dwarf_Signed * fde_element_count,
    Dwarf_Error * error)
{
    int res = _dwarf_load_section(dbg, &dbg->de_debug_frame,error);
    if (res != DW_DLV_OK) {
        return res;
    }

    res = _dwarf_get_fde_list_internal(dbg, cie_data,
        cie_element_count,
        fde_data,
        fde_element_count,
        dbg->de_debug_frame.dss_data,
        dbg->de_debug_frame.dss_index,
        dbg->de_debug_frame.dss_size,
        DW_CIE_ID,
        /* use_gnu_cie_calc= */ 0,
        error);

    return res;
}


/*
   Only works on dwarf sections, not eh_frame
   Given a Dwarf_Die, see if it has a
   DW_AT_MIPS_fde attribute and if so use that
   to get an fde offset.
   Then create a Dwarf_Fde to return thru the ret_fde pointer.
   Also creates a cie (pointed at from the Dwarf_Fde).
*/
int
dwarf_get_fde_for_die(Dwarf_Debug dbg,
    Dwarf_Die die,
    Dwarf_Fde * ret_fde, Dwarf_Error * error)
{
    Dwarf_Attribute attr;
    Dwarf_Unsigned fde_offset = 0;
    Dwarf_Signed signdval = 0;
    Dwarf_Fde new_fde = 0;
    unsigned char *fde_ptr = 0;
    unsigned char *cie_ptr = 0;
    Dwarf_Unsigned cie_id = 0;

    /* Fields for the current Cie being read. */
    int res = 0;
    int resattr = 0;
    int sdatares = 0;

    struct cie_fde_prefix_s prefix;
    struct cie_fde_prefix_s prefix_c;

    if (die == NULL) {
        _dwarf_error(NULL, error, DW_DLE_DIE_NULL);
        return (DW_DLV_ERROR);
    }

    resattr = dwarf_attr(die, DW_AT_MIPS_fde, &attr, error);
    if (resattr != DW_DLV_OK) {
        return resattr;
    }

    /* why is this formsdata? FIX */
    sdatares = dwarf_formsdata(attr, &signdval, error);
    if (sdatares != DW_DLV_OK) {
        return sdatares;
    }

    res = _dwarf_load_section(dbg, &dbg->de_debug_frame,error);
    if (res != DW_DLV_OK) {
        return res;
    }

    fde_offset = signdval;
    fde_ptr = (dbg->de_debug_frame.dss_data + fde_offset);


    /* First read in the 'common prefix' to figure out what * we are to
       do with this entry. */
    memset(&prefix_c, 0, sizeof(prefix_c));
    memset(&prefix, 0, sizeof(prefix));
    res = dwarf_read_cie_fde_prefix(dbg, fde_ptr,
        dbg->de_debug_frame.dss_data,
        dbg->de_debug_frame.dss_index,
        dbg->de_debug_frame.dss_size,
        &prefix,
        error);
    if (res == DW_DLV_ERROR) {
        return res;
    }
    if (res == DW_DLV_NO_ENTRY)
        return res;
    fde_ptr = prefix.cf_addr_after_prefix;
    cie_id = prefix.cf_cie_id;
    /* Pass NULL, not section pointer, for 3rd argument.
       de_debug_frame.dss_data has no eh_frame relevance. */
    res = dwarf_create_fde_from_after_start(dbg, &prefix,
        (Dwarf_Small *) NULL,
        fde_ptr,
        /* use_gnu_cie_calc= */ 0,
        /* Dwarf_Cie = */ 0,
        &new_fde, error);
    if (res == DW_DLV_ERROR) {
        return res;
    } else if (res == DW_DLV_NO_ENTRY) {
        return res;
    }
    /* DW_DLV_OK */

    /* now read the cie corresponding to the fde */
    cie_ptr = new_fde->fd_section_ptr + cie_id;
    res = dwarf_read_cie_fde_prefix(dbg, cie_ptr,
        dbg->de_debug_frame.dss_data,
        dbg->de_debug_frame.dss_index,
        dbg->de_debug_frame.dss_size,
        &prefix_c, error);
    if (res == DW_DLV_ERROR) {
        return res;
    }
    if (res == DW_DLV_NO_ENTRY)
        return res;

    cie_ptr = prefix_c.cf_addr_after_prefix;
    cie_id = prefix_c.cf_cie_id;

    if (cie_id == DW_CIE_ID) {
        int res2 = 0;
        Dwarf_Cie new_cie = 0;

        /* Pass NULL, not section pointer, for 3rd argument.
           de_debug_frame.dss_data has no eh_frame relevance. */
        res2 = dwarf_create_cie_from_after_start(dbg,
            &prefix_c,
            (Dwarf_Small *) NULL,
            cie_ptr,
            /* cie_count= */ 0,
            /* use_gnu_cie_calc= */
            0, &new_cie, error);
        if (res2 == DW_DLV_ERROR) {
            dwarf_dealloc(dbg, new_fde, DW_DLA_FDE);
            return res;
        } else if (res2 == DW_DLV_NO_ENTRY) {
            dwarf_dealloc(dbg, new_fde, DW_DLA_FDE);
            return res;
        }
        new_fde->fd_cie = new_cie;
    } else {
        _dwarf_error(dbg, error, DW_DLE_NO_CIE_FOR_FDE);
        return (DW_DLV_ERROR);
    }

    *ret_fde = new_fde;
    return DW_DLV_OK;
}

/* A dwarf consumer operation, see the consumer library documentation.
*/
int
dwarf_get_fde_range(Dwarf_Fde fde,
    Dwarf_Addr * low_pc,
    Dwarf_Unsigned * func_length,
    Dwarf_Ptr * fde_bytes,
    Dwarf_Unsigned * fde_byte_length,
    Dwarf_Off * cie_offset,
    Dwarf_Signed * cie_index,
    Dwarf_Off * fde_offset, Dwarf_Error * error)
{
    Dwarf_Debug dbg;

    if (fde == NULL) {
        _dwarf_error(NULL, error, DW_DLE_FDE_NULL);
        return (DW_DLV_ERROR);
    }

    dbg = fde->fd_dbg;
    if (dbg == NULL) {
        _dwarf_error(NULL, error, DW_DLE_FDE_DBG_NULL);
        return (DW_DLV_ERROR);
    }


