xref: /third_party/zlib/zutil.c (revision 275793ea) 
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
13z_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
27const char * ZEXPORT zlibVersion(void)
28{
29    return ZLIB_VERSION;
30}
31
32uLong ZEXPORT zlibCompileFlags(void)
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    /*
65#if defined(ASMV) || defined(ASMINF)
66    flags += 1 << 9;
67#endif
68     */
69#ifdef ZLIB_WINAPI
70    flags += 1 << 10;
71#endif
72#ifdef BUILDFIXED
73    flags += 1 << 12;
74#endif
75#ifdef DYNAMIC_CRC_TABLE
76    flags += 1 << 13;
77#endif
78#ifdef NO_GZCOMPRESS
79    flags += 1L << 16;
80#endif
81#ifdef NO_GZIP
82    flags += 1L << 17;
83#endif
84#ifdef PKZIP_BUG_WORKAROUND
85    flags += 1L << 20;
86#endif
87#ifdef FASTEST
88    flags += 1L << 21;
89#endif
90#if defined(STDC) || defined(Z_HAVE_STDARG_H)
91#  ifdef NO_vsnprintf
92    flags += 1L << 25;
93#    ifdef HAS_vsprintf_void
94    flags += 1L << 26;
95#    endif
96#  else
97#    ifdef HAS_vsnprintf_void
98    flags += 1L << 26;
99#    endif
100#  endif
101#else
102    flags += 1L << 24;
103#  ifdef NO_snprintf
104    flags += 1L << 25;
105#    ifdef HAS_sprintf_void
106    flags += 1L << 26;
107#    endif
108#  else
109#    ifdef HAS_snprintf_void
110    flags += 1L << 26;
111#    endif
112#  endif
113#endif
114    return flags;
115}
116
117#ifdef ZLIB_DEBUG
118#include <stdlib.h>
119#  ifndef verbose
120#    define verbose 0
121#  endif
122int ZLIB_INTERNAL z_verbose = verbose;
123
124void ZLIB_INTERNAL z_error(char *m)
125{
126    fprintf(stderr, "%s\n", m);
127    exit(1);
128}
129#endif
130
131/* exported to allow conversion of error code to string for compress() and
132 * uncompress()
133 */
134const char * ZEXPORT zError(int err)
135{
136    return ERR_MSG(err);
137}
138
139#if defined(_WIN32_WCE) && _WIN32_WCE < 0x800
140    /* The older 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
149void ZLIB_INTERNAL zmemcpy(Bytef* dest, const Bytef* source, uInt len)
150{
151    if (len == 0) return;
152    do {
153        *dest++ = *source++; /* ??? to be unrolled */
154    } while (--len != 0);
155}
156
157int ZLIB_INTERNAL zmemcmp(const Bytef* s1, const Bytef* s2, uInt len)
158{
159    uInt j;
160
161    for (j = 0; j < len; j++) {
162        if (s1[j] != s2[j]) return 2*(s1[j] > s2[j])-1;
163    }
164    return 0;
165}
166
167void ZLIB_INTERNAL zmemzero(Bytef* dest, uInt len)
168{
169    if (len == 0) return;
170    do {
171        *dest++ = 0;  /* ??? to be unrolled */
172    } while (--len != 0);
173}
174#endif
175
176#ifndef Z_SOLO
177
178#ifdef SYS16BIT
179
180#ifdef __TURBOC__
181/* Turbo C in 16-bit mode */
182
183#  define MY_ZCALLOC
184
185/* Turbo C malloc() does not allow dynamic allocation of 64K bytes
186 * and farmalloc(64K) returns a pointer with an offset of 8, so we
187 * must fix the pointer. Warning: the pointer must be put back to its
188 * original form in order to free it, use zcfree().
189 */
190
191#define MAX_PTR 10
192/* 10*64K = 640K */
193
194local int next_ptr = 0;
195
196typedef struct ptr_table_s {
197    voidpf org_ptr;
198    voidpf new_ptr;
199} ptr_table;
200
201local ptr_table table[MAX_PTR];
202/* This table is used to remember the original form of pointers
203 * to large buffers (64K). Such pointers are normalized with a zero offset.
204 * Since MSDOS is not a preemptive multitasking OS, this table is not
205 * protected from concurrent access. This hack doesn't work anyway on
206 * a protected system like OS/2. Use Microsoft C instead.
207 */
208
209voidpf ZLIB_INTERNAL zcalloc(voidpf opaque, unsigned items, unsigned size)
210{
211    voidpf buf;
212    ulg bsize = (ulg)items*size;
213
214    (void)opaque;
215
216    /* If we allocate less than 65520 bytes, we assume that farmalloc
217     * will return a usable pointer which doesn't have to be normalized.
218     */
219    if (bsize < 65520L) {
220        buf = farmalloc(bsize);
221        if (*(ush*)&buf != 0) return buf;
222    } else {
223        buf = farmalloc(bsize + 16L);
224    }
225    if (buf == NULL || next_ptr >= MAX_PTR) return NULL;
226    table[next_ptr].org_ptr = buf;
227
228    /* Normalize the pointer to seg:0 */
229    *((ush*)&buf+1) += ((ush)((uch*)buf-0) + 15) >> 4;
230    *(ush*)&buf = 0;
231    table[next_ptr++].new_ptr = buf;
232    return buf;
233}
234
235void ZLIB_INTERNAL zcfree(voidpf opaque, voidpf ptr)
236{
237    int n;
238
239    (void)opaque;
240
241    if (*(ush*)&ptr != 0) { /* object < 64K */
242        farfree(ptr);
243        return;
244    }
245    /* Find the original pointer */
246    for (n = 0; n < next_ptr; n++) {
247        if (ptr != table[n].new_ptr) continue;
248
249        farfree(table[n].org_ptr);
250        while (++n < next_ptr) {
251            table[n-1] = table[n];
252        }
253        next_ptr--;
254        return;
255    }
256    Assert(0, "zcfree: ptr not found");
257}
258
259#endif /* __TURBOC__ */
260
261
262#ifdef M_I86
263/* Microsoft C in 16-bit mode */
264
265#  define MY_ZCALLOC
266
267#if (!defined(_MSC_VER) || (_MSC_VER <= 600))
268#  define _halloc  halloc
269#  define _hfree   hfree
270#endif
271
272voidpf ZLIB_INTERNAL zcalloc(voidpf opaque, uInt items, uInt size)
273{
274    (void)opaque;
275    return _halloc((long)items, size);
276}
277
278void ZLIB_INTERNAL zcfree(voidpf opaque, voidpf ptr)
279{
280    (void)opaque;
281    _hfree(ptr);
282}
283
284#endif /* M_I86 */
285
286#endif /* SYS16BIT */
287
288
289#ifndef MY_ZCALLOC /* Any system without a special alloc function */
290
291#ifndef STDC
292extern voidp malloc(uInt size);
293extern voidp calloc(uInt items, uInt size);
294extern void free(voidpf ptr);
295#endif
296
297voidpf ZLIB_INTERNAL zcalloc(voidpf opaque, unsigned items, unsigned size)
298{
299    (void)opaque;
300    return sizeof(uInt) > 2 ? (voidpf)malloc(items * size) :
301                              (voidpf)calloc(items, size);
302}
303
304void ZLIB_INTERNAL zcfree(voidpf opaque, voidpf ptr)
305{
306    (void)opaque;
307    free(ptr);
308}
309
310#endif /* MY_ZCALLOC */
311
312#endif /* !Z_SOLO */
313