Installing the GNU C Library
****************************
- Before you do anything else, you should read the file `FAQ' found at
-the top level of the source tree. This file answers common questions
+Before you do anything else, you should read the FAQ at
+`http://sourceware.org/glibc/wiki/FAQ'. It answers common questions
and describes problems you may experience with compilation and
-installation. It is updated more frequently than this manual.
-
- Two components of GNU Libc are distributed as "add-on" bundles
-separate from the main distribution. Unless you are doing an unusual
-installation, you should get them both. Support for the `crypt'
-function is distributed separately because of US export restrictions.
-If you are outside the US or Canada, you must get `crypt' support from
-a site outside the US, such as `ftp.ifi.uio.no'. (Most non-US mirrors
-of `ftp.gnu.org' will have it too.) The file you need is
-`glibc-crypt-VERSION.tar.gz'. Support for POSIX threads is maintained
-by someone else, so it's in a separate package. At the moment it is
-only available for Linux systems; this will change in the future. Get
-it from the same place you got the main bundle; the file is
-`glibc-linuxthreads-VERSION.tar.gz'. Both add-on bundles should be
-unpacked into the top level of the libc source tree.
+installation.
+
+Features can be added to the GNU C Library via "add-on" bundles. These
+are separate tar files, which you unpack into the top level of the
+source tree. Then you give `configure' the `--enable-add-ons' option
+to activate them, and they will be compiled into the library.
You will need recent versions of several GNU tools: definitely GCC
-and GNU Make, and possibly others. *Note Tools for Installation::,
+and GNU Make, and possibly others. *Note Tools for Compilation::,
below.
-Configuring and compiling GNU Libc
-==================================
+Configuring and compiling the GNU C Library
+===========================================
- GNU Libc cannot be compiled in the source directory. You must
-create a separate directory for the object files. This directory
-should be outside the source tree. For example, if you have unpacked
-the glibc sources in `/src/gnu/glibc-2.1.0', create a directory
-`/src/gnu/glibc-build' to put the object files in.
+The GNU C Library cannot be compiled in the source directory. You must
+build it in a separate build directory. For example, if you have
+unpacked the GNU C Library sources in `/src/gnu/glibc-VERSION', create
+a directory `/src/gnu/glibc-build' to put the object files in. This
+allows removing the whole build directory in case an error occurs,
+which is the safest way to get a fresh start and should always be done.
- From your object directory, run the shell script `configure' found
+ From your object directory, run the shell script `configure' located
at the top level of the source tree. In the scenario above, you'd type
- $ ../glibc-2.1.0/configure ARGS...
+ $ ../glibc-VERSION/configure ARGS...
+
+ Please note that even though you're building in a separate build
+directory, the compilation may need to create or modify files and
+directories in the source directory.
-`configure' takes many options, but you can get away with knowing only
-two: `--enable-add-ons' and `--prefix'. The `--enable-add-ons' option
-tells configure to use all the add-on bundles it finds in the source
-directory. Since important functionality is provided in add-ons, you
-should always give this option. The `--prefix' option tells configure
-where you want glibc installed. This defaults to `/usr/local'. If you
-are installing glibc as your primary C library, give the option
-`--prefix=/usr', which will put components in `/usr' or `/' as
-appropriate.
+`configure' takes many options, but the only one that is usually
+mandatory is `--prefix'. This option tells `configure' where you want
+the GNU C Library installed. This defaults to `/usr/local', but the
+normal setting to install as the standard system library is
+`--prefix=/usr' for GNU/Linux systems and `--prefix=' (an empty prefix)
+for GNU/Hurd systems.
It may also be useful to set the CC and CFLAGS variables in the
environment when running `configure'. CC selects the C compiler that
will be used, and CFLAGS sets optimization options for the compiler.
