src/liblzma/api/lzma.h

   1 /* SPDX-License-Identifier: 0BSD */
   2
   3 /**
   4  * \file        api/lzma.h
   5  * \brief       The public API of liblzma data compression library
   6  * \mainpage
   7  *
   8  * liblzma is a general-purpose data compression library with a zlib-like API.
   9  * The native file format is .xz, but also the old .lzma format and raw (no
  10  * headers) streams are supported. Multiple compression algorithms (filters)
  11  * are supported. Currently LZMA2 is the primary filter.
  12  *
  13  * liblzma is part of XZ Utils <https://tukaani.org/xz/>. XZ Utils
  14  * includes a gzip-like command line tool named xz and some other tools.
  15  * XZ Utils is developed and maintained by Lasse Collin.
  16  *
  17  * Major parts of liblzma are based on code written by Igor Pavlov,
  18  * specifically the LZMA SDK <https://7-zip.org/sdk.html>.
  19  *
  20  * The SHA-256 implementation in liblzma is based on code written by
  21  * Wei Dai in Crypto++ Library <https://www.cryptopp.com/>.
  22  *
  23  * liblzma is distributed under the BSD Zero Clause License (0BSD).
  24  */
  25
  26 /*
  27  * Author: Lasse Collin
  28  */
  29
  30 #ifndef LZMA_H
  31 #define LZMA_H
  32
  33 /*****************************
  34  * Required standard headers *
  35  *****************************/
  36
  37 /*
  38  * liblzma API headers need some standard types and macros. To allow
  39  * including lzma.h without requiring the application to include other
  40  * headers first, lzma.h includes the required standard headers unless
  41  * they already seem to be included already or if LZMA_MANUAL_HEADERS
  42  * has been defined.
  43  *
  44  * Here's what types and macros are needed and from which headers:
  45  *  - stddef.h: size_t, NULL
  46  *  - stdint.h: uint8_t, uint32_t, uint64_t, UINT32_C(n), uint64_C(n),
  47  *    UINT32_MAX, UINT64_MAX
  48  *
  49  * However, inttypes.h is a little more portable than stdint.h, although
  50  * inttypes.h declares some unneeded things compared to plain stdint.h.
  51  *
  52  * The hacks below aren't perfect, specifically they assume that inttypes.h
  53  * exists and that it typedefs at least uint8_t, uint32_t, and uint64_t,
  54  * and that, in case of incomplete inttypes.h, unsigned int is 32-bit.
  55  * If the application already takes care of setting up all the types and
  56  * macros properly (for example by using gnulib's stdint.h or inttypes.h),
  57  * we try to detect that the macros are already defined and don't include
  58  * inttypes.h here again. However, you may define LZMA_MANUAL_HEADERS to
  59  * force this file to never include any system headers.
  60  *
  61  * Some could argue that liblzma API should provide all the required types,
  62  * for example lzma_uint64, LZMA_UINT64_C(n), and LZMA_UINT64_MAX. This was
  63  * seen as an unnecessary mess, since most systems already provide all the
  64  * necessary types and macros in the standard headers.
  65  *
  66  * Note that liblzma API still has lzma_bool, because using stdbool.h would
  67  * break C89 and C++ programs on many systems. sizeof(bool) in C99 isn't
  68  * necessarily the same as sizeof(bool) in C++.
  69  */
  70
  71 #ifndef LZMA_MANUAL_HEADERS
  72         /*
  73          * I suppose this works portably also in C++. Note that in C++,
  74          * we need to get size_t into the global namespace.
  75          */
  76 #       include <stddef.h>
  77
  78         /*
  79          * Skip inttypes.h if we already have all the required macros. If we
  80          * have the macros, we assume that we have the matching typedefs too.
  81          */
  82 #       if !defined(UINT32_C) || !defined(UINT64_C) \
  83                         || !defined(UINT32_MAX) || !defined(UINT64_MAX)
  84                 /*
  85                  * MSVC versions older than 2013 have no C99 support, and
  86                  * thus they cannot be used to compile liblzma. Using an
  87                  * existing liblzma.dll with old MSVC can work though(*),
  88                  * but we need to define the required standard integer
  89                  * types here in a MSVC-specific way.
  90                  *
  91                  * (*) If you do this, the existing liblzma.dll probably uses
  92                  *     a different runtime library than your MSVC-built
  93                  *     application. Mixing runtimes is generally bad, but
  94                  *     in this case it should work as long as you avoid
  95                  *     the few rarely-needed liblzma functions that allocate
  96                  *     memory and expect the caller to free it using free().
