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      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()
     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 */
    326