    /* We have always already done the section load here, so no need to
       load the section. We did the section load in order to create the
       Dwarf_Fde pointer passed in here. */


    if (low_pc != NULL)
        *low_pc = fde->fd_initial_location;
    if (func_length != NULL)
        *func_length = fde->fd_address_range;
    if (fde_bytes != NULL)
        *fde_bytes = fde->fd_fde_start;
    if (fde_byte_length != NULL)
        *fde_byte_length = fde->fd_length;
    if (cie_offset != NULL)
        *cie_offset = fde->fd_cie_offset;
    if (cie_index != NULL)
        *cie_index = fde->fd_cie_index;
    if (fde_offset != NULL)
        *fde_offset = fde->fd_fde_start - fde->fd_section_ptr;

    return DW_DLV_OK;
}

/* IRIX specific function.   The exception tables
   have C++ destructor information and are
   at present undocumented.  */
int
dwarf_get_fde_exception_info(Dwarf_Fde fde,
    Dwarf_Signed *
    offset_into_exception_tables,
    Dwarf_Error * error)
{
    Dwarf_Debug dbg;

    dbg = fde->fd_dbg;
    if (dbg == NULL) {
        _dwarf_error(NULL, error, DW_DLE_FDE_DBG_NULL);
        return (DW_DLV_ERROR);
    }
    *offset_into_exception_tables =
        fde->fd_offset_into_exception_tables;
    return DW_DLV_OK;
}


/* A consumer code function.
   Given a CIE pointer, return the normal CIE data thru
   pointers.
   Special augmentation data is not returned here.
*/
int
dwarf_get_cie_info(Dwarf_Cie cie,
    Dwarf_Unsigned * bytes_in_cie,
    Dwarf_Small * ptr_to_version,
    char **augmenter,
    Dwarf_Unsigned * code_alignment_factor,
    Dwarf_Signed * data_alignment_factor,
    Dwarf_Half * return_address_register,
    Dwarf_Ptr * initial_instructions,
    Dwarf_Unsigned * initial_instructions_length,
    Dwarf_Error * error)
{
    Dwarf_Debug dbg;

    if (cie == NULL) {
        _dwarf_error(NULL, error, DW_DLE_CIE_NULL);
        return (DW_DLV_ERROR);
    }

    dbg = cie->ci_dbg;
    if (dbg == NULL) {
        _dwarf_error(NULL, error, DW_DLE_CIE_DBG_NULL);
        return (DW_DLV_ERROR);
    }

    if (ptr_to_version != NULL)
        *ptr_to_version = cie->ci_cie_version_number;
    if (augmenter != NULL)
        *augmenter = cie->ci_augmentation;
    if (code_alignment_factor != NULL)
        *code_alignment_factor = cie->ci_code_alignment_factor;
    if (data_alignment_factor != NULL)
        *data_alignment_factor = cie->ci_data_alignment_factor;
    if (return_address_register != NULL)
        *return_address_register = cie->ci_return_address_register;
    if (initial_instructions != NULL)
        *initial_instructions = cie->ci_cie_instr_start;
    if (initial_instructions_length != NULL) {
        *initial_instructions_length = cie->ci_length +
            cie->ci_length_size +
            cie->ci_extension_size -
            (cie->ci_cie_instr_start - cie->ci_cie_start);

    }
    *bytes_in_cie = (cie->ci_length);
    return (DW_DLV_OK);
}

/* Return the register rules for all registers at a given pc.
*/
static int
_dwarf_get_fde_info_for_a_pc_row(Dwarf_Fde fde,
    Dwarf_Addr pc_requested,
    Dwarf_Frame table,
    Dwarf_Half cfa_reg_col_num,
    Dwarf_Error * error)
{
    Dwarf_Debug dbg = 0;
    Dwarf_Cie cie = 0;
    int dw_err = 0;
    Dwarf_Sword icount = 0;
    int res = 0;

    if (fde == NULL) {
        _dwarf_error(NULL, error, DW_DLE_FDE_NULL);
        return (DW_DLV_ERROR);
    }

    dbg = fde->fd_dbg;
    if (dbg == NULL) {
        _dwarf_error(NULL, error, DW_DLE_FDE_DBG_NULL);
        return (DW_DLV_ERROR);
    }

    if (pc_requested < fde->fd_initial_location ||
        pc_requested >=
        fde->fd_initial_location + fde->fd_address_range) {
        _dwarf_error(dbg, error, DW_DLE_PC_NOT_IN_FDE_RANGE);
        return (DW_DLV_ERROR);
    }

    cie = fde->fd_cie;
    if (cie->ci_initial_table == NULL) {
        cie->ci_initial_table = _dwarf_get_alloc(dbg, DW_DLA_FRAME, 1);

        if (cie->ci_initial_table == NULL) {
            _dwarf_error(dbg, error, DW_DLE_ALLOC_FAIL);
            return (DW_DLV_ERROR);
        }
        _dwarf_init_regrule_table(cie->ci_initial_table->fr_reg,
            dbg->de_frame_reg_rules_entry_count,
            dbg->de_frame_rule_initial_value);
        _dwarf_init_regrule_table(&cie->ci_initial_table->fr_cfa_rule,
            1, dbg->de_frame_rule_initial_value);
        res = _dwarf_exec_frame_instr( /* make_instr= */ false,
            /* ret_frame_instr= */ NULL,
            /* search_pc */ false,
            /* search_pc_val */ 0,
            /* location */ 0,
            cie->ci_cie_instr_start,
            cie->ci_cie_instr_start + (cie->ci_length +
                cie->ci_length_size +
                cie->ci_extension_size -
                (cie->ci_cie_instr_start -
                cie->ci_cie_start)),
            cie->ci_initial_table, cie, dbg,
            cfa_reg_col_num, &icount,
            &dw_err);
        if (res == DW_DLV_ERROR) {
            _dwarf_error(dbg, error, dw_err);
            return (res);
        } else if (res == DW_DLV_NO_ENTRY) {
            return res;
        }
    }

