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1f77f049 1@include macros.texi
8b748aed 2@include pkgvers.texi
3c20b9b6 3
d136c6dc 4@ifclear plain
3d2abe79 5@node Installation, Maintenance, Library Summary, Top
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6@end ifclear
7
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8@c %MENU% How to install the GNU C Library
9@appendix Installing @theglibc{}
3c20b9b6 10
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11Before you do anything else, you should read the FAQ at
12@url{http://sourceware.org/glibc/wiki/FAQ}. It answers common
13questions and describes problems you may experience with compilation
14and installation.
3c20b9b6 15
1f77f049 16Features can be added to @theglibc{} via @dfn{add-on} bundles. These are
a4d62195 17separate tar files, which you unpack into the top level of the source
1792d4db 18tree. Then you give @code{configure} the @samp{--enable-add-ons} option
b3af1a24 19to activate them, and they will be compiled into the library.
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20
21You will need recent versions of several GNU tools: definitely GCC and
fe959e1e 22GNU Make, and possibly others. @xref{Tools for Compilation}, below.
00c1176b 23
ee0a148a 24@ifclear plain
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25@menu
26* Configuring and compiling:: How to compile and test GNU libc.
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27* Running make install:: How to install it once you've got it
28 compiled.
00c1176b 29* Tools for Compilation:: You'll need these first.
90d1d40b 30* Linux:: Specific advice for GNU/Linux systems.
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31* Reporting Bugs:: So they'll get fixed.
32@end menu
ee0a148a 33@end ifclear
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34
35@node Configuring and compiling
1f77f049 36@appendixsec Configuring and compiling @theglibc{}
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37@cindex configuring
38@cindex compiling
00c1176b 39
1f77f049 40@Theglibc{} cannot be compiled in the source directory. You must build
3858bf28 41it in a separate build directory. For example, if you have unpacked
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42the @glibcadj{} sources in @file{/src/gnu/glibc-@var{version}},
43create a directory
e8b1163e 44@file{/src/gnu/glibc-build} to put the object files in. This allows
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45removing the whole build directory in case an error occurs, which is
46the safest way to get a fresh start and should always be done.
00c1176b 47
a4d62195 48From your object directory, run the shell script @file{configure} located
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49at the top level of the source tree. In the scenario above, you'd type
50
51@smallexample
f1e86fca 52$ ../glibc-@var{version}/configure @var{args@dots{}}
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53@end smallexample
54
3858bf28 55Please note that even though you're building in a separate build
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56directory, the compilation may need to create or modify files and
57directories in the source directory.
f76d7052 58
00c1176b 59@noindent
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60@code{configure} takes many options, but the only one that is usually
61mandatory is @samp{--prefix}. This option tells @code{configure}
1f77f049 62where you want @theglibc{} installed. This defaults to @file{/usr/local},
3858bf28 63but the normal setting to install as the standard system library is
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64@samp{--prefix=/usr} for @gnulinuxsystems{} and @samp{--prefix=} (an
65empty prefix) for @gnuhurdsystems{}.
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66
67It may also be useful to set the @var{CC} and @var{CFLAGS} variables in
68the environment when running @code{configure}. @var{CC} selects the C
69compiler that will be used, and @var{CFLAGS} sets optimization options
70for the compiler.
71
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72The following list describes all of the available options for
73 @code{configure}:
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74
75@table @samp
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76@item --prefix=@var{directory}
77Install machine-independent data files in subdirectories of
78@file{@var{directory}}. The default is to install in @file{/usr/local}.
79
80@item --exec-prefix=@var{directory}
81Install the library and other machine-dependent files in subdirectories
82of @file{@var{directory}}. The default is to the @samp{--prefix}
04b9968b 83directory if that option is specified, or @file{/usr/local} otherwise.
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84
85@item --with-headers=@var{directory}
86Look for kernel header files in @var{directory}, not
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87@file{/usr/include}. @Theglibc{} needs information from the kernel's header
88files describing the interface to the kernel. @Theglibc{} will normally
abd923db 89look in @file{/usr/include} for them,
04b9968b 90but if you specify this option, it will look in @var{DIRECTORY} instead.
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91
92This option is primarily of use on a system where the headers in
1f77f049 93@file{/usr/include} come from an older version of @theglibc{}. Conflicts can
02c4bbad 94occasionally happen in this case. You can also use this option if you want to
1f77f049 95compile @theglibc{} with a newer set of kernel headers than the ones found in
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96@file{/usr/include}.