  97                  */
  98 #               if defined(_WIN32) && defined(_MSC_VER) && _MSC_VER < 1800
  99                         typedef unsigned __int8 uint8_t;
 100                         typedef unsigned __int32 uint32_t;
 101                         typedef unsigned __int64 uint64_t;
 102 #               else
 103                         /* Use the standard inttypes.h. */
 104 #                       ifdef __cplusplus
 105                                 /*
 106                                  * C99 sections 7.18.2 and 7.18.4 specify
 107                                  * that C++ implementations define the limit
 108                                  * and constant macros only if specifically
 109                                  * requested. Note that if you want the
 110                                  * format macros (PRIu64 etc.) too, you need
 111                                  * to define __STDC_FORMAT_MACROS before
 112                                  * including lzma.h, since re-including
 113                                  * inttypes.h with __STDC_FORMAT_MACROS
 114                                  * defined doesn't necessarily work.
 115                                  */
 116 #                               ifndef __STDC_LIMIT_MACROS
 117 #                                       define __STDC_LIMIT_MACROS 1
 118 #                               endif
 119 #                               ifndef __STDC_CONSTANT_MACROS
 120 #                                       define __STDC_CONSTANT_MACROS 1
 121 #                               endif
 122 #                       endif
 123
 124 #                       include <inttypes.h>
 125 #               endif
 126
 127                 /*
 128                  * Some old systems have only the typedefs in inttypes.h, and
 129                  * lack all the macros. For those systems, we need a few more
 130                  * hacks. We assume that unsigned int is 32-bit and unsigned
 131                  * long is either 32-bit or 64-bit. If these hacks aren't
 132                  * enough, the application has to setup the types manually
 133                  * before including lzma.h.
 134                  */
 135 #               ifndef UINT32_C
 136 #                       if defined(_WIN32) && defined(_MSC_VER)
 137 #                               define UINT32_C(n) n ## UI32
 138 #                       else
 139 #                               define UINT32_C(n) n ## U
 140 #                       endif
 141 #               endif
 142
 143 #               ifndef UINT64_C
 144 #                       if defined(_WIN32) && defined(_MSC_VER)
 145 #                               define UINT64_C(n) n ## UI64
 146 #                       else
 147                                 /* Get ULONG_MAX. */
 148 #                               include <limits.h>
 149 #                               if ULONG_MAX == 4294967295UL
 150 #                                       define UINT64_C(n) n ## ULL
 151 #                               else
 152 #                                       define UINT64_C(n) n ## UL
 153 #                               endif
 154 #                       endif
 155 #               endif
 156
 157 #               ifndef UINT32_MAX
 158 #                       define UINT32_MAX (UINT32_C(4294967295))
 159 #               endif
 160
 161 #               ifndef UINT64_MAX
 162 #                       define UINT64_MAX (UINT64_C(18446744073709551615))
 163 #               endif
 164 #       endif
 165 #endif /* ifdef LZMA_MANUAL_HEADERS */
 166
 167
 168 /******************
 169  * LZMA_API macro *
 170  ******************/
 171
 172 /*
 173  * Some systems require that the functions and function pointers are
 174  * declared specially in the headers. LZMA_API_IMPORT is for importing
 175  * symbols and LZMA_API_CALL is to specify the calling convention.
 176  *
 177  * By default it is assumed that the application will link dynamically
 178  * against liblzma. #define LZMA_API_STATIC in your application if you
 179  * want to link against static liblzma. If you don't care about portability
 180  * to operating systems like Windows, or at least don't care about linking
 181  * against static liblzma on them, don't worry about LZMA_API_STATIC. That
 182  * is, most developers will never need to use LZMA_API_STATIC.
 183  *
 184  * The GCC variants are a special case on Windows (Cygwin and MinGW-w64).
 185  * We rely on GCC doing the right thing with its auto-import feature,
 186  * and thus don't use __declspec(dllimport). This way developers don't
 187  * need to worry about LZMA_API_STATIC. Also the calling convention is
 188  * omitted on Cygwin but not on MinGW-w64.