    {
        Dwarf_Small *instr_end = fde->fd_fde_instr_start +
            fde->fd_length +
            fde->fd_length_size +
            fde->fd_extension_size - (fde->fd_fde_instr_start -
                                      fde->fd_fde_start);

        res = _dwarf_exec_frame_instr( /* make_instr= */ false,
            /* ret_frame_instr= */ NULL,
            /* search_pc */ true,
            /* search_pc_val */ pc_requested,
            fde->fd_initial_location,
            fde->fd_fde_instr_start,
            instr_end,
            table,
            cie, dbg,
            cfa_reg_col_num, &icount,
            &dw_err);
    }
    if (res == DW_DLV_ERROR) {
        _dwarf_error(dbg, error, dw_err);
        return (res);
    } else if (res == DW_DLV_NO_ENTRY) {
        return res;
    }

    return DW_DLV_OK;
}

/* A consumer call for efficiently getting the register info
   for all registers in one call.

   The output table rules array is size DW_REG_TABLE_SIZE.
   The frame info  rules array in fde_table is of size
   DW_REG_TABLE_SIZE too.

   This interface  really only works well with MIPS/IRIX
   where DW_FRAME_CFA_COL is zero (in that case it's safe).

   It is also restricted to the case  where
   DW_REG_TABLE_SIZE == DW_FRAME_LAST_REG_NUM  ==
   dbg->de_frame_reg_rules_entry_count (true for MIPS/IRIX).
   If this condition is not met calling this routine can result in
   incorrect output or in memory corruption.

   It is much better to use dwarf_get_fde_info_for_all_regs3()
   instead of this interface.
*/
int
dwarf_get_fde_info_for_all_regs(Dwarf_Fde fde,
    Dwarf_Addr pc_requested,
    Dwarf_Regtable * reg_table,
    Dwarf_Addr * row_pc,
    Dwarf_Error * error)
{

    /* Table size: DW_REG_TABLE_SIZE */
    struct Dwarf_Frame_s fde_table;
    Dwarf_Sword i = 0;
    struct Dwarf_Reg_Rule_s *rule = NULL;
    struct Dwarf_Regtable_Entry_s *out_rule = NULL;
    int res = 0;
    Dwarf_Debug dbg = 0;

    /* For this interface the size is fixed at compile time. */
    int output_table_real_data_size = DW_REG_TABLE_SIZE;

    FDE_NULL_CHECKS_AND_SET_DBG(fde, dbg);

    res = dwarf_initialize_fde_table(dbg, &fde_table,
        output_table_real_data_size,
        error);
    if (res != DW_DLV_OK)
        return res;

    /* _dwarf_get_fde_info_for_a_pc_row will perform more sanity checks
     */
    res = _dwarf_get_fde_info_for_a_pc_row(fde, pc_requested,
        &fde_table, dbg->de_frame_cfa_col_number, error);
    if (res != DW_DLV_OK) {
        dwarf_free_fde_table(&fde_table);
        return res;
    }

    out_rule = &reg_table->rules[0];
    rule = &fde_table.fr_reg[0];
    for (i = 0; i < output_table_real_data_size;
         i++, ++out_rule, ++rule) {
        out_rule->dw_offset_relevant = rule->ru_is_off;
        out_rule->dw_value_type = rule->ru_value_type;
        out_rule->dw_regnum = rule->ru_register;
        out_rule->dw_offset = rule->ru_offset_or_block_len;
    }
    for (; i < DW_REG_TABLE_SIZE; ++i, ++out_rule) {
        out_rule->dw_offset_relevant = 0;
        out_rule->dw_value_type = DW_EXPR_OFFSET;
        out_rule->dw_regnum = dbg->de_frame_undefined_value_number;
        out_rule->dw_offset = 0;
    }

    /* The test is just in case it's not inside the table. For non-MIPS
       it could be outside the table and that is just fine, it was
       really a mistake to put it in the table in 1993.  */
    /* CONSTCOND */
    if (dbg->de_frame_cfa_col_number < DW_REG_TABLE_SIZE) {
        out_rule = &reg_table->rules[dbg->de_frame_cfa_col_number];
        out_rule->dw_offset_relevant = fde_table.fr_cfa_rule.ru_is_off;
        out_rule->dw_value_type = fde_table.fr_cfa_rule.ru_value_type;
        out_rule->dw_regnum = fde_table.fr_cfa_rule.ru_register;
        out_rule->dw_offset =
            fde_table.fr_cfa_rule.ru_offset_or_block_len;
    }

    if (row_pc != NULL)
        *row_pc = fde_table.fr_loc;
    dwarf_free_fde_table(&fde_table);
    return DW_DLV_OK;
}

/* A consumer call for efficiently getting the register info
   for all registers in one call.

