8 1.2. Platform-specific notes
9 1.2.1. Darwin (Mac OS X)
14 1.3. Adding support for new platforms
16 3. xzgrep and other scripts
20 4.1. "No C99 compiler was found."
21 4.1. "No POSIX conforming shell (sh) was found."
22 4.2. configure works but build fails at crc32_x86.S
28 If you aren't familiar with building packages that use GNU Autotools,
29 see the file INSTALL.generic for generic instructions before reading
32 If you are going to build a package for distribution, see also the
33 file PACKAGERS. It contains information that should help making the
34 binary packages as good as possible, but the information isn't very
35 interesting to those making local builds for private use or for use
36 in special situations like embedded systems.
39 1. Supported platforms
40 ----------------------
42 XZ Utils are developed on GNU/Linux, but they should work on many
43 POSIX-like operating systems like *BSDs and Solaris, and even on
44 a few non-POSIX operating systems.
49 A C99 compiler is required to compile XZ Utils. If you use GCC, you
50 need at least version 3.x.x. GCC version 2.xx.x doesn't support some
51 C99 features used in XZ Utils source code, thus GCC 2 won't compile
54 XZ Utils takes advantage of some GNU C extensions when building
55 with GCC. Because these extensions are used only when building
56 with GCC, it should be possible to use any C99 compiler.
59 1.2. Platform-specific notes
61 1.2.1. Darwin (Mac OS X)
63 You may need --disable-assembler if building universal binaries on
64 Darwin. This is because different files are built when assembler is
65 enabled, and there's no way to make it work with universal build.
66 If you want to keep the assembler code, consider building one
67 architecture at a time, and then combining the results to create
68 universal binaries (see lipo(1)).
73 If you try to use the native C compiler on Tru64 (passing CC=cc to
74 configure), it is possible that the configure script will complain
75 that no C99 compiler was found even when the native compiler supports
76 C99. You can safely override the test for C99 compiler by passing
77 ac_cv_prog_cc_c99= as the argument to the configure script.
82 Building XZ Utils on Windows is supported under MinGW and Cygwin.
83 If the Autotools based build gives you trouble with MinGW, you may
84 want try the alternative method found from the "windows" directory.
86 MSVC doesn't support C99, thus it is not possible to use MSVC to
87 compile XZ Utils. However, it is possible to use liblzma.dll from
88 MSVC once liblzma.dll has been built with MinGW. The required
89 import library for MSVC can be created from liblzma.def using the
90 "lib" command shipped in MSVC:
92 lib /def:liblzma.def /out:liblzma.lib /machine:ix86
94 On x86-64, the /machine argument has to naturally be changed:
96 lib /def:liblzma.def /out:liblzma.lib /machine:x64
101 There is an experimental Makefile in the "dos" directory to build
102 XZ Utils on DOS using DJGPP. Support for long file names (LFN) is
105 GNU Autotools based build hasn't been tried on DOS.
110 You will need to pass --disable-assembler to configure when building
114 1.3. Adding support for new platforms
116 If you have written patches to make XZ Utils to work on previously
117 unsupported platform, please send the patches to me! I will consider
118 including them to the official version. It's nice to minimize the
119 need of third-party patching.
121 One exception: Don't request or send patches to change the whole
122 source package to C89. I find C99 substantially nicer to write and
123 maintain. However, the public library headers must be in C89 to
124 avoid frustrating those who maintain programs, which are strictly
131 In most cases, the defaults are what you want. Most of the options
132 below are useful only when building a size-optimized version of
133 liblzma or command line tools.
135 --enable-encoders=LIST
137 Specify a comma-separated LIST of filter encoders to
138 build. See "./configure --help" for exact list of
139 available filter encoders. The default is to build all
142 If LIST is empty or --disable-encoders is used, no filter
143 encoders will be built and also the code shared between
144 encoders will be omitted.
146 Disabling encoders will remove some symbols from the
147 liblzma ABI, so this option should be used only when it
148 is known to not cause problems.
150 --enable-decoders=LIST
152 This is like --enable-encoders but for decoders. The
153 default is to build all supported decoders.
155 --enable-match-finders=LIST
156 liblzma includes two categories of match finders:
157 hash chains and binary trees. Hash chains (hc3 and hc4)
158 are quite fast but they don't provide the best compression
159 ratio. Binary trees (bt2, bt3 and bt4) give excellent
160 compression ratio, but they are slower and need more
161 memory than hash chains.
163 You need to enable at least one match finder to build the
164 LZMA1 or LZMA2 filter encoders. Usually hash chains are
165 used only in the fast mode, while binary trees are used to
166 when the best compression ratio is wanted.
168 The default is to build all the match finders if LZMA1
169 or LZMA2 filter encoders are being built.
172 liblzma support multiple integrity checks. CRC32 is
173 mandatory, and cannot be omitted. See "./configure --help"
174 for exact list of available integrity check types.
176 liblzma and the command line tools can decompress files
177 which use unsupported integrity check type, but naturally
178 the file integrity cannot be verified in that case.