- Here are all the useful options known by `configure':
+ The following list describes all of the available options for
+`configure':
`--prefix=DIRECTORY'
Install machine-independent data files in subdirectories of
`--exec-prefix=DIRECTORY'
Install the library and other machine-dependent files in
subdirectories of `DIRECTORY'. The default is to the `--prefix'
- directory if that option is given, or `/usr/local' otherwise.
+ directory if that option is specified, or `/usr/local' otherwise.
`--with-headers=DIRECTORY'
Look for kernel header files in DIRECTORY, not `/usr/include'.
- Glibc needs information from the kernel's private header files.
- It will normally look in `/usr/include' for them, but if you give
- this option, it will look in DIRECTORY instead.
+ The GNU C Library needs information from the kernel's header files
+ describing the interface to the kernel. The GNU C Library will
+ normally look in `/usr/include' for them, but if you specify this
+ option, it will look in DIRECTORY instead.
This option is primarily of use on a system where the headers in
- `/usr/include' come from an older version of glibc. Conflicts can
- occasionally happen in this case. Note that Linux libc5 qualifies
- as an older version of glibc. You can also use this option if you
- want to compile glibc with a newer set of kernel headers than the
- ones found in `/usr/include'.
+ `/usr/include' come from an older version of the GNU C Library.
+ Conflicts can occasionally happen in this case. You can also use
+ this option if you want to compile the GNU C Library with a newer
+ set of kernel headers than the ones found in `/usr/include'.
`--enable-add-ons[=LIST]'
- Enable add-on packages in your source tree. If this option is
- given with no list, it enables all the add-on packages it finds.
- If you do not wish to use some add-on package that you have
- present in your source tree, give this option a list of the
- add-ons that you *do* want used, like this:
- `--enable-add-ons=crypt,linuxthreads'
+ Specify add-on packages to include in the build. If this option is
+ specified with no list, it enables all the add-on packages it
+ finds in the main source directory; this is the default behavior.
+ You may specify an explicit list of add-ons to use in LIST,
+ separated by spaces or commas (if you use spaces, remember to
+ quote them from the shell). Each add-on in LIST can be an
+ absolute directory name or can be a directory name relative to the
+ main source directory, or relative to the build directory (that
+ is, the current working directory). For example,
+ `--enable-add-ons=nptl,../glibc-libidn-VERSION'.
+
+`--enable-kernel=VERSION'
+ This option is currently only useful on GNU/Linux systems. The
+ VERSION parameter should have the form X.Y.Z and describes the
+ smallest version of the Linux kernel the generated library is
+ expected to support. The higher the VERSION number is, the less
+ compatibility code is added, and the faster the code gets.
`--with-binutils=DIRECTORY'
Use the binutils (assembler and linker) in `DIRECTORY', not the
- ones the C compiler would default to. You could use this option if
+ ones the C compiler would default to. You can use this option if
the default binutils on your system cannot deal with all the
- constructs in the GNU C library. (`configure' will detect the
- problem and suppress these constructs, so the library will still
- be usable, but functionality may be lost--for example, you can not
- build a shared libc with old binutils.)
+ constructs in the GNU C Library. In that case, `configure' will
+ detect the problem and suppress these constructs, so that the
+ library will still be usable, but functionality may be lost--for
+ example, you can't build a shared libc with old binutils.
`--without-fp'
Use this option if your computer lacks hardware floating-point
support and your operating system does not emulate an FPU.
-`--disable-static'
- Don't build static libraries. Static libraries aren't that useful
- these days, but we recommend you build them in case you need them.
-
`--disable-shared'
- Don't build shared libraries even if we could. Not all systems
- support shared libraries; you need ELF support and (currently) the
- GNU linker.
+ Don't build shared libraries even if it is possible. Not all
+ systems support shared libraries; you need ELF support and
+ (currently) the GNU linker.
`--disable-profile'
Don't build libraries with profiling information. You may want to
use this option if you don't plan to do profiling.