   The output table rules array is size output_table_real_data_size.
   (normally  DW_REG_TABLE_SIZE).
   The frame info  rules array in fde_table is normally of size
   DW_FRAME_LAST_REG_NUM.
*/
int
dwarf_get_fde_info_for_all_regs3(Dwarf_Fde fde,
    Dwarf_Addr pc_requested,
    Dwarf_Regtable3 * reg_table,
    Dwarf_Addr * row_pc,
    Dwarf_Error * error)
{

    struct Dwarf_Frame_s fde_table;
    Dwarf_Sword i = 0;
    int res = 0;
    struct Dwarf_Reg_Rule_s *rule = NULL;
    struct Dwarf_Regtable_Entry3_s *out_rule = NULL;
    Dwarf_Debug dbg = 0;
    int output_table_real_data_size = reg_table->rt3_reg_table_size;

    FDE_NULL_CHECKS_AND_SET_DBG(fde, dbg);

    output_table_real_data_size =
        MIN(output_table_real_data_size,
            dbg->de_frame_reg_rules_entry_count);

    res = dwarf_initialize_fde_table(dbg, &fde_table,
       output_table_real_data_size,
       error);

    /* _dwarf_get_fde_info_for_a_pc_row will perform more sanity checks
     */
    res = _dwarf_get_fde_info_for_a_pc_row(fde, pc_requested,
        &fde_table,
        dbg->de_frame_cfa_col_number,
        error);
    if (res != DW_DLV_OK) {
        dwarf_free_fde_table(&fde_table);
        return res;
    }

    out_rule = &reg_table->rt3_rules[0];
    rule = &fde_table.fr_reg[0];
    for (i = 0; i < output_table_real_data_size;
         i++, ++out_rule, ++rule) {
        out_rule->dw_offset_relevant = rule->ru_is_off;
        out_rule->dw_value_type = rule->ru_value_type;
        out_rule->dw_regnum = rule->ru_register;
        out_rule->dw_offset_or_block_len = rule->ru_offset_or_block_len;
        out_rule->dw_block_ptr = rule->ru_block;
    }
    for (; i < reg_table->rt3_reg_table_size; i++, ++out_rule) {
        out_rule->dw_offset_relevant = 0;
        out_rule->dw_value_type = DW_EXPR_OFFSET;
        out_rule->dw_regnum = dbg->de_frame_undefined_value_number;
        out_rule->dw_offset_or_block_len = 0;
        out_rule->dw_block_ptr = 0;
    }
    reg_table->rt3_cfa_rule.dw_offset_relevant =
        fde_table.fr_cfa_rule.ru_is_off;
    reg_table->rt3_cfa_rule.dw_value_type =
        fde_table.fr_cfa_rule.ru_value_type;
    reg_table->rt3_cfa_rule.dw_regnum =
        fde_table.fr_cfa_rule.ru_register;
    reg_table->rt3_cfa_rule.dw_offset_or_block_len =
        fde_table.fr_cfa_rule.ru_offset_or_block_len;
    reg_table->rt3_cfa_rule.dw_block_ptr =
        fde_table.fr_cfa_rule.ru_block;

    if (row_pc != NULL)
        *row_pc = fde_table.fr_loc;

    dwarf_free_fde_table(&fde_table);
    return DW_DLV_OK;
}


/* Gets the register info for a single register at a given PC value
   for the FDE specified.

   This is the old MIPS interface and should no longer be used.
   Use dwarf_get_fde_info_for_reg3() instead.
*/
int
dwarf_get_fde_info_for_reg(Dwarf_Fde fde,
    Dwarf_Half table_column,
    Dwarf_Addr pc_requested,
    Dwarf_Signed * offset_relevant,
    Dwarf_Signed * register_num,
    Dwarf_Signed * offset,
    Dwarf_Addr * row_pc, Dwarf_Error * error)
{
    struct Dwarf_Frame_s fde_table;
    int res = DW_DLV_ERROR;
    Dwarf_Debug dbg = 0;
    int output_table_real_data_size = 0;

    FDE_NULL_CHECKS_AND_SET_DBG(fde, dbg);
    output_table_real_data_size = dbg->de_frame_reg_rules_entry_count;

    res = dwarf_initialize_fde_table(dbg, &fde_table,
        output_table_real_data_size,
        error);
    if (res != DW_DLV_OK)
        return res;

    if (table_column >= output_table_real_data_size) {
        dwarf_free_fde_table(&fde_table);
        _dwarf_error(dbg, error, DW_DLE_FRAME_TABLE_COL_BAD);
        return (DW_DLV_ERROR);
    }

    /* _dwarf_get_fde_info_for_a_pc_row will perform more sanity checks
     */
    res =
        _dwarf_get_fde_info_for_a_pc_row(fde, pc_requested, &fde_table,
            dbg->de_frame_cfa_col_number, error);
    if (res != DW_DLV_OK) {
        dwarf_free_fde_table(&fde_table);
        return res;
    }

    if (fde_table.fr_reg[table_column].ru_value_type != DW_EXPR_OFFSET) {
        /* The problem here is that this interface cannot deal with
           other sorts of (newer) dwarf frame values.  Code must
           use dwarf_get_fde_info_for_reg3() to get these
           values correctly.  We error rather than return
           misleading incomplete data. */
        dwarf_free_fde_table(&fde_table);
        _dwarf_error(NULL, error,
            DW_DLE_FRAME_REGISTER_UNREPRESENTABLE);
        return (DW_DLV_ERROR);
    }
    if(table_column == dbg->de_frame_cfa_col_number) {
        if (register_num != NULL)
            *register_num = fde_table.fr_cfa_rule.ru_register;
        if (offset != NULL)
            *offset = fde_table.fr_cfa_rule.ru_offset_or_block_len;
        if (row_pc != NULL)
            *row_pc = fde_table.fr_loc;
        *offset_relevant = fde_table.fr_cfa_rule.ru_is_off;

    } else {
        if (register_num != NULL)
            *register_num = fde_table.fr_reg[table_column].ru_register;
        if (offset != NULL)
            *offset = fde_table.fr_reg[table_column].ru_offset_or_block_len;
        if (row_pc != NULL)
            *row_pc = fde_table.fr_loc;

        *offset_relevant = fde_table.fr_reg[table_column].ru_is_off;
    }
    dwarf_free_fde_table(&fde_table);
    return DW_DLV_OK;
}