 189  */
 190 #ifndef LZMA_API_IMPORT
 191 #       if !defined(LZMA_API_STATIC) && defined(_WIN32) && !defined(__GNUC__)
 192 #               define LZMA_API_IMPORT __declspec(dllimport)
 193 #       else
 194 #               define LZMA_API_IMPORT
 195 #       endif
 196 #endif
 197
 198 #ifndef LZMA_API_CALL
 199 #       if defined(_WIN32) && !defined(__CYGWIN__)
 200 #               define LZMA_API_CALL __cdecl
 201 #       else
 202 #               define LZMA_API_CALL
 203 #       endif
 204 #endif
 205
 206 #ifndef LZMA_API
 207 #       define LZMA_API(type) LZMA_API_IMPORT type LZMA_API_CALL
 208 #endif
 209
 210
 211 /***********
 212  * nothrow *
 213  ***********/
 214
 215 /*
 216  * None of the functions in liblzma may throw an exception. Even
 217  * the functions that use callback functions won't throw exceptions,
 218  * because liblzma would break if a callback function threw an exception.
 219  */
 220 #ifndef lzma_nothrow
 221 #       if defined(__cplusplus)
 222 #               if __cplusplus >= 201103L || (defined(_MSVC_LANG) \
 223                                 && _MSVC_LANG >= 201103L)
 224 #                       define lzma_nothrow noexcept
 225 #               else
 226 #                       define lzma_nothrow throw()
 227 #               endif
 228 #       elif defined(__GNUC__) && (__GNUC__ > 3 \
 229                         || (__GNUC__ == 3 && __GNUC_MINOR__ >= 3))
 230 #               define lzma_nothrow __attribute__((__nothrow__))
 231 #       else
 232 #               define lzma_nothrow
 233 #       endif
 234 #endif
 235
 236
 237 /********************
 238  * GNU C extensions *
 239  ********************/
 240
 241 /*
 242  * GNU C extensions are used conditionally in the public API. It doesn't
 243  * break anything if these are sometimes enabled and sometimes not, only
 244  * affects warnings and optimizations.
 245  */
 246 #if defined(__GNUC__) && __GNUC__ >= 3
 247 #       ifndef lzma_attribute
 248 #               define lzma_attribute(attr) __attribute__(attr)
 249 #       endif
 250
 251         /* warn_unused_result was added in GCC 3.4. */
 252 #       ifndef lzma_attr_warn_unused_result
 253 #               if __GNUC__ == 3 && __GNUC_MINOR__ < 4
 254 #                       define lzma_attr_warn_unused_result
 255 #               endif
 256 #       endif
 257
 258 #else
 259 #       ifndef lzma_attribute
 260 #               define lzma_attribute(attr)
 261 #       endif
 262 #endif
 263
 264
 265 #ifndef lzma_attr_pure
 266 #       define lzma_attr_pure lzma_attribute((__pure__))
 267 #endif
 268
 269 #ifndef lzma_attr_const
 270 #       define lzma_attr_const lzma_attribute((__const__))
 271 #endif
 272
 273 #ifndef lzma_attr_warn_unused_result
 274 #       define lzma_attr_warn_unused_result \
 275                 lzma_attribute((__warn_unused_result__))
 276 #endif
 277
 278
 279 /**************
 280  * Subheaders *
 281  **************/
 282
 283 #ifdef __cplusplus
 284 extern "C" {
 285 #endif
 286
 287 /*
 288  * Subheaders check that this is defined. It is to prevent including
 289  * them directly from applications.
 290  */
 291 #define LZMA_H_INTERNAL 1
 292
 293 /* Basic features */
 294 #include "lzma/version.h"
 295 #include "lzma/base.h"
 296 #include "lzma/vli.h"
 297 #include "lzma/check.h"
 298
 299 /* Filters */
 300 #include "lzma/filter.h"
 301 #include "lzma/bcj.h"
 302 #include "lzma/delta.h"
 303 #include "lzma/lzma12.h"
 304
 305 /* Container formats */
 306 #include "lzma/container.h"
 307
 308 /* Advanced features */
 309 #include "lzma/stream_flags.h"
 310 #include "lzma/block.h"
 311 #include "lzma/index.h"
 312 #include "lzma/index_hash.h"
 313
 314 /* Hardware information */
 315 #include "lzma/hardware.h"
 316
 317 /*
 318  * All subheaders included. Undefine LZMA_H_INTERNAL to prevent applications
 319  * re-including the subheaders.
 320  */
 321 #undef LZMA_H_INTERNAL
 322
 323 #ifdef __cplusplus
 324 }
 325 #endif
 326
 327 #endif /* ifndef LZMA_H */