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zutil.c revision 1.1.1.5 
      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 */
    300