/* In this interface, table_column of DW_FRAME_CFA_COL
   is not meaningful.
   Use  dwarf_get_fde_info_for_cfa_reg3() to get the CFA.
   Call dwarf_set_frame_cfa_value() to set the correct column
   after calling dwarf_init()
   (DW_FRAME_CFA_COL3 is a sensible column to use).
*/
int
dwarf_get_fde_info_for_reg3(Dwarf_Fde fde,
    Dwarf_Half table_column,
    Dwarf_Addr pc_requested,
    Dwarf_Small * value_type,
    Dwarf_Signed * offset_relevant,
    Dwarf_Signed * register_num,
    Dwarf_Signed * offset_or_block_len,
    Dwarf_Ptr * block_ptr,
    Dwarf_Addr * row_pc_out,
    Dwarf_Error * error)
{
    struct Dwarf_Frame_s fde_table;
    int res = DW_DLV_ERROR;

    Dwarf_Debug dbg = 0;
    int table_real_data_size = 0;

    FDE_NULL_CHECKS_AND_SET_DBG(fde, dbg);
    table_real_data_size = dbg->de_frame_reg_rules_entry_count;
    res = dwarf_initialize_fde_table(dbg, &fde_table,
        table_real_data_size, error);
    if (res != DW_DLV_OK)
        return res;
    if (table_column >= table_real_data_size) {
        dwarf_free_fde_table(&fde_table);
        _dwarf_error(dbg, error, DW_DLE_FRAME_TABLE_COL_BAD);
        return (DW_DLV_ERROR);
    }

    /* _dwarf_get_fde_info_for_a_pc_row will perform more sanity checks
     */
    res = _dwarf_get_fde_info_for_a_pc_row(fde, pc_requested, &fde_table,
        dbg->de_frame_cfa_col_number,
        error);
    if (res != DW_DLV_OK) {
        dwarf_free_fde_table(&fde_table);
        return res;
    }

    if (register_num != NULL)
        *register_num = fde_table.fr_reg[table_column].ru_register;
    if (offset_or_block_len != NULL)
        *offset_or_block_len =
            fde_table.fr_reg[table_column].ru_offset_or_block_len;
    if (row_pc_out != NULL)
        *row_pc_out = fde_table.fr_loc;
    if (block_ptr)
        *block_ptr = fde_table.fr_reg[table_column].ru_block;

    /* Without value_type the data cannot be understood, so we insist
       on it being present, we don't test it. */
    *value_type = fde_table.fr_reg[table_column].ru_value_type;
    *offset_relevant = (fde_table.fr_reg[table_column].ru_is_off);
    dwarf_free_fde_table(&fde_table);
    return DW_DLV_OK;

}

/* For latest DWARF, this is the preferred interface.
   It more portably deals with the  CFA by not
   making the CFA a column number, which means
   DW_FRAME_CFA_COL3 becomes, like DW_CFA_SAME_VALUE,
   a special value, not something one uses as an index.

   Call dwarf_set_frame_cfa_value() to set the correct column
   after calling dwarf_init()
   (DW_FRAME_CFA_COL3 is a sensible column to use, and
   is the default unless '--enable-oldframecol'
   is used to configure libdwarf).  */
int
dwarf_get_fde_info_for_cfa_reg3(Dwarf_Fde fde,
    Dwarf_Addr pc_requested,
    Dwarf_Small * value_type,
    Dwarf_Signed * offset_relevant,
    Dwarf_Signed * register_num,
    Dwarf_Signed * offset_or_block_len,
    Dwarf_Ptr * block_ptr,
    Dwarf_Addr * row_pc_out,
    Dwarf_Error * error)
{
    struct Dwarf_Frame_s fde_table;
    int res = DW_DLV_ERROR;
    Dwarf_Debug dbg = 0;

    int table_real_data_size = 0;

    FDE_NULL_CHECKS_AND_SET_DBG(fde, dbg);

    table_real_data_size = dbg->de_frame_reg_rules_entry_count;
    res = dwarf_initialize_fde_table(dbg, &fde_table,
        table_real_data_size, error);
    if (res != DW_DLV_OK)
        return res;
    res = _dwarf_get_fde_info_for_a_pc_row(fde, pc_requested, &fde_table,
          dbg->de_frame_cfa_col_number,error);
    if (res != DW_DLV_OK) {
        dwarf_free_fde_table(&fde_table);
        return res;
    }

    if (register_num != NULL)
        *register_num = fde_table.fr_cfa_rule.ru_register;
    if (offset_or_block_len != NULL)
        *offset_or_block_len =
            fde_table.fr_cfa_rule.ru_offset_or_block_len;
    if (row_pc_out != NULL)
        *row_pc_out = fde_table.fr_loc;
    if (block_ptr)
        *block_ptr = fde_table.fr_cfa_rule.ru_block;

    /* Without value_type the data cannot be understood, so we insist
       on it being present, we don't test it. */
    *value_type = fde_table.fr_cfa_rule.ru_value_type;
    *offset_relevant = fde_table.fr_cfa_rule.ru_is_off;
    dwarf_free_fde_table(&fde_table);
    return DW_DLV_OK;
}



/*
        Return pointer to the instructions in the dwarf
        fde.
*/
int
dwarf_get_fde_instr_bytes(Dwarf_Fde inFde, Dwarf_Ptr * outinstraddr,
    Dwarf_Unsigned * outaddrlen,
    Dwarf_Error * error)
{
    Dwarf_Unsigned len = 0;
    unsigned char *instrs = 0;
    Dwarf_Debug dbg = 0;

    if (inFde == NULL) {
        _dwarf_error(dbg, error, DW_DLE_FDE_NULL);
        return (DW_DLV_ERROR);
    }

    dbg = inFde->fd_dbg;
    if (dbg == NULL) {
        _dwarf_error(dbg, error, DW_DLE_FDE_DBG_NULL);
        return (DW_DLV_ERROR);
    }

    instrs = inFde->fd_fde_instr_start;

    len = (inFde->fd_fde_start + inFde->fd_length +
           inFde->fd_length_size + inFde->fd_extension_size) - instrs;

