Add an unpatched version of xz, XZ Utils, to /trunk/deps/third_party

xz/INSTALL

+
+XZ Utils Installation
+=====================
+
+    0. Preface
+    1. Supported platforms
+       1.1. Compilers
+       1.2. Platform-specific notes
+            1.2.1. IRIX
+            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. IRIX
+
+    MIPSpro 7.4.4m has been reported to produce broken code if using
+    the -O2 optimization flag ("make check" fails). Using -O1 should
+    work.
+
+
+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 + MSYS and
+    Cygwin. There is windows/build.sh to ease packaging XZ Utils with
+    MinGW + MSYS into a redistributable .zip or .7z file. See
+    windows/INSTALL-Windows.txt for more information.
+
+    It might be possible to build liblzma with a non-GNU toolchain too,
+    but that will probably require writing a separate makefile. Building
+    the command line tools with non-GNU toolchains will be harder than
+    building only liblzma.
+
+    Even if liblzma is built with MinGW, the resulting DLL or static
+    library can be used by other compilers and linkers, including MSVC.
+    Thus, it shouldn't be a problem to use MinGW to build liblzma even
+    if you cannot use MinGW to build the rest of your project. See
+    windows/README-Windows.txt for details.
+
+
+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. See dos/README for more information.
+
+    GNU Autotools based build hasn't been tried on DOS. If you try, I
+    would like to hear if it worked.
+
+
+1.2.5. 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 128 MiB, which allows decompressing files
+                created with "xz -9".
+
+                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 <http://www.mktemp.org/>. 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).
+