nasmlib/saa.c

   1 /* ----------------------------------------------------------------------- *
   2  *
   3  *   Copyright 1996-2017 The NASM Authors - All Rights Reserved
   4  *   See the file AUTHORS included with the NASM distribution for
   5  *   the specific copyright holders.
   6  *
   7  *   Redistribution and use in source and binary forms, with or without
   8  *   modification, are permitted provided that the following
   9  *   conditions are met:
  10  *
  11  *   * Redistributions of source code must retain the above copyright
  12  *     notice, this list of conditions and the following disclaimer.
  13  *   * Redistributions in binary form must reproduce the above
  14  *     copyright notice, this list of conditions and the following
  15  *     disclaimer in the documentation and/or other materials provided
  16  *     with the distribution.
  17  *
  18  *     THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
  19  *     CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
  20  *     INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  21  *     MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  22  *     DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
  23  *     CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  24  *     SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  25  *     NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  26  *     LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  27  *     HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  28  *     CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
  29  *     OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
  30  *     EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  31  *
  32  * ----------------------------------------------------------------------- */
  33
  34 #include "compiler.h"
  35 #include "nasmlib.h"
  36 #include "saa.h"
  37
  38 /* Aggregate SAA components smaller than this */
  39 #define SAA_BLKSHIFT    16
  40 #define SAA_BLKLEN      ((size_t)1 << SAA_BLKSHIFT)
  41
  42 struct SAA *saa_init(size_t elem_len)
  43 {
  44     struct SAA *s;
  45     char *data;
  46
  47     s = nasm_zalloc(sizeof(struct SAA));
  48
  49     if (elem_len >= SAA_BLKLEN)
  50         s->blk_len = elem_len;
  51     else
  52         s->blk_len = SAA_BLKLEN - (SAA_BLKLEN % elem_len);
  53
  54     s->elem_len = elem_len;
  55     s->length = s->blk_len;
  56     data = nasm_malloc(s->blk_len);
  57     s->nblkptrs = s->nblks = 1;
  58     s->blk_ptrs = nasm_malloc(sizeof(char *));
  59     s->blk_ptrs[0] = data;
  60     s->wblk = s->rblk = &s->blk_ptrs[0];
  61
  62     return s;
  63 }
  64
  65 void saa_free(struct SAA *s)
  66 {
  67     char **p;
  68     size_t n;
  69
  70     for (p = s->blk_ptrs, n = s->nblks; n; p++, n--)
  71         nasm_free(*p);
  72
  73     nasm_free(s->blk_ptrs);
  74     nasm_free(s);
  75 }
  76
  77 /* Add one allocation block to an SAA */
  78 static void saa_extend(struct SAA *s)
  79 {
  80     size_t blkn = s->nblks++;
  81
  82     if (blkn >= s->nblkptrs) {
  83         size_t rindex = s->rblk - s->blk_ptrs;
  84         size_t windex = s->wblk - s->blk_ptrs;
  85
  86         s->nblkptrs <<= 1;
  87         s->blk_ptrs =
  88             nasm_realloc(s->blk_ptrs, s->nblkptrs * sizeof(char *));
  89
  90         s->rblk = s->blk_ptrs + rindex;
  91         s->wblk = s->blk_ptrs + windex;
  92     }
  93
  94     s->blk_ptrs[blkn] = nasm_malloc(s->blk_len);
  95     s->length += s->blk_len;
  96 }
  97
  98 void *saa_wstruct(struct SAA *s)
  99 {
 100     void *p;
 101
 102     nasm_assert((s->wpos % s->elem_len) == 0);
 103
 104     if (s->wpos + s->elem_len > s->blk_len) {
 105         nasm_assert(s->wpos == s->blk_len);
 106         if (s->wptr + s->elem_len > s->length)
 107             saa_extend(s);
 108         s->wblk++;
 109         s->wpos = 0;
 110     }
 111
 112     p = *s->wblk + s->wpos;
 113     s->wpos += s->elem_len;
 114     s->wptr += s->elem_len;
 115
 116     if (s->wptr > s->datalen)
 117         s->datalen = s->wptr;
 118
 119     return p;
 120 }
 121
 122 void saa_wbytes(struct SAA *s, const void *data, size_t len)
 123 {
 124     const char *d = data;
 125
 126     while (len) {
 127         size_t l = s->blk_len - s->wpos;
 128         if (l > len)
 129             l = len;
 130         if (l) {
 131             if (d) {
 132                 memcpy(*s->wblk + s->wpos, d, l);
 133                 d += l;
 134             } else
 135                 memset(*s->wblk + s->wpos, 0, l);
 136             s->wpos += l;
 137             s->wptr += l;
 138             len -= l;
 139
 140             if (s->datalen < s->wptr)
 141                 s->datalen = s->wptr;
 142         }
 143         if (len) {
 144             if (s->wptr >= s->length)
 145                 saa_extend(s);
 146             s->wblk++;
 147             s->wpos = 0;
 148         }
 149     }
 150 }
 151
 152 /*
 153  * Writes a string, *including* the final null, to the specified SAA,
 154  * and return the number of bytes written.
