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