saa.c

   1 #include "compiler.h"
   2 #include "nasmlib.h"
   3 #include "saa.h"
   4
   5 /* Aggregate SAA components smaller than this */
   6 #define SAA_BLKSHIFT    16
   7 #define SAA_BLKLEN      ((size_t)1 << SAA_BLKSHIFT)
   8
   9 struct SAA *saa_init(size_t elem_len)
  10 {
  11     struct SAA *s;
  12     char *data;
  13
  14     s = nasm_zalloc(sizeof(struct SAA));
  15
  16     if (elem_len >= SAA_BLKLEN)
  17         s->blk_len = elem_len;
  18     else
  19         s->blk_len = SAA_BLKLEN - (SAA_BLKLEN % elem_len);
  20
  21     s->elem_len = elem_len;
  22     s->length = s->blk_len;
  23     data = nasm_malloc(s->blk_len);
  24     s->nblkptrs = s->nblks = 1;
  25     s->blk_ptrs = nasm_malloc(sizeof(char *));
  26     s->blk_ptrs[0] = data;
  27     s->wblk = s->rblk = &s->blk_ptrs[0];
  28
  29     return s;
  30 }
  31
  32 void saa_free(struct SAA *s)
  33 {
  34     char **p;
  35     size_t n;
  36
  37     for (p = s->blk_ptrs, n = s->nblks; n; p++, n--)
  38         nasm_free(*p);
  39
  40     nasm_free(s->blk_ptrs);
  41     nasm_free(s);
  42 }
  43
  44 /* Add one allocation block to an SAA */
  45 static void saa_extend(struct SAA *s)
  46 {
  47     size_t blkn = s->nblks++;
  48
  49     if (blkn >= s->nblkptrs) {
  50         size_t rindex = s->rblk - s->blk_ptrs;
  51         size_t windex = s->wblk - s->blk_ptrs;
  52
  53         s->nblkptrs <<= 1;
  54         s->blk_ptrs =
  55             nasm_realloc(s->blk_ptrs, s->nblkptrs * sizeof(char *));
  56
  57         s->rblk = s->blk_ptrs + rindex;
  58         s->wblk = s->blk_ptrs + windex;
  59     }
  60
  61     s->blk_ptrs[blkn] = nasm_malloc(s->blk_len);
  62     s->length += s->blk_len;
  63 }
  64
  65 void *saa_wstruct(struct SAA *s)
  66 {
  67     void *p;
  68
  69     if (s->wpos % s->elem_len)
  70         nasm_malloc_error(ERR_PANIC | ERR_NOFILE,
  71                           "misaligned wpos in saa_wstruct");
  72
  73     if (s->wpos + s->elem_len > s->blk_len) {
  74         if (s->wpos != s->blk_len)
  75             nasm_malloc_error(ERR_PANIC | ERR_NOFILE,
  76                               "unfilled block in saa_wstruct");
  77
  78         if (s->wptr + s->elem_len > s->length)
  79             saa_extend(s);
  80         s->wblk++;
  81         s->wpos = 0;
  82     }
  83
  84     p = *s->wblk + s->wpos;
  85     s->wpos += s->elem_len;
  86     s->wptr += s->elem_len;
  87
  88     if (s->wptr > s->datalen)
  89         s->datalen = s->wptr;
  90
  91     return p;
  92 }
  93
  94 void saa_wbytes(struct SAA *s, const void *data, size_t len)
  95 {
  96     const char *d = data;
  97
  98     while (len) {
  99         size_t l = s->blk_len - s->wpos;
 100         if (l > len)
 101             l = len;
 102         if (l) {
 103             if (d) {
 104                 memcpy(*s->wblk + s->wpos, d, l);
 105                 d += l;
 106             } else
 107                 memset(*s->wblk + s->wpos, 0, l);
 108             s->wpos += l;
 109             s->wptr += l;
 110             len -= l;
 111
 112             if (s->datalen < s->wptr)
 113                 s->datalen = s->wptr;
 114         }
 115         if (len) {
 116             if (s->wptr >= s->length)