97
98@item --enable-add-ons[=@var{list}]
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99Specify add-on packages to include in the build. If this option is
100specified with no list, it enables all the add-on packages it finds in
101the main source directory; this is the default behavior. You may
102specify an explicit list of add-ons to use in @var{list}, separated by
103spaces or commas (if you use spaces, remember to quote them from the
104shell). Each add-on in @var{list} can be an absolute directory name
105or can be a directory name relative to the main source directory, or
106relative to the build directory (that is, the current working directory).
f1e86fca 107For example, @samp{--enable-add-ons=nptl,../glibc-libidn-@var{version}}.
00c1176b 108
d2830ba4 109@item --enable-kernel=@var{version}
a7a93d50 110This option is currently only useful on @gnulinuxsystems{}. The
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111@var{version} parameter should have the form X.Y.Z and describes the
112smallest version of the Linux kernel the generated library is expected
113to support. The higher the @var{version} number is, the less
114compatibility code is added, and the faster the code gets.
115
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116@item --with-binutils=@var{directory}
117Use the binutils (assembler and linker) in @file{@var{directory}}, not
a4d62195 118the ones the C compiler would default to. You can use this option if
3c20b9b6 119the default binutils on your system cannot deal with all the constructs
1f77f049 120in @theglibc{}. In that case, @code{configure} will detect the
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121problem and suppress these constructs, so that the library will still be
122usable, but functionality may be lost---for example, you can't build a
123shared libc with old binutils.
3c20b9b6 124
3c20b9b6 125@item --without-fp
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126Use this option if your computer lacks hardware floating-point support
127and your operating system does not emulate an FPU.
128
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129@c disable static doesn't work currently
130@c @item --disable-static
fb06851d 131@c Don't build static libraries. Static libraries aren't that useful these
b5ca0fb0 132@c days, but we recommend you build them in case you need them.
3c20b9b6 133
00c1176b 134@item --disable-shared
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135Don't build shared libraries even if it is possible. Not all systems
136support shared libraries; you need ELF support and (currently) the GNU
137linker.
3c20b9b6 138
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139@item --disable-profile
140Don't build libraries with profiling information. You may want to use
141this option if you don't plan to do profiling.
f12944ec 142
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143@item --enable-static-nss
144Compile static versions of the NSS (Name Service Switch) libraries.
145This is not recommended because it defeats the purpose of NSS; a program
146linked statically with the NSS libraries cannot be dynamically
147reconfigured to use a different name database.
148
8d4b5a8a 149@item --without-tls
a4d62195 150By default the C library is built with support for thread-local storage
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151if the used tools support it. By using @samp{--without-tls} this can be
152prevented though there generally is no reason since it creates
153compatibility problems.
154
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155@item --enable-hardcoded-path-in-tests
156By default, dynamic tests are linked to run with the installed C library.
157This option hardcodes the newly built C library path in dynamic tests
158so that they can be invoked directly.
159
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160@item --enable-lock-elision=yes
161Enable lock elision for pthread mutexes by default.
162
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163@pindex pt_chown
164@findex grantpt
165@item --enable-pt_chown
166The file @file{pt_chown} is a helper binary for @code{grantpt}
167(@pxref{Allocation, Pseudo-Terminals}) that is installed setuid root to
168fix up pseudo-terminal ownership. It is not built by default because
169systems using the Linux kernel are commonly built with the @code{devpts}
170filesystem enabled and mounted at @file{/dev/pts}, which manages
171pseudo-terminal ownership automatically. By using
172@samp{--enable-pt_chown}, you may build @file{pt_chown} and install it
173setuid and owned by @code{root}. The use of @file{pt_chown} introduces
174additional security risks to the system and you should enable it only if
175you understand and accept those risks.
176
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177@item --disable-werror
178By default, @theglibc{} is built with @option{-Werror}. If you wish
179to build without this option (for example, if building with a newer
180version of GCC than this version of @theglibc{} was tested with, so
181new warnings cause the build with @option{-Werror} to fail), you can
182configure with @option{--disable-werror}.
