XZ Utils Installation ===================== 0. Preface 1. Supported platforms 1.1. Compilers 1.2. Platform-specific notes 1.2.1. Darwin (Mac OS X) 1.2.2. Tru64 1.2.3. Windows 1.2.4. DOS 1.2.5. OS/2 1.2.6. OpenVMS 1.3. Adding support for new platforms 2. configure options 3. xzgrep and other scripts 3.1. Dependencies 3.2. PATH 4. Troubleshooting 4.1. "No C99 compiler was found." 4.1. "No POSIX conforming shell (sh) was found." 4.2. configure works but build fails at crc32_x86.S 0. Preface ---------- If you aren't familiar with building packages that use GNU Autotools, see the file INSTALL.generic for generic instructions before reading further. If you are going to build a package for distribution, see also the file PACKAGERS. It contains information that should help making the binary packages as good as possible, but the information isn't very interesting to those making local builds for private use or for use in special situations like embedded systems. 1. Supported platforms ---------------------- XZ Utils are developed on GNU/Linux, but they should work on many POSIX-like operating systems like *BSDs and Solaris, and even on a few non-POSIX operating systems. 1.1. Compilers A C99 compiler is required to compile XZ Utils. If you use GCC, you need at least version 3.x.x. GCC version 2.xx.x doesn't support some C99 features used in XZ Utils source code, thus GCC 2 won't compile XZ Utils. XZ Utils takes advantage of some GNU C extensions when building with GCC. Because these extensions are used only when building with GCC, it should be possible to use any C99 compiler. 1.2. Platform-specific notes 1.2.1. Darwin (Mac OS X) You may need --disable-assembler if building universal binaries on Darwin. This is because different files are built when assembler is enabled, and there's no way to make it work with universal build. If you want to keep the assembler code, consider building one architecture at a time, and then combining the results to create universal binaries (see lipo(1)). 1.2.2. Tru64 If you try to use the native C compiler on Tru64 (passing CC=cc to configure), it is possible that the configure script will complain that no C99 compiler was found even when the native compiler supports C99. You can safely override the test for C99 compiler by passing ac_cv_prog_cc_c99= as the argument to the configure script. 1.2.3. Windows Building XZ Utils on Windows is supported under MinGW and Cygwin. If the Autotools based build gives you trouble with MinGW, you may want try the alternative method found from the "windows" directory. MSVC doesn't support C99, thus it is not possible to use MSVC to compile XZ Utils. However, it is possible to use liblzma.dll from MSVC once liblzma.dll has been built with MinGW. The required import library for MSVC can be created from liblzma.def using the "lib" command shipped in MSVC: lib /def:liblzma.def /out:liblzma.lib /machine:ix86 On x86-64, the /machine argument has to naturally be changed: lib /def:liblzma.def /out:liblzma.lib /machine:x64 1.2.4. DOS There is an experimental Makefile in the "dos" directory to build XZ Utils on DOS using DJGPP. Support for long file names (LFN) is needed. GNU Autotools based build hasn't been tried on DOS. 1.2.5. OS/2 You will need to pass --disable-assembler to configure when building on OS/2. To omit large number of harmless warnings about visibility support, pass gl_cv_cc_visibility=no as an argument to the configure script. This isn't mandatory since it should have no effect on the resulting binaries. 1.2.6. OpenVMS XZ Utils can be built for OpenVMS, but the build system files are currently not included in the XZ Utils source package. The required OpenVMS-specific files are maintained by Jouk Jansen and can be downloaded here: http://nchrem.tnw.tudelft.nl/openvms/software2.html#xzutils 1.3. Adding support for new platforms If you have written patches to make XZ Utils to work on previously unsupported platform, please send the patches to me! I will consider including them to the official version. It's nice to minimize the need of third-party patching. One exception: Don't request or send patches to change the whole source package to C89. I find C99 substantially nicer to write and maintain. However, the public library headers must be in C89 to avoid frustrating those who maintain programs, which are strictly in C89 or C++. 2. configure options -------------------- In most cases, the defaults are what you want. Most of the options below are useful only when building a size-optimized version of liblzma or command line tools. --enable-encoders=LIST --disable-encoders Specify a comma-separated LIST of filter encoders to build. See "./configure --help" for exact list of available filter encoders. The default is to build all supported encoders. If LIST is empty or --disable-encoders is used, no filter encoders will be built and also the code shared between encoders will be omitted. Disabling encoders will remove some symbols from the liblzma ABI, so this option should be used only when it is known to not cause problems. --enable-decoders=LIST --disable-decoders This is like --enable-encoders but for decoders. The default is to build all supported decoders. --enable-match-finders=LIST liblzma includes two categories of match finders: hash chains and binary trees. Hash chains (hc3 and hc4) are quite fast but they don't provide the best compression ratio. Binary trees (bt2, bt3 and bt4) give excellent compression ratio, but they are slower and need more memory than hash chains. You need to enable at least one match finder to build the LZMA1 or LZMA2 filter encoders. Usually hash chains are used only in the fast mode, while binary trees are used to when the best compression ratio is wanted. The default is to build all the match finders if LZMA1 or LZMA2 filter encoders are being built. --enable-checks=LIST liblzma support multiple integrity checks. CRC32 is mandatory, and cannot be omitted. See "./configure --help" for exact list of available integrity check types. liblzma and the command line tools can decompress files which use unsupported integrity check type, but naturally the file integrity cannot be verified in that case. Disabling integrity checks may remove some symbols from the liblzma ABI, so this option should be used only when it is known to not cause problems. --disable-assembler liblzma includes some assembler optimizations. Currently there is