    *outinstraddr = instrs;
    *outaddrlen = len;
    return DW_DLV_OK;
}

/* Allows getting an fde from its table via an index.
   With more error checking than simply indexing oneself.
*/
int
dwarf_get_fde_n(Dwarf_Fde * fde_data,
    Dwarf_Unsigned fde_index,
    Dwarf_Fde * returned_fde, Dwarf_Error * error)
{
    Dwarf_Debug dbg = 0;
    Dwarf_Signed fdecount = 0;

    if (fde_data == NULL) {
        _dwarf_error(dbg, error, DW_DLE_FDE_PTR_NULL);
        return (DW_DLV_ERROR);
    }

    FDE_NULL_CHECKS_AND_SET_DBG(*fde_data, dbg);
    /* Assumes fde_data table has at least one entry. */
    fdecount = fde_data[0]->fd_is_eh?
        dbg->de_fde_count_eh:dbg->de_fde_count;
    if (fde_index >= fdecount) {
        return (DW_DLV_NO_ENTRY);
    }
    *returned_fde = (*(fde_data + fde_index));
    return DW_DLV_OK;
}


/*
    Lopc and hipc are extensions to the interface to
    return the range of addresses that are described
    by the returned fde.
*/
int
dwarf_get_fde_at_pc(Dwarf_Fde * fde_data,
    Dwarf_Addr pc_of_interest,
    Dwarf_Fde * returned_fde,
    Dwarf_Addr * lopc,
    Dwarf_Addr * hipc, Dwarf_Error * error)
{
    Dwarf_Debug dbg = NULL;
    Dwarf_Fde fde = NULL;
    Dwarf_Fde entryfde = NULL;
    Dwarf_Signed fdecount = 0;

    if (fde_data == NULL) {
        _dwarf_error(NULL, error, DW_DLE_FDE_PTR_NULL);
        return (DW_DLV_ERROR);
    }

    /* Assumes fde_data table has at least one entry. */
    entryfde = *fde_data;
    FDE_NULL_CHECKS_AND_SET_DBG(entryfde, dbg);

    if (dbg == NULL) {
        _dwarf_error(NULL, error, DW_DLE_FDE_DBG_NULL);
        return (DW_DLV_ERROR);
    }
    fdecount = entryfde->fd_is_eh?
        dbg->de_fde_count_eh:dbg->de_fde_count;
    {
        /* The fde's are sorted by their addresses. Binary search to
           find correct fde. */
        Dwarf_Signed low = 0;
        Dwarf_Signed high = fdecount - 1L;
        Dwarf_Signed middle = 0;
        Dwarf_Fde cur_fde;

        while (low <= high) {
            middle = (low + high) / 2;
            cur_fde = fde_data[middle];
            if (pc_of_interest < cur_fde->fd_initial_location) {
                high = middle - 1;
            } else if (pc_of_interest >=
                       (cur_fde->fd_initial_location +
                        cur_fde->fd_address_range)) {
                low = middle + 1;
            } else {
                fde = fde_data[middle];
                break;
            }
        }
    }

    if (fde) {
        if (lopc != NULL)
            *lopc = fde->fd_initial_location;
        if (hipc != NULL)
            *hipc =
                fde->fd_initial_location + fde->fd_address_range - 1;
        *returned_fde = fde;
        return (DW_DLV_OK);
    }

    return (DW_DLV_NO_ENTRY);
}


/* Expands a single frame instruction block
   from a specific cie
   into a n array of Dwarf_Frame_Op-s.
   This depends on having the cfa column set sensibly.

   Call dwarf_set_frame_cfa_value() to set the correct column
   after calling dwarf_init() unless you are using
   the old MIPS frame interfaces (in which case the default
   will be ok). (DW_FRAME_CFA_COL3 is a sensible column to use ).
*/
int
dwarf_expand_frame_instructions(Dwarf_Cie cie,
    Dwarf_Ptr instruction,
    Dwarf_Unsigned i_length,
    Dwarf_Frame_Op ** returned_op_list,
    Dwarf_Signed * returned_op_count,
    Dwarf_Error * error)
{
    Dwarf_Sword instr_count;
    int res = DW_DLV_ERROR;
    int dw_err;
    Dwarf_Debug dbg = 0;

    if (cie == 0) {
        _dwarf_error(NULL, error, DW_DLE_DBG_NULL);
        return (DW_DLV_ERROR);
    }
    dbg = cie->ci_dbg;

    if (returned_op_list == 0 || returned_op_count == 0) {
        _dwarf_error(dbg, error, DW_DLE_RET_OP_LIST_NULL);
        return (DW_DLV_ERROR);
    }

    /* The cast to Dwarf_Ptr may get a compiler warning, but it is safe
       as it is just an i_length offset from 'instruction' itself. A
       caller has made a big mistake if the result is not a valid
       pointer. */
    res = _dwarf_exec_frame_instr( /* make_instr= */ true,
        returned_op_list,
        /* search_pc */ false,
        /* search_pc_val */ 0,
        /* location */ 0,
        instruction,
        (Dwarf_Ptr)((char *)instruction + i_length),
        /* Dwarf_Frame */ NULL,
        cie,
        dbg,
        dbg->de_frame_cfa_col_number, &instr_count,
        &dw_err);
    if (res != DW_DLV_OK) {
        if (res == DW_DLV_ERROR) {
            _dwarf_error(dbg, error, dw_err);
        }
        return (res);
    }