183
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184@item --build=@var{build-system}
185@itemx --host=@var{host-system}
04b9968b 186These options are for cross-compiling. If you specify both options and
00c1176b 187@var{build-system} is different from @var{host-system}, @code{configure}
1f77f049 188will prepare to cross-compile @theglibc{} from @var{build-system} to be used
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189on @var{host-system}. You'll probably need the @samp{--with-headers}
190option too, and you may have to override @var{configure}'s selection of
191the compiler and/or binutils.
192
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193If you only specify @samp{--host}, @code{configure} will prepare for a
194native compile but use what you specify instead of guessing what your
cf822e3c 195system is. This is most useful to change the CPU submodel. For example,
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196if @code{configure} guesses your machine as @code{i686-pc-linux-gnu} but
197you want to compile a library for 586es, give
198@samp{--host=i586-pc-linux-gnu} or just @samp{--host=i586-linux} and add
199the appropriate compiler flags (@samp{-mcpu=i586} will do the trick) to
a4d62195 200@var{CFLAGS}.
1792d4db 201
a4d62195 202If you specify just @samp{--build}, @code{configure} will get confused.
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203
204@item --with-pkgversion=@var{version}
205Specify a description, possibly including a build number or build
206date, of the binaries being built, to be included in
207@option{--version} output from programs installed with @theglibc{}.
208For example, @option{--with-pkgversion='FooBar GNU/Linux glibc build
209123'}. The default value is @samp{GNU libc}.
210
211@item --with-bugurl=@var{url}
212Specify the URL that users should visit if they wish to report a bug,
213to be included in @option{--help} output from programs installed with
214@theglibc{}. The default value refers to the main bug-reporting
215information for @theglibc{}.
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216@end table
217
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218To build the library and related programs, type @code{make}. This will
219produce a lot of output, some of which may look like errors from
220@code{make} but isn't. Look for error messages from @code{make}
a4d62195 221containing @samp{***}. Those indicate that something is seriously wrong.
00c1176b 222
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223The compilation process can take a long time, depending on the
224configuration and the speed of your machine. Some complex modules may
225take a very long time to compile, as much as several minutes on slower
226machines. Do not panic if the compiler appears to hang.
3c20b9b6 227
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228If you want to run a parallel make, simply pass the @samp{-j} option
229with an appropriate numeric parameter to @code{make}. You need a recent
230GNU @code{make} version, though.
f12944ec 231
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232To build and run test programs which exercise some of the library
233facilities, type @code{make check}. If it does not complete
234successfully, do not use the built library, and report a bug after
235verifying that the problem is not already known. @xref{Reporting Bugs},
236for instructions on reporting bugs. Note that some of the tests assume
237they are not being run by @code{root}. We recommend you compile and
1f77f049 238test @theglibc{} as an unprivileged user.
3c20b9b6 239
8eadd4f3 240Before reporting bugs make sure there is no problem with your system.
a4d62195 241The tests (and later installation) use some pre-existing files of the
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242system such as @file{/etc/passwd}, @file{/etc/nsswitch.conf} and others.
243These files must all contain correct and sensible content.
244
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245Normally, @code{make check} will run all the tests before reporting
246all problems found and exiting with error status if any problems
247occurred. You can specify @samp{stop-on-test-failure=y} when running
248@code{make check} to make the test run stop and exit with an error
249status immediately when a failure occurs.
250
3c20b9b6 251To format the @cite{GNU C Library Reference Manual} for printing, type
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252@w{@code{make dvi}}. You need a working @TeX{} installation to do
253this. The distribution builds the on-line formatted version of the
254manual, as Info files, as part of the build process. You can build
255them manually with @w{@code{make info}}.
1792d4db 256
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257The library has a number of special-purpose configuration parameters
258which you can find in @file{Makeconfig}. These can be overwritten with
259the file @file{configparms}. To change them, create a
260@file{configparms} in your build directory and add values as appropriate
261for your system. The file is included and parsed by @code{make} and has
262to follow the conventions for makefiles.
263
1f77f049 264It is easy to configure @theglibc{} for cross-compilation by
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265setting a few variables in @file{configparms}. Set @code{CC} to the
266cross-compiler for the target you configured the library for; it is
267important to use this same @code{CC} value when running
268@code{configure}, like this: @samp{CC=@var{target}-gcc configure
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269@var{target}}. Set @code{BUILD_CC} to the compiler to use for programs
270run on the build system as part of compiling the library. You may need to
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271set @code{AR} to cross-compiling versions of @code{ar}
272if the native tools are not configured to work with
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273object files for the target you configured for. When cross-compiling
274@theglibc{}, it may be tested using @samp{make check
275test-wrapper="@var{srcdir}/scripts/cross-test-ssh.sh @var{hostname}"},
276where @var{srcdir} is the absolute directory name for the main source
277directory and @var{hostname} is the host name of a system that can run
278the newly built binaries of @theglibc{}. The source and build
279directories must be visible at the same locations on both the build
280system and @var{hostname}.