only assembler code for CRC32 and CRC64 for 32-bit x86. All the assembler code in liblzma is position-independent code, which is suitable for use in shared libraries and position-independent executables. So far only i386 instructions are used, but the code is optimized for i686 class CPUs. If you are compiling liblzma exclusively for pre-i686 systems, you may want to disable the assembler code. --enable-unaligned-access Allow liblzma to use unaligned memory access for 16-bit and 32-bit loads and stores. This should be enabled only when the hardware supports this, i.e. when unaligned access is fast. Some operating system kernels emulate unaligned access, which is extremely slow. This option shouldn't be used on systems that rely on such emulation. Unaligned access is enabled by default on x86, x86-64, and big endian PowerPC. --enable-small Reduce the size of liblzma by selecting smaller but semantically equivalent version of some functions, and omit precomputed lookup tables. This option tends to make liblzma slightly slower. Note that while omitting the precomputed tables makes liblzma smaller on disk, the tables are still needed at run time, and need to be computed at startup. This also means that the RAM holding the tables won't be shared between applications linked against shared liblzma. This option doesn't modify CFLAGS to tell the compiler to optimize for size. You need to add -Os or equivalent flag(s) to CFLAGS manually. --enable-assume-ram=SIZE On the most common operating systems, XZ Utils is able to detect the amount of physical memory on the system. This information is used to set the default memory usage limit. On some systems, there is no code to detect the amount of RAM though. Using --enable-assume-ram one can set how much memory to assume on these systems. SIZE is given as MiB. The default is 32 MiB, which is probably too low for most systems, but it is enough to allow decompressing .xz files created with the default settings. Feel free to send patches to add support for detecting the amount of RAM on the operating system you use. See src/common/tuklib_physmem.c for details. --disable-threads Disable threading support. This makes some things thread-unsafe, meaning that if multithreaded application calls liblzma functions from more than one thread, something bad may happen. Use this option if threading support causes you trouble, or if you know that you will use liblzma only from single-threaded applications and want to avoid dependency on libpthread. --enable-dynamic=TYPE Specify how command line tools should be linked against liblzma. Possible TYPES: yes All command line tools are linked against shared liblzma (if shared liblzma was built). This is equivalent to --enable-dynamic (i.e. no =TYPE). mixed Some tools are linked against static liblzma and some against shared liblzma. This is the default and recommended way. no All command line tools are linked against static liblzma (if static liblzma was built). This is equivalent to --disable-dynamic. This option is mostly useful for packagers, if distro policy requires linking against shared libaries. See the file PACKAGERS for more information about pros and cons of this option. --enable-debug This enables the assert() macro and possibly some other run-time consistency checks. It makes the code slower, so you normally don't want to have this enabled. --enable-werror If building with GCC, make all compiler warnings an error, that abort the compilation. This may help catching bugs, and should work on most systems. This has no effect on the resulting binaries. 3. xzgrep and other scripts --------------------------- 3.1. Dependencies POSIX shell (sh) and bunch of other standard POSIX tools are required to run the scripts. The configure script tries to find a POSIX compliant sh, but if it fails, you can force the shell by passing gl_cv_posix_shell=/path/to/posix-sh as an argument to the configure script. Some of the scripts require also mktemp. The original mktemp can be found from . On GNU, most will use the mktemp program from GNU coreutils instead of the original implementation. Both mktemp versions are fine for XZ Utils (and practically for everything else too). 3.2. PATH The scripts assume that the required tools (standard POSIX utilities, mktemp, and xz) are in PATH; the scripts don't set the PATH themselves. Some people like this while some think this is a bug. Those in the latter group can easily patch the scripts before running the configure script by taking advantage of a placeholder line in the scripts. For example, to make the scripts prefix /usr/bin:/bin to PATH: perl -pi -e 's|^#SET_PATH.*$|PATH=/usr/bin:/bin:\$PATH|' \ src/scripts/xz*.in 4. Troubleshooting ------------------ 4.1. "No C99 compiler was found." You need a C99 compiler to build XZ Utils. If the configure script cannot find a C99 compiler and you think you have such a compiler installed, set the compiler command by passing CC=/path/to/c99 as an argument to the configure script. If you get this error even when you think your compiler supports C99, you can override the test by passing ac_cv_prog_cc_c99= as an argument to the configure script. The test for C99 compiler is not perfect (and it is not as easy to make it perfect as it sounds), so sometimes this may be needed. You will get a compile error if your compiler doesn't support enough C99. 4.1. "No POSIX conforming shell (sh) was found." xzgrep and other scripts need a shell that (roughly) conforms to POSIX. The configure script tries to find such a shell. If it fails, you can force the shell to be used by passing gl_cv_posix_shell=/path/to/posix-sh as an argument to the configure script. 4.2. configure works but build fails at crc32_x86.S The easy fix is to pass --disable-assembler to the configure script. The configure script determines if assembler code can be used by looking at the configure triplet; there is currently no check if the assembler code can actually actually be built. The x86 assembler code should work on x86 GNU/Linux, *BSDs, Solaris, Darwin, MinGW, Cygwin, and DJGPP. On other x86 systems, there may be problems and the assembler code may need to be disabled with the configure option. If you get this error when building for x86-64, you have specified or the configure script has misguessed your architecture. Pass the correct configure triplet using the --build=CPU-COMPANY-SYSTEM option (see INSTALL.generic).