    *returned_op_count = instr_count;
    return DW_DLV_OK;
}


/* Used by dwarfdump -v to print offsets, for debugging
   dwarf info.
   The dwarf_ version is preferred over the obsolete _dwarf version.
   _dwarf version kept for compatibility.
*/
/* ARGSUSED 4 */
int
_dwarf_fde_section_offset(Dwarf_Debug dbg, Dwarf_Fde in_fde,
    Dwarf_Off * fde_off, Dwarf_Off * cie_off,
    Dwarf_Error * err)
{
  return dwarf_fde_section_offset(dbg,in_fde,fde_off,
     cie_off,err);
}
/* ARGSUSED 4 */
int
dwarf_fde_section_offset(Dwarf_Debug dbg, Dwarf_Fde in_fde,
    Dwarf_Off * fde_off, Dwarf_Off * cie_off,
    Dwarf_Error * err)
{
    char *start = 0;
    char *loc = 0;



    start = (char *) in_fde->fd_section_ptr;
    loc = (char *) in_fde->fd_fde_start;

    *fde_off = (loc - start);
    *cie_off = in_fde->fd_cie_offset;
    return DW_DLV_OK;
}

/* Used by dwarfdump -v to print offsets, for debugging
   dwarf info.
   The dwarf_ version is preferred over the obsolete _dwarf version.
   _dwarf version kept for compatibility.
*/
/* ARGSUSED 4 */
int
_dwarf_cie_section_offset(Dwarf_Debug dbg, Dwarf_Cie in_cie,
    Dwarf_Off * cie_off, Dwarf_Error * err)
{
    return dwarf_cie_section_offset(dbg,in_cie,cie_off,err);
}
/* ARGSUSED 4 */
int
dwarf_cie_section_offset(Dwarf_Debug dbg, Dwarf_Cie in_cie,
    Dwarf_Off * cie_off, Dwarf_Error * err)
{
    char *start = 0;
    char *loc = 0;

    start = (char *) in_cie->ci_section_ptr;
    loc = (char *) in_cie->ci_cie_start;

    *cie_off = (loc - start);
    return DW_DLV_OK;
}

/* Returns  a pointer to target-specific augmentation data thru augdata
   and returns the length of the data thru augdata_len.

   It's up to the consumer code to know how to interpret the bytes
   of target-specific data (endian issues apply too, these
   are just raw bytes pointed to).
   See  Linux Standard Base Core Specification version 3.0 for
   the details on .eh_frame info.

   Returns DW_DLV_ERROR if fde is NULL or some other serious
   error.
   Returns DW_DLV_NO_ENTRY if there is no target-specific
   augmentation data.

   The bytes pointed to are in the Dwarf_Cie, and as long as that
   is valid the bytes are there. No 'dealloc' call is needed
   for the bytes.
*/
int
dwarf_get_cie_augmentation_data(Dwarf_Cie cie,
    Dwarf_Small ** augdata,
    Dwarf_Unsigned * augdata_len,
    Dwarf_Error * error)
{
    if (cie == NULL) {
        _dwarf_error(NULL, error, DW_DLE_CIE_NULL);
        return (DW_DLV_ERROR);
    }
    if (cie->ci_gnu_eh_augmentation_len == 0) {
        return DW_DLV_NO_ENTRY;
    }
    *augdata = (Dwarf_Small *) (cie->ci_gnu_eh_augmentation_bytes);
    *augdata_len = cie->ci_gnu_eh_augmentation_len;
    return DW_DLV_OK;
}


/* Returns  a pointer to target-specific augmentation data thru augdata
   and returns the length of the data thru augdata_len.

   It's up to the consumer code to know how to interpret the bytes
   of target-specific data (endian issues apply too, these
   are just raw bytes pointed to).
   See  Linux Standard Base Core Specification version 3.0 for
   the details on .eh_frame info.

   Returns DW_DLV_ERROR if fde is NULL or some other serious
   error.
   Returns DW_DLV_NO_ENTRY if there is no target-specific
   augmentation data.

   The bytes pointed to are in the Dwarf_Fde, and as long as that
   is valid the bytes are there. No 'dealloc' call is needed
   for the bytes.

*/
int
dwarf_get_fde_augmentation_data(Dwarf_Fde fde,
    Dwarf_Small * *augdata,
    Dwarf_Unsigned * augdata_len,
    Dwarf_Error * error)
{
    Dwarf_Cie cie = 0;

    if (fde == NULL) {
        _dwarf_error(NULL, error, DW_DLE_FDE_NULL);
        return (DW_DLV_ERROR);
    }
    cie = fde->fd_cie;
    if (cie == NULL) {
        _dwarf_error(NULL, error, DW_DLE_CIE_NULL);
        return (DW_DLV_ERROR);
    }
    if (cie->ci_gnu_eh_augmentation_len == 0) {
        return DW_DLV_NO_ENTRY;
    }
    *augdata = (Dwarf_Small *) fde->fd_gnu_eh_augmentation_bytes;
    *augdata_len = fde->fd_gnu_eh_augmentation_len;
    return DW_DLV_OK;
}


/* Initialize with same_value , a value which makes sense
   for IRIX/MIPS.
   The correct value to use is ABI dependent.
   For register-windows machines most
   or all registers should get DW_FRAME_UNDEFINED_VAL as the
   correct initial value.
   Some think DW_FRAME_UNDEFINED_VAL is always the
   right value.

   For some ABIs a setting which varies by register
   would be more appropriate.

   FIXME. */

static void
_dwarf_init_regrule_table(struct Dwarf_Reg_Rule_s *t1reg,
    int last_reg_num, int initial_value)
{
    struct Dwarf_Reg_Rule_s *t1end = t1reg + last_reg_num;

    for (; t1reg < t1end; t1reg++) {
        t1reg->ru_is_off = 0;
        t1reg->ru_value_type = DW_EXPR_OFFSET;
        t1reg->ru_register = initial_value;
        t1reg->ru_offset_or_block_len = 0;
        t1reg->ru_block = 0;
    }
}