2e8048e5 281
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282In general, when testing @theglibc{}, @samp{test-wrapper} may be set
283to the name and arguments of any program to run newly built binaries.
284This program must preserve the arguments to the binary being run, its
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285working directory and the standard input, output and error file
286descriptors. If
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287@samp{@var{test-wrapper} env} will not work to run a program with
288environment variables set, then @samp{test-wrapper-env} must be set to
289a program that runs a newly built program with environment variable
290assignments in effect, those assignments being specified as
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291@samp{@var{var}=@var{value}} before the name of the program to be
292run. If multiple assignments to the same variable are specified,
293the last assignment specified must take precedence.
0eb69512 294
2e8048e5 295
085320f5 296@node Running make install
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297@appendixsec Installing the C Library
298@cindex installing
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299
300To install the library and its header files, and the Info files of the
686554bf 301manual, type @code{make install}. This will
a4d62195 302build things, if necessary, before installing them; however, you should
1f77f049 303still compile everything first. If you are installing @theglibc{} as your
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304primary C library, we recommend that you shut the system down to
305single-user mode first, and reboot afterward. This minimizes the risk
306of breaking things when the library changes out from underneath.
1792d4db 307
02c4bbad 308@samp{make install} will do the entire job of upgrading from a
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309previous installation of @theglibc{} version 2.x. There may sometimes
310be headers
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311left behind from the previous installation, but those are generally
312harmless. If you want to avoid leaving headers behind you can do
313things in the following order.
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314
315You must first build the library (@samp{make}), optionally check it
316(@samp{make check}), switch the include directories and then install
317(@samp{make install}). The steps must be done in this order. Not moving
318the directory before install will result in an unusable mixture of header
319files from both libraries, but configuring, building, and checking the
320library requires the ability to compile and run programs against the old
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321library. The new @file{/usr/include}, after switching the include
322directories and before installing the library should contain the Linux
323headers, but nothing else. If you do this, you will need to restore
1f77f049 324any headers from libraries other than @theglibc{} yourself after installing the
62075f0f 325library.
c559a3ca 326
1f77f049 327You can install @theglibc{} somewhere other than where you configured it to go
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328by setting the @code{install_root} variable on the command line for
329@samp{make install}. The value of this variable is prepended to all the
330paths for installation. This is useful when setting up a chroot
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331environment or preparing a binary distribution. The directory should be
332specified with an absolute file name.
1792d4db 333
1f77f049 334@Theglibc{} includes a daemon called @code{nscd}, which you
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335may or may not want to run. @code{nscd} caches name service lookups; it
336can dramatically improve performance with NIS+, and may help with DNS as
a0edd63e 337well.
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338
339One auxiliary program, @file{/usr/libexec/pt_chown}, is installed setuid
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340@code{root} if the @samp{--enable-pt_chown} configuration option is used.
341This program is invoked by the @code{grantpt} function; it sets the
342permissions on a pseudoterminal so it can be used by the calling process.
343If you are using a Linux kernel with the @code{devpts} filesystem enabled
344and mounted at @file{/dev/pts}, you don't need this program.
3c20b9b6 345
d01d6319 346After installation you might want to configure the timezone and locale
1f77f049 347installation of your system. @Theglibc{} comes with a locale
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348database which gets configured with @code{localedef}. For example, to
349set up a German locale with name @code{de_DE}, simply issue the command
8fc1e2ca 350@samp{localedef -i de_DE -f ISO-8859-1 de_DE}. To configure all locales
1f77f049 351that are supported by @theglibc{}, you can issue from your build directory the
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352command @samp{make localedata/install-locales}.
353
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354To configure the locally used timezone, set the @code{TZ} environment
355variable. The script @code{tzselect} helps you to select the right value.