-`--enable-omitfp'
- Use maximum optimization for the normal (static and shared)
- libraries, and compile separate static libraries with debugging
- information and no optimisation. We recommend against this. The
- extra optimization doesn't gain you much, it may provoke compiler
- bugs, and you won't be able to trace bugs through the C library.
-
-`--disable-versioning'
- Don't compile the shared libraries with symbol version information.
- Doing this will make the library that's built incompatible with old
- binaries, so it's not recommended.
-
`--enable-static-nss'
Compile static versions of the NSS (Name Service Switch) libraries.
This is not recommended because it defeats the purpose of NSS; a
program linked statically with the NSS libraries cannot be
dynamically reconfigured to use a different name database.
+`--without-tls'
+ By default the C library is built with support for thread-local
+ storage if the used tools support it. By using `--without-tls'
+ this can be prevented though there generally is no reason since it
+ creates compatibility problems.
+
+`--enable-hardcoded-path-in-tests'
+ By default, dynamic tests are linked to run with the installed C
+ library. This option hardcodes the newly built C library path in
+ dynamic tests so that they can be invoked directly.
+
+`--enable-lock-elision=yes'
+ Enable lock elision for pthread mutexes by default.
+
+`--enable-pt_chown'
+ The file `pt_chown' is a helper binary for `grantpt' (*note
+ Pseudo-Terminals: Allocation.) that is installed setuid root to
+ fix up pseudo-terminal ownership. It is not built by default
+ because systems using the Linux kernel are commonly built with the
+ `devpts' filesystem enabled and mounted at `/dev/pts', which
+ manages pseudo-terminal ownership automatically. By using
+ `--enable-pt_chown', you may build `pt_chown' and install it
+ setuid and owned by `root'. The use of `pt_chown' introduces
+ additional security risks to the system and you should enable it
+ only if you understand and accept those risks.
+
`--build=BUILD-SYSTEM'
`--host=HOST-SYSTEM'
- These options are for cross-compiling. If you give them both and
- BUILD-SYSTEM is different from HOST-SYSTEM, `configure' will
- prepare to cross-compile glibc from BUILD-SYSTEM to be used on
- HOST-SYSTEM. You'll probably need the `--with-headers' option
- too, and you may have to override CONFIGURE's selection of the
- compiler and/or binutils.
-
- If you give just one of these, `configure' will get confused. If
- `configure' doesn't correctly guess your system type for a native
- build, report that as a bug.
+ These options are for cross-compiling. If you specify both
+ options and BUILD-SYSTEM is different from HOST-SYSTEM, `configure'
+ will prepare to cross-compile the GNU C Library from BUILD-SYSTEM
+ to be used on HOST-SYSTEM. You'll probably need the
+ `--with-headers' option too, and you may have to override
+ CONFIGURE's selection of the compiler and/or binutils.
+
+ If you only specify `--host', `configure' will prepare for a
+ native compile but use what you specify instead of guessing what
+ your system is. This is most useful to change the CPU submodel.
+ For example, if `configure' guesses your machine as
+ `i686-pc-linux-gnu' but you want to compile a library for 586es,
+ give `--host=i586-pc-linux-gnu' or just `--host=i586-linux' and add
+ the appropriate compiler flags (`-mcpu=i586' will do the trick) to
+ CFLAGS.
+
+ If you specify just `--build', `configure' will get confused.
+
+`--with-pkgversion=VERSION'
+ Specify a description, possibly including a build number or build
+ date, of the binaries being built, to be included in `--version'
+ output from programs installed with the GNU C Library. For
+ example, `--with-pkgversion='FooBar GNU/Linux glibc build 123''.
+ The default value is `GNU libc'.
+
+`--with-bugurl=URL'
+ Specify the URL that users should visit if they wish to report a
+ bug, to be included in `--help' output from programs installed with
+ the GNU C Library. The default value refers to the main
+ bug-reporting information for the GNU C Library.
