libs/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 /* @(#) $Id$ */
   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(void) {
  28     return ZLIB_VERSION;
  29 }
  30
  31 uLong ZEXPORT zlibCompileFlags(void) {
  32     uLong flags;
  33
  34     flags = 0;
  35     switch ((int)(sizeof(uInt))) {
  36     case 2:     break;
  37     case 4:     flags += 1;     break;
  38     case 8:     flags += 2;     break;
  39     default:    flags += 3;
  40     }
  41     switch ((int)(sizeof(uLong))) {
  42     case 2:     break;
  43     case 4:     flags += 1 << 2;        break;
  44     case 8:     flags += 2 << 2;        break;
  45     default:    flags += 3 << 2;
  46     }
  47     switch ((int)(sizeof(voidpf))) {
  48     case 2:     break;
  49     case 4:     flags += 1 << 4;        break;
  50     case 8:     flags += 2 << 4;        break;
  51     default:    flags += 3 << 4;
  52     }
  53     switch ((int)(sizeof(z_off_t))) {
  54     case 2:     break;
  55     case 4:     flags += 1 << 6;        break;
  56     case 8:     flags += 2 << 6;        break;
  57     default:    flags += 3 << 6;
  58     }
  59 #ifdef ZLIB_DEBUG
  60     flags += 1 << 8;
  61 #endif
  62     /*
  63 #if defined(ASMV) || defined(ASMINF)
  64     flags += 1 << 9;
  65 #endif
  66      */
  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(char *m) {
 123     fprintf(stderr, "%s\n", m);
 124     exit(1);
 125 }
 126 #endif
 127
 128 /* exported to allow conversion of error code to string for compress() and
 129  * uncompress()
 130  */
 131 const char * ZEXPORT zError(int err) {
 132     return ERR_MSG(err);
 133 }
 134
 135 #if defined(_WIN32_WCE) && _WIN32_WCE < 0x800
 136     /* The older Microsoft C Run-Time Library for Windows CE doesn't have
 137      * errno.  We define it as a global variable to simplify porting.
 138      * Its value is always 0 and should not be used.
 139      */
 140     int errno = 0;
 141 #endif
 142
 143 #ifndef HAVE_MEMCPY
 144
 145 void ZLIB_INTERNAL zmemcpy(Bytef* dest, const Bytef* source, uInt len) {
 146     if (len == 0) return;
 147     do {
 148         *dest++ = *source++; /* ??? to be unrolled */
 149     } while (--len != 0);
 150 }
 151
 152 int ZLIB_INTERNAL zmemcmp(const Bytef* s1, const Bytef* s2, uInt len) {
 153     uInt j;
 154
 155     for (j = 0; j < len; j++) {
 156         if (s1[j] != s2[j]) return 2*(s1[j] > s2[j])-1;
 157     }
 158     return 0;
 159 }
 160
 161 void ZLIB_INTERNAL zmemzero(Bytef* dest, uInt len) {
 162     if (len == 0) return;
 163     do {
 164         *dest++ = 0;  /* ??? to be unrolled */
 165     } while (--len != 0);
 166 }
 167 #endif
 168
 169 #ifndef Z_SOLO
 170
 171 #ifdef SYS16BIT
 172
 173 #ifdef __TURBOC__
 174 /* Turbo C in 16-bit mode */
 175
 176 #  define MY_ZCALLOC
 177
 178 /* Turbo C malloc() does not allow dynamic allocation of 64K bytes
 179  * and farmalloc(64K) returns a pointer with an offset of 8, so we
 180  * must fix the pointer. Warning: the pointer must be put back to its
 181  * original form in order to free it, use zcfree().
 182  */
 183
 184 #define MAX_PTR 10
 185 /* 10*64K = 640K */
 186
 187 local int next_ptr = 0;
 188
 189 typedef struct ptr_table_s {
 190     voidpf org_ptr;
 191     voidpf new_ptr;
 192 } ptr_table;
 193
 194 local ptr_table table[MAX_PTR];
 195 /* This table is used to remember the original form of pointers
 196  * to large buffers (64K). Such pointers are normalized with a zero offset.