180 Disabling integrity checks may remove some symbols from
181 the liblzma ABI, so this option should be used only when
182 it is known to not cause problems.
185 liblzma includes some assembler optimizations. Currently
186 there is only assembler code for CRC32 and CRC64 for
189 All the assembler code in liblzma is position-independent
190 code, which is suitable for use in shared libraries and
191 position-independent executables. So far only i386
192 instructions are used, but the code is optimized for i686
193 class CPUs. If you are compiling liblzma exclusively for
194 pre-i686 systems, you may want to disable the assembler
197 --enable-unaligned-access
198 Allow liblzma to use unaligned memory access for 16-bit
199 and 32-bit loads and stores. This should be enabled only
200 when the hardware supports this, i.e. when unaligned
201 access is fast. Some operating system kernels emulate
202 unaligned access, which is extremely slow. This option
203 shouldn't be used on systems that rely on such emulation.
205 Unaligned access is enabled by default on x86, x86-64,
206 and big endian PowerPC.
209 Reduce the size of liblzma by selecting smaller but
210 semantically equivalent version of some functions, and
211 omit precomputed lookup tables. This option tends to
212 make liblzma slightly slower.
214 Note that while omitting the precomputed tables makes
215 liblzma smaller on disk, the tables are still needed at
216 run time, and need to be computed at startup. This also
217 means that the RAM holding the tables won't be shared
218 between applications linked against shared liblzma.
221 Disable threading support. This makes some things
222 thread-unsafe, meaning that if multithreaded application
223 calls liblzma functions from more than one thread,
224 something bad may happen.
226 Use this option if threading support causes you trouble,
227 or if you know that you will use liblzma only from
228 single-threaded applications and want to avoid dependency
232 Link the command line tools against shared liblzma. The
233 default (and recommended way) is to link the command line
234 tools against static liblzma.
236 This option is mostly useful for packagers, if distro
237 policy requires linking against shared libaries. See the
238 file PACKAGERS for more information about pros and cons
242 This enables the assert() macro and possibly some other
243 run-time consistency checks. It makes the code slower, so
244 you normally don't want to have this enabled.
247 If building with GCC, make all compiler warnings an error,
248 that abort the compilation. This may help catching bugs,
249 and should work on most systems. This has no effect on the
253 3. xzgrep and other scripts
254 ---------------------------
258 POSIX shell (sh) and bunch of other standard POSIX tools are required
259 to run the scripts. The configure script tries to find a POSIX
260 compliant sh, but if it fails, you can force the shell by passing
261 gl_cv_posix_shell=/path/to/posix-sh as an argument to the configure
264 Some of the scripts require also mktemp. The original mktemp can be
265 found from <http://www.mktemp.org/>. On GNU, most will use the mktemp
266 program from GNU coreutils instead of the original implementation.
267 Both mktemp versions are fine for XZ Utils (and practically for
268 everything else too).
273 The scripts assume that the required tools (standard POSIX utilities,
274 mktemp, and xz) are in PATH; the scripts don't set the PATH themselves.
275 Some people like this while some think this is a bug. Those in the
276 latter group can easily patch the scripts before running the configure
277 script by taking advantage of a placeholder line in the scripts.
279 For example, to make the scripts prefix /usr/bin:/bin to PATH:
281 perl -pi -e 's|^#SET_PATH.*$|PATH=/usr/bin:/bin:\$PATH|' \
288 4.1. "No C99 compiler was found."
290 You need a C99 compiler to build XZ Utils. If the configure script
291 cannot find a C99 compiler and you think you have such a compiler
292 installed, set the compiler command by passing CC=/path/to/c99 as
293 an argument to the configure script.
295 If you get this error even when you think your compiler supports C99,
296 you can override the test by passing ac_cv_prog_cc_c99= as an argument
297 to the configure script. The test for C99 compiler is not perfect (and
298 it is not as easy to make it perfect as it sounds), so sometimes this
299 may be needed. You will get a compile error if your compiler doesn't
303 4.1. "No POSIX conforming shell (sh) was found."
305 xzgrep and other scripts need a shell that (roughly) conforms
306 to POSIX. The configure script tries to find such a shell. If
307 it fails, you can force the shell to be used by passing
308 gl_cv_posix_shell=/path/to/posix-sh as an argument to the configure
312 4.2. configure works but build fails at crc32_x86.S
314 The easy fix is to pass --disable-assembler to the configure script.
316 The configure script determines if assembler code can be used by
317 looking at the configure triplet; there is currently no check if
318 the assembler code can actually actually be built. The x86 assembler
319 code should work on x86 GNU/Linux, *BSDs, Solaris, Darwin, MinGW,
320 Cygwin, and DJGPP. On other x86 systems, there may be problems and
321 the assembler code may need to be disabled with the configure option.
323 If you get this error when building for x86-64, you have specified or
324 the configure script has misguessed your architecture. Pass the
325 correct configure triplet using the --build=CPU-COMPANY-SYSTEM option
326 (see INSTALL.generic).