356As an example, for Germany, @code{tzselect} would tell you to use
357@samp{TZ='Europe/Berlin'}. For a system wide installation (the given
358paths are for an installation with @samp{--prefix=/usr}), link the
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359timezone file which is in @file{/usr/share/zoneinfo} to the file
360@file{/etc/localtime}. For Germany, you might execute @samp{ln -s
361/usr/share/zoneinfo/Europe/Berlin /etc/localtime}.
362
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363@node Tools for Compilation
364@appendixsec Recommended Tools for Compilation
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365@cindex installation tools
366@cindex tools, for installing library
367
368We recommend installing the following GNU tools before attempting to
1f77f049 369build @theglibc{}:
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370
371@itemize @bullet
372@item
2bbc70d5 373GNU @code{make} 3.79 or newer
3c20b9b6 374
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375You need the latest version of GNU @code{make}. Modifying @theglibc{}
376to work with other @code{make} programs would be so difficult that
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377we recommend you port GNU @code{make} instead. @strong{Really.} We
378recommend GNU @code{make} version 3.79. All earlier versions have severe
379bugs or lack features.
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380
381@item
4863355a 382GCC 4.6 or newer
0e7727f7 383
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384GCC 4.6 or higher is required. In general it is recommended to use
385the newest version of the compiler that is known to work for building
386@theglibc{}, as newer compilers usually produce better code. As of
387release time, GCC 4.9 is the newest compiler verified to work to build
388@theglibc{}.
91ea72b7 389
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390You can use whatever compiler you like to compile programs that use
391@theglibc{}.
3c20b9b6 392
90d1d40b 393Check the FAQ for any special compiler issues on particular platforms.
5713a71e 394
3c20b9b6 395@item
bd805071 396GNU @code{binutils} 2.22 or later
00c1176b 397
1f77f049 398You must use GNU @code{binutils} (as and ld) to build @theglibc{}.
0c02c85f 399No other assembler or linker has the necessary functionality at the
2231b60e 400moment.
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401
402@item
3a12c70f 403GNU @code{texinfo} 4.7 or later
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404
405To correctly translate and install the Texinfo documentation you need
406this version of the @code{texinfo} package. Earlier versions do not
407understand all the tags used in the document, and the installation
1792d4db 408mechanism for the info files is not present or works differently.
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409
410@item
12086fb4 411GNU @code{awk} 3.1.2, or higher
00c1176b 412
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413@code{awk} is used in several places to generate files.
414Some @code{gawk} extensions are used, including the @code{asorti}
415function, which was introduced in version 3.1.2 of @code{gawk}.
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416
417@item
418Perl 5
419
420Perl is not required, but it is used if present to test the
421installation. We may decide to use it elsewhere in the future.
3c20b9b6 422
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423@item
424GNU @code{sed} 3.02 or newer
425
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426@code{Sed} is used in several places to generate files. Most scripts work
427with any version of @code{sed}. The known exception is the script
d66732e0 428@code{po2test.sed} in the @code{intl} subdirectory which is used to
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429generate @code{msgs.h} for the test suite. This script works correctly
430only with GNU @code{sed} 3.02. If you like to run the test suite, you
b8668434 431should definitely upgrade @code{sed}.
d66732e0 432
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433@end itemize
434
435@noindent
cb8a6dbd 436If you change any of the @file{configure.ac} files you will also need
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437
438@itemize @bullet
439@item
f3f5d895 440GNU @code{autoconf} 2.69 (exactly)
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441@end itemize
442
443@noindent
444and if you change any of the message translation files you will need
445
446@itemize @bullet
447@item
c26b4f64 448GNU @code{gettext} 0.10.36 or later
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449@end itemize
450
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451@noindent
452If you wish to regenerate the @code{yacc} parser code in the @file{intl}
453subdirectory you will need
454
455@itemize @bullet
456@item
457GNU @code{bison} 2.7 or later
458@end itemize
459
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460@noindent
461You may also need these packages if you upgrade your source tree using
462patches, although we try to avoid this.
463
1792d4db 464@node Linux
a7a93d50 465@appendixsec Specific advice for @gnulinuxsystems{}
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466@cindex kernel header files
467
a7a93d50 468If you are installing @theglibc{} on @gnulinuxsystems{}, you need to have
d0f5b3f8 469the header files from a 2.6.32 or newer kernel around for reference.