To build the library and related programs, type `make'. This will
produce a lot of output, some of which may look like errors from `make'
but isn't. Look for error messages from `make' containing `***'.
-Those indicate that something is really wrong.
-
- The compilation process takes several hours even on fast hardware.
-Expect at least two hours for the default configuration on i586 for
-Linux. For Hurd times are much longer. Except for EGCS 1.1 (and later
-versions of EGCS), all supported versions of GCC have a problem which
-causes them to take several minutes to compile certain files in the
-iconvdata directory. Do not panic if the compiler appears to hang.
-
- If you want to run a parallel make, you can't just give `make' the
-`-j' option, because it won't be passed down to the sub-makes.
-Instead, edit the generated `Makefile' and uncomment the line
-
- # PARALLELMFLAGS = -j 4
-
-You can change the `4' to some other number as appropriate for your
-system.
-
- To build and run some test programs which exercise some of the
-library facilities, type `make check'. This should complete
-successfully; if it doesn't, do not use the built library, and report a
-bug. *Note Reporting Bugs::, for how to do that. Note that some of
-the tests assume they are not being run by `root'. We recommend you
-compile and test glibc as an unprivileged user.
+Those indicate that something is seriously wrong.
+
+ The compilation process can take a long time, depending on the
+configuration and the speed of your machine. Some complex modules may
+take a very long time to compile, as much as several minutes on slower
+machines. Do not panic if the compiler appears to hang.
+
+ If you want to run a parallel make, simply pass the `-j' option with
+an appropriate numeric parameter to `make'. You need a recent GNU
+`make' version, though.
+
+ To build and run test programs which exercise some of the library
+facilities, type `make check'. If it does not complete successfully,
+do not use the built library, and report a bug after verifying that the
+problem is not already known. *Note Reporting Bugs::, for instructions
+on reporting bugs. Note that some of the tests assume they are not
+being run by `root'. We recommend you compile and test the GNU C
+Library as an unprivileged user.
+
+ Before reporting bugs make sure there is no problem with your system.
+The tests (and later installation) use some pre-existing files of the
+system such as `/etc/passwd', `/etc/nsswitch.conf' and others. These
+files must all contain correct and sensible content.
+
+ Normally, `make check' will run all the tests before reporting all
+problems found and exiting with error status if any problems occurred.
+You can specify `stop-on-test-failure=y' when running `make check' to
+make the test run stop and exit with an error status immediately when a
+failure occurs.
To format the `GNU C Library Reference Manual' for printing, type
-`make dvi'. You need a working TeX installation to do this.
+`make dvi'. You need a working TeX installation to do this. The
+distribution builds the on-line formatted version of the manual, as
+Info files, as part of the build process. You can build them manually
+with `make info'.
+
+ The library has a number of special-purpose configuration parameters
+which you can find in `Makeconfig'. These can be overwritten with the
+file `configparms'. To change them, create a `configparms' in your
+build directory and add values as appropriate for your system. The
+file is included and parsed by `make' and has to follow the conventions
+for makefiles.
+
+ It is easy to configure the GNU C Library for cross-compilation by
+setting a few variables in `configparms'. Set `CC' to the
+cross-compiler for the target you configured the library for; it is
+important to use this same `CC' value when running `configure', like
+this: `CC=TARGET-gcc configure TARGET'. Set `BUILD_CC' to the compiler
+to use for programs run on the build system as part of compiling the
+library. You may need to set `AR' to cross-compiling versions of `ar'
+if the native tools are not configured to work with object files for
+the target you configured for. When cross-compiling the GNU C Library,
+it may be tested using `make check
+test-wrapper="SRCDIR/scripts/cross-test-ssh.sh HOSTNAME"', where SRCDIR
+is the absolute directory name for the main source directory and
+HOSTNAME is the host name of a system that can run the newly built
+binaries of the GNU C Library. The source and build directories must
+be visible at the same locations on both the build system and HOSTNAME.