 155  */
 156 size_t saa_wcstring(struct SAA *s, const char *str)
 157 {
 158     size_t bytes = strlen(str) + 1;
 159
 160     saa_wbytes(s, str, bytes);
 161
 162     return bytes;
 163 }
 164
 165 void saa_rewind(struct SAA *s)
 166 {
 167     s->rblk = s->blk_ptrs;
 168     s->rpos = s->rptr = 0;
 169 }
 170
 171 void *saa_rstruct(struct SAA *s)
 172 {
 173     void *p;
 174
 175     if (s->rptr + s->elem_len > s->datalen)
 176         return NULL;
 177
 178     nasm_assert((s->rpos % s->elem_len) == 0);
 179
 180     if (s->rpos + s->elem_len > s->blk_len) {
 181         s->rblk++;
 182         s->rpos = 0;
 183     }
 184
 185     p = *s->rblk + s->rpos;
 186     s->rpos += s->elem_len;
 187     s->rptr += s->elem_len;
 188
 189     return p;
 190 }
 191
 192 const void *saa_rbytes(struct SAA *s, size_t * lenp)
 193 {
 194     const void *p;
 195     size_t len;
 196
 197     if (s->rptr >= s->datalen) {
 198         *lenp = 0;
 199         return NULL;
 200     }
 201
 202     if (s->rpos >= s->blk_len) {
 203         s->rblk++;
 204         s->rpos = 0;
 205     }
 206
 207     len = *lenp;
 208     if (len > s->datalen - s->rptr)
 209         len = s->datalen - s->rptr;
 210     if (len > s->blk_len - s->rpos)
 211         len = s->blk_len - s->rpos;
 212
 213     *lenp = len;
 214     p = *s->rblk + s->rpos;
 215
 216     s->rpos += len;
 217     s->rptr += len;
 218
 219     return p;
 220 }
 221
 222 void saa_rnbytes(struct SAA *s, void *data, size_t len)
 223 {
 224     char *d = data;
 225
 226     nasm_assert(s->rptr + len <= s->datalen);
 227
 228     while (len) {
 229         size_t l;
 230         const void *p;
 231
 232         l = len;
 233         p = saa_rbytes(s, &l);
 234
 235         memcpy(d, p, l);
 236         d += l;
 237         len -= l;
 238     }
 239 }
 240
 241 /* Same as saa_rnbytes, except position the counter first */
 242 void saa_fread(struct SAA *s, size_t posn, void *data, size_t len)
 243 {
 244     size_t ix;
 245
 246     nasm_assert(posn + len <= s->datalen);
 247
 248     if (likely(s->blk_len == SAA_BLKLEN)) {
 249         ix = posn >> SAA_BLKSHIFT;
 250         s->rpos = posn & (SAA_BLKLEN - 1);
 251     } else {
 252         ix = posn / s->blk_len;
 253         s->rpos = posn % s->blk_len;
 254     }
 255     s->rptr = posn;
 256     s->rblk = &s->blk_ptrs[ix];
 257
 258     saa_rnbytes(s, data, len);
 259 }
 260
 261 /* Same as saa_wbytes, except position the counter first */
 262 void saa_fwrite(struct SAA *s, size_t posn, const void *data, size_t len)
 263 {
 264     size_t ix;
 265
 266     /* Seek beyond the end of the existing array not supported */
 267     nasm_assert(posn <= s->datalen);
 268
 269     if (likely(s->blk_len == SAA_BLKLEN)) {
