zlib/zutil.c

   1 /* zutil.c -- target dependent utility functions for the compression library
   2  * Copyright (C) 1995-2017 Jean-loup Gailly
   3  * For conditions of distribution and use, see copyright notice in zlib.h
   4  */
   5
   6 /* @(#) $Id: zutil.c,v 1.1.1.2 2002/03/11 21:53:27 tromey Exp $ */
   7
   8 #include "zutil.h"
   9 #ifndef Z_SOLO
  10 #  include "gzguts.h"
  11 #endif
  12
  13 z_const char * const z_errmsg[10] = {
  14     (z_const char *)"need dictionary",     /* Z_NEED_DICT       2  */
  15     (z_const char *)"stream end",          /* Z_STREAM_END      1  */
  16     (z_const char *)"",                    /* Z_OK              0  */
  17     (z_const char *)"file error",          /* Z_ERRNO         (-1) */
  18     (z_const char *)"stream error",        /* Z_STREAM_ERROR  (-2) */
  19     (z_const char *)"data error",          /* Z_DATA_ERROR    (-3) */
  20     (z_const char *)"insufficient memory", /* Z_MEM_ERROR     (-4) */
  21     (z_const char *)"buffer error",        /* Z_BUF_ERROR     (-5) */
  22     (z_const char *)"incompatible version",/* Z_VERSION_ERROR (-6) */
  23     (z_const char *)""
  24 };
  25
  26
  27 const char * ZEXPORT zlibVersion()
  28 {
  29     return ZLIB_VERSION;
  30 }
  31
  32 uLong ZEXPORT zlibCompileFlags()
  33 {
  34     uLong flags;
  35
  36     flags = 0;
  37     switch ((int)(sizeof(uInt))) {
  38     case 2:     break;
  39     case 4:     flags += 1;     break;
  40     case 8:     flags += 2;     break;
  41     default:    flags += 3;
  42     }
  43     switch ((int)(sizeof(uLong))) {
  44     case 2:     break;
  45     case 4:     flags += 1 << 2;        break;
  46     case 8:     flags += 2 << 2;        break;
  47     default:    flags += 3 << 2;
  48     }
  49     switch ((int)(sizeof(voidpf))) {
  50     case 2:     break;
  51     case 4:     flags += 1 << 4;        break;
  52     case 8:     flags += 2 << 4;        break;
  53     default:    flags += 3 << 4;
  54     }
  55     switch ((int)(sizeof(z_off_t))) {
  56     case 2:     break;
  57     case 4:     flags += 1 << 6;        break;
  58     case 8:     flags += 2 << 6;        break;
  59     default:    flags += 3 << 6;
  60     }
  61 #ifdef ZLIB_DEBUG
  62     flags += 1 << 8;
  63 #endif
  64 #if defined(ASMV) || defined(ASMINF)
  65     flags += 1 << 9;
  66 #endif
  67 #ifdef ZLIB_WINAPI
  68     flags += 1 << 10;
  69 #endif
  70 #ifdef BUILDFIXED
  71     flags += 1 << 12;
  72 #endif
  73 #ifdef DYNAMIC_CRC_TABLE
  74     flags += 1 << 13;
  75 #endif
  76 #ifdef NO_GZCOMPRESS
  77     flags += 1L << 16;
  78 #endif
  79 #ifdef NO_GZIP
  80     flags += 1L << 17;
  81 #endif
  82 #ifdef PKZIP_BUG_WORKAROUND
  83     flags += 1L << 20;
  84 #endif
  85 #ifdef FASTEST
  86     flags += 1L << 21;
  87 #endif
  88 #if defined(STDC) || defined(Z_HAVE_STDARG_H)
  89 #  ifdef NO_vsnprintf
  90     flags += 1L << 25;
  91 #    ifdef HAS_vsprintf_void
  92     flags += 1L << 26;
  93 #    endif
  94 #  else
  95 #    ifdef HAS_vsnprintf_void
  96     flags += 1L << 26;
  97 #    endif
  98 #  endif
  99 #else
 100     flags += 1L << 24;
 101 #  ifdef NO_snprintf
 102     flags += 1L << 25;
 103 #    ifdef HAS_sprintf_void
 104     flags += 1L << 26;
 105 #    endif
 106 #  else
 107 #    ifdef HAS_snprintf_void
 108     flags += 1L << 26;
 109 #    endif
 110 #  endif
 111 #endif
 112     return flags;
 113 }
 114
 115 #ifdef ZLIB_DEBUG
 116 #include <stdlib.h>
 117 #  ifndef verbose
 118 #    define verbose 0
 119 #  endif
 120 int ZLIB_INTERNAL z_verbose = verbose;
 121
 122 void ZLIB_INTERNAL z_error (m)
 123     char *m;
 124 {
 125     fprintf(stderr, "%s\n", m);
 126     exit(1);
 127 }
 128 #endif
 129
 130 /* exported to allow conversion of error code to string for compress() and
 131  * uncompress()
 132  */
 133 const char * ZEXPORT zError(err)
 134     int err;
 135 {
 136     return ERR_MSG(err);
 137 }
 138
 139 #if defined(_WIN32_WCE)
 140     /* The Microsoft C Run-Time Library for Windows CE doesn't have
 141      * errno.  We define it as a global variable to simplify porting.
 142      * Its value is always 0 and should not be used.