#if 0
/* Used solely for debugging libdwarf. */
static void
dump_frame_rule(char *msg, struct Dwarf_Reg_Rule_s *reg_rule)
{
    printf
        ("%s type %s (" DW_PR_DUx "), is_off "
         DW_PR_DUu " reg " DW_PR_DUu " offset " DW_PR_DUx " blockp "
         DW_PR_DUx "\n",
         msg,
         (reg_rule->ru_value_type == DW_EXPR_OFFSET) ?
             "DW_EXPR_OFFSET" :
          (reg_rule->ru_value_type == DW_EXPR_VAL_OFFSET) ?
             "DW_EXPR_VAL_OFFSET" :
          (reg_rule->ru_value_type == DW_EXPR_VAL_EXPRESSION) ?
             "DW_EXPR_VAL_EXPRESSION" :
          (reg_rule->ru_value_type == DW_EXPR_EXPRESSION) ?
             "DW_EXPR_EXPRESSION" : "Unknown",
         (Dwarf_Unsigned) reg_rule->ru_value_type,
         (Dwarf_Unsigned) reg_rule->ru_is_off,
         (Dwarf_Unsigned) reg_rule->ru_register,
         (Dwarf_Unsigned) reg_rule->ru_offset_or_block_len,
         (Dwarf_Unsigned) reg_rule->ru_block);
    return;
}
#endif

/* This allows consumers to set the 'initial value' so that
   an ISA/ABI specific default can be used, dynamically,
   at run time.  Useful for dwarfdump and non-MIPS architectures..
   The value  defaults to one of
        DW_FRAME_SAME_VALUE or DW_FRAME_UNKNOWN_VALUE
   but dwarfdump can dump multiple ISA/ABI objects so
   we may want to get this set to what the ABI says is correct.

   Returns the value that was present before we changed it here.
*/
Dwarf_Half
dwarf_set_frame_rule_initial_value(Dwarf_Debug dbg, Dwarf_Half value)
{
    Dwarf_Half orig = dbg->de_frame_rule_initial_value;
    dbg->de_frame_rule_initial_value = value;
    return orig;
}

/* The following spelling for backwards compatibility. */
Dwarf_Half
dwarf_set_frame_rule_inital_value(Dwarf_Debug dbg, Dwarf_Half value)
{
    return dwarf_set_frame_rule_initial_value(dbg,value);
}

/* This allows consumers to set the array size of the  reg rules
   table so that
   an ISA/ABI specific value can be used, dynamically,
   at run time.  Useful for non-MIPS archtectures.
   The value  defaults  to DW_FRAME_LAST_REG_NUM.
   but dwarfdump can dump multiple ISA/ABI objects so
   consumers want to get this set to what the ABI says is correct.

   Returns the value that was present before we changed it here.
*/

Dwarf_Half
dwarf_set_frame_rule_table_size(Dwarf_Debug dbg, Dwarf_Half value)
{
    Dwarf_Half orig = dbg->de_frame_reg_rules_entry_count;
    dbg->de_frame_reg_rules_entry_count = value;
    return orig;
}
/* This allows consumers to set the CFA register value
 * so that an ISA/ABI specific value can be used, dynamically,
 * at run time.  Useful for non-MIPS archtectures.
 * The value  defaults  to DW_FRAME_CFA_COL3 and should be
 * higher than any real register in the ABI.
 * Dwarfdump can dump multiple ISA/ABI objects so
 * consumers want to get this set to what the ABI says is correct.

 * Returns the value that was present before we changed it here.
 * */

Dwarf_Half
dwarf_set_frame_cfa_value(Dwarf_Debug dbg, Dwarf_Half value)
{
    Dwarf_Half orig = dbg->de_frame_cfa_col_number;
    dbg->de_frame_cfa_col_number = value;
    return orig;
}
/* Similar to above, but for the other crucial fields for frames. */
Dwarf_Half
dwarf_set_frame_same_value(Dwarf_Debug dbg, Dwarf_Half value)
{
    Dwarf_Half orig = dbg->de_frame_same_value_number;
    dbg->de_frame_same_value_number = value;
    return orig;
}
Dwarf_Half
dwarf_set_frame_undefined_value(Dwarf_Debug dbg, Dwarf_Half value)
{
    Dwarf_Half orig = dbg->de_frame_same_value_number;
    dbg->de_frame_undefined_value_number = value;
    return orig;
}





static int
dwarf_initialize_fde_table(Dwarf_Debug dbg,
    struct Dwarf_Frame_s *fde_table,
    unsigned table_real_data_size,
    Dwarf_Error * error)
{
    unsigned entry_size = sizeof(struct Dwarf_Frame_s);

    fde_table->fr_loc = 0;
    fde_table->fr_reg_count = table_real_data_size;
    fde_table->fr_next = 0;

    fde_table->fr_reg = (struct Dwarf_Reg_Rule_s *)
        calloc(entry_size, table_real_data_size);
    if (fde_table->fr_reg == 0) {
        _dwarf_error(dbg, error, DW_DLE_DF_ALLOC_FAIL);
        return (DW_DLV_ERROR);
    }
    return DW_DLV_OK;

}
static void
dwarf_free_fde_table(struct Dwarf_Frame_s *fde_table)
{
    free(fde_table->fr_reg);
    fde_table->fr_reg_count = 0;
    fde_table->fr_reg = 0;
}


/* Return DW_DLV_OK if we succeed. else return DW_DLV_ERROR.
*/
int
_dwarf_frame_constructor(Dwarf_Debug dbg, void *frame)
{
    struct Dwarf_Frame_s *fp = frame;

    if (!dbg) {
        return DW_DLV_ERROR;
    }

    fp->fr_reg = calloc(dbg->de_frame_reg_rules_entry_count,
                        sizeof(struct Dwarf_Reg_Rule_s));
    if (!fp->fr_reg) {
        return DW_DLV_ERROR;
    }
    fp->fr_reg_count = dbg->de_frame_reg_rules_entry_count;
    return DW_DLV_OK;
}

void
_dwarf_frame_destructor(void *frame)
{
    struct Dwarf_Frame_s *fp = frame;

    if (fp->fr_reg) {
        free(fp->fr_reg);
    }
    fp->fr_reg = 0;
    fp->fr_reg_count = 0;
}