+
+ In general, when testing the GNU C Library, `test-wrapper' may be set
+to the name and arguments of any program to run newly built binaries.
+This program must preserve the arguments to the binary being run, its
+working directory and the standard input, output and error file
+descriptors. If `TEST-WRAPPER env' will not work to run a program with
+environment variables set, then `test-wrapper-env' must be set to a
+program that runs a newly built program with environment variable
+assignments in effect, those assignments being specified as `VAR=VALUE'
+before the name of the program to be run. If multiple assignments to
+the same variable are specified, the last assignment specified must
+take precedence.
+
+Installing the C Library
+========================
+
+To install the library and its header files, and the Info files of the
+manual, type `make install'. This will build things, if necessary,
+before installing them; however, you should still compile everything
+first. If you are installing the GNU C Library as your primary C
+library, we recommend that you shut the system down to single-user mode
+first, and reboot afterward. This minimizes the risk of breaking
+things when the library changes out from underneath.
+
+ `make install' will do the entire job of upgrading from a previous
+installation of the GNU C Library version 2.x. There may sometimes be
+headers left behind from the previous installation, but those are
+generally harmless. If you want to avoid leaving headers behind you
+can do things in the following order.
+
+ You must first build the library (`make'), optionally check it
+(`make check'), switch the include directories and then install (`make
+install'). The steps must be done in this order. Not moving the
+directory before install will result in an unusable mixture of header
+files from both libraries, but configuring, building, and checking the
+library requires the ability to compile and run programs against the old
+library. The new `/usr/include', after switching the include
+directories and before installing the library should contain the Linux
+headers, but nothing else. If you do this, you will need to restore
+any headers from libraries other than the GNU C Library yourself after
+installing the library.
+
+ You can install the GNU C Library somewhere other than where you
+configured it to go by setting the `install_root' variable on the
+command line for `make install'. The value of this variable is
+prepended to all the paths for installation. This is useful when
+setting up a chroot environment or preparing a binary distribution.
+The directory should be specified with an absolute file name.
+
+ The GNU C Library includes a daemon called `nscd', which you may or
+may not want to run. `nscd' caches name service lookups; it can
+dramatically improve performance with NIS+, and may help with DNS as
+well.
- To install the library and its header files, and the Info files of
-the manual, type `make install'. This will build things if necessary,
-before installing them. If you want to install the files in a different
-place than the one specified at configuration time you can specify a
-value for the Makefile variable `install_root' on the command line.
-This is useful to create chroot'ed environment or to prepare binary
-releases.
+ One auxiliary program, `/usr/libexec/pt_chown', is installed setuid
+`root' if the `--enable-pt_chown' configuration option is used. This
+program is invoked by the `grantpt' function; it sets the permissions
+on a pseudoterminal so it can be used by the calling process. If you
+are using a Linux kernel with the `devpts' filesystem enabled and
+mounted at `/dev/pts', you don't need this program.
+
+ After installation you might want to configure the timezone and
+locale installation of your system. The GNU C Library comes with a
+locale database which gets configured with `localedef'. For example, to
+set up a German locale with name `de_DE', simply issue the command
+`localedef -i de_DE -f ISO-8859-1 de_DE'. To configure all locales
+that are supported by the GNU C Library, you can issue from your build
+directory the command `make localedata/install-locales'.
+
+ To configure the locally used timezone, set the `TZ' environment
+variable. The script `tzselect' helps you to select the right value.
+As an example, for Germany, `tzselect' would tell you to use
+`TZ='Europe/Berlin''. For a system wide installation (the given paths
+are for an installation with `--prefix=/usr'), link the timezone file
+which is in `/usr/share/zoneinfo' to the file `/etc/localtime'. For
+Germany, you might execute `ln -s /usr/share/zoneinfo/Europe/Berlin
+/etc/localtime'.