 143      */
 144     int errno = 0;
 145 #endif
 146
 147 #ifndef HAVE_MEMCPY
 148
 149 void ZLIB_INTERNAL zmemcpy(dest, source, len)
 150     Bytef* dest;
 151     const Bytef* source;
 152     uInt  len;
 153 {
 154     if (len == 0) return;
 155     do {
 156         *dest++ = *source++; /* ??? to be unrolled */
 157     } while (--len != 0);
 158 }
 159
 160 int ZLIB_INTERNAL zmemcmp(s1, s2, len)
 161     const Bytef* s1;
 162     const Bytef* s2;
 163     uInt  len;
 164 {
 165     uInt j;
 166
 167     for (j = 0; j < len; j++) {
 168         if (s1[j] != s2[j]) return 2*(s1[j] > s2[j])-1;
 169     }
 170     return 0;
 171 }
 172
 173 void ZLIB_INTERNAL zmemzero(dest, len)
 174     Bytef* dest;
 175     uInt  len;
 176 {
 177     if (len == 0) return;
 178     do {
 179         *dest++ = 0;  /* ??? to be unrolled */
 180     } while (--len != 0);
 181 }
 182 #endif
 183
 184 #ifndef Z_SOLO
 185
 186 #ifdef SYS16BIT
 187
 188 #ifdef __TURBOC__
 189 /* Turbo C in 16-bit mode */
 190
 191 #  define MY_ZCALLOC
 192
 193 /* Turbo C malloc() does not allow dynamic allocation of 64K bytes
 194  * and farmalloc(64K) returns a pointer with an offset of 8, so we
 195  * must fix the pointer. Warning: the pointer must be put back to its
 196  * original form in order to free it, use zcfree().
 197  */
 198
 199 #define MAX_PTR 10
 200 /* 10*64K = 640K */
 201
 202 local int next_ptr = 0;
 203
 204 typedef struct ptr_table_s {
 205     voidpf org_ptr;
 206     voidpf new_ptr;
 207 } ptr_table;
 208
 209 local ptr_table table[MAX_PTR];
 210 /* This table is used to remember the original form of pointers
 211  * to large buffers (64K). Such pointers are normalized with a zero offset.
 212  * Since MSDOS is not a preemptive multitasking OS, this table is not
 213  * protected from concurrent access. This hack doesn't work anyway on
 214  * a protected system like OS/2. Use Microsoft C instead.
 215  */
 216
 217 voidpf ZLIB_INTERNAL zcalloc (voidpf opaque, unsigned items, unsigned size)
 218 {
 219     voidpf buf;
 220     ulg bsize = (ulg)items*size;
 221
 222     (void)opaque;
 223
 224     /* If we allocate less than 65520 bytes, we assume that farmalloc
 225      * will return a usable pointer which doesn't have to be normalized.
 226      */
 227     if (bsize < 65520L) {
 228         buf = farmalloc(bsize);
 229         if (*(ush*)&buf != 0) return buf;
 230     } else {
 231         buf = farmalloc(bsize + 16L);
 232     }
 233     if (buf == NULL || next_ptr >= MAX_PTR) return NULL;
 234     table[next_ptr].org_ptr = buf;
 235
 236     /* Normalize the pointer to seg:0 */
 237     *((ush*)&buf+1) += ((ush)((uch*)buf-0) + 15) >> 4;
 238     *(ush*)&buf = 0;
 239     table[next_ptr++].new_ptr = buf;
 240     return buf;
 241 }
 242
 243 void ZLIB_INTERNAL zcfree (voidpf opaque, voidpf ptr)
 244 {
 245     int n;
 246
 247     (void)opaque;
 248
 249     if (*(ush*)&ptr != 0) { /* object < 64K */
 250         farfree(ptr);
 251         return;
 252     }
 253     /* Find the original pointer */
 254     for (n = 0; n < next_ptr; n++) {
 255         if (ptr != table[n].new_ptr) continue;
 256
 257         farfree(table[n].org_ptr);
 258         while (++n < next_ptr) {
 259             table[n-1] = table[n];
 260         }
 261         next_ptr--;
 262         return;
 263     }
 264     Assert(0, "zcfree: ptr not found");
 265 }
 266
 267 #endif /* __TURBOC__ */
 268
 269
 270 #ifdef M_I86
 271 /* Microsoft C in 16-bit mode */
 272
 273 #  define MY_ZCALLOC
 274
 275 #if (!defined(_MSC_VER) || (_MSC_VER <= 600))
 276 #  define _halloc  halloc
 277 #  define _hfree   hfree
 278 #endif
 279
 280 voidpf ZLIB_INTERNAL zcalloc (voidpf opaque, uInt items, uInt size)
 281 {
 282     (void)opaque;
 283     return _halloc((long)items, size);
 284 }
 285
 286 void ZLIB_INTERNAL zcfree (voidpf opaque, voidpf ptr)
 287 {
 288     (void)opaque;
 289     _hfree(ptr);
 290 }
 291
 292 #endif /* M_I86 */
 293
 294 #endif /* SYS16BIT */
 295
 296
 297 #ifndef MY_ZCALLOC /* Any system without a special alloc function */
 298
 299 #ifndef STDC
 300 extern voidp  malloc OF((uInt size));
 301 extern voidp  calloc OF((uInt items, uInt size));
 302 extern void   free   OF((voidpf ptr));
 303 #endif
 304
 305 voidpf ZLIB_INTERNAL zcalloc (opaque, items, size)
 306     voidpf opaque;
 307     unsigned items;
 308     unsigned size;
 309 {
 310     (void)opaque;
 311     return sizeof(uInt) > 2 ? (voidpf)malloc(items * size) :
 312                               (voidpf)calloc(items, size);
 313 }
 314
 315 void ZLIB_INTERNAL zcfree (opaque, ptr)
 316     voidpf opaque;
 317     voidpf ptr;
 318 {
 319     (void)opaque;
 320     free(ptr);
 321 }
 322
 323 #endif /* MY_ZCALLOC */
 324
 325 #endif /* !Z_SOLO */