 117                 saa_extend(s);
 118             s->wblk++;
 119             s->wpos = 0;
 120         }
 121     }
 122 }
 123
 124 void saa_rewind(struct SAA *s)
 125 {
 126     s->rblk = s->blk_ptrs;
 127     s->rpos = s->rptr = 0;
 128 }
 129
 130 void *saa_rstruct(struct SAA *s)
 131 {
 132     void *p;
 133
 134     if (s->rptr + s->elem_len > s->datalen)
 135         return NULL;
 136
 137     if (s->rpos % s->elem_len)
 138         nasm_malloc_error(ERR_PANIC | ERR_NOFILE,
 139                           "misaligned rpos in saa_rstruct");
 140
 141     if (s->rpos + s->elem_len > s->blk_len) {
 142         s->rblk++;
 143         s->rpos = 0;
 144     }
 145
 146     p = *s->rblk + s->rpos;
 147     s->rpos += s->elem_len;
 148     s->rptr += s->elem_len;
 149
 150     return p;
 151 }
 152
 153 const void *saa_rbytes(struct SAA *s, size_t * lenp)
 154 {
 155     const void *p;
 156     size_t len;
 157
 158     if (s->rptr >= s->datalen) {
 159         *lenp = 0;
 160         return NULL;
 161     }
 162
 163     if (s->rpos >= s->blk_len) {
 164         s->rblk++;
 165         s->rpos = 0;
 166     }
 167
 168     len = *lenp;
 169     if (len > s->datalen - s->rptr)
 170         len = s->datalen - s->rptr;
 171     if (len > s->blk_len - s->rpos)
 172         len = s->blk_len - s->rpos;
 173
 174     *lenp = len;
 175     p = *s->rblk + s->rpos;
 176
 177     s->rpos += len;
 178     s->rptr += len;
 179
 180     return p;
 181 }
 182
 183 void saa_rnbytes(struct SAA *s, void *data, size_t len)
 184 {
 185     char *d = data;
 186
 187     if (s->rptr + len > s->datalen) {
 188         nasm_malloc_error(ERR_PANIC | ERR_NOFILE,
 189                           "overrun in saa_rnbytes");
 190         return;
 191     }
 192
 193     while (len) {
 194         size_t l;
 195         const void *p;
 196
 197         l = len;
 198         p = saa_rbytes(s, &l);
 199
 200         memcpy(d, p, l);
 201         d += l;
 202         len -= l;
 203     }
 204 }
 205
 206 /* Same as saa_rnbytes, except position the counter first */
 207 void saa_fread(struct SAA *s, size_t posn, void *data, size_t len)
 208 {
 209     size_t ix;
 210
 211     if (posn + len > s->datalen) {
 212         nasm_malloc_error(ERR_PANIC | ERR_NOFILE, "overrun in saa_fread");
 213         return;
 214     }
 215
 216     if (likely(s->blk_len == SAA_BLKLEN)) {
 217         ix = posn >> SAA_BLKSHIFT;
 218         s->rpos = posn & (SAA_BLKLEN - 1);
 219     } else {
 220         ix = posn / s->blk_len;
 221         s->rpos = posn % s->blk_len;
 222     }
 223     s->rptr = posn;
 224     s->rblk = &s->blk_ptrs[ix];
 225
 226     saa_rnbytes(s, data, len);
 227 }
 228
 229 /* Same as saa_wbytes, except position the counter first */
 230 void saa_fwrite(struct SAA *s, size_t posn, const void *data, size_t len)
 231 {
 232     size_t ix;
 233
 234     if (posn > s->datalen) {
 235         /* Seek beyond the end of the existing array not supported */
 236         nasm_malloc_error(ERR_PANIC | ERR_NOFILE, "overrun in saa_fwrite");
 237         return;
 238     }
 239
 240     if (likely(s->blk_len == SAA_BLKLEN)) {
 241         ix = posn >> SAA_BLKSHIFT;
 242         s->wpos = posn & (SAA_BLKLEN - 1);
 243     } else {
 244         ix = posn / s->blk_len;