 197  * Since MSDOS is not a preemptive multitasking OS, this table is not
 198  * protected from concurrent access. This hack doesn't work anyway on
 199  * a protected system like OS/2. Use Microsoft C instead.
 200  */
 201
 202 voidpf ZLIB_INTERNAL zcalloc(voidpf opaque, unsigned items, unsigned size) {
 203     voidpf buf;
 204     ulg bsize = (ulg)items*size;
 205
 206     (void)opaque;
 207
 208     /* If we allocate less than 65520 bytes, we assume that farmalloc
 209      * will return a usable pointer which doesn't have to be normalized.
 210      */
 211     if (bsize < 65520L) {
 212         buf = farmalloc(bsize);
 213         if (*(ush*)&buf != 0) return buf;
 214     } else {
 215         buf = farmalloc(bsize + 16L);
 216     }
 217     if (buf == NULL || next_ptr >= MAX_PTR) return NULL;
 218     table[next_ptr].org_ptr = buf;
 219
 220     /* Normalize the pointer to seg:0 */
 221     *((ush*)&buf+1) += ((ush)((uch*)buf-0) + 15) >> 4;
 222     *(ush*)&buf = 0;
 223     table[next_ptr++].new_ptr = buf;
 224     return buf;
 225 }
 226
 227 void ZLIB_INTERNAL zcfree(voidpf opaque, voidpf ptr) {
 228     int n;
 229
 230     (void)opaque;
 231
 232     if (*(ush*)&ptr != 0) { /* object < 64K */
 233         farfree(ptr);
 234         return;
 235     }
 236     /* Find the original pointer */
 237     for (n = 0; n < next_ptr; n++) {
 238         if (ptr != table[n].new_ptr) continue;
 239
 240         farfree(table[n].org_ptr);
 241         while (++n < next_ptr) {
 242             table[n-1] = table[n];
 243         }
 244         next_ptr--;
 245         return;
 246     }
 247     Assert(0, "zcfree: ptr not found");
 248 }
 249
 250 #endif /* __TURBOC__ */
 251
 252
 253 #ifdef M_I86
 254 /* Microsoft C in 16-bit mode */
 255
 256 #  define MY_ZCALLOC
 257
 258 #if (!defined(_MSC_VER) || (_MSC_VER <= 600))
 259 #  define _halloc  halloc
 260 #  define _hfree   hfree
 261 #endif
 262
 263 voidpf ZLIB_INTERNAL zcalloc(voidpf opaque, uInt items, uInt size) {
 264     (void)opaque;
 265     return _halloc((long)items, size);
 266 }
 267
 268 void ZLIB_INTERNAL zcfree(voidpf opaque, voidpf ptr) {
 269     (void)opaque;
 270     _hfree(ptr);
 271 }
 272
 273 #endif /* M_I86 */
 274
 275 #endif /* SYS16BIT */
 276
 277
 278 #ifndef MY_ZCALLOC /* Any system without a special alloc function */
 279
 280 #ifndef STDC
 281 extern voidp malloc(uInt size);
 282 extern voidp calloc(uInt items, uInt size);
 283 extern void free(voidpf ptr);
 284 #endif
 285
 286 voidpf ZLIB_INTERNAL zcalloc(voidpf opaque, unsigned items, unsigned size) {
 287     (void)opaque;
 288     return sizeof(uInt) > 2 ? (voidpf)malloc(items * size) :
 289                               (voidpf)calloc(items, size);
 290 }
 291
 292 void ZLIB_INTERNAL zcfree(voidpf opaque, voidpf ptr) {
 293     (void)opaque;
 294     free(ptr);
 295 }
 296
 297 #endif /* MY_ZCALLOC */
 298
 299 #endif /* !Z_SOLO */