Recommended Tools for Compilation
=================================
- We recommend installing the following GNU tools before attempting to
-build the GNU C library:
+We recommend installing the following GNU tools before attempting to
+build the GNU C Library:
- * GNU `make' 3.75
+ * GNU `make' 3.79 or newer
You need the latest version of GNU `make'. Modifying the GNU C
- Library to work with other `make' programs would be so hard that we
- recommend you port GNU `make' instead. *Really.* We recommend
- version GNU `make' version 3.75 or 3.77. All earlier versions
- have severe bugs or lack features. Version 3.76 is known to have
- bugs which only show up in big projects like GNU `libc'. Version
- 3.76.1 seems OK but some people have reported problems.
+ Library to work with other `make' programs would be so difficult
+ that we recommend you port GNU `make' instead. *Really.* We
+ recommend GNU `make' version 3.79. All earlier versions have
+ severe bugs or lack features.
+
+ * GCC 4.4 or newer, GCC 4.6 recommended
- * EGCS 1.1 or 1.0.3
+ GCC 4.4 or higher is required; as of this writing, GCC 4.6 is the
+ compiler we advise to use to build the GNU C Library.
- The GNU C library can only be compiled with the GNU C compiler
- family. We recommend EGCS 1.0.3 or higher. GCC 2.8.1 and older
- versions of EGCS may have problems, particularly on non-Intel
- architectures. GCC 2.7.x has catastrophic bugs and cannot be used
- at all.
+ You can use whatever compiler you like to compile programs that use
+ the GNU C Library.
- * GNU `binutils' 2.8.1.0.23, 2.9.1, or 2.9.0.15
+ Check the FAQ for any special compiler issues on particular
+ platforms.
- You must use GNU binutils (as and ld) if you want to build a shared
- library. Even if you don't, we recommend you use them anyway. No
- one has tested compilation with non-GNU binutils in a long time.
+ * GNU `binutils' 2.20 or later
- The quality of binutils releases has varied a bit recently. The
- bugs are in obscure features, but glibc uses quite a few of those.
- 2.8.1.0.23, 2.9.1, and 2.9.0.15 are known to work. Versions after
- 2.8.1.0.23 may or may not work. Older versions definitely don't.
+ You must use GNU `binutils' (as and ld) to build the GNU C Library.
+ No other assembler or linker has the necessary functionality at the
+ moment.
- * GNU `texinfo' 3.11
+ * GNU `texinfo' 4.5 or later
To correctly translate and install the Texinfo documentation you
need this version of the `texinfo' package. Earlier versions do
not understand all the tags used in the document, and the
- installation mechanisms for the info files is not present or works
+ installation mechanism for the info files is not present or works
differently.
- On some Debian Linux based systems the `install-info' program
- supplied with the system works differently from the one we expect.
- You must therefore run `make install' like this:
-
- make INSTALL_INFO=/path/to/GNU/install-info install
-
- * GNU `awk' 3.0, or some other POSIX awk
+ * GNU `awk' 3.1.2, or higher
- Awk is used in several places to generate files. The scripts
- should work with any POSIX-compliant awk implementation; GNU awk
- 3.0 and `mawk' 1.3 are known to work.
+ `awk' is used in several places to generate files. Some `gawk'
+ extensions are used, including the `asorti' function, which was
+ introduced in version 3.1.2 of `gawk'.
* Perl 5
Perl is not required, but it is used if present to test the
installation. We may decide to use it elsewhere in the future.
-If you change any of the `configure.in' files you will also need
+ * GNU `sed' 3.02 or newer
+
+ `Sed' is used in several places to generate files. Most scripts
+ work with any version of `sed'. The known exception is the script
+ `po2test.sed' in the `intl' subdirectory which is used to generate
+ `msgs.h' for the test suite. This script works correctly only
+ with GNU `sed' 3.02. If you like to run the test suite, you
+ should definitely upgrade `sed'.
