1/*
2
3  Copyright (C) 2000,2004 Silicon Graphics, Inc.  All Rights Reserved.
4
5  This program is free software; you can redistribute it and/or modify it
6  under the terms of version 2.1 of the GNU Lesser General Public License
7  as published by the Free Software Foundation.
8
9  This program is distributed in the hope that it would be useful, but
10  WITHOUT ANY WARRANTY; without even the implied warranty of
11  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
12
13  Further, this software is distributed without any warranty that it is
14  free of the rightful claim of any third person regarding infringement
15  or the like.  Any license provided herein, whether implied or
16  otherwise, applies only to this software file.  Patent licenses, if
17  any, provided herein do not apply to combinations of this program with
18  other software, or any other product whatsoever.
19
20  You should have received a copy of the GNU Lesser General Public
21  License along with this program; if not, write the Free Software
22  Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston MA 02110-1301,
23  USA.
24
25  Contact information:  Silicon Graphics, Inc., 1500 Crittenden Lane,
26  Mountain View, CA 94043, or:
27
28  http://www.sgi.com
29
30  For further information regarding this notice, see:
31
32  http://oss.sgi.com/projects/GenInfo/NoticeExplan
33
34*/
35
36
37
38#include "config.h"
39#include "libdwarfdefs.h"
40#include <string.h>
41#include "pro_incl.h"
42
43#define MORE_BYTES      0x80
44#define DATA_MASK       0x7f
45#define DIGIT_WIDTH     7
46#define SIGN_BIT        0x40
47
48
49/*-------------------------------------------------------------
50        Encode val as a leb128. This encodes it as an unsigned
51        number.
52---------------------------------------------------------------*/
53/* return DW_DLV_ERROR or DW_DLV_OK.
54** space to write leb number is provided by caller, with caller
55** passing length.
56** number of bytes used returned thru nbytes arg
57*/
58int
59_dwarf_pro_encode_leb128_nm(Dwarf_Unsigned val, int *nbytes,
60                            char *space, int splen)
61{
62    char *a;
63    char *end = space + splen;
64
65    a = space;
66    do {
67        unsigned char uc;
68
69        if (a >= end) {
70            return DW_DLV_ERROR;
71        }
72        uc = val & DATA_MASK;
73        val >>= DIGIT_WIDTH;
74        if (val != 0) {
75            uc |= MORE_BYTES;
76        }
77        *a = uc;
78        a++;
79    } while (val);
80    *nbytes = a - space;
81    return DW_DLV_OK;
82}
83
84/* return DW_DLV_ERROR or DW_DLV_OK.
85** space to write leb number is provided by caller, with caller
86** passing length.
87** number of bytes used returned thru nbytes arg
88** encodes a signed number.
89*/
90int
91_dwarf_pro_encode_signed_leb128_nm(Dwarf_Signed value, int *nbytes,
92                                   char *space, int splen)
93{
94    char *str;
95    Dwarf_Signed sign = -(value < 0);
96    int more = 1;
97    char *end = space + splen;
98
99    str = space;
100
101    do {
102        unsigned char byte = value & DATA_MASK;
103
104        value >>= DIGIT_WIDTH;
105
106        if (str >= end) {
107            return DW_DLV_ERROR;
108        }
109        /*
110         * Remaining chunks would just contain the sign bit, and this chunk
111         * has already captured at least one sign bit.
112         */
113        if (value == sign && ((byte & SIGN_BIT) == (sign & SIGN_BIT))) {
114            more = 0;
115        } else {
116            byte |= MORE_BYTES;
117        }
118        *str = byte;
119        str++;
120    } while (more);
121    *nbytes = str - space;
122    return DW_DLV_OK;
123}
124