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470These headers must be installed using @samp{make headers_install}; the
471headers present in the kernel source directory are not suitable for
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472direct use by @theglibc{}. You do not need to use that kernel, just have
473its headers installed where @theglibc{} can access them, referred to here as
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474@var{install-directory}. The easiest way to do this is to unpack it
475in a directory such as @file{/usr/src/linux-@var{version}}. In that
476directory, run @samp{make headers_install
1f77f049 477INSTALL_HDR_PATH=@var{install-directory}}. Finally, configure @theglibc{}
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478with the option @samp{--with-headers=@var{install-directory}/include}.
479Use the most recent kernel you can get your hands on. (If you are
1f77f049 480cross-compiling @theglibc{}, you need to specify
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481@samp{ARCH=@var{architecture}} in the @samp{make headers_install}
482command, where @var{architecture} is the architecture name used by the
483Linux kernel, such as @samp{x86} or @samp{powerpc}.)
a8d87c92 484
1f77f049 485After installing @theglibc{}, you may need to remove or rename
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486directories such as @file{/usr/include/linux} and
487@file{/usr/include/asm}, and replace them with copies of directories
488such as @file{linux} and @file{asm} from
489@file{@var{install-directory}/include}. All directories present in
490@file{@var{install-directory}/include} should be copied, except that
1f77f049 491@theglibc{} provides its own version of @file{/usr/include/scsi}; the
abd923db 492files provided by the kernel should be copied without replacing those
1f77f049 493provided by @theglibc{}. The @file{linux}, @file{asm} and
abd923db 494@file{asm-generic} directories are required to compile programs using
1f77f049 495@theglibc{}; the other directories describe interfaces to the kernel but
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496are not required if not compiling programs using those interfaces.
497You do not need to copy kernel headers if you did not specify an
498alternate kernel header source using @samp{--with-headers}.
1792d4db 499
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500The Filesystem Hierarchy Standard for @gnulinuxsystems{} expects some
501components of the @glibcadj{} installation to be in
1792d4db 502@file{/lib} and some in @file{/usr/lib}. This is handled automatically
1f77f049 503if you configure @theglibc{} with @samp{--prefix=/usr}. If you set some other
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504prefix or allow it to default to @file{/usr/local}, then all the
505components are installed there.
506
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507@node Reporting Bugs
508@appendixsec Reporting Bugs
509@cindex reporting bugs
510@cindex bugs, reporting
511
1f77f049 512There are probably bugs in @theglibc{}. There are certainly
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513errors and omissions in this manual. If you report them, they will get
514fixed. If you don't, no one will ever know about them and they will
515remain unfixed for all eternity, if not longer.
516
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517It is a good idea to verify that the problem has not already been
518reported. Bugs are documented in two places: The file @file{BUGS}
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519describes a number of well known bugs and the central @glibcadj{}
520bug tracking system has a
612fdf25 521WWW interface at
c0ed9d7d 522@url{http://sourceware.org/bugzilla/}. The WWW
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523interface gives you access to open and closed reports. A closed report
524normally includes a patch or a hint on solving the problem.
612fdf25 525
a4d62195 526To report a bug, first you must find it. With any luck, this will be the
3c20b9b6 527hard part. Once you've found a bug, make sure it's really a bug. A
1f77f049 528good way to do this is to see if @theglibc{} behaves the same way
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529some other C library does. If so, probably you are wrong and the
530libraries are right (but not necessarily). If not, one of the libraries
1f77f049 531is probably wrong. It might not be @theglibc{}. Many historical
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532Unix C libraries permit things that we don't, such as closing a file
533twice.
534
1f77f049 535If you think you have found some way in which @theglibc{} does not
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536conform to the ISO and POSIX standards (@pxref{Standards and
537Portability}), that is definitely a bug. Report it!
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538
539Once you're sure you've found a bug, try to narrow it down to the
540smallest test case that reproduces the problem. In the case of a C
541library, you really only need to narrow it down to one library
542function call, if possible. This should not be too difficult.
543
544The final step when you have a simple test case is to report the bug.
8b748aed 545Do this at @value{REPORT_BUGS_TO}.
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546
547If you are not sure how a function should behave, and this manual
548doesn't tell you, that's a bug in the manual. Report that too! If the
549function's behavior disagrees with the manual, then either the library
550or the manual has a bug, so report the disagreement. If you find any
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551errors or omissions in this manual, please report them to the
552bug database. If you refer to specific
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553sections of the manual, please include the section names for easier
554identification.