+
+
+If you change any of the `configure.ac' files you will also need
- * GNU `autoconf' 2.12
+ * GNU `autoconf' 2.53 or higher
and if you change any of the message translation files you will need
- * GNU `gettext' 0.10.35 or later
+ * GNU `gettext' 0.10.36 or later
You may also need these packages if you upgrade your source tree using
patches, although we try to avoid this.
-Supported Configurations
-========================
-
- The GNU C Library currently supports configurations that match the
-following patterns:
-
- alpha-*-linux
- arm-*-linuxaout
- arm-*-none
- iX86-*-gnu
- iX86-*-linux
- m68k-*-linux
- powerpc-*-linux
- sparc-*-linux
- sparc64-*-linux
-
- Former releases of this library (version 1.09.1 and perhaps earlier
-versions) used to run on the following configurations:
-
- alpha-dec-osf1
- alpha-*-linuxecoff
- iX86-*-bsd4.3
- iX86-*-isc2.2
- iX86-*-isc3.N
- iX86-*-sco3.2
- iX86-*-sco3.2v4
- iX86-*-sysv
- iX86-*-sysv4
- iX86-force_cpu386-none
- iX86-sequent-bsd
- i960-nindy960-none
- m68k-hp-bsd4.3
- m68k-mvme135-none
- m68k-mvme136-none
- m68k-sony-newsos3
- m68k-sony-newsos4
- m68k-sun-sunos4.N
- mips-dec-ultrix4.N
- mips-sgi-irix4.N
- sparc-sun-solaris2.N
- sparc-sun-sunos4.N
-
- Since no one has volunteered to test and fix these configurations,
-they are not supported at the moment. They probably don't compile;
-they definitely don't work anymore. Porting the library is not hard.
-If you are interested in doing a port, please contact the glibc
-maintainers by sending electronic mail to <bug-glibc@gnu.org>.
-
- Each case of `iX86' can be `i386', `i486', `i586', or `i686'. All
-of those configurations produce a library that can run on any of these
-processors. The library will be optimized for the specified processor,
-but will not use instructions not available on all of them.
-
- While no other configurations are supported, there are handy aliases
-for these few. (These aliases work in other GNU software as well.)
-
- decstation
- hp320-bsd4.3 hp300bsd
- i486-gnu
- i586-linux
- i386-sco
- i386-sco3.2v4
- i386-sequent-dynix
- i386-svr4
- news
- sun3-sunos4.N sun3
- sun4-solaris2.N sun4-sunos5.N
- sun4-sunos4.N sun4
+Specific advice for GNU/Linux systems
+=====================================
+
+If you are installing the GNU C Library on GNU/Linux systems, you need
+to have the header files from a 2.6.32 or newer kernel around for
+reference. These headers must be installed using `make
+headers_install'; the headers present in the kernel source directory
+are not suitable for direct use by the GNU C Library. You do not need
+to use that kernel, just have its headers installed where the GNU C
+Library can access them, referred to here as INSTALL-DIRECTORY. The
+easiest way to do this is to unpack it in a directory such as
+`/usr/src/linux-VERSION'. In that directory, run `make headers_install
+INSTALL_HDR_PATH=INSTALL-DIRECTORY'. Finally, configure the GNU C
+Library with the option `--with-headers=INSTALL-DIRECTORY/include'.
+Use the most recent kernel you can get your hands on. (If you are
+cross-compiling the GNU C Library, you need to specify
+`ARCH=ARCHITECTURE' in the `make headers_install' command, where
+ARCHITECTURE is the architecture name used by the Linux kernel, such as
+`x86' or `powerpc'.)