 245         s->wpos = posn % s->blk_len;
 246     }
 247     s->wptr = posn;
 248     s->wblk = &s->blk_ptrs[ix];
 249
 250     if (!s->wpos) {
 251         s->wpos = s->blk_len;
 252         s->wblk--;
 253     }
 254
 255     saa_wbytes(s, data, len);
 256 }
 257
 258 void saa_fpwrite(struct SAA *s, FILE * fp)
 259 {
 260     const char *data;
 261     size_t len;
 262
 263     saa_rewind(s);
 264     while (len = s->datalen, (data = saa_rbytes(s, &len)) != NULL)
 265         fwrite(data, 1, len, fp);
 266 }
 267
 268 void saa_write8(struct SAA *s, uint8_t v)
 269 {
 270     saa_wbytes(s, &v, 1);
 271 }
 272
 273 #ifdef WORDS_LITTEENDIAN
 274
 275 void saa_write16(struct SAA *s, uint16_t v)
 276 {
 277     saa_wbytes(s, &v, 2);
 278 }
 279
 280 void saa_write32(struct SAA *s, uint32_t v)
 281 {
 282     saa_wbytes(s, &v, 4);
 283 }
 284
 285 void saa_write64(struct SAA *s, uint64_t v)
 286 {
 287     saa_wbytes(s, &v, 8);
 288 }
 289
 290 #else                           /* not WORDS_LITTLEENDIAN */
 291
 292 void saa_write16(struct SAA *s, uint16_t v)
 293 {
 294     uint8_t b[2];
 295
 296     b[0] = v;
 297     b[1] = v >> 8;
 298     saa_wbytes(s, b, 2);
 299 }
 300
 301 void saa_write32(struct SAA *s, uint32_t v)
 302 {
 303     uint8_t b[4];
 304
 305     b[0] = v;
 306     b[1] = v >> 8;
 307     b[2] = v >> 16;
 308     b[3] = v >> 24;
 309     saa_wbytes(s, b, 4);
 310 }
 311
 312 void saa_write64(struct SAA *s, uint64_t v)
 313 {
 314     uint8_t b[8];
 315
 316     b[0] = v;
 317     b[1] = v >> 8;
 318     b[2] = v >> 16;
 319     b[3] = v >> 24;
 320     b[4] = v >> 32;
 321     b[5] = v >> 40;
 322     b[6] = v >> 48;
 323     b[7] = v >> 56;
 324     saa_wbytes(s, b, 8);
 325 }
 326
 327 #endif                          /* WORDS_LITTLEENDIAN */
 328
 329 /* write unsigned LEB128 value to SAA */
 330 void saa_wleb128u(struct SAA *psaa, int value)
 331 {
 332     char temp[64], *ptemp;
 333     uint8_t byte;
 334     int len;
 335
 336     ptemp = temp;
 337     len = 0;
 338     do {
 339         byte = value & 127;
 340         value >>= 7;
 341         if (value != 0)         /* more bytes to come */
 342             byte |= 0x80;
 343         *ptemp = byte;
 344         ptemp++;
 345         len++;
 346     } while (value != 0);
 347     saa_wbytes(psaa, temp, len);
 348 }
 349
 350 /* write signed LEB128 value to SAA */
 351 void saa_wleb128s(struct SAA *psaa, int value)
 352 {
 353     char temp[64], *ptemp;
 354     uint8_t byte;
 355     bool more, negative;
 356     int size, len;
 357
 358     ptemp = temp;
 359     more = 1;
 360     negative = (value < 0);
 361     size = sizeof(int) * 8;
 362     len = 0;
 363     while (more) {
 364         byte = value & 0x7f;
 365         value >>= 7;
 366         if (negative)
 367             /* sign extend */
 368             value |= -(1 << (size - 7));
 369         /* sign bit of byte is second high order bit (0x40) */
 370         if ((value == 0 && !(byte & 0x40)) ||
 371             ((value == -1) && (byte & 0x40)))
 372             more = 0;
 373         else
 374             byte |= 0x80;
 375         *ptemp = byte;
 376         ptemp++;
 377         len++;
 378     }
 379     saa_wbytes(psaa, temp, len);
 380 }