src/zlib/zutil.c

   1 /* zutil.c -- target dependent utility functions for the compression library
   2  * Copyright (C) 1995-2005, 2010, 2011, 2012 Jean-loup Gailly.
   3  * For conditions of distribution and use, see copyright notice in zlib.h
   4  */
   5
   6
   7 #include "zutil.h"
   8 #ifndef Z_SOLO
   9 #  include "gzguts.h"
  10 #endif
  11
  12 #ifndef NO_DUMMY_DECL
  13 struct internal_state      {int dummy;}; /* for buggy compilers */
  14 #endif
  15
  16 z_const char * const z_errmsg[10] = {
  17 "need dictionary",     /* Z_NEED_DICT       2  */
  18 "stream end",          /* Z_STREAM_END      1  */
  19 "",                    /* Z_OK              0  */
  20 "file error",          /* Z_ERRNO         (-1) */
  21 "stream error",        /* Z_STREAM_ERROR  (-2) */
  22 "data error",          /* Z_DATA_ERROR    (-3) */
  23 "insufficient memory", /* Z_MEM_ERROR     (-4) */
  24 "buffer error",        /* Z_BUF_ERROR     (-5) */
  25 "incompatible version",/* Z_VERSION_ERROR (-6) */
  26 ""};
  27
  28
  29 const char * ZEXPORT zlibVersion()
  30 {
  31     return ZLIB_VERSION;
  32 }
  33
  34 uLong ZEXPORT zlibCompileFlags()
  35 {
  36     uLong flags;
  37
  38     flags = 0;
  39     switch ((int)(sizeof(uInt))) {
  40     case 2:     break;
  41     case 4:     flags += 1;     break;
  42     case 8:     flags += 2;     break;
  43     default:    flags += 3;
  44     }
  45     switch ((int)(sizeof(uLong))) {
  46     case 2:     break;
  47     case 4:     flags += 1 << 2;        break;
  48     case 8:     flags += 2 << 2;        break;
  49     default:    flags += 3 << 2;
  50     }
  51     switch ((int)(sizeof(voidpf))) {
  52     case 2:     break;
  53     case 4:     flags += 1 << 4;        break;
  54     case 8:     flags += 2 << 4;        break;
  55     default:    flags += 3 << 4;
  56     }
  57     switch ((int)(sizeof(z_off_t))) {
  58     case 2:     break;
  59     case 4:     flags += 1 << 6;        break;
  60     case 8:     flags += 2 << 6;        break;
  61     default:    flags += 3 << 6;
  62     }
  63 #ifdef DEBUG
  64     flags += 1 << 8;
  65 #endif
  66 #if defined(ASMV) || defined(ASMINF)
  67     flags += 1 << 9;
  68 #endif
  69 #ifdef ZLIB_WINAPI
  70     flags += 1 << 10;
  71 #endif
  72 #ifdef BUILDFIXED
  73     flags += 1 << 12;
  74 #endif
  75 #ifdef DYNAMIC_CRC_TABLE
  76     flags += 1 << 13;
  77 #endif
  78 #ifdef NO_GZCOMPRESS
  79     flags += 1L << 16;
  80 #endif
  81 #ifdef NO_GZIP
  82     flags += 1L << 17;
  83 #endif
  84 #ifdef PKZIP_BUG_WORKAROUND
  85     flags += 1L << 20;
  86 #endif
  87 #ifdef FASTEST
  88     flags += 1L << 21;
  89 #endif
  90 #if defined(STDC) || defined(Z_HAVE_STDARG_H)
  91 #  ifdef NO_vsnprintf
  92     flags += 1L << 25;
  93 #    ifdef HAS_vsprintf_void
  94     flags += 1L << 26;
  95 #    endif
  96 #  else
  97 #    ifdef HAS_vsnprintf_void
  98     flags += 1L << 26;
  99 #    endif
 100 #  endif
 101 #else
 102     flags += 1L << 24;
 103 #  ifdef NO_snprintf
 104     flags += 1L << 25;
 105 #    ifdef HAS_sprintf_void
 106     flags += 1L << 26;
 107 #    endif
 108 #  else
 109 #    ifdef HAS_snprintf_void
 110     flags += 1L << 26;
 111 #    endif
 112 #  endif
 113 #endif
 114     return flags;
 115 }
 116
 117 #ifdef DEBUG
 118
 119 #  ifndef verbose
 120 #    define verbose 0
 121 #  endif
 122 int ZLIB_INTERNAL z_verbose = verbose;
 123
 124 void ZLIB_INTERNAL z_error (m)
 125     char *m;
 126 {
 127     fprintf(stderr, "%s\n", m);
 128     exit(1);
 129 }
 130 #endif
 131
 132 /* exported to allow conversion of error code to string for compress() and
 133  * uncompress()
 134  */
 135 const char * ZEXPORT zError(err)
 136     int err;
 137 {
 138     return ERR_MSG(err);
 139 }
 140
 141 #if defined(_WIN32_WCE)
 142     /* The Microsoft C Run-Time Library for Windows CE doesn't have
 143      * errno.  We define it as a global variable to simplify porting.
 144      * Its value is always 0 and should not be used.