+
+ After installing the GNU C Library, you may need to remove or rename
+directories such as `/usr/include/linux' and `/usr/include/asm', and
+replace them with copies of directories such as `linux' and `asm' from
+`INSTALL-DIRECTORY/include'. All directories present in
+`INSTALL-DIRECTORY/include' should be copied, except that the GNU C
+Library provides its own version of `/usr/include/scsi'; the files
+provided by the kernel should be copied without replacing those
+provided by the GNU C Library. The `linux', `asm' and `asm-generic'
+directories are required to compile programs using the GNU C Library;
+the other directories describe interfaces to the kernel but are not
+required if not compiling programs using those interfaces. You do not
+need to copy kernel headers if you did not specify an alternate kernel
+header source using `--with-headers'.
+
+ The Filesystem Hierarchy Standard for GNU/Linux systems expects some
+components of the GNU C Library installation to be in `/lib' and some
+in `/usr/lib'. This is handled automatically if you configure the GNU
+C Library with `--prefix=/usr'. If you set some other prefix or allow
+it to default to `/usr/local', then all the components are installed
+there.
Reporting Bugs
==============
- There are probably bugs in the GNU C library. There are certainly
+There are probably bugs in the GNU C Library. There are certainly
errors and omissions in this manual. If you report them, they will get
fixed. If you don't, no one will ever know about them and they will
remain unfixed for all eternity, if not longer.
- To report a bug, first you must find it. Hopefully, this will be the
-hard part. Once you've found a bug, make sure it's really a bug. A
-good way to do this is to see if the GNU C library behaves the same way
-some other C library does. If so, probably you are wrong and the
-libraries are right (but not necessarily). If not, one of the libraries
-is probably wrong.
+ It is a good idea to verify that the problem has not already been
+reported. Bugs are documented in two places: The file `BUGS' describes
+a number of well known bugs and the central GNU C Library bug tracking
+system has a WWW interface at `http://sourceware.org/bugzilla/'. The
+WWW interface gives you access to open and closed reports. A closed
+report normally includes a patch or a hint on solving the problem.
+
+ To report a bug, first you must find it. With any luck, this will
+be the hard part. Once you've found a bug, make sure it's really a
+bug. A good way to do this is to see if the GNU C Library behaves the
+same way some other C library does. If so, probably you are wrong and
+the libraries are right (but not necessarily). If not, one of the
+libraries is probably wrong. It might not be the GNU C Library. Many
+historical Unix C libraries permit things that we don't, such as
+closing a file twice.
+
+ If you think you have found some way in which the GNU C Library does
+not conform to the ISO and POSIX standards (*note Standards and
+Portability::), that is definitely a bug. Report it!
Once you're sure you've found a bug, try to narrow it down to the
smallest test case that reproduces the problem. In the case of a C
call, if possible. This should not be too difficult.
The final step when you have a simple test case is to report the bug.
-When reporting a bug, send your test case, the results you got, the
-results you expected, what you think the problem might be (if you've
-thought of anything), your system type, and the version of the GNU C
-library which you are using. Also include the files `config.status'
-and `config.make' which are created by running `configure'; they will
-be in whatever directory was current when you ran `configure'.
-
- If you think you have found some way in which the GNU C library does
-not conform to the ISO and POSIX standards (*note Standards and
-Portability::.), that is definitely a bug. Report it!
-
- Send bug reports to the Internet address <bug-glibc@gnu.org> using
-the `glibcbug' script which is installed by the GNU C library. If you
-have other problems with installation or use, please report those as
-well.
+Do this at `http://www.gnu.org/software/libc/bugs.html'.
If you are not sure how a function should behave, and this manual
doesn't tell you, that's a bug in the manual. Report that too! If the
function's behavior disagrees with the manual, then either the library
or the manual has a bug, so report the disagreement. If you find any
-errors or omissions in this manual, please report them to the Internet
-address <bug-glibc-manual@gnu.org>. If you refer to specific sections
-when reporting on the manual, please include the section names for
-easier identification.
-
+errors or omissions in this manual, please report them to the bug
+database. If you refer to specific sections of the manual, please
+include the section names for easier identification.