 270         ix = posn >> SAA_BLKSHIFT;
 271         s->wpos = posn & (SAA_BLKLEN - 1);
 272     } else {
 273         ix = posn / s->blk_len;
 274         s->wpos = posn % s->blk_len;
 275     }
 276     s->wptr = posn;
 277     s->wblk = &s->blk_ptrs[ix];
 278
 279     if (!s->wpos) {
 280         s->wpos = s->blk_len;
 281         s->wblk--;
 282     }
 283
 284     saa_wbytes(s, data, len);
 285 }
 286
 287 void saa_fpwrite(struct SAA *s, FILE * fp)
 288 {
 289     const char *data;
 290     size_t len;
 291
 292     saa_rewind(s);
 293     while (len = s->datalen, (data = saa_rbytes(s, &len)) != NULL)
 294         nasm_write(data, len, fp);
 295 }
 296
 297 void saa_write8(struct SAA *s, uint8_t v)
 298 {
 299     saa_wbytes(s, &v, 1);
 300 }
 301
 302 void saa_write16(struct SAA *s, uint16_t v)
 303 {
 304     v = cpu_to_le16(v);
 305     saa_wbytes(s, &v, 2);
 306 }
 307
 308 void saa_write32(struct SAA *s, uint32_t v)
 309 {
 310     v = cpu_to_le32(v);
 311     saa_wbytes(s, &v, 4);
 312 }
 313
 314 void saa_write64(struct SAA *s, uint64_t v)
 315 {
 316     v = cpu_to_le64(v);
 317     saa_wbytes(s, &v, 8);
 318 }
 319
 320 void saa_writeaddr(struct SAA *s, uint64_t v, size_t len)
 321 {
 322     v = cpu_to_le64(v);
 323     saa_wbytes(s, &v, len);
 324 }
 325
 326 /* write unsigned LEB128 value to SAA */
 327 void saa_wleb128u(struct SAA *psaa, int value)
 328 {
 329     char temp[64], *ptemp;
 330     uint8_t byte;
 331     int len;
 332
 333     ptemp = temp;
 334     len = 0;
 335     do {
 336         byte = value & 127;
 337         value >>= 7;
 338         if (value != 0)         /* more bytes to come */
 339             byte |= 0x80;
 340         *ptemp = byte;
 341         ptemp++;
 342         len++;
 343     } while (value != 0);
 344     saa_wbytes(psaa, temp, len);
 345 }
 346
 347 /* write signed LEB128 value to SAA */
 348 void saa_wleb128s(struct SAA *psaa, int value)
 349 {
 350     char temp[64], *ptemp;
 351     uint8_t byte;
 352     bool more, negative;
 353     int size, len;
 354
 355     ptemp = temp;
 356     more = 1;
 357     negative = (value < 0);
 358     size = sizeof(int) * 8;
 359     len = 0;
 360     while (more) {
 361         byte = value & 0x7f;
 362         value >>= 7;
 363         if (negative)
 364             /* sign extend */
 365             value |= -(1 << (size - 7));
 366         /* sign bit of byte is second high order bit (0x40) */
 367         if ((value == 0 && !(byte & 0x40)) ||
 368             ((value == -1) && (byte & 0x40)))
 369             more = 0;
 370         else
 371             byte |= 0x80;
 372         *ptemp = byte;
 373         ptemp++;
 374         len++;
 375     }
 376     saa_wbytes(psaa, temp, len);
 377 }