 145      */
 146     int errno = 0;
 147 #endif
 148
 149 #ifndef HAVE_MEMCPY
 150
 151 void ZLIB_INTERNAL zmemcpy(dest, source, len)
 152     Bytef* dest;
 153     const Bytef* source;
 154     uInt  len;
 155 {
 156     if (len == 0) return;
 157     do {
 158         *dest++ = *source++; /* ??? to be unrolled */
 159     } while (--len != 0);
 160 }
 161
 162 int ZLIB_INTERNAL zmemcmp(s1, s2, len)
 163     const Bytef* s1;
 164     const Bytef* s2;
 165     uInt  len;
 166 {
 167     uInt j;
 168
 169     for (j = 0; j < len; j++) {
 170         if (s1[j] != s2[j]) return 2*(s1[j] > s2[j])-1;
 171     }
 172     return 0;
 173 }
 174
 175 void ZLIB_INTERNAL zmemzero(dest, len)
 176     Bytef* dest;
 177     uInt  len;
 178 {
 179     if (len == 0) return;
 180     do {
 181         *dest++ = 0;  /* ??? to be unrolled */
 182     } while (--len != 0);
 183 }
 184 #endif
 185
 186 #ifndef Z_SOLO
 187
 188 #ifdef SYS16BIT
 189
 190 #ifdef __TURBOC__
 191 /* Turbo C in 16-bit mode */
 192
 193 #  define MY_ZCALLOC
 194
 195 /* Turbo C malloc() does not allow dynamic allocation of 64K bytes
 196  * and farmalloc(64K) returns a pointer with an offset of 8, so we
 197  * must fix the pointer. Warning: the pointer must be put back to its
 198  * original form in order to free it, use zcfree().
 199  */
 200
 201 #define MAX_PTR 10
 202 /* 10*64K = 640K */
 203
 204 local int next_ptr = 0;
 205
 206 typedef struct ptr_table_s {
 207     voidpf org_ptr;
 208     voidpf new_ptr;
 209 } ptr_table;
 210
 211 local ptr_table table[MAX_PTR];
 212 /* This table is used to remember the original form of pointers
 213  * to large buffers (64K). Such pointers are normalized with a zero offset.
 214  * Since MSDOS is not a preemptive multitasking OS, this table is not
 215  * protected from concurrent access. This hack doesn't work anyway on
 216  * a protected system like OS/2. Use Microsoft C instead.
 217  */
 218
 219 voidpf ZLIB_INTERNAL zcalloc (voidpf opaque, unsigned items, unsigned size)
 220 {
 221     voidpf buf = opaque; /* just to make some compilers happy */
 222     ulg bsize = (ulg)items*size;
 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     if (*(ush*)&ptr != 0) { /* object < 64K */
 247         farfree(ptr);
 248         return;
 249     }
 250     /* Find the original pointer */
 251     for (n = 0; n < next_ptr; n++) {
 252         if (ptr != table[n].new_ptr) continue;
 253
 254         farfree(table[n].org_ptr);
 255         while (++n < next_ptr) {
 256             table[n-1] = table[n];
 257         }
 258         next_ptr--;
 259         return;
 260     }
 261     ptr = opaque; /* just to make some compilers happy */
 262     Assert(0, "zcfree: ptr not found");
 263 }
 264
 265 #endif /* __TURBOC__ */
 266
 267
 268 #ifdef M_I86
 269 /* Microsoft C in 16-bit mode */
 270
 271 #  define MY_ZCALLOC
 272
 273 #if (!defined(_MSC_VER) || (_MSC_VER <= 600))
 274 #  define _halloc  halloc
 275 #  define _hfree   hfree
 276 #endif
 277
 278 voidpf ZLIB_INTERNAL zcalloc (voidpf opaque, uInt items, uInt size)
 279 {
 280     if (opaque) opaque = 0; /* to make compiler happy */
 281     return _halloc((long)items, size);
 282 }
 283
 284 void ZLIB_INTERNAL zcfree (voidpf opaque, voidpf ptr)
 285 {
 286     if (opaque) opaque = 0; /* to make compiler happy */
 287     _hfree(ptr);
 288 }
 289
 290 #endif /* M_I86 */
 291
 292 #endif /* SYS16BIT */
 293
 294
 295 #ifndef MY_ZCALLOC /* Any system without a special alloc function */
 296
 297 #ifndef STDC
 298 extern voidp  malloc OF((uInt size));
 299 extern voidp  calloc OF((uInt items, uInt size));
 300 extern void   free   OF((voidpf ptr));
 301 #endif
 302
 303 voidpf ZLIB_INTERNAL zcalloc (opaque, items, size)
 304     voidpf opaque;
 305     unsigned items;
 306     unsigned size;
 307 {
 308     if (opaque) items += size - size; /* make compiler happy */
 309     return sizeof(uInt) > 2 ? (voidpf)malloc(items * size) :
 310                               (voidpf)calloc(items, size);
 311 }
 312
 313 void ZLIB_INTERNAL zcfree (opaque, ptr)
 314     voidpf opaque;
 315     voidpf ptr;
 316 {
 317     free(ptr);
 318     if (opaque) return; /* make compiler happy */
 319 }
 320
 321 #endif /* MY_ZCALLOC */
 322
 323 #endif /* !Z_SOLO */