sys/contrib/ia64/libuwx/src/uwx_bstream.c

   1 /*
   2 Copyright (c) 2003-2006 Hewlett-Packard Development Company, L.P.
   3 Permission is hereby granted, free of charge, to any person
   4 obtaining a copy of this software and associated documentation
   5 files (the "Software"), to deal in the Software without
   6 restriction, including without limitation the rights to use,
   7 copy, modify, merge, publish, distribute, sublicense, and/or sell
   8 copies of the Software, and to permit persons to whom the
   9 Software is furnished to do so, subject to the following
  10 conditions:
  11
  12 The above copyright notice and this permission notice shall be
  13 included in all copies or substantial portions of the Software.
  14
  15 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  16 EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
  17 OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  18 NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
  19 HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
  20 WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  21 FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  22 OTHER DEALINGS IN THE SOFTWARE.
  23 */
  24
  25 #include "uwx_env.h"
  26 #include "uwx_bstream.h"
  27
  28
  29 /* uwx_init_bstream: initialize a byte stream for reading */
  30
  31 void uwx_init_bstream(
  32     struct uwx_bstream *bstream,
  33     struct uwx_env *env,
  34     uint64_t source,
  35     unsigned int len,
  36     int request)
  37 {
  38     bstream->buf = 0;
  39     if (env->remote) {
  40         bstream->source = source;
  41         bstream->bufp = (unsigned char *) &bstream->buf;
  42         bstream->nbuf = 0;
  43         bstream->copyin = env->copyin;
  44         bstream->cb_token = env->cb_token;
  45         bstream->request = request;
  46     }
  47     else {
  48         bstream->source = 0;
  49         bstream->bufp = (unsigned char *) (intptr_t) source;
  50         bstream->nbuf = len;
  51         bstream->copyin = 0;
  52         bstream->cb_token = 0;
  53         bstream->request = 0;
  54     }
  55     bstream->ntotal = len;
  56     bstream->peekc = -1;
  57 }
  58
  59
  60 /* uwx_get_byte: read the next byte from the byte stream */
  61
  62 int uwx_get_byte(struct uwx_bstream *bstream)
  63 {
  64     int len;
  65     int n;
  66     int b;
  67
  68     if (bstream->peekc >= 0) {
  69         b = bstream->peekc;
  70         bstream->peekc = -1;
  71         return b;
  72     }
  73     if (bstream->ntotal <= 0)
  74         return -1;
  75     if (bstream->nbuf <= 0) {
  76         if (bstream->source & 0x7 || bstream->ntotal < sizeof(uint64_t))
  77             len = sizeof(uint32_t);
  78         else
  79             len = sizeof(uint64_t);
  80         n = (*bstream->copyin)(bstream->request, (char *)&bstream->buf,
  81                 bstream->source, len, bstream->cb_token);
  82         if (n != len)
  83             return -1;
  84         bstream->bufp = (unsigned char *) &bstream->buf;
  85         bstream->nbuf = n;
  86         bstream->source += n;
  87     }
  88
  89     b = *bstream->bufp++;
  90     bstream->nbuf--;
  91     bstream->ntotal--;
  92     return b;
  93 }
  94
  95
  96 /* uwx_unget_byte: push a byte back onto the byte stream */
  97
  98 int uwx_unget_byte(struct uwx_bstream *bstream, int b)
  99 {
 100     bstream->peekc = b;
 101     return 0;
 102 }
 103
 104
 105 /* uwx_get_uleb128: read a ULEB128 value from the byte stream */
 106
 107 int uwx_get_uleb128(struct uwx_bstream *bstream, uint64_t *valp)
 108 {
 109     uint64_t val;
 110     int i;
 111     int b;
 112
 113     b = uwx_get_byte(bstream);
 114     val = (uint64_t)(b & 0x7f) << 56;
 115     for (i = 0; i < 8; i++) {
 116         val = val >> 7;
 117         if (b & 0x80) {
 118             b = uwx_get_byte(bstream);
 119             val |= (uint64_t)(b & 0x7f) << 56;
 120         }
 121     }
 122     if (b & 0x80) {
 123         b = uwx_get_byte(bstream);
 124         val |= (uint64_t)(b & 0x7f) << 63;
 125     }
 126     if (b & 0x80)
 127         return -1;
 128     *valp = val;
 129     return 0;
 130 }
 131
 132 #if 0
 133 int uwx_get_uleb128_alt(struct uwx_bstream *bstream, uint64_t *valp)
 134 {
 135     uint64_t val;
 136     int b;
 137
 138     b = uwx_get_byte(bstream);
 139     val = b & 0x7f;
 140     if (b & 0x80) {
 141         b = uwx_get_byte(bstream);
 142         val |= (uint64_t)(b & 0x7f) << 7;
 143         if (b & 0x80) {
 144             b = uwx_get_byte(bstream);
 145             val |= (uint64_t)(b & 0x7f) << 14;
 146             if (b & 0x80) {
 147                 b = uwx_get_byte(bstream);
 148                 val |= (uint64_t)(b & 0x7f) << 21;
 149                 if (b & 0x80) {
 150                     b = uwx_get_byte(bstream);
 151                     val |= (uint64_t)(b & 0x7f) << 28;
 152                     if (b & 0x80) {
 153                         b = uwx_get_byte(bstream);
 154                         val |= (uint64_t)(b & 0x7f) << 35;
 155                         if (b & 0x80) {
 156                             b = uwx_get_byte(bstream);
 157                             val |= (uint64_t)(b & 0x7f) << 42;
 158                             if (b & 0x80) {
 159                                 b = uwx_get_byte(bstream);
 160                                 val |= (uint64_t)(b & 0x7f) << 49;
 161                                 if (b & 0x80) {
 162                                     b = uwx_get_byte(bstream);
 163                                     val |= (uint64_t)(b & 0x7f) << 56;
 164                                     if (b & 0x80) {
 165                                         b = uwx_get_byte(bstream);
 166                                         val |= (uint64_t)(b & 0x7f) << 63;
 167                                         if (b & 0x80)
 168                                             return -1;
 169                                     }
 170                                 }
 171                             }
 172                         }
 173                     }
 174                 }
 175             }
 176         }
 177     }
 178     *valp = val;
 179     return 0;
 180 }
 181 #endif