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      1 /* zutil.c -- target dependent utility functions for the compression library
      2  * Copyright (C) 1995-2005, 2010 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 
     10 #ifndef NO_DUMMY_DECL
     11 struct internal_state      {int dummy;}; /* for buggy compilers */
     12 #endif
     13 
     14 const char * const z_errmsg[10] = {
     15 "need dictionary",     /* Z_NEED_DICT       2  */
     16 "stream end",          /* Z_STREAM_END      1  */
     17 "",                    /* Z_OK              0  */
     18 "file error",          /* Z_ERRNO         (-1) */
     19 "stream error",        /* Z_STREAM_ERROR  (-2) */
     20 "data error",          /* Z_DATA_ERROR    (-3) */
     21 "insufficient memory", /* Z_MEM_ERROR     (-4) */
     22 "buffer error",        /* Z_BUF_ERROR     (-5) */
     23 "incompatible version",/* Z_VERSION_ERROR (-6) */
     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 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 #ifdef STDC
     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 DEBUG
    116 
    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 
    185 #ifdef SYS16BIT
    186 
    187 #ifdef __TURBOC__
    188 /* Turbo C in 16-bit mode */
    189 
    190 #  define MY_ZCALLOC
    191 
    192 /* Turbo C malloc() does not allow dynamic allocation of 64K bytes
    193  * and farmalloc(64K) returns a pointer with an offset of 8, so we
    194  * must fix the pointer. Warning: the pointer must be put back to its
    195  * original form in order to free it, use zcfree().
    196  */
    197 
    198 #define MAX_PTR 10
    199 /* 10*64K = 640K */
    200 
    201 local int next_ptr = 0;
    202 
    203 typedef struct ptr_table_s {
    204     voidpf org_ptr;
    205     voidpf new_ptr;
    206 } ptr_table;
    207 
    208 local ptr_table table[MAX_PTR];
    209 /* This table is used to remember the original form of pointers
    210  * to large buffers (64K). Such pointers are normalized with a zero offset.
    211  * Since MSDOS is not a preemptive multitasking OS, this table is not
    212  * protected from concurrent access. This hack doesn't work anyway on
    213  * a protected system like OS/2. Use Microsoft C instead.
    214  */
    215 
    216 voidpf ZLIB_INTERNAL zcalloc (voidpf opaque, unsigned items, unsigned size)
    217 {
    218     voidpf buf = opaque; /* just to make some compilers happy */
    219     ulg bsize = (ulg)items*size;
    220 
    221     /* If we allocate less than 65520 bytes, we assume that farmalloc
    222      * will return a usable pointer which doesn't have to be normalized.
    223      */
    224     if (bsize < 65520L) {
    225         buf = farmalloc(bsize);
    226         if (*(ush*)&buf != 0) return buf;
    227     } else {
    228         buf = farmalloc(bsize + 16L);
    229     }
    230     if (buf == NULL || next_ptr >= MAX_PTR) return NULL;
    231     table[next_ptr].org_ptr = buf;
    232 
    233     /* Normalize the pointer to seg:0 */
    234     *((ush*)&buf+1) += ((ush)((uch*)buf-0) + 15) >> 4;
    235     *(ush*)&buf = 0;
    236     table[next_ptr++].new_ptr = buf;
    237     return buf;
    238 }
    239 
    240 void ZLIB_INTERNAL zcfree (voidpf opaque, voidpf ptr)
    241 {
    242     int n;
    243     if (*(ush*)&ptr != 0) { /* object < 64K */
    244         farfree(ptr);
    245         return;
    246     }
    247     /* Find the original pointer */
    248     for (n = 0; n < next_ptr; n++) {
    249         if (ptr != table[n].new_ptr) continue;
    250 
    251         farfree(table[n].org_ptr);
    252         while (++n < next_ptr) {
    253             table[n-1] = table[n];
    254         }
    255         next_ptr--;
    256         return;
    257     }
    258     ptr = opaque; /* just to make some compilers happy */
    259     Assert(0, "zcfree: ptr not found");
    260 }
    261 
    262 #endif /* __TURBOC__ */
    263 
    264 
    265 #ifdef M_I86
    266 /* Microsoft C in 16-bit mode */
    267 
    268 #  define MY_ZCALLOC
    269 
    270 #if (!defined(_MSC_VER) || (_MSC_VER <= 600))
    271 #  define _halloc  halloc
    272 #  define _hfree   hfree
    273 #endif
    274 
    275 voidpf ZLIB_INTERNAL zcalloc (voidpf opaque, uInt items, uInt size)
    276 {
    277     if (opaque) opaque = 0; /* to make compiler happy */
    278     return _halloc((long)items, size);
    279 }
    280 
    281 void ZLIB_INTERNAL zcfree (voidpf opaque, voidpf ptr)
    282 {
    283     if (opaque) opaque = 0; /* to make compiler happy */
    284     _hfree(ptr);
    285 }
    286 
    287 #endif /* M_I86 */
    288 
    289 #endif /* SYS16BIT */
    290 
    291 
    292 #ifndef MY_ZCALLOC /* Any system without a special alloc function */
    293 
    294 #ifndef STDC
    295 extern voidp  malloc OF((uInt size));
    296 extern voidp  calloc OF((uInt items, uInt size));
    297 extern void   free   OF((voidpf ptr));
    298 #endif
    299 
    300 voidpf ZLIB_INTERNAL zcalloc (opaque, items, size)
    301     voidpf opaque;
    302     unsigned items;
    303     unsigned size;
    304 {
    305     if (opaque) items += size - size; /* make compiler happy */
    306     return sizeof(uInt) > 2 ? (voidpf)malloc(items * size) :
    307                               (voidpf)calloc(items, size);
    308 }
    309 
    310 void ZLIB_INTERNAL zcfree (opaque, ptr)
    311     voidpf opaque;
    312     voidpf ptr;
    313 {
    314     free(ptr);
    315     if (opaque) return; /* make compiler happy */
    316 }
    317 
    318 #endif /* MY